ANNUNCIATING OR POWER VENDING CIRCUIT BREAKER FOR AN ELECTRIC LOAD
A circuit breaker for an electric load includes first and second terminals; a number of first separable contacts each electrically connected between one of the first terminals and one of the second terminals; a first mechanism to open, close or trip open the first contacts; a number of second separable contacts each electrically connected in series with a corresponding one of the first contacts; a second mechanism to open or close the second contacts; a processor to cause the second mechanism to open or close the second contacts, annunciate through one of the second terminals a power circuit electrical parameter for the electric load, receive from a number of the second terminals a confirmation from or on behalf of the electric load to cause the second mechanism to close the second contacts, and determine a fault state operatively associated with current flowing through the second contacts.
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This application is related to commonly assigned, copending U.S. patent application Ser. No. ______, filed ______, entitled “Electric Power Distribution System Including Metering Function and Method of Evaluating Energy Metering” (Attorney Docket No. 12-CCB-853).
BACKGROUND1. Field
The disclosed concept pertains generally to electrical switching apparatus and, more particularly, to circuit breakers.
2. Background Information
Circuit breakers used in residential and light commercial applications are commonly referred to as miniature circuit breakers because of their limited size. Such circuit breakers typically have a pair of separable contacts opened and closed by a spring biased operating mechanism. A thermal-magnetic trip device actuates the operating mechanism to open the separable contacts in response to a persistent overcurrent condition or a short circuit.
In some applications, it has been found convenient to use circuit breakers for other purposes than just protection, for instance, for load shedding. It is desirable to be able to perform this function remotely, and even automatically, such as under the control of a computer. However, the spring biased operating mechanisms are designed for manual reclosure and are not easily adapted for reclosing remotely. In any event, such operating mechanisms are not designed for repeated operation over an extended period of time.
Remotely controllable circuit breakers or remotely operated circuit breakers introduce a second pair of separable contacts in series with the main separable contacts. See, for example, U.S. Pat. Nos. 5,301,083; 5,373,411; 6,477,022; and 6,507,255. The main contacts still interrupt the overcurrent, while the secondary contacts perform discretionary switching operations. For example, the secondary contacts are controlled by a solenoid, which is spring biased to close the contacts, or by a latching solenoid.
Conventional ground fault circuit breakers provide ground fault detection and thermal-magnetic overload sections that are coupled with a single circuit breaker operating handle to indicate on, tripped and off states, and to control opening and closing of the power circuit.
An electric vehicle (EV) charging station, also called an EV charging station, electric recharging point, charging point, and EVSE (Electric Vehicle Supply Equipment), is an element in an infrastructure that supplies electric energy for the recharging of electric vehicles, plug-in hybrid electric-gasoline vehicles, or semi-static and mobile electrical units such as exhibition stands.
An EV charging station is a device that safely allows electricity to flow. These charging stations and the protocols established to create them are known as EVSE, and they enhance safety by enabling two-way communication between the charging station and the EV.
The 1996 NEC Article 625 defines EVSE as being the conductors, including the ungrounded, grounded, and equipment grounding conductors, the EV connectors, attachment plugs, and all other fittings, devices, power outlets or apparatus installed specifically for the purpose of delivering energy from premises wiring to an EV.
EVSE is defined by the Society of Automotive Engineers (SAE) recommended practice J1772™ and the National Fire Protection Association (NFPA) National Electric Code (NEC) Article 625. While the NEC defines several safety requirements, J1772™ defines the physical conductive connection type, five pin functions (i.e., two power pins (Hot1 and Hot2 or neutral; or Line 1 and Line 2), one ground pin, one control pilot pin, and one proximity pin), the EVSE to EV handshake over the pilot pin, and how both parts (EVSE and EV) are supposed to function.
Two-way communication seeks to ensure that the current passed to the EV is both below the limits of the EV charging station itself, below the limits of the cordset connecting the EV charging station to the EV, and below the tripping limit of upstream protection devices, such as circuit breakers. The EV is the load and the load dictates how much power is being pulled. The EV knows its own limits and since it sets the amount of current being pulled, communication is not required in order to protect the EV. Instead, communication is employed to protect all of the distribution equipment delivering power to the EV.
There are additional safety features, such as a load interlock, that does not allow current to flow from the EV charging station until the EV connector or EV plug is physically inserted into the EV and the EV is ready to accept energy. Once the EV signals that it is finished accepting energy or the EV is unplugged, the load interlock continues to prevent current flow.
SAE J1772™ in the United States and the IEC 61851 standard in the rest of the world or where applicable use a very simple but effective pilot circuit and handshake in the EVSE. For charging a vehicle using alternating current (AC), basically a signal is generated on the pilot pin, starting at a constant +12 Vdc open circuit when measured to the ground pin. When the EVSE cable and connector is plugged into an EV inlet of a compliant vehicle, the vehicle's circuit has a resistor and a diode in series that ties to ground in order to drop the +12 Vdc to +9 Vdc. After the EVSE sees this drop in voltage, it turns on a pulse-width modulated (PWM) generator that defines the maximum available line current (ALC) on the charging circuit. This generated PWM signal oscillates between +12 Vdc and −12 Vdc when measured at its source. The vehicle charge controller reads the percentage of the duty cycle of the PWM signal, which is equivalent to a set amperage, and sets the maximum current draw on the onboard vehicle rectifier/charger, in order to not trip an upstream circuit interrupter, such as a circuit breaker. The vehicle, in turn, adds another resistor in parallel with the resistor of the vehicle's resistor and diode series combination, which then drops the top level of the PWM pilot signal to +6 Vdc while leaving the bottom level at −12 Vdc. This tells the EVSE that the vehicle is ready to charge and that it is actually a vehicle and not simply a resistance such as a person's finger which caused the voltage drop. In response, the EVSE closes an internal relay/contactor to allow AC power to flow to the vehicle.
Known EV charging stations consist generally of a completely separate device from a load center, panelboard, or normal upstream protection. Such EV charging stations are a special box with indicators for power and state along with a connected EV cable/connector for the intended purpose of charging the EV. These EV charging stations require an upstream circuit breaker, and a completely separate, special enclosure and an EV cable/connector.
Electric utilities desire to separately meter and bill power going to an EV or other electric loads deemed applicable by the utility or other authority. Known methods require a separately derived metering system, which is relatively expensive and complex to install and manage. This prohibits technology adoption and implementation. There is room for improvement in sub-metering, billing against, and managing electric loads deemed “special” or otherwise applicable by electric utilities or other authorities.
There is room for improvement in circuit breakers and EV charging stations.
SUMMARYThese needs and others are met by various embodiments of the disclosed concept in which a circuit breaker processor annunciates a power circuit electrical parameter for an electric load (e.g., without limitation, an electric vehicle), receives a confirmation from or on behalf of the electric load to cause a mechanism to close the separable contacts, and determines a fault state operatively associated with current flowing through the separable contacts.
In accordance with one aspect of the disclosed concept, a circuit breaker for an electric load comprises a plurality of first terminals; a plurality of second terminals; a number of first separable contacts each of which is electrically connected between one of the first terminals and one of the second terminals; a first mechanism structured to open, close or trip open the number of first separable contacts; a number of second separable contacts each of which is electrically connected in series with a corresponding one of the number of first separable contacts and electrically connected between one of the first terminals and one of the second terminals; a second mechanism structured to open or close the number of second separable contacts; a processor structured to cause the second mechanism to open or close the number of second separable contacts, annunciate through one of the second terminals a power circuit electrical parameter for the electric load, receive from a number of the second terminals a confirmation from or on behalf of the electric load to cause the second mechanism to close the number of second separable contacts, and determine a fault state operatively associated with current flowing through the number of second separable contacts.
As another aspect of the disclosed concept, a power vending circuit breaker for an electric load comprises: a plurality of first terminals; a plurality of second terminals; a number of separable contacts, at least one of the number of separable contacts being electrically connected between one of the first terminals and one of the second terminals; a thermal-magnetic protection circuit electrically connected in series with the at least one of the number of separable contacts between the one of the first terminals and the one of the second terminals; a metering circuit within the power vending circuit breaker and operatively associated with power flowing through the number of separable contacts between the one of the first terminals and the one of the second terminals; a mechanism structured to open or close the number of separable contacts; a processor within the power vending circuit breaker and structured to cause the mechanism to open or close the number of separable contacts, to input a plurality of power values from the metering circuit and to determine a plurality of energy values; and a communication mechanism cooperating with the processor to communicate the energy values to a remote location.
As another aspect of the disclosed concept, a circuit breaker for an electric load comprises: a plurality of first terminals; a plurality of second terminals; a number of separable contacts each of which is electrically connected between one of the first terminals and one of the second terminals; a mechanism structured to open or close the number of separable contacts; and a processor structured to cause the mechanism to open or close the number of separable contacts, annunciate through one of the second terminals a power circuit electrical parameter for the electric load, receive from a number of the second terminals a confirmation from or on behalf of the electric load to cause the mechanism to close the number of separable contacts, and determine a fault state operatively associated with current flowing through the number of separable contacts.
A full understanding of the disclosed concept can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:
As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality).
As employed herein, the term “processor” shall mean a programmable analog and/or digital device that can store, retrieve, and process data; a computer; a workstation; a personal computer; a microprocessor; a microcontroller; a microcomputer; a central processing unit; a mainframe computer; a mini-computer; a server; a networked processor; control electronics; a logic circuit; or any suitable processing device or apparatus.
As employed herein, the statement that two or more parts are “connected” or “coupled” together shall mean that the parts are joined together either directly or joined through one or more intermediate parts. Further, as employed herein, the statement that two or more parts are “attached” shall mean that the parts are joined together directly.
The disclosed concept is described in association with circuit breakers having one, two or three poles for electric loads, although the disclosed concept is applicable to a wide range of circuit breakers having any suitable number of poles for a wide range of electric loads (e.g., without limitation, electric vehicles).
Referring to
The circuit breaker 2 can, for example and without limitation, charge the example EV 4 using SAE J1772™, but can also provide a controllable point to provide more general power vending capabilities as will be discussed in connection with
The example circuit breaker 2 can employ any suitable form factor (e.g., without limitation, a miniature circuit breaker; a molded case circuit breaker; any other suitable circuit interrupter form factor). In this example, the circuit breaker 2 is a single-pole circuit breaker. In territories where IEC is required, a single-pole circuit breaker may be employed (e.g., in a DIN rail mountable form factor).
Example 3Although the circuit breaker 2 could be constructed with only one circuit breaking element per conductor as will be discussed in connection with
For example, for the EV 4, the CCID function 8 continuously monitors the differential current from a ground fault sensor (e.g., current transformer (CT) 52) among all of the current-carrying conductors in a grounded system and rapidly interrupts the circuit under conditions where the differential current exceeds the rated value (e.g., without limitation, 5 mA; 20 mA) of the charging circuit interrupting device. The CCID function 8 may include any suitable combination of basic insulation, double insulation, grounding monitors, insulation monitors with interrupters, isolation monitoring (depending on whether it is grounded or not) and/or leakage current monitors. Alternatively, for non-EV load applications, a GFCI function can be provided with either personnel protection or equipment protection.
Example 4The example EV interlock function 10: (1) controls the CCID function 8; (2) generates and monitors the example pilot signal 22 (
Alternatively, rather than annunciating a maximum value of current permitted (e.g., available line current (ALC)) to flow through the separable contacts 24 to the electric load (e.g., the EV 4), this can annunciate a maximum and/or a minimum value of voltage permitted to be applied through the separable contacts 24 to the electric load, a direction (i.e., forward or reverse) of power flow through the separable contacts 24 to or from the electric load, a minimum power factor permitted for the electric load, and a minimum conversion efficiency permitted by the electric load.
Example 5The example EV interlock function 10 can provide one or more of the following optional functions: (1) other metering, allocation, authentication, communication and/or additional protective functionality may be employed in or with the circuit breaker 2 (see, for example, Examples 20-24); (2) another wire termination point 30 is employed by the EVSE connector 28 (
The optional SAE J1772™ pilot signal specification for the pilot signal 22 is one example way to achieve the annunciator/interlock functions. A generator/monitor or other suitable communications path (e.g., without limitation, an optional power line carrier (PLC)), can be employed to form a similar, but different, encoding of information to: (a) communicate available line current (of the power circuit) as determined by the rating of the components or a controller; (b) communicate readiness/state/condition (of the circuit breaker 2 or EV 4); (c) communicate protective functions (of the circuit breaker 2 or EV 4); and/or (d) communicate load characteristics back to the circuit breaker 2 (or EV 4). The communication can provide, for example and without limitation, a power vending (e.g., power metering, delivery, control, and management) capability (Examples 20-24) with annunciation and interlocking from a circuit breaker, such as 2, to a load, such as the EV 4. This replaces the pilot signal 22 with digital communications over a power line, device to device.
Example 7For example, for the interlock of the third option of Example 4, the interlock does not close the protected power circuit until a resistor value is read. The resistor's value represents different current ratings predefined in a corresponding industry standard. As a more specific example, the IEC method for charging EVs has a detachable cable with EV connectors on both sides. Each EV connector has a resistor tied from proximity (e.g., 36 of
For example, for the second option of Example 4, the circuit breaker 2 includes a termination point 34 (
By employing an EV connector latch button as a reset by monitoring the proximity conductor 36, the circuit breaker 2 can be programmed, in order that when a button is pressed, the proximity circuit is opened and the circuit breaker 2 performs the same function as if a local test/reset button 46 (
The circuit breaker 2 can include a local indication of state through a suitable indicator (e.g., without limitation, indication light; LED; color; flag). Example states include ready, charging, and trouble. As shown in
The circuit breaker 2′ of
The thermal-magnetic overload circuit breaking function 6 of
FIGS. 2 and 4A-4B show the single-phase, two-line, double-pole circuit breaker 2′, which can be used in connection with the EV 4. The circuit breaker 2′ includes a double-pole thermal-magnetic overload circuit breaking function 6′, a double-pole CCID function 8′, and the example EV interlock function 10. The circuit breaker 2′ further includes inputs for two lines L1 12′ and L2 12″, and ground (G) 16, and output terminations for the load (e.g., hot/line 1 18 and hot/line 2 20). In this example, a neutral is not employed. Control electronics 68 are powered by an alternating current to direct current power supply 69 (
For the double-pole thermal-magnetic overload circuit breaking function 6′, thermal-magnetic devices are employed on any hot or ungrounded conductors coming into the circuit breaker 2′. In contrast, for the single-pole circuit breaker 2 of
The double-pole CCID function 8′ of
The circuit breaker 2′ can support the following example fault categories: (1) circuit breaker trip; (2) permanent fault; (3) lockout fault; and (4) temporary fault. Each example fault also has a corresponding reset: (1) reset the physical circuit breaker operating handle 66; (2) reboot the software of the control electronics 68; (3) clear a lockout fault; and (4) clear a temporary fault.
Resetting the circuit breaker operating handle 66 reboots the software, clears a lockout, and clears a temporary fault. Rebooting the software clears a lockout, and clears a temporary fault. Clearing a lockout also clears a temporary fault. Unplugging the load (e.g., the EV 4) also clears a lockout and clears a temporary fault.
The thermal-magnetic overload circuit breaking function 6′ faults in a conventional manner by tripping open the two example separable contacts 48′ and the circuit breaker operating handle 66 in response to a short circuit or other overload current condition.
The relay 44 can trip for any of the following reasons (additionally, for example and without limitation, it can detect arc faults) in Table 1:
Lockout faults are shown in Table 2:
EVSE states are shown in Table 3:
On the other hand, if it is determined that the circuit breaker is tripped at 104, then the circuit breaker is tripped at 120 (e.g., in response to a short circuit or other overload condition as shown in
If it is determined that there is a fault state at 106, then it is determined if there is a temporary fault state at 122. If the fault state is not temporary, then there is a permanent fault at 124. Nothing is then done until there is a suitable reset (Example 14), which causes a reboot of the control electronics software at 125 after which normal circuit breaker operation is resumed at 116.
If it is determined that the test did not pass at 110, then the permanent fault is entered at 126 followed by 124.
If there is a temporary fault state at 122, then at 128 it is determined if a lockout occurred. If so, then a lockout state is entered at 130 and nothing is done until there is a suitable reset (Example 14). Normal circuit breaker operation is resumed at 116 in response to the end of a plug session or lockout is cleared at 131.
On the other hand, if no lockout occurred at 128, then the fault is reset at 132 followed by resuming normal circuit breaker operation at 116.
Example 16If the self-check 203 fails at 214, then a permanent fault is entered at 215. The self-check 203 can only be restarted by a power-up restart at 202, or by a software reboot at 216.
Also, any of 206,208,210,212 can transition to a fault detected state 217 in response to detection of a fault. The state 217 determines the fault type at 218. Then, at 219, it is determined the nature of the fault type. If the fault type is temporary, then at 220 it is determined if the number of temporary faults is greater than a lockout limit. If the lockout limit is reached, then the lockout state is entered at 222. From state 222, the load is either unplugged or the lockout is cleared at 223 to re-enter state 206 and wait for the load to connect. Otherwise, if the lockout limit was not exceeded at 220, then at state 224 a manual reset or an auto-reclosure is awaited. State 224 is exited at 226 if the load is unplugged after which state 206 is re-entered to wait for the load to connect, or at 228 in response to a temporary fault reset or auto-reclosure after which state 210 is re-entered to annunciate ALC.
The control electronics 68 of
Otherwise, if a proximity rating is not supported at 304, then 312 is executed.
If a proximity rating is not detected at 306, then at 314, it is determined if a proximity rating is required. If so, then a fault state is entered at 316. Otherwise, 312 is executed.
Example 18After a ground fault is detected at 402, it is determined at 404 if the sensed ground fault current is higher than a maximum allowed ground fault current. If the ground fault current is larger than this value (e.g., without limitation, 350 mA), then a fault is detected at 405 and the fault routine 500 of
Next, at 408, if there is sufficient time remaining since the initial measurement to take another measurement and still trip open the relay 44 if the ground fault current remains constant, then another measurement is taken at 410. On the other hand, if there is insufficient time at 408, then a fault is detected at 405 and the fault routine 500 of
After 410, at 412, if the ground fault current read is zero, then there is no ground fault and normal circuit breaker operation is resumed at 414. Otherwise, if the current read is nonzero, then the average current with the elapsed amount of time is used to calculate the time remaining to trip and step 404 is repeated. The process continues until the ground fault monitoring circuit causes a trip after 405, or the ground fault current goes to zero and normal circuit breaker operation is resumed at 414.
Example 19As will be discussed, below, in connection with
When an electricity source, such as an electric utility 618 (shown in phantom line drawing in
Alternatively, the electric utility 618 can download the database 608 of each circuit breaker, such as 600, in its entirety, query the energy values 606 as appropriate, and then apply a suitable rate structure using the timestamps, specific circuits, and any allocation flags.
Examples 21-23 (
Referring to
In this example, there is both a hot line and a neutral line through the PVM circuit breaker 600 along with corresponding current sensors 648,649, voltage sensors 650,651, and separable contacts 630A,630B for each line or power conductor. A power metering circuit 652 of the metering function 602 inputs from the current sensors 648,649 and the voltage sensors 650,651, and outputs corresponding power values to the logic circuit 604, which uses a timer/clock function 654 to provide the corresponding timestamped energy values 606 in the database 608 of the memory 610. The current sensors 648,649 can be electrically connected in series with the respective separable contacts 630A,630B, can be current transformers coupled to the power lines, or can be any suitable current sensing device. The voltage sensors 650,651 can be electrically connected to the respective power lines in series with the respective separable contacts 630A,630B, can be potential transformers, or can be any suitable voltage sensing device.
Example 23The module 700 includes a first conductor finger 708 for a first hot line to the PVM circuit breaker 600, and a second conductor finger 710 for a second hot line or a neutral to such PVM circuit breaker. The conductor fingers 708,710 are electrically connected to respective terminals 712,714 for an electric load 715. These terminals are used to provide AC power into the EV connector (e.g., 32 of
A number of current sensors 716 sense a differential current for a ground fault protection circuit 718, which can output a fault signal and other current information to a logic circuit 720. The logic circuit 720, in turn, can communicate externally through a communication circuit 722 to a first expansion port 724 (e.g., without limitation, to provide a trip signal to the PVM circuit breaker 600) and/or a second expansion port 726 to communicate with other local or remote devices (not shown). Details of the expansion ports 724,726 are discussed, below, in connection with
The logic circuit 720 also communicates with a memory 728 and the external user interface 706, which can include a number of indicator lights 730 and a reset button 732. In support of various EV interface functions, the logic circuit 720 further communicates with a DC, PWM output and sensor function 734 that interfaces the pilot signal 702 at terminal 736 and an optional proximity circuit 738 that interfaces the optional proximity signal 704 (or proximity resistor (not shown)) at terminal 740 for an IEC style EV add-on module. The module 700 also includes a ground pigtail 742 that provides a ground to a ground terminal 744.
The example module 700 can be employed with the PVM circuit breaker 600 or any suitable circuit breaker disclosed herein that feeds a suitable electric load. Example protective functions performed by such circuit breakers can include overcurrent, ground fault, overvoltage, load interlock and/or a safe automatic reset. Example control functions include interfaces to the module 700, a suitable algorithm for the load (e.g., EV) and state management for the load (e.g., EV).
Example authentication functions performed by the module 700 include verification of permission to access power or control of the circuit breaker (i.e., vending power to a load), either locally or remotely, and additional logic and interlock settings. As an example, these include determining whether you are allowed to use power for the load (e.g., to charge an EV), or determining if you are an administrator allowed to control the circuit breakers.
Example allocation functions performed by the PVM circuit breaker 600 include tracking energy usage by department, circuit or user, limiting the amount of energy usage, and utility grade energy metering (e.g., 0.2% accuracy of metering).
Example optional and additional protection and control functions that can be enabled in the PVM circuit breaker 600 by the module 700 include interchangeable communication interfaces, remote control and additional trip curves.
Example 25The disclosed circuit breakers 2,2′,2″ and module 800 can provide a DC string protector (e.g., an electronic circuit breaker with improved DC overcurrent/reverse current protection, ground fault detection, and arc fault circuit interruption) and a PV module shutdown switches monitoring system, which monitors PV string current and voltage, along with a relatively small window I-V curve around maximum power for maximum power point tracking.
For a solar generation system (not shown), the disclosed module 800 enables a simple installation, with automatic electrical permitting and inspection to replace the need for electrical permits and inspections. A single electrical listing of the entire plug and play PV system is used to allow a standard PV plug to connect the PV inverter 806 to the add-on module 800 without additional permits or inspections, and with automatic structural permitting and inspection. The add-on module 800 includes a suitable communication interface, such as the inverter communication port 802, to notify the authority having jurisdiction (AHJ) of the solar installation and automatically commission and permit the installation without having an inspector visit the site to the extent possible. The add-on module 800 further includes a suitable communication interface, such as the utility communication port 804, to permit automatic grid interconnection by notifying the utility of the solar installation and automatically provisioning the installation to backfeed into the grid.
Other optional features of the add-on module 800 can include: (1) grid support communication functions (e.g., without limitation, status check/self diagnostics, which check the status of individual components of the inverter 806 and the corresponding PV modules (not shown) using artificial neural network based pattern recognition techniques; (2) self configuration/self-healing, in order that when there is a problem with components, the circuit breaker can still operate to provide power to the grid safely until the system is fixed (e.g., a limp home capability); (3) performance monitoring and lifetime estimation for performance monitoring of components for degradation, including notification for preemptive replacement; (4) volt/var support by the use of intelligent/smart/connected inverters (via the add-on module 800) to perform grid stability functions (this allows inverters to improve grid voltage or power factor); (5) utility power demand/frequency control (e.g., the utility might not want the PV inverter 806 connected or might need relatively lower power); (6) load as a resource by leveraging other loads in a PV module panel (not shown); and (7) GridEye™ or other suitable power quality monitors or sensors, which send the utility, frequency, voltage, and phase angle information as well as PV inverter power quality information. GridEye™ covers a wide-area grid monitoring network for the three North American power grids. This provides additional monitoring points at planned renewable generation sites—such as wind farms—to characterize the system's dynamic behavior before and after the installation of renewable sources. This produces dynamic system behavior data for insight into how renewable generation assets change the dynamic behavior of the electric grid. These data can also be used to estimate dynamic modeling parameters for planning and operation
If used in a PV module panel (not shown), a different add-on module 800 can alternatively perform automatic transfer switch (ATS) functionality with utility islanding. For example, a software interlock of a main circuit breaker (not shown) and the generation system (not shown) would allow backfeeding if the utility power is present. Otherwise, when loss of utility power is detected, the add-on module 800 will: (1) command opening the main circuit breaker (not shown); (2) command closing the generation/energy storage circuit (not shown); and (3) send a signal to start the supply of power to the on premise generation source to able to supply power, such as a diesel generator. The load circuits are allowed to run in island mode in the premise. This safely electrically islands the premise to protect workers on the utility line while retaining power at the PV module equipped site. This ATS and islanding functionality could be a different add-on module 800 (for other energy sources that are not solar), but without PV-specific features.
Example 26Further to Example 25, the example add-on module 800 enables relatively quick and easy installation of PV components, in order that the entire process may be conducted safely without the need of professional electrical services or on-site permitting. Pre-installed infrastructure (e.g., meters; load centers; circuit breakers; communication gateways) are enabled to support the future installation of PV components. After purchase, this PV equipment seamlessly connects to the existing infrastructure without the need for inspection. Pre-installation can be made for the anticipation to install any new smart grid-enabled equipment, including PV, as well as electric vehicle supply equipment (EVSE), local energy storage, smart water heaters, or other devices that can be justified on a broader smart-grid basis. This pre-installation approach can potentially be correlated with smart meter rollouts and utility-driven home energy management programs for retrofit upgrades or implanted into requirements for new construction. Furthermore, in order to accomplish these tasks, both internal connectivity and external connectivity to utility companies and AHJ's is critical to ensure safe installation, continued operations, and maintenance.
Example 27The example module 900 can replace a conventional thermostat and place all HVAC wiring in a load center (not shown). For a commercial building (not shown), this can include control (e.g., without limitation, of actuators; dampers). A number of communicating temperature sensors (not shown) can be located throughout the building to provide temperature input (e.g., through the expansion or wireless communication ports 726,902) to the HVAC add-on module 900 and can also be used to adjust temperature settings. The module 900 can also perform actions to save energy (e.g., without limitation, cycling a compressor; setting heating and cooling schedules).
The module 1000 can provide analog inputs (e.g., for control signals), analog outputs, digital outputs (e.g., for external systems; relays; control signals) or digital inputs (e.g., for digital switches). The analog or digital inputs can be communicated through the example circuit breakers, such as 2,2′,2″,600, disclosed herein and can provide program control of such circuit breakers (e.g., without limitation, solar harvesting; digital switches; shunt trip; relay commands).
Further to Example 1, the add-on module 1000 can perform Boolean algebra and basic if-then-else functions with the logic circuit 720 using its inputs and outputs, and/or can be used as a binary status indicator (e.g., without limitation, to indicate that a main circuit breaker is open or closed) with the indicator lights 730.
The add-on module 1000 can employ the set of controllable, general purpose I/O terminals 1004 whose capabilities may include, for example and without limitation, direction (e.g., the terminals can be configured to be input or output using an enable mask); enabled/disabled; input values are readable (e.g., without limitation, high=1, low=0); output values are writable/readable; and input values can be used as interrupt request lines (e.g., without limitation, for wakeup events).
The add-on module 1000 can employ direct memory access (DMA) to efficiently move relatively large quantities of data into or out of the module, or provide support for “bitbanging”, which can provide software emulation of a hardware protocol.
The example general purpose I/O add-on module 1000 can enable generic serial communication with a load (not shown). By providing a corresponding device, such as the example circuit breakers, with embedded intelligence and communication, this can provide an interface that connects that device to the “smart grid”. Non-limiting examples of such communication include sending utility billing rates and time-of-use rate structures from the utility back office, through this add-on module 1000 and down to the load (e.g., without limitation, a washer; dryer; dishwasher), in order that the device can decide when the optimum time is to perform their function (e.g., to turn themselves on when energy is cheapest).
Examples 29 and 30 (
For example, multiple circuit breakers 1204 and/or add-on modules 1206,1208 are daisy-chained through expansion ports (e.g., 624 of
These signals 1322,1324 are referenced to signal ground 1314. COMM+ 1318 and COMM− 1326 either provide communications between the circuit breaker 1302 and the add-on module 1304, or route the COMM+ 1318 and COMM− 1326 signals of the circuit breaker 1302 through the add-on module 1304. CONTROL PWR+ 1320 and CONTROL PWR− 1328 provide power from the circuit breaker 1302 to the add-on module 1304.
The example serial port provided by COMM+ 1318 and COMM− 1326 exchanges on/off control, provides an interface for external and/or remote communication, reports status information (e.g., without limitation, on/off/tripped; fault reason; fault time; time until reset; number of operations; serial number; clock; firmware version; time/clock), and reports metering values (e.g., without limitation, time-stamped values; voltage; current; power consumed by the load; power generated and fed into the panel). The time-stamped values can include net energy (watt-hours) (e.g., broken down by real, active, and reactive types, where each type contains forward, reverse, net, and total); and peak demand (watts) (e.g., calculated within a configurable time window size and reset at configurable time intervals). The example serial port includes a suitable serial bus in order to pass communications between multiple circuit breakers and add-on modules as was discussed above in connection with
The expansion port controls the controllable separable contacts 630 of the PVM circuit breaker 600 (
The power prongs or stabs (e.g., 708,710 of
The add-on module expansion port receptacles 1310 have the same communication format as the expansion port pins 1312, but are the opposite gender for mating with the circuit breaker expansion port pins 1308.
Example 32In contrast to Example 3, the thermal-magnetic protection is, instead, implemented, for example and without limitation, in control electronics firmware of the logic circuit 604, somewhat similar to how the ground fault protection is provided thereby.
For example, the single sets of separable contacts 1406A,1406B can each be solid-state, with all protective and electric load (e.g., EV) functions being provided by a single electronic switching device.
The disclosed relay 44 of
Although separable contacts 24′,1406A,1406B are disclosed, suitable solid state separable contacts can be employed. For example, the disclosed circuit breaker 2 includes a suitable circuit interrupter mechanism, such as the separable contacts 24′ that are opened and closed by the operating mechanism of the relay 44, although the disclosed concept is applicable to a wide range of circuit interruption mechanisms (e.g., without limitation, solid state switches like FET or IGBT devices; contactor contacts) and/or solid state based control/protection devices (e.g., without limitation, drives; soft-starters; DC/DC converters) and/or operating mechanisms (e.g., without limitation, electrical, electro-mechanical, or mechanical mechanisms).
Example 33In the PVM circuit breaker 1400 of
In this example, the thermal-magnetic protection separable contacts (first circuit breaking element) 629 of
If a resettable fuse 1404 is employed, then it would automatically reset after a fault was cleared. Otherwise, the fuse 1404 would blow and, therefore, need replacement after a fault current. The single set of separable contacts 1406 can be used at all other times.
Alternatively, software of the logic circuit 604 can emulate the fuse 1404 and trip the relay 44 (not shown, but see
The circuit breaker 1450 of
Since PVM circuit breakers, such as for example 600,1400,1450, can include a wide range of features, various different add-on modules can be employed. For example, the EV add-on module 700 (
Examples 36-62 discuss a variety of different add-on modules, such as 626 of
An authentication add-on module performs user authentication using, for example and without limitation, RFID or the Internet. This can allocate usage of power into, for example, groups, power circuits, and users.
Example 37A tenant billing software add-on module reads metering information from the PVM circuit breaker expansion port 624 and performs tenant metering/billing for a property owner. This function can be combined with the authentication add-on module (Example 36) (e.g., as shown with the add-on module 1206 and the “stacked” add-on module 1208 of
A communications/protocol add-on module enables the PVM circuit breaker 600 to communicate using different protocols or languages to the electric utility, customer or end devices. This can include controlling the PVM circuit breaker 600 or displaying usage information, for example and without limitation, on a local webpage, through a cloud service, or on a suitable smart phone. Non-limiting communication examples include: Wi-Fi; cellular; Ethernet; serial; Smart Energy®; OpenADR™; BacNET™; Modbus®; power line carrier (PLC); SmartWire DT; IEC 61850; and DNP3.
Example 39A schedule add-on module performs scheduling to turn on/off electric loads. This can be employed, for example and without limitation, to control exterior lighting with sunset/sunrise, cycle a pool pump to reduce energy usage, and have different and programmable holiday schedules.
Example 40An analog/digital input add-on module allows analog or digital inputs to be communicated through PVM circuit breakers, such as 600, and program control thereof (e.g., without limitation, solar harvesting; digital switches; shunt trip).
Example 41A programmable logic controller (PLC) add-on module implements PLC ladder logic for control and/or monitoring.
Example 42A proprietary main circuit breaker add-on module provides all of the functionality of a corresponding proprietary main circuit breaker inside of the add-on module.
Example 43A group control add-on module allows programming to control groups of circuit breakers instead of just one circuit breaker.
Example 44A lighting add-on module provides scheduling and dimming functions. This can also provide alerts when the lights go out by detecting a corresponding drop in current.
Example 45A power signature add-on module performs analysis of the voltage/current (V-I) curves for a known, dedicated load type and determines, notifies and/or trips for any failures that occur.
Example 46A load ID add-on module identifies a specific load (e.g., down to the serial number) or load category (e.g., in terms of current rating or device type) when it is electrically connected. This module can employ, for example and without limitation, NFC/RFID (Near Field Communications/RFID) or power line carrier for identification purposes).
Example 47A load annunciation and power interlock add-on module provides EV interfaces for EV applications.
Example 48A surge protection add-on module provides surge protection for an individual circuit breaker, for a main circuit breaker, or for an entire circuit breaker panel.
Example 49A battery management system add-on module controls an external inverter to properly charge batteries.
Example 50A DC inverter/DC distribution system add-on module places an inverter and DC distribution system inside the circuit breaker panel to provide DC power from the load center. This could be used to charge electronics and power other DC devices.
Example 51A data storage add-on module increases the storage capacity for a PVM circuit breaker. This can be employed, for example and without limitation, to store relatively larger amounts of metering data, keep a plug session history for the EV add-on module, or store relatively larger amounts of allocation to specific users.
Example 52A power manager—load coordinator add-on module commands loads to operate in a coordinated fashion to minimize power/energy demand and ultimately cost based on time-of-use or real-time prices.
Example 53A ground fault add-on module provides ground fault protection with adjustable ground fault current thresholds.
Example 54An arc fault add-on module provides arc fault protection.
Example 55A building automation controller add-on module permits a load center to perform building automation connectivity, management and programming.
Example 56An HVAC controller add-on module controls and cycles a compressor (e.g., turns off the compressor, but leave the fan running), provides augmented learning techniques, and saves energy. For commercial buildings, it controls devices, such as actuators and dampers.
Example 57A remote control add-on module controls a power circuit with a switch or a smart phone application. A simple variant is a dry contact to control the circuit breaker. A more advanced version is securely connected to the cloud to be controlled from any remote location.
Example 58An advanced metering add-on module provides advanced metering functions (e.g., without limitation, harmonics; sags; swells; power factor; waveform capture for faults).
Example 59An energy efficiency and analysis add-on module provides recommendations for how to save energy. This can include, for example and without limitation, reports on usage (e.g., down to branch circuits) combined with weather, solar output, and which circuits have phantom loads that could be turned off.
Example 60A meter verification add-on module verifies an individual meter by taking a circuit breaker out of service, running known amounts of energy through the circuit breaker, and comparing the meter output. This can be performed on a schedule or on demand with the results reported back to the electric utility or other facility.
Example 61An islanding main circuit breaker add-on module trips the main circuit breaker when power is lost from the electric utility (and closes it when it is reestablished) in order to safely allow a home with power generation capability to have electric power in a utility islanded mode. Otherwise, a serious safety issue can occur which could kill or seriously injure an outside utility worker by having electric power appear upstream where it normally should not be (e.g., during maintenance activities).
Example 62A circuit breaker add-on module can provide circuit breaker control and monitoring through the circuit breaker expansion port 624 (
While specific embodiments of the disclosed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.
Claims
1. A circuit breaker for an electric load, said circuit breaker comprising:
- a plurality of first terminals;
- a plurality of second terminals;
- a number of first separable contacts each of which is electrically connected between one of said first terminals and one of said second terminals;
- a first mechanism structured to open, close or trip open said number of first separable contacts;
- a number of second separable contacts each of which is electrically connected in series with a corresponding one of said number of first separable contacts and electrically connected between one of said first terminals and one of said second terminals;
- a second mechanism structured to open or close said number of second separable contacts;
- a processor structured to cause said second mechanism to open or close said number of second separable contacts, annunciate through one of said second terminals a power circuit electrical parameter for said electric load, receive from a number of said second terminals a confirmation from or on behalf of said electric load to cause said second mechanism to close said number of second separable contacts, and determine a fault state operatively associated with current flowing through said number of second separable contacts.
2. The circuit breaker of claim 1 wherein one of said second terminals receives a remote reset input; wherein said processor inputs said remote reset input; and wherein when said remote reset input is active, said processor causes said second mechanism to close said number of second separable contacts after receiving said confirmation from or on behalf of said electric load.
3. The circuit breaker of claim 1 wherein one of said second terminals receives an output from said processor; and wherein said processor is structured to determine if said output from said processor is momentarily electrically disconnected from and then electrically reconnected to a remote load and responsively cause said second mechanism to close said number of second separable contacts after receiving said confirmation from or on behalf of said electric load.
4. The circuit breaker of claim 3 wherein said output from said processor is a pulse width modulated signal.
5. The circuit breaker of claim 1 wherein said processor is structured to determine a fault state and responsively cause said second mechanism to open said number of second separable contacts; wherein one of said second terminals receives an output from said processor; and wherein said processor is structured to determine if said output from said processor is momentarily electrically disconnected from and then electrically reconnected to a remote load and responsively cause said second mechanism to close said number of second separable contacts if said fault state is active.
6. The circuit breaker of claim 1 wherein one of said second terminals receives a proximity input to said processor; and wherein said processor is structured to determine if said proximity input is momentarily electrically disconnected from and then electrically reconnected to a remote load and responsively cause said second mechanism to close said number of second separable contacts after receiving said confirmation from or on behalf of said electric load.
7. The circuit breaker of claim 1 wherein one of said first terminals is a ground; and wherein one of said second terminals is said ground.
8. The circuit breaker of claim 1 wherein one of said second terminals is a proximity input to said processor to indicate that said electric load is electrically connected to said number of second separable contacts and to a corresponding number of said second terminals.
9. The circuit breaker of claim 1 wherein said processor further comprises a remote communications circuit.
10. The circuit breaker of claim 1 wherein said processor further comprises a test/reset input structured to cause said processor to test said second mechanism or to cause said second mechanism to close said number of second separable contacts.
11. The circuit breaker of claim 1 wherein said processor further comprises an alternating current to direct current power supply powered from said first terminals.
12. The circuit breaker of claim 1 wherein said processor further comprises a number of indicators structured to indicate at least one of a fault state determined by said processor and current flowing through said number of second separable contacts.
13. The circuit breaker of claim 1 wherein said first mechanism comprises a thermal-magnetic trip mechanism.
14. The circuit breaker of claim 1 wherein said first terminals comprise a first line input and one of a second line input and a neutral; and wherein said second terminals comprise a first load output and one of a second load output and a load neutral.
15. The circuit breaker of claim 1 wherein said processor and said second mechanism cooperate to provide a ground fault trip mechanism.
16. The circuit breaker of claim 15 wherein one of said second terminals is electrically connected to a conductor having a pilot signal output by said processor to annunciate the maximum value of current permitted to flow through said number of second separable contacts and input by said processor to receive the confirmation from or on behalf of said electric load to cause said second mechanism to close said number of second separable contacts; wherein said processor is further structured to determine a fault state responsive to a ground fault detected by said ground fault trip mechanism or a pilot error operatively associated with said pilot signal and responsively cause said second mechanism to open said number of second separable contacts; and wherein said processor is further structured to cause said second mechanism to reclose said number of second separable contacts after a predetermined time.
17. The circuit breaker of claim 1 wherein one of said second terminals receives an output from said processor; and wherein said processor is structured to determine if said output from said processor is momentarily electrically disconnected from and then electrically reconnected to a remote load and responsively cause said second mechanism to close said number of second separable contacts after receiving said confirmation from or on behalf of said load.
18. The circuit breaker of claim 1 wherein one of said second terminals receives an output from said processor; and wherein said processor is structured to determine if said output from said processor is momentarily electrically disconnected from and then electrically reconnected to a remote resistance of said load and responsively cause said second mechanism to close said number of second separable contacts after receiving said confirmation from or on behalf of said load.
19. The circuit breaker of claim 1 wherein one of said second terminals receives a proximity input to said processor; and wherein said processor is structured to determine if said proximity input is momentarily electrically disconnected from and then electrically reconnected to a remote resistance of said load and responsively cause said second mechanism to close said number of second separable contacts after receiving said confirmation from or on behalf of said load.
21. A power vending circuit breaker for an electric load, said power vending circuit breaker comprising:
- a plurality of first terminals;
- a plurality of second terminals;
- a number of separable contacts, at least one of said number of separable contacts being electrically connected between one of said first terminals and one of said second terminals;
- a thermal-magnetic protection circuit electrically connected in series with said at least one of said number of separable contacts between said one of said first terminals and said one of said second terminals;
- a metering circuit within said power vending circuit breaker and operatively associated with power flowing through said at least one of said number of separable contacts between said one of said first terminals and said one of said second terminals;
- a mechanism structured to open or close said number of separable contacts;
- a processor within said power vending circuit breaker and structured to cause said mechanism to open or close said number of separable contacts, to input a plurality of power values from said metering circuit and to determine a plurality of energy values; and
- a communication mechanism cooperating with said processor to communicate said energy values to a remote location.
22. The power vending circuit breaker of claim 21 wherein said number of separable contacts comprises a plurality of sets of separable contacts; wherein said at least one of said number of separable contacts is a first one of said sets of separable contacts; and wherein said metering circuit comprises a first current sensor electrically connected in series with said first one of said sets of separable contacts between said one of said first terminals and said one of said second terminals, a second current sensor electrically connected in series with a second one of said sets of separable contacts between another one of said first terminals and another one of said second terminals, a first voltage sensor sensing a first voltage operatively associated with said first one of said sets of separable contacts, a second voltage sensor sensing a second voltage operatively associated with said second one of said sets of separable contacts, and a power metering circuit cooperating with said first and second current sensors and said first and second voltage sensors to provide the plurality of power values to said processor.
23. The power vending circuit breaker of claim 21 wherein said communication mechanism includes an expansion port communicating with a number of add-on modules.
24. The power vending circuit breaker of claim 23 wherein said electric load is an electric vehicle; and wherein said number of add-on modules is an electric vehicle add-on module interfacing said electric vehicle, said electric vehicle add-on module being structured to communicate with said electric vehicle, detect a ground fault in a power circuit between said power vending circuit breaker and said electric vehicle, and control said plurality of sets of separable contacts through said expansion port.
25. The power vending circuit breaker of claim 23 wherein said electric load is an inverter; and wherein said number of add-on modules is a solar or photovoltaic add-on module interfacing said inverter.
26. The power vending circuit breaker of claim 25 wherein said solar or photovoltaic add-on module comprises a communication circuit interfaced to said expansion port; said communication circuit including a first communication port structured to interface said inverter and a second communication port structured to interface an electric utility.
27. The power vending circuit breaker of claim 23 wherein said electric load is HVAC equipment; and wherein said number of add-on modules is an HVAC add-on module interfacing said HVAC equipment, said HVAC add-on module comprising a communication circuit interfaced to said expansion port, a wireless communication circuit interfaced to said communication circuit, a thermostat, a plurality of solid state relays, a plurality of terminals for HVAC signals driven by said solid state relays, and a processor cooperating with said communication circuit, said thermostat and said solid state relays to control and monitor said HVAC equipment.
28. The power vending circuit breaker of claim 23 wherein said number of add-on modules is a plurality of add-on modules comprising a first add-on module and a second add-on module, said first add-on module comprising a communication circuit interfaced to said expansion port, said second add-on module being interfaced to said first add-on module.
29. The power vending circuit breaker of claim 28 wherein said electric load is an electric vehicle; wherein said first add-on module is an electric vehicle add-on module interfacing said electric vehicle, said electric vehicle add-on module being structured to communicate with said electric vehicle, detect a ground fault in a power circuit between said power vending circuit breaker and said electric vehicle, and control said plurality of sets of separable contacts through said expansion port; and wherein said second add-on module is an RFID authentication add-on module structured to authenticate a user operatively associated with said electric vehicle.
30. The power vending circuit breaker of claim 23 wherein said power vending circuit breaker is a two-pole circuit breaker; and wherein said number of add-on modules is a two-pole add-on module coupled to one end of said two-pole circuit breaker or coupled to one side of said two-pole circuit breaker with a plurality of jumpers therebetween.
31. The power vending circuit breaker of claim 23 wherein said expansion port is a first expansion port comprising a plurality of conductors for a serial communication interface between said first expansion port and said add-on module, signal ground, neutral, control power, status of said power vending circuit breaker, and control of said number of separable contacts.
32. A circuit breaker for an electric load, said circuit breaker comprising:
- a plurality of first terminals;
- a plurality of second terminals;
- a number of separable contacts each of which is electrically connected between one of said first terminals and one of said second terminals;
- a mechanism structured to open or close said number of separable contacts; and
- a processor structured to cause said mechanism to open or close said number of separable contacts, annunciate through one of said second terminals a power circuit electrical parameter for said electric load, receive from a number of said second terminals a confirmation from or on behalf of said electric load to cause said mechanism to close said number of separable contacts, and determine a fault state operatively associated with current flowing through said number of separable contacts.
33. The circuit breaker of claim 32 wherein said first terminals include a line terminal and a neutral terminal; and wherein said number of separable contacts are two sets of separable contacts; wherein said second terminals include a load terminal and a load neutral terminal; wherein a first set of said two sets of separable contacts is electrically connected between said line terminal and said load terminal; and wherein a second set of said two sets of separable contacts is electrically connected between said neutral terminal and said load neutral terminal.
34. The circuit breaker of claim 32 wherein a fuse is electrically connected in series with one of said number of separable contacts; and wherein each of said number of separable contacts is a solid state switching device.
Type: Application
Filed: Jan 30, 2013
Publication Date: Jul 31, 2014
Applicant: EATON CORPORATION (CLEVELAND, OH)
Inventors: RONALD L. THOMPSON (KNOXVILLE, TN), JASON-DAVID NITZBERG (CINCINNATI, OH), DAVID AUSTIN ELDRIDGE (KNOXVILLE, TN), BRANDON J. ROGERS (KNOXVILLE, TN)
Application Number: 13/753,793
International Classification: H01H 9/54 (20060101); H01H 83/02 (20060101);