Abstract: An electromagnetic braking system includes an electrically conductive disc coupled to a rotatable shaft of a power generation system for operating in an island mode. The rotatable shaft is operatively coupled between a prime mover and a generator for supplying power to an island grid. The electromagnetic braking system further includes a controller for receiving at least one status or synchronization signal and for generating a control signal based on the at least one signal and an inducting unit for applying an electromagnetic braking force on the electrically conductive disc when commanded by the control signal to regulate a rotational speed of the rotatable shaft.

Abstract: Provided are a method and a device for controlling an internal combustion engine driven generator set to run in parallel. The method includes: each time an internal combustion engine is started, a controller detects whether a voltage is outputted in an output voltage circuit; obtaining of respective active power and effective values of output currents; seeking of corresponding output voltage amplitudes in respective droop characteristic curves according to the effective values of the respective output currents, and seeking of corresponding inner power factor angles in the respective droop characteristic curves according to the respective active power; the droop characteristic curves of each generator have the same slope; and each generator is controlled to reach the respective corresponding output voltage amplitudes and inner power factor angles.

Abstract: A method for no break power transfer in a variable frequency power generating system, the power generating system comprising a first bus connected to a first generator and a second bus connected to a second generator includes configuring a power transfer device to output power that is synchronized to match a voltage and a frequency of the second bus to the second bus; reconfiguring the power transfer device to output power that is synchronized to match a voltage and a frequency of the first bus to the second bus; and closing a tie switch located between the first bus and the second bus.

Abstract: An object of the invention is to make the charging power as high as possible in a battery charging control system for selectively charging a plurality of batteries having different voltages with energy generated by an alternator. To achieve the object, the battery charging control system according to the invention includes an alternator having a variable generation voltage and a plurality of batteries having different charging voltages, wherein maximum generation power defined as the highest power that the alternator can generate and maximum charging power defined as the highest power that each battery can accept are obtained, and a battery for which the charging power is highest is selected to be charged based on a comparison of the maximum generation power and the maximum charging power.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A system includes a rack, computing devices coupled to the rack, a rack PDU, and one or more input power cables. The rack PDU includes an enclosure, two or more power input receptacles on the enclosure, and two or more power output receptacles on the enclosure. The output power receptacles supply power to the computing devices. The input power cables are coupled in one or more of the power input receptacles. The input power cables supply electrical power from an electrical power system to the rack PDU.

Abstract: A method and apparatus for monitoring an AC line for impedance change. In one embodiment, the method, comprises superimposing a tone on an AC current coupled to the AC line, wherein the tone is a higher frequency than an AC voltage waveform on the AC line; applying a correlation over a sampled AC voltage waveform, obtained by sampling the AC voltage waveform, to generate a correlated signal; and determining whether at least one change in characteristic of the correlated signal occurs.

Abstract: A continuous grounding system for use in an alternating current system including a transformer is disclosed. The system includes a switch assembly connected between a transformer neutral of a transformer and a ground, the switch assembly having an open position and a closed position, the open position disrupting the path through the switch assembly between the electrical connection and the transformer neutral, and the closed position establishing a path connecting the electrical connection to the transformer neutral through the switch assembly, wherein in normal operation of the alternating current electrical device the switch assembly remains in a closed position. The system also includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground.

Abstract: An energy storage system includes a plurality of battery units; a plurality of thermistors detecting a temperature of the plurality of battery units; a multiplexer performing multiplexing on the plurality of thermistors, and connecting a thermistor selected from among the plurality of thermistors to a reference resistor; a power switch unit arranged between the reference resistor and a power voltage terminal; and a control signal input unit receiving a control signal applied to the multiplexer and the power switch unit, and receiving two or more control bits contained in the control signal. In the energy storage system, a temperature measurement operation is performed at a plurality of measurement positions, whereby a current state of a battery may be accurately detected, an entire circuit may be reduced and simplified, and low power consumption may be realized.

Abstract: A system parallels engine-generators on a common bus and includes circuit breakers and automatic voltage regulators. Each engine-generator includes an output having an alternating current voltage. Each breaker is between the output of a corresponding engine-generator and the bus. Each regulator includes a first mode controlling field excitation for a corresponding engine-generator and a second mode automatically controlling the AC voltage.

Abstract: An apparatus for providing power to a multipole in a mass spectrometer is provided. The apparatus comprises a first resonant LC circuit; at least one inductor for forming a second resonant LC circuit with the multipole, the second resonant LC circuit connected in cascade with the first resonant LC circuit, when the at least one inductor is connected to the multipole; an RF power source for providing an RF signal; and a step-up transformer connected in parallel to the RF power source on a primary side and the first resonant LC circuit on a secondary side, the step-up transformer providing voltage gain for the RF signal thereby reducing the loaded Q of the resonant LC circuits.

Abstract: A polyphase power management system (PMS) and a method of operating the same. In one embodiment, the PMS includes: (1) a switching unit having a polyphase mains input with a neutral, a backup power input, a rectifier output and an other loads output, (2) a mains monitor/controller coupled to the switching unit and configured to monitor the polyphase mains input and route various phases of the polyphase mains input or the backup power input to the rectifier output and the other loads output based on the number of phases that are nominal at the polyphase mains input.

Abstract: It is an object of the present invention to suppress such a situation that electric power selling becomes impossible while the deterioration of supply power is prevented. The electric power selling system of the present invention comprises a solar battery 3 as a power generator, and a control unit 7 which is connected with the solar battery 3 and a distribution line and configured to convert output voltage of the solar battery 3 into variable voltage for electric power selling. The electric power selling system further comprises a transmitter 60 connected with the distribution line, said transmitter 60 being configured to measure voltage of the distribution line and to supply the control unit 7 with an instruction value obtained based on the measured voltage value. The control unit 7 is configured to convert the output voltage of the solar battery 3 into the voltage for electric power selling based on the instruction value.

Abstract: A phase detector for a phase-locked loop includes a phase detector that is configured to become unstable, oscillate and drift rapidly in frequency in a predictable manner when a reference frequency signal is not available. When applied, for example, to a power converter connected to a power distribution grid, the predictable oscillatory and rapid frequency drift behavior when the phase detector is unstable allows very rapid and reliable detection of disconnection from the grid, referred to as islanding.

Abstract: A protection method in a distributed power system including of DC power sources and multiple power modules which include inputs coupled to the DC power sources. The power modules include outputs coupled in series with one or more other power modules to form a serial string. An inverter is coupled to the serial string. The inverter converts power input from the string and produces output power. When the inverter stops production of the output power, each of the power modules is shut down and thereby the power input to the inverter is ceased.

Abstract: A power regulation system for an electrical grid has a store of electrical energy connected through a first switch to a source of electrical energy. The response time of the store is faster than that of the source. A second switch is connected to the store at one side with the opposite side for connection to the grid. A first controller monitors energy stored in the store and energy available from said source and selectively controls the first switch to close to transfer energy from the source to the store. A second controller monitors energy stored in said store and, on receiving an indication that additional energy is needed in the grid, if the energy stored in the store exceeds a supply threshold, controls the second switch to close to transfer energy from the store to the grid.

Abstract: A detection method for use in a primary unit of an inductive power transfer system, the primary unit being operable to transmit power wirelessly by electromagnetic induction to at least one secondary unit of the system located in proximity to the primary unit and/or to a foreign object located in said proximity, the method comprising: driving the primary unit so that in a driven state the magnitude of an electrical drive signal supplied to one or more primary coils of the primary unit changes from a first value to a second value; assessing the effect of such driving on an electrical characteristic of the primary unit; and detecting in dependence upon the assessed effect the presence of a said secondary unit and/or a foreign object located in proximity to said primary unit.

Abstract: A power supply system (100) includes an uninterruptable power-supply apparatus (5) supplying power to a load, a switch (6) connecting a bypass power supply (1) to the load, and a switching circuit (7) turning the switch (6) on when the uninterruptable power-supply apparatus (5) is stopped. In a case where the uninterruptable power-supply apparatus (5) is stopped, the switching circuit (6) turns the switch (6) on when a phase of an output voltage of the bypass power supply (1) is equal to a phase of an output voltage of the uninterruptable power-supply apparatus (5) at a stopped timing.

Abstract: A fuel cell system is disclosed with a fuel cell stack having a plurality of fuel cells, the fuel cell stack including an external electrical circuit adapted to control current from the fuel cell stack, a sensor for measuring at least one of an environmental condition affecting the fuel cell stack and a characteristic of the fuel cell stack, wherein the sensor generates a sensor signal representing a measurement of the sensor, and a processor for receiving the sensor signal, analyzing the sensor signal, and controlling an adaptive load applied to the external electrical circuit based upon the analysis of the sensor signal.

Abstract: There is provided an apparatus for the anti-islanding of a power conditioning system. The apparatus for the anti-islanding of a power conditioning system according to the present invention is applied to a power conditioning system including a DC/DC converter and a DC/AC inverter in order to transfer power from a solar cell array to a grid. The apparatus for the anti-islanding of a power conditioning system may include an injection signal generator generating an injection signal, an adder generating a final fundamental wave command value, a main controller performing the power control according to the final fundamental wave command value and stopping the operation of the power conditioning system when the level of the detected injection signal has reached the predetermined reference level or more, and an injection signal detector detecting the injection signal included in voltage and providing them to the main controller.

Abstract: A control system for use with a genset is disclosed. The control system may have a bus configured to receive power from the generator set, and a first sensor configured to generate a first signal indicative of a characteristic of power on the bus. The control system may also have a second sensor configured to generate a second signal indicative of an engine parameter of the generator set, and a controller in communication with the first and second sensors. The controller may be configured to synchronize an electrical output of the generator set with the power on the bus based on the first and second signals.

Abstract: Embodiments described include voltage generators having reduced or eliminated cross current. Dynamic adjustment of a low or high threshold voltage used in a voltage generator is described. Use of a folded cascade amplifier in a voltage generator is also described.

Abstract: A power supply for use in a UV curing lamp assembly is disclosed. The power supply is powered by two intermediate frequency (200-400 Hz) low voltage sinusoidal power sources that drive the primary windings of a dual laminated transformer. The low voltage sinusoidal power sources are configured to have different phases. The out-of-phase low voltage sine wave sources are converted to high voltage sine waves on the secondary windings of the dual laminated transformer having the same phase difference relationship. A single rectifier comprising six high voltage diodes, called a ladder rectifier, combine the two out-of-phase sine waves into a single, approximately DC output power source. By modulating a phase difference between two input sine wave power sources, the approximate DC output voltage exiting the ladder rectifier may be alternated between a low ripple mode of about a 13.84% ripple, a high current mode, a high voltage mode, and an intermediate mode with a ripple in the range of about 13.84% to about 100%.

Abstract: This disclosure generally relates to stabilizing energy provided by an energy source, and more particularly to systems and methods for using multiple types of energy storage devices to selectively capture and provide energy. An energy source provides energy, and the energy storage devices selectively capture energy provided by the energy source in excess of an immediate energy requirement of a load and selectively provide energy when the immediate energy requirement of the load exceeds the energy provided by the energy source.

Abstract: A power supply system includes a main power storage device and a plurality of sub power storage devices. A converter is sequentially connected to one of the sub power storage devices to convert voltage between the selected sub power storage device and an electric power feeding line bidirectionally. The sub power storage device undergoes a connection switching process, and when there is no new sub power storage device remaining for replacement, then, in accordance with that sub power storage device's SOC and the vehicle's state, a request is generated to disconnect the sub power storage device. Here, when a condition regarding a temperature of at least one of the main power storage device and the plurality of sub power storage devices is satisfied, generation of a disconnection request is prohibited, in order to protect the main power storage device.

Abstract: Provided are a method and a device for controlling an internal combustion engine driven generator set to run in parallel. The method includes: each time an internal combustion engine is started, a controller detects whether a voltage is outputted in an output voltage circuit; obtaining of respective active power and effective values of output currents; seeking of corresponding output voltage amplitudes in respective droop characteristic curves according to the effective values of the respective output currents, and seeking of corresponding inner power factor angles in the respective droop characteristic curves according to the respective active power; the droop characteristic curves of each generator have the same slope; and each generator is controlled to reach the respective corresponding output voltage amplitudes and inner power factor angles.

Abstract: A method for power management of a multi-cell battery includes identifying a desired power value and voltage value, determining a battery voltage value and a battery current value for a battery, determining a number of battery banks from a plurality of battery banks to use for the battery, where each battery bank includes one or more battery cells (or battery modules), checking availability of each of the one or more battery cells (or battery modules), selecting one or more battery banks from the plurality of battery banks, where the selection of a battery bank is based on the availability of the battery cells (or battery modules) included in the battery pack, and a quantity of the selected battery banks is equal to the determined number of battery banks, and connecting the available battery cells (or battery modules) in the selected one or more battery banks to form the battery.

Abstract: A battery system comprises a first battery unit; a DC voltage bus; a second battery unit electrically connected to the DC voltage bus; a current-limiting component; and switching circuitry for connecting the first battery unit to the DC voltage bus, where the switching circuitry is configured to electrically connect the first battery unit to the DC voltage bus either directly or through a current-limiting component, depending on an operating parameter of the first battery unit.

Abstract: A sequential shunt regulator switch system and method is disclosed. A power switch is controlled to switch a first current from a power source to an electrical bus. Further, a current controllable switch provides a controlled current from the power source to the electrical bus.

Abstract: Three or more portable generators are linked for synchronized operation. Power cables link each generator to a linkage box which connects the power in parallel and connects an outlet thereto. Communication cables link a software module in each generator with the linkage box. The modules vary the generator operation to generate a voltage amplitude and phase matching that of the first generator that is connected to the box that begins power generation, so that all generators share the load equally until their power output limits are reached.

Abstract: A ferroresonant transformer comprises a core, a main shunt, first windings, second windings, and third windings. The main shunt arranged relative to the core to define a primary side and a secondary side of the ferroresonant transformer. The first windings are arranged on the primary side of the ferroresonant transformer and are operatively connected to the primary power source. The second windings are arranged on the secondary side of the ferroresonant transformer and are operatively connected to the secondary power source. The third windings are arranged on the secondary side of the ferroresonant transformer and are operatively connected to the resonant capacitor. When a primary signal is present on the first windings, a first output signal is present on at least a portion of the third windings. When a secondary power is present on the second windings, a second output signal is present on at least a portion of the third windings.

Abstract: A charging unit comprises a first input connectable to a first power source, a second input connectable to a second power source, and an output for connection to a battery to be charged. The charging unit also comprises a power supply unit operable simultaneously to provide power from the first input and power from the second input to the output.

Abstract: A wind turbine is provided. The wind turbine includes a transformer having a low-voltage side and a high-voltage side. The transformer is configured to step up a voltage of the low-voltage side of the transformer to a voltage of an external grid. The wind turbine further includes an electrical power generating unit which is connected to the low-voltage side of the transformer and configured to feed an ac-power to the low-voltage side of the transformer. A charging device of the wind turbine is connected to the low-voltage side of the transformer and configured to charge the low-voltage side of the transformer when the generator does not feed ac-power to the low-voltage side of the transformer.

Abstract: There is provided a power supply unit, comprising: a converter transformer; a first low voltage generation unit to generate a first voltage on a secondary side of the converter transformer and output the first voltage; a first controller that controls an activation state of a primary side of the converter transformer based on the first voltage; an inactivation unit to inactivate operation of the first controller based on the first voltage to let the first low voltage generation unit to suspend output of the first voltage; a high voltage supply unit to output a high voltage higher than the first voltage by using the first voltage; a detection unit to detect an anomalous state concerning output of the high voltage of the high voltage supply unit. The high voltage supply unit inactivates the operation of the first controller through the inactivation unit when the anomalous state is detected.

Abstract: Conventional circuits often have undesirable characteristics to due “hot spots” or use a large amount of area. Here, however, a charging circuit is provides that uses an improved driver. Namely, an amplifier within a current sensor is used to control the rate that a switch can charge an external capacitor. This is accomplished through the adjustment of the gain of the amplifier during a charging mode.

Abstract: The present invention discloses a power conversion circuit. A control module controls a pulse width modulation regulator to regulate a duty cycle of a DC-DC converter according to the direct current link voltage of the DC-DC converter and the output current and voltage of a renewable power supply. The control module also controls the pulse width modulation regulator to regulate a duty cycle of a DC-AC inverter according to the direct current link voltage of the DC-DC converter, output voltage of a utility power supply, and the output current and voltage of the renewable power supply.

Abstract: The invention relates to a grid synchroniser for connecting an AC output of a power converter to the AC grid mains. In one aspect the invention provides a grid synchroniser comprising an inverter controller to control an AC output of the inverter, the controller including a receiver to receive grid data from a grid sensor location remote from said inverter. In another aspect we describe techniques for rapid removal of charge from a control terminal of a power switching device such as a MOSFET, IGBT or Thyristor using a particular driver circuit.

Abstract: The invention relates to a process of connecting an AC output of a transformerless inverter of a solar power plant to an internal AC power grid at an input side of a galvanic isolation, while an offset voltage for shifting a potential center point of a photovoltaic generator connected to the inverter is applied. The process includes: (i) synchronizing the inverter with the power grid; (ii) essentially matching a potential center point of the current-carrying lines of the AC output and a potential center point of the power grid, while only one of the potential center points of the current-carrying lines and the power grid is yet shifted by the offset voltage; and (iii) galvanically connecting all current-carrying lines of the AC output with the power grid only after the steps of synchronizing and essentially matching.

Abstract: An energy harvesting system receives a low power input from an energy harvesting device such as a photovoltaic device or similar, and controls the storage of power in power management logic. The stored power eventually reaches a level that permits it to be supplied to power conversion block for supply of a regulated voltage to a load.

Abstract: A power system for use in a power facility is disclosed. The power system may have a first generator set with a first engine drivingly coupled to a first generator, and a second generator set with a second engine drivingly coupled to a second generator. The power system may also have a common bus, and a controller in communication with the first and second generator sets. The controller may be configured to direct power from the first generator to the common bus, and synchronize a power output from the second generator with a power output from the first generator. The controller may be further configured to postpone power from the second generator being directed to the common bus until the first and second engines are substantially mechanically synchronized.

Abstract: This disclosure generally relates to stabilizing energy provided by an energy source, and more particularly to systems and methods for using multiple types of energy storage devices to selectively capture and provide energy. An energy source provides energy, and the energy storage devices selectively capture energy provided by the energy source in excess of an immediate energy requirement of a load and selectively provide energy when the immediate energy requirement of the load exceeds the energy provided by the energy source.

Abstract: When charge power or discharge power of each individual sodium-sulfur battery included in a plurality of sodium-sulfur batteries becomes 1/n (n is a natural number) or less of a rated output, individual sodium-sulfur batteries are sequentially stopped. This prevents the discharge power (or the charge power) of the sodium-sulfur battery from becoming minute, so that a battery depth (or a stored energy) of the sodium-sulfur battery can be accurately managed.

Abstract: A method is provided for synchronizing an electric machine with an electric grid. The method includes synchronizing the frequency of a generator with a frequency of the grid, and regulating the voltage of the generator towards the voltage of the grid, by connecting the generator to the grid when the voltage of the generator reaches a first voltage value lower than the grid voltage. The present disclosure also provides arrangements of an electric generator and an electric grid.

Abstract: A method of assembling a motor stall correction system includes coupling an inverter-based electric power generation device to an electric power inverter assembly. The method also includes coupling the electric power inverter assembly to at least one induction motor. The method further includes operatively coupling at least one controller to the electric power inverter assembly. The controller is programmed to transmit electric current from the inverter-based electric power generation device to the electric power inverter assembly. The controller is also programmed to transmit real current and reactive current from the electric power inverter assembly to the induction motor. The controller is further programmed to modulate the real current and the reactive current as a function of at least one of an electric power grid frequency and an electric power grid voltage.

Abstract: A power regulator circuit automatically disables an internal pass transistor when a detection circuit detects the presence of an external pass device. The internal pass transistor is made in an integrated circuit along with a detection circuit and a switch for disabling the internal pass transistor. The detection circuit detects a presence of an external pass device external to the integrated circuit. The switch automatically disables the internal pass transistor when the detection circuit detects the presence of the external pass device. The detection circuit has a comparator for comparing a signal on an outside connection of the integrated circuit and a latch to operate the switch. The comparator compares a voltage on an outside connection of the integrated circuit against a reference after power up of the regulator and can delay operation of the comparison until a predetermined time after power up. An integrated circuit can contain the power regulator circuit and the internal pass transistor.

Abstract: Disclosed herein are systems and methods for converting data samples representing alternating electric currents. The data samples may be obtained by sampling a first alternating electric current having a first frequency at a sampling frequency, sampling a second alternating electric current having a second frequency at the sampling frequency, and converting the data samples using a conversion algorithm to compensate for any discrepancy caused by the difference between the first frequency and the second frequency. The corrected data samples may be utilized to determine various characteristics of the alternating electric current, such as voltage magnitude, voltage phase angle, current magnitude, current phase angle, and other related attributes. In one application, the systems and methods disclosed herein may be utilized in connection with an intelligent electronic device used to couple a first electrical system, such as a power generator, to a second electrical system, such as a utility intertie.

Abstract: The present disclosure generally pertains to systems and methods for swapping span power modules that are used for supplying power to network interface units (NIUs). A span power module in accordance with one exemplary embodiment of the present disclosure has logic capable of communicating with logic of another span power module. When one module is to be swapped for the other module, the module being swapped-in is configured to automatically disable the other module shortly after it has powered up and is supplying electrical power across a span line. The amount of time that both modules supply power to the span line is sufficiently small such that damage to electrical communication equipment receiving power from the span line is prevented.

Abstract: A linear voltage regulator circuit includes first and second voltage input terminals to receive a first or second external voltage, a voltage output terminal, a voltage regulator unit, a voltage switch unit, and a voltage detecting unit. The voltage regulator unit selectively receives the first or second external voltage controlled by the voltage switch unit. The voltage detecting unit outputs a first control signal to control the voltage switch unit to output the first external voltage to the voltage regulator unit, in response to an output voltage of the voltage output terminal being less than or equal to a predetermined value. The voltage detecting unit outputs a second control signal to control the voltage switch unit to output the second external voltage to the voltage regulator unit in response to the output voltage being greater than the predetermined value.

Abstract: A method and systems of adaptation of an active power supply set using an event trigger are disclosed. In an embodiment, a method includes providing power to a system load using an active power supply set. The active power supply set includes a power supply in an active mode. The method also includes detecting an event trigger. In addition, the method includes increasing a power mode of an additional power supply when the event trigger is detected. The method may include detecting an additional event trigger and decreasing the power mode of a unit of the active power supply set when the additional event trigger is detected.

Abstract: This disclosure includes systems and methods for managing the interaction between inverter-based DC and other power systems. In one embodiment, a 3-phase isolation transformer is fluxed to create a 3-phase rotating field from the output of a source inverter. An inductive filter turns that output into three sine waves. A secondary inverter regenerates the system, sometimes after the isolation transformer is fluxed, and by advancing or retarding the secondary inverter's phase, current (and, thus, the DC voltage and power direction) is controlled. In another embodiment, an inverter is supplied by a DC source. The inverter is controlled to match its output voltage, current, and phase to a live AC grid, then the two are connected. The inverter frequency is then driven to advance the phase of the inverter in relation to the grid. Alternatively, the inverter voltage is then driven at a level greater than that of the grid.