Abstract: A protective relay, system, and relay operation method which allows logic functions to be distributed amongst multiple protective relays associated with a power distribution system. The protective relays include communications ports for exchanging messages over a peer-to-peer communications network, and include programmable logic. Each protective relay receives logic operands contained in the messages from remote protective relays, executes logic equations using the received operands, provides protective control if needed, and outputs operands to other protective relays.

Abstract: An electrical connector for interconnecting a display to a printed circuit board is disclosed. One application of the invention provides connection between a liquid crystal display (“LCD”) and a circuit board. The connector is capable of serving a dual function as both a lightguide that disperses light for the display, and as an electrical connector for interconnection of the display with the circuit board. A leg member is mounted on the connector, and the leg member includes a row of contact feet for electrical communication. The connector may include a plurality of spaced apart U-shaped strip members mounted in parallel upon a leg member, with contact feet that extend upwardly to resiliently mate with contact pads of the display and downwardly to resiliently mate with contact pads of a printed circuit board.

Abstract: In systems embodying the invention, a “downed” power line is detected by sensing whether there is an open circuit along the power line and producing an indication that an open circuit condition exists. In response to an indication that an open circuit condition exists, the system compares the nature of the voltage and/or current signals present on the power line at the time an open circuit condition is indicated to exist, with a preprogrammed stored condition which includes typical signals to be expected when a “break” occurs along a power line. When a downed power line is detected, power is then removed from the affected line.

Abstract: A voltage recovery system and its method of operation provides voltage protection to a load connected to a distribution network of a utility power system or network by boosting the voltage on a distribution line, during a momentary voltage sag caused by a fault or other contingency. The method includes voltage protection from a voltage recovery system to a load connected to a distribution network of a utility power network. A voltage protection characteristic required by the load is selected. On the basis of electrical characteristics of the voltage recovery system and the distribution network, a determination is made as to whether the voltage recovery system is capable of providing the required first voltage protection characteristic.

Abstract: A fault protection apparatus is disclosed for use in a time graded fault protection scheme. The apparatus comprises a circuit breaker having a normally closed trip contact provided in a line, current measurement apparatus adapted to produce an output signal indicative to the current in the line at the circuit breaker, and fault signal processing apparatus adapted to process the output signal from the current measurement apparatus to detect an initial fault on the line at a first instance. The fault signal processing apparatus is further adapted to process the output of the current measurement apparatus after the initial fault has been detected and to produce an accelerated opening signal in the event that the output signal meets a predetermined criteria, and a control device which is adapted to open said circuit breaker trip contact in response to said accelerated opening signal.

Abstract: A protection relay device for distribution equipment is provided with breakers respectively disposed at branches of a distribution system having the branches in a hierarchical structure, relays respectively disposed at the branches and detecting a short-circuit failure in a lower-rank section and outputting a detection signal, and a central control device receiving the detection signals output by the relays, determining a short-circuit failure section where a short-circuit failure has occurred from the detection signal received, and operating the relay of the branch corresponding to the short-circuit failure section to open the breaker corresponding to the relay.

Abstract: Method and apparatus for controlling an electric power distribution system including the use and coordination of information conveyed over communications to dynamically modify the protection characteristics of distribution devices (including but not limited to substation breakers, reclosing substation breakers, and line reclosers). In this way, overall protection and reconfigurability of the distribution system or “team” is greatly enhanced. According to additional aspects of the invention, devices within the system recognize the existence of cooperating devices outside of the team's domain of direct control, managing information from these devices such that more intelligent local decision making and inter-team coordination can be performed. This information may include logical status indications, control requests, analog values or other data.

Abstract: A control system is used in an intelligent power distribution network. The power distribution network includes multiple branches, each of which is connected to a power source, electrical devices connected to the branches, and a normally-open device connected between two or more branches. The control system includes control elements, each control elements being associated with an electrical device connected to a branch of the distribution network. The control system also includes a master control element associated with the normally-open device. The master control element communicates with the control elements and, when a fault occurs on the distribution network, prevents the normally-open device from closing when information from the control elements indicate that conditions potentially disruptive to the distribution network would occur if the normally-open device were closed.

Abstract: This invention relates to an arrangement for sensing a change in pressure from a first state to a second state. This is function in a grid system which has a fault undetected by flow measurement devices. This arrangement consisting of remote monitors powered by a communication system with a stand alone power supply which will sense a significant change in pressure. The monitors, with time delay built in, transmit this change in status to a central host computer for grid system analysis. In normal means for stabilizing the grid system, a remote signal is sent from the host computer to an isolation device for isolating the fault from the remainder of the network system. Subsequently, the host computer notifies the operating department with written notice of the isolation action.

Abstract: The present invention relates to an apparatus and method for distributing electrical power from power substation circuits. The apparatus of the present invention is responsive to overcurrent conditions and selectively actuates a switching network so as to restore power to at least a portion of the users connected to the faulty circuit of the power distribution system.

Abstract: An electrical power distribution system having geographically separated plural generation stations and geographically separated loads is improved by dynamically offsetting a nominal real power operating point of a main control system driving a power control element that variably feeds electrical power onto a network of transmission lines between the stations and the loads in response to deviations in frequency and/or phase of alternating current power on the network. The generation station can include an actuator control circuit for driving the control element in response to a power setting signal, the actuator control circuit incorporating a delay component, an offset signal connection downstream of the actuator control circuit bypassing the delay component. Preferably the system further includes means for monitoring a threshold level of the deviations, and means for inhibiting the means for dynamically offsetting until the deviations exceed the threshold level.

Abstract: A system and method which detects and responds to abnormalities in a distribution system by reconfiguring nodes of the system to minimize the effects of the abnormality without the requirement of communicating with a central controller. The nodes in the system coordinate a response to a system abnormality through a process of self-organization in which each node acts based on its own programming, sensors, and stored data. Each node keeps other nodes apprised of its actions so that they may in turn decide what actions are appropriate for them to take.

Abstract: A load center monitor (10) is disclosed for monitoring and analyzing data gathered by electronic circuit breakers (40) in a power distribution system and communicated to the load center monitor (10) via a network (26) coupling the load center monitor (10) and the circuit breakers (40) together. The load center monitor (10) includes a first communication port (24) for communicating with the circuit breakers (40), a second communication port (20 or 22) for communicating with an external device and third communication port (28) for providing diagnostic information. The load center monitor (10) further includes audible (30) and visible (34) annunciators for providing alarm or status indications. A processor (76), coupled to the communication ports and to a memory (70) having a real-time clock for time stamping data provides monitoring, control, analysis and data generating capability in the load center monitor (10).

Abstract: A system including a load center monitor (10) connected to a plurality of digitally enhanced circuit breakers (40) by a communication bus (26) forms a network of reconfigurable circuit breakers which provides advanced monitoring and control of an electrical power distribution system. A user port (20) and a service port (22) provide a communication interface with an external computer. Visual indicators (34) and an audible alarm (30) provide for alerting persons to certain conditions in the system. Buttons are provided for CLEAR (38), RESET (36), and TEST functions, and a diagnostic port (24) is also provided. The load center monitor (10) is operable to monitor the operation of the circuit breakers (40) and download information therefrom for storage in the load center monitor (10) as in the form of historical data.

Abstract: A method of communicating data with a plurality of electronic circuit breakers operatively connected in a power distribution system is disclosed and claimed herein. Each circuit breaker includes a communication port coupled to a network. The method comprises coupling a communication terminal, having a processing circuit and a first communication port coupled to the processing circuit, to the network via the first communication port; operating a first communication protocol for automatically addressing individual ones of the circuit breakers and for controlling message traffic on the network; and transmitting and receiving data on the network under control of the first communication protocol relating to the monitoring and control of the individually addressable ones of the plurality of electronic circuit breakers coupled to the network.

Abstract: Embodiments of this invention provide for coupling an accessory device to a back face of a handheld computer while electrically connecting to the handheld computer through a communications or output port. In one embodiment, the accessory device "piggy-backs" on the handheld computer so that the accessory device and handheld computer form a portable combination. An insertion coupling may be used to detachably secure the accessory device with the handheld computer. The insertion coupling used with embodiments of the invention is preferably a snap-in coupling having one or more biased members. The biased members may be contracted to engage an aperture on a back face of the handled computer. When released, the biased members secure the accessory device to the handheld computer.

Abstract: A system and method which detects and responds to abnormalities in a distribution system by reconfiguring nodes of the system to minimize the effects of the abnormality without the requirement of communicating with a central controller. The nodes in the system coordinate a response to a system abnormality through a process of self-organization in which each node acts based on its own programming, sensors, and stored data. Each node keeps other nodes apprised of its actions so that they may in turn decide what actions are appropriate for them to take.

Abstract: A system and method which detects and responds to abnormalities in a distribution system by reconfiguring nodes of the system to minimize the effects of the abnormality without the requirement of communicating with a central controller. The nodes in the system coordinate a response to a system abnormality through a process of self-organization in which each node acts based on its own programming, sensors, and stored data. Each node keeps other nodes apprised of its actions so that they may in turn decide what actions are appropriate for them to take.

Abstract: A communication terminal (10) is coupled to and operable in a power line network with at least one of plurality of intelligent circuit breakers (40) wherein each such circuit breaker (40) has a communication port. The terminal (10) includes a housing and connection means (12, 14) for connecting the terminal (10) to the power line network. The terminal (10) includes a processing circuit (76) and communication ports (24, 22, 20) for communicating over communication links with the circuit breakers (40) or other external devices according to a message protocol defined for the system.

Abstract: A first trip unit for interconnection with a second trip unit includes current transformers and potential transformers for sensing current, voltage and frequency conditions of a circuit breaker's separable contacts. A microprocessor-based trip mechanism provides a trip signal, which is employed by the circuit breaker's operating mechanism to open the separable contacts as a function of the sensed electrical conditions and related predetermined operating values. The microcomputer's transceiver communicates with the second trip unit over a passive two-wire communication cable to acquire the predetermined settings of the second trip unit. The microcomputer includes a firmware routine which employs the acquired predetermined settings as its predetermined values.

Abstract: A system for monitoring and controlling an electrical distribution network comprises an electrical distribution substation having a local area network (LAN), a feeder subsystem and a gateway. The feeder subsystem is coupled to the substation and receives electrical energy therefrom for distribution to customers, and includes slave devices for performing switching functions. The gateway provides remote access to the slave devices and the LAN.

Abstract: A redundant communications scheme for a protective relay which allows high-speed, reliable, and fault tolerant communications between peer protective devices in a power distribution network. Communications over a selectable primary communication channel are interrupted and switched to a secondary communication channel, which can operate according to a different communication protocol, when a fault is detected on the primary communication channel. The fault detection and switching is performed transparently to the main protective relay processor.

Abstract: An arrangement for transmitting electric power from a source point to a load point comprises (i) a first sensor to monitor the amount of power being supplied from the source point, (ii) a second sensor to monitor the amount of power being received by the load point, and (iii) communication circuit for communicating to a control circuit information in respect to the amount of power supplied from the source point as well as that received by the load point. The control circuit then compares the amount of power supplied versus that received, and provides a warning and/or halts the supply of power in case a substantive discrepancy were to occur between power supplied versus power received. Thus, in case an improper loading were to occur between the source point and the load point, it would be detected by the control circuit, which would then instigate protective action.

Abstract: The present invention relates to a method of monitoring electrical wear on selector switch disconnectors in a bay of a high voltage station that includes a set of distribution busbars connected to at least three electrical circuits constituted by an inlet bay, an outlet bay, and a bay for coupling together the busbars.

Abstract: Intrinsically compressed device coded data is sent in radio packets with end use programs expanding the coded data for other purposes. Intelligent electronic devices are physically combined with radio communication mean to avert the coupling of interfering electromagnetic transients into the system processing and sending the data.

Abstract: The present invention relates to an apparatus and method for distributing electrical power from power substation circuits. The apparatus of the present invention is responsive to overcurrent conditions and selectively actuates a switching network so as to restore power to at least a portion of the users connected to the faulty circuit of the power distribution system.

Abstract: A protective relaying system includes a local protective relay operatively coupled to a protected line segment at a first location, and a remote protective relay operatively coupled to the protected line segment at a second location. The remote protective relay generates a signal (PILOT RECEIVE) to indicate the detection of a fault. This signal is communicated to the local protective relay and employed therein to supervise single-pole trip operations.

Abstract: A relay test apparatus for testing a protective relay operation of a protective relay system comprises GPS receivers, respectively connected to the protective relays, each GPS receiver analyzing time data included in a signal transmitted from a satellite and outputting a time signal, simulation signal generators, respectively connected to the protective relays, each simulation signal generator generating a simulation signal and inputting the simulation signal to a corresponding protective relay, and synchronous starting units, respectively provided in the protective relays, each synchronous starting unit starting a corresponding simulation signal generator to generate the simulation signal, when time signals output from the GPS receivers coincide with a preset time at a same time.

Abstract: A control method and apparatus is provided for isolating network faults via the communication between neighboring network locations and the control of sectionalizing switches at the network locations. Control apparatus is provided at particular network locations which responds to detected fault conditions and communicates the detected fault condition to the control apparatus at neighboring network locations. The appropriate control apparatus, in response to the information received from neighboring network locations, opens a sectionalizing switch to isolate the fault condition. In one particular arrangement, each control apparatus that detects a fault condition sends a signal to appropriate source-side, neighboring control apparatus to inhibit the source-side control apparatus from opening their respective sectionalizing switches. Further, any control apparatus that detected a fault condition and that does not receive an inhibiting signal, controls its sectionalizing switch to open.

Abstract: A safety switch arrangement having a first supply line; a first computer unit coupled to the first supply line, the first computer unit having a first operating voltage; a first pair of bidirectional lines, one of the first pair of bidirectional lines having a first switch; a first actuator coupled to the first computer unit by the first pair of bidirectional lines, the first actuator having a first switch, which has first semiconductor elements; a second supply line; a second computer unit coupled to the second supply line, the second computer unit having a second operating voltage; a second pair of bidirectional lines, one of the second pair of bidirectional lines having a second switch; a second actuator coupled to the second computer unit by the second pair of bidirectional lines, the second actuator having a second switch, which has second semiconductor elements; a working device coupled to the first and second actuators and having an operating state, the first and the second actuators controlling the op

Abstract: The present invention relates to an apparatus and method for distributing electrical power from power substation circuits. The apparatus of the present invention is responsive to overcurrent conditions and selectively actuates a switching network so as to restore power to at least a portion of the users connected to the faulty circuit of the power distribution system.

Abstract: A relay test apparatus for testing a protective relay operation of a protective relay system comprises GPS receivers, respectively connected to the protective relays, each GPS receiver analyzing time data included in a signal transmitted from a satellite and outputting a time signal, simulation signal generators, respectively connected to the protective relays, each simulation signal generator generating a simulation signal and inputting the simulation signal to a corresponding protective relay, and synchronous starting units, respectively provided in the protective relays, each synchronous starting unit starting a corresponding simulation signal generator to generate the simulation signal, when time signals output from the GPS receivers coincide with a preset time at a same time.

Abstract: A power distribution circuit is provided that isolates both power source and load faults. In one embodiment, the power distribution circuit includes two power MOSFETs connected with the channels of the power MOSFETs in series and having their gates electrically connected together. The body diode of one power MOSFET is aligned with the opposite polarity with respect to polarity of the body diode of the second power MOSFET. The power MOSFETs are adapted to be coupled between a first power source and a load. The power distribution circuit also includes a first sensor that detects when the power MOSFETs conduct too much current and switches the power MOSFETs off by discharging the gate voltage of both power MOSFETs during such overcurrent conditions. Accordingly, when both power MOSFETs are switched off, the opposing polarity of the body diodes in the power MOSFETs ensures that one of the body diodes will be reversed biased in case of a short circuit failure in either the load or the power source.

Abstract: In order to achieve improved release characteristics in the case of a protective device for power supply lines, a protection release method is proposed in which at least one signal (i, u) is supplied to a filter device (3, 16), and a release decision is made as a function of its output signal (SA, Z). If the conditions are insufficient for release, a change is made to the filter characteristics. The filter device (3, 16) in this case preferably comprises adaptive filters or combinations of filters. In a further refinement, a fuzzy region, which is used as the release criterion, is formed as a function of a change in the output signal.

Abstract: A power stoppage minimizing system for a distribution line and a method of using a distribution line minimize a power stoppage section and a power stoppage time when a short circuit occurs in the distribution line, and employs a first and a second distribution line each connected through a circuit breaker to a corresponding bus and each having switches in position thereon; a normally open tie point switchgear provided between adjacent ends of the first and second distribution lines; a protective relay for opening, when a short circuit has occurred, the circuit breaker a fixed time after the occurrence of the short circuit on the first distribution line; a first unit for opening a switch on the side of a power source and nearest a point where the short circuit has occurred; a second unit for opening, after the switch is opened by the first unit, a switch on the side of a load nearest the switch opened by the first unit; and a third unit for closing the tie point switchgear after the opening of the switch by th

Abstract: A relay test apparatus for testing a protective relay operation of a protective relay system comprises GPS receivers, respectively connected to the protective relays, each GPS receiver analyzing time data included in a signal transmitted from a satellite and outputting a time signal, simulation signal generators, respectively connected to the protective relays, each simulation signal generator generating a simulation signal and inputting the simulation signal to a corresponding protective relay, and synchronous starting units, respectively provided in the protective relays, each synchronous starting unit starting a corresponding simulation signal generator to generate the simulation signal, when time signals output from the GPS receivers coincide with a preset time at a same time.

Abstract: A method and a device for determining the direction to a fault on a power transmission line in relation to a measuring station with the aid of phase currents and voltages, measured in the measuring station, by means of which change values .DELTA.U in the phase voltage, change values in the phase voltage .DELTA.UM of a line model and change values in the derivative .DELTA.I' of the phase current can be determined, and wherein for each measuring loop phase-ground the signal .DELTA.QL=(.DELTA.U-.DELTA.UM).multidot..DELTA.UI' is formed and if this value is smaller than a negative value assumed in advance, a fault lying ahead, in relation to the measuring station, has been detected, and wherein for each measuring loop phase-ground the signal .DELTA.QB =.DELTA.U.multidot..DELTA.UI' is formed and if this value is greater than a positive value assumed in advance, a fault lying behind, in relation to the measuring station, has been detected.

Abstract: The disclosure relates to the methods and devices that enable series type buses to be protected against the consequences of a short-circuit in the decentralized units connected to this bus. There are provided means to detect the equalization of the potentials of the data wires and means enabling the disconnection, under the control of these detection means, of the decentralized unit responsible for the short circuit. A device is also provided to short circuit the supply wires of the bus according to a predetermined sequence in order to inform the central processing unit of the disconnection of said decentralized unit. The disclosure enables the protection of the central processing unit and of the decentralized units, connected to the bus, that are not malfunctioning.

Abstract: In a pilot wire relay electrical power distribution protection system, an audio band interface apparatus acquires a Hz pilot wire signal from the pilot wire relay and produces signals having frequencies within the frequency band pass of fibre optic communication channels. The apparatus enables pilot relays, which previously communicated over hard wire connections such as dedicated telephone lines, to communicate through a fibre optic communication channel without the necessity for extensive modifications to the pilot wire relay.

Abstract: Control and self-monitoring system for an electrical apparatus comprising three poles, each including a closing coil and an opening coil, an opened auxiliary contact, and a closed auxiliary contact, wherein each of the poles is provided with a microprocessor receiving, in particular, information from the opened auxiliary contacts and controlling two static relays in series respectively with the circuit of the opening coil and in the circuit of the closing coil, the microprocessors being subscribers to a local bus comprising a serial bus under the control of a management member and connected to a processor station receiving the signals collected by the microprocessors and the signals issued by the protection devices or by the operator.

Abstract: A system for detecting a high impedance fault in a phase conductor having a potential device connected to the phase conductor, the system including a signal injection device having an input from the potential device which detects a reduction in voltage at the phase conductor and outputs a first signal in response to detecting a reduction in voltage at the phase conductor and a signal receiver which receives the first signal and provides a second signal to an interruption device in response to having received the first signal to cause the interruption device to open the circuit to the phase conductor.

Abstract: A main controller installed in a distribution substation of an electric power system sends a request signal to each of section controllers installed in individual section switches upon detecting a distribution line fault. Each of the section controllers performs fault detection individually. Each section controller judges whether its associated section switch is dividing the distribution line between faulty and normal line sections on the basis of fault detect signals from the other section controllers. If it is judged that its associated section switch is dividing the distribution line between faulty and normal line sections, that section controller opens its associated section switch.

Abstract: A remote control residential and commercial lighting and appliance branch circuit breaker provides both overload current protection and load management. Structure is provided enabling packaging in a three-quarter inch width case, including a first set of contacts in the case provided by a pair of separable overload breaker contacts, trip structure in the case for causing separation of the overload breaker contacts in response to overload currents therethrough, a second set of contacts in the case provided by a pair of switching relay contacts having open and closed conditions and electrically connected in series with the overload breaker contacts, and an actuator in the case energizable to mechanically actuate the switching relay contacts. Feedback circuitry is included providing status indication of the condition of the switching relay contacts. Structure is provided for reducing actuator and spring requirements and sizes.

Abstract: A system to stop or reduce electrical short circuits in homes. This invention is a refinement of the breaker box function. A computer controls breaker switching in the breaker box. A sum of the theoretical power consumption in a given breaker helps the computer determine if an electrical short is present. Outlet modules attach themselves to the home's standard electrical outlet (socket). They tell the computer when a new load (finite resistance) is to change the old theoretical breaker limit. The computer adjusts the theoretical limit to a new limit (never above maximum permitted) and allows the power drain on the breaker.

Abstract: Method and apparatus for providing protected power to a computer. A computer monitors the terminal voltage and/or current of a battery supplying power to the computer and uses this information or data to determine when, in the event of failure of the AC utility normally supplying power to the computer, to initiate a pre-programmed automatic shutdown of the computer. The determination is based upon the estimated remaining charge of the battery and the total time required to close all active programs in an orderly fashion; thus allowing the computer to be restarted in a well-defined state.

Abstract: Monitoring and control of analog electromechanical protective relays and digital mcroprocessor based relays is integrated through a system including slave stations which record and time tag contact activity at each of the analog relays. The slave stations continuously retain digital samples of a predetermined number of the most recent cycles of the currents and voltages at the analog relays and when a trip occurs store the retained samples as pre-fault values together with a preset number of post-fault samples. A master station communicates with the slave stations monitoring the analog relays and with the digital relays through a two way communications network. The master station repetitively polls the slave stations and digital relays for contact activity. Detailed data such as the time tags and pre-fault and post-fault currents and voltages are then requested from those stations reporting contact activity.

Abstract: The square wave phase comparison signals generated for each phase of a power distribution system by phase comparison relays at each end of a protected three phase transmission line segment are combined to generate a single, multi-level signal with discrete values for each instantaneous combination of square wave signals. The single, multi-level signal is used to modulate a carrier signal which is transmitted over a single channel of a two-way communications link to the other terminal where the carrier signal is demodulated to reproduce the multi-level signal. The reproduced multi-level signal is then decoded to generate remote square wave signals which are compared with the phase of locally generated square wave signals to generate trip signals for circuit breakers at the respective terminals. Square waves representative of priority functions, such as direct transfer trips, can be integrated into the single, multi-level signal transmitted to the other terminal.

Abstract: A directional comparison relaying system includes forward looking pilot relays at each terminal of a protected line segment and monitors which detect predetermined incremental changes in line currents and voltages indicative of a fault. These predetermined incremental changes in current or voltages, which can be detected before the pilot relays respond, generate local blocking signals which are transmitted to the other terminal as remote blocking signals over a two-way communications channel. Trip signals for tripping circuit breakers at the associated terminals are generated from forward fault signals produced by the pilot relays but are blocked by the presence of either a local or remote blocking signal. However, the forward fault signal cancels the local blocking signal and the corresponding remote blocking signal at the other terminal so that when both pilot relays see an internal fault, the circuit breakers at the two terminals are tripped simultaneously.

Abstract: A system is disclosed for sequentially disconnecting multiple phases of a first power source (12) from an electrical load (14) requiring a minimum of interruption and connecting a second power source (28) to the electrical load. A first embodiment of the invention disconnects immediately the phase in which a trip condition requiring disconnection of the first source power is detected and disconnects phases of a first power source (12) in which a trip condition is not detected upon the detection of zero current flow in those phases. In a second embodiment of the invention, each of the phases of the first power source (12) is disconnected immediately from the electrical load (14) upon the detection of a trip condition in any one of the phases requiring disconnection of the first power source. In both embodiments of the invention, the phases of the second backup power source (28) are connected upon the detection of the occurrence of zero voltage points in the respective phases.

Abstract: A power distribution system includes a plurality of power sources and load transfer units including transistors and diodes connected in series and leading to a common power output, each of the transistors being controller switchable subject to voltage levels of the respective input and output sides of said transistors, and the voltage and current level of said common power output. The system is part of an interconnection scheme in which all but one of the power sources is connected to a single load transfer unit, enabling the survival of at least a single power source with the failure of one of the load transfer units.