Abstract: A method of operating a windfarm connected to an electric grid via a point of injection for injecting power from the windfarm to the electric grid, the windfarm including at least two generating units and a windfarm controller, the method comprising: measuring 302 voltage and/or frequency characteristics of an electrical signal of the electric grid at the point of injection, communicating 304 to at least two generating units of the at least two generating units of the windfarm at least one control signal based at least in part on the measured voltage and/or frequency characteristics of the electrical signal of the electric grid at the point of injection, the at least one control signal being indicative of a grid situation at the point of injection; controlling 306 the at least two generating units of the at least two generating units of the windfarm at least in part based on the communicated at least one control signal.

Abstract: Various implementations described herein are directed to systems and methods for managing a plurality of loads connected to a plurality of power sources using a switching apparatus. Apparatuses described herein may include multi-throw switches designed for fast and efficient switching of loads. Methods described herein may include selecting one or more loads from a group of loads to connect to one or more alternative power sources, and selecting one or more loads to connect to a main (e.g. utility) electrical grid.

Abstract: In order to output sufficient reactive power for voltage stabilization of a utility grid, and calculate an appropriate consideration according to an amount of the output reactive power, is provided a control device for controlling a distributed power source connected to the utility grid, comprising: a range setting unit where an allowable range of reactive and active powers output at normal times is set; an output control unit for controlling the reactive and active powers supplied from the distributed power source to the utility grid within the allowable range set in the range setting unit; and a reception unit for receiving, from a command device in the utility grid, an excess output command indicating that the reactive power exceeding the allowable range should be output, wherein the output control unit is for outputting the reactive power out of the allowable range when the reception unit receives the excess output command.

Abstract: Regulating a power ramp rate of a wind park at a point of common coupling (PCC) between the wind park and a utility grid. The method comprises receiving a power reference for the wind park; determining the power ramp rate of the wind park as a function of the power output of each individual wind turbine in the park, wherein the power ramp rate of the wind park is based on the power ramp rates of the individual wind turbines and determining a corresponding plurality of power set-points for each wind turbine based on the power ramp rates and power reference. The corresponding plurality of power set-points is dispatched to the plurality of wind turbines for regulating the power ramp rate of the wind park in dependency of the power ramp rates of the plurality of wind turbines.

Abstract: Devices and systems for determining an alternator condition in a motor vehicle are provided. The method includes performing a plurality of micro wakeups to capture voltage values during a cranking event, determining the maximum cranking voltage and its timestamp, detecting an ignition signal, determining the maximum device voltage and its timestamp, and determining a potential alternator undercharging condition if a duration between the maximum cranking voltage timestamp and the maximum device voltage timestamp is greater than an undercharging indicator duration threshold. Advantageously, an alternator may be repaired or replaced before it fails thus averting having the motor vehicles inoperable.

Abstract: Rotating electric machine comprising a main electric machine, an excitation machine whose rotor is adapted to rotate with a rotor of the main electric machine and produce magnetizing power to the main electric machine, and a controllable rectifier bridge electrically connected to the excitation machine for feeding a field magnetization current to a rotor winding of the main electric machine and comprising controllable semiconductor components for controlling the field magnetization current. The rotating electric machine comprises a controllable circuit connected in parallel with the rotor winding and adapted to lower the magnetization of said rotor winding. The controllable circuit is a self-controlled circuit configured to self-act depending on the voltage across said rotor winding and comprises a discharge resistor dissipating the field magnetization current to lower the magnetization of said rotor winding.

Abstract: A device according to an embodiment includes at least one assembled battery; first switches that switch an electrical connection state of main circuits connected between the assembled battery and the load; second switches that switch an electrical connection state of second main circuits branched from the main circuits and are connected between the assembled battery and the load; a BMU that controls operations of the first switches based on an operation command supplied from the load; and a power supply circuit that supplies power to the BMU and second switches when a start command supplied from the outside is ON.

Abstract: A detection device includes a first detection unit that detects whether a power source may be in an islanding operation based on a frequency of an power supplied from a power source connected to a system, a power processing unit that changes the amount of power supplied from the power supply to the system in response to that the first detection unit detects that the power source may be in the islanding operation, a second detection unit that detects a voltage of a system with the power supply amount having been changed, and a disconnection processing unit that determines whether to disconnect a power source from a system in response to a change in a voltage of a system with the power supply amount having been changed.

Abstract: A method for determining parameters for controlling N electric generators at an instant t, the method including, for a required power Ptot(t)=?i=1NPi(t) at an instant t with Pi(t) the electric power supplied by the electric generator i at the instant t and a reserve power Preserve(t)??i=1N(Pimax?Pi(t)×?i(t) at an instant t with Pimax the maximum power that the electric generator i can develop and ?i(t) the coefficient of activation of the electric generator i which is equal to 1 when the electric generator is on and 0 when the electric generator is off, a step of determining the optimal power Piopt(t) at the instant t associated with each electric generator i so as to minimise the fuel consumption per unit of electrical energy produced sfc ? ( t ) = 1 P tot ? ( t ) ? ? i = 1 N ? f i ? ( P i ? ( t ) ) × P i ? ( t ) with fi(x) the function giving the fuel consumption of the electric generator i for the electric power x.

Abstract: The movable body includes a pivot and a contact portion. The pivot is rotatably supported. The contact portion is disposed at a position contactable with a contact piece. The movable body rotates around the pivot and presses the contact piece via the contact portion to move the second contact close to the first contact. The actuator presses the movable body to rotate the movable body around the pivot. The contact piece has a curved portion located between the second contact and the support. The pivot is located on a side where the support is disposed with respect to the curved portion. The actuator includes a pressing member which presses the movable body. The pressing member moves in an axial direction of the pressing member to press the movable body.

Abstract: A wind turbine system comprising a plurality of wind turbines mounted to a common support structure, wherein each of the plurality of wind turbines includes a rotor and a power generation system driven by the rotor, wherein the wind turbine system further comprises: localised control means including a plurality of local control modules, wherein each of the local control modules is operable to monitor the operation of a respective one of the plurality of wind turbines, and to issue local control commands thereto to achieve a set of local control objectives; and centralised control means configured to monitor the operation of the wind turbine system and provide centralised control commands to the plurality of wind turbines in order to achieve a set of supervisory control objectives associated with at least two of the plurality of wind turbines.

Abstract: A method for detecting a fault in a generator unit that has an electrical machine including a rotor winding and a stator winding and a rectifier connected thereto, via which the electrical machine is connected to an electrical system of a motor vehicle. Whether or not the fault exists is determined as a function of an excitation current traversing the rotor winding of the electrical machine and as a function of a setpoint value of the excitation current.

Abstract: The control of the power output of wind turbine generator that operates in a derated mode to generate a produced power output level lower than an available power level. A pitch system sets the blade pitch of a rotor to a pitch value based on the received power reference signal. A power system controls the produced power output level of the wind turbine to the requested power output level. Moreover, the blade pitch of the rotor is further controlled by a pitch feedback control loop that modifies the pitch value based on a difference between the produced power output level and the requested power output level.

Abstract: Systems and methods for providing generated power to a power grid subject to active power, reactive power and voltage requirements during varying conditions. An expanded reactive follower for distributed generation including but not limited to wind power plant and solar power plants and loads of other reactive controllers; that includes at least one reactive power generator coupled to an electric power system with a distributed power plant. The reactive power generator (e.g. a rapidly switched capacitor bank with fast reinsertion resistors, or inverter based reactive power generator) is located on either side of the point of interconnection of the power plant. A reactive follower controller controls the reactive power generator on the basis of an estimated reactive power commanded by a reactive power management system for distributed generation plant (e.g. Solar, Wind, Battery, etc. . . . ).

Abstract: An apparatus for determining insulation resistance at a PV generator includes a first unit configured to shift a generator potential at an output terminal of the PV generator, and a second unit. The second unit is configured to determine the insulation resistance by: connecting a measurement voltage to the output terminal of the PV generator, measuring a first current value and a first voltage value at the output terminal of the PV generator before the measurement voltage is connected, measuring a second current value and a second voltage value at the output terminal of the PV generator after the measurement voltage is connected, and determining the insulation resistance of the PV generator based on the measured first and second current values and the measured first and second voltage values. The first and second units are connected in series.

Abstract: A power tool is provided including a brushless direct-current (BLDC) electric motor having a stator and a rotor. The power tool includes power switches including high-side switches and low-side switches disposed on a direct-current (DC) bus line between a power supply and the electric motor, and a controller configured to electronically brake the motor by simultaneously closing the high-side switches or the low-side switches to electrically short the stator windings. In an embodiment, the controller is configured to monitor a voltage of the DC bus line, and if the voltage of the DC bus line is lower than a voltage threshold, execute electronic braking by toggling between closing the high-side switches and closing the low-side switches over braking cycles, and if the voltage of the DC bus line is greater than the voltage threshold, execute braking by closing only the high-side switches or the low-side switches over the braking cycles.

Abstract: Provided herein are improved current monitoring systems for monitoring currents having large ranges. A current monitor can include two or more current sensors. At least two of the current sensors can have different current measurement ranges and different current measurement sensitivities. Each current sensor can be associated with one or more current monitoring thresholds. A time delay or time threshold can correspond to each current monitoring threshold. Each current sensor can monitor a same current having a large range of possible current values. When a predetermined current threshold is exceeded for an amount of time exceeding a corresponding time threshold, a signal can be generated by the current sensor. The generated signal can indicate that the measured current exceeds the predetermined current threshold for the corresponding predetermined period of time.

Abstract: The present disclosure is directed to a system and method for controlling an electrical power system connected to a power grid. The method includes determining, via a negative sequence regulator programmed in a controller of the electrical power system, a negative sequence component of at least one electrical condition of the electrical power system. Further, the method includes determining a desired current response based on the negative sequence component of the at least one electrical condition of the electrical power system. Thus, the method also includes determining a control command for the power converter as a function of the desired current response so as to achieve a desired relationship between a voltage condition in the power grid and the negative sequence component of the electrical condition of the electrical power system.

Abstract: Method of operating a wind turbine having a tower, a rotor with a plurality of blades arranged on the tower, one or more pitch systems for pitching the blades, a system for determining an instantaneous representative wind speed, and a system for determining a distance between a blade and the tower. The method comprises determining the instantaneous representative wind speed, and determining the distance between the tower and one of the blades when said blade is in the shadow of the tower. The method further comprises determining a tower distance pitch adjustment depending on the determined distance between the tower and the blade in the shadow of the tower and on the determined instantaneous representative wind speed. The method still further comprises the one or more pitch systems applying the determined tower distance pitch adjustment to at least the next blade to be in the shadow of the tower.

Abstract: An example method of operating a power distribution system including a plurality of source and tie circuit protection devices coupled between at least one source and a protection zone is disclosed. The protection zone includes a distribution bus and a plurality of feeder circuit protection devices coupled between the distribution bus and a plurality of loads. The method includes determining an electric current flowing through each source and tie circuit protection device, determining whether any of the feeder circuit protection devices is outputting a ZSI blocking signal, and controlling operation of the plurality of source and tie circuit protection devices according to an enhanced partial differential protection scheme based on a combination of the determined currents through the source and tie circuit protection devices and the determination of whether any of the feeder circuit protection devices is outputting a ZSI blocking signal.

Abstract: A power distribution system capable of automatic fault detection includes a lateral, a switch unit and a feeder terminal unit. The switch unit includes a circuit breaker coupled for transmitting electrical power to the lateral when making electrical connection, and a protection relay to provide a control signal that causes the circuit breaker to break electrical connection upon determining that the magnitude of a current provided by the circuit breaker is greater than a threshold current value. The feeder terminal unit detects whether or not the protection relay generates the control signal, so as to determine whether or not a fault has occurred in the lateral.

Abstract: Methods and apparatus for dynamically balancing at least one load characterized by an associated energy reservoir with at least one renewable energy source where both the load and the renewable energy source coupled to a power transmission system. A central controller regulates energy delivery to one or more loads over the power transmission system by anticipating energy demand over an interval of time, accounting for the status of the associated energy reservoir. Each load is linked with at least one renewable energy source. The anticipated energy demand is synchronized with delivery of energy by the renewable energy source by commands delivered to a local switching and monitoring device coupled to the load and subject to override by a local user.

Abstract: Methods, controllers and computer program products for controlling a wind turbine. Under de-rated operating conditions in which the power requested from a wind turbine is less than the available power, a controller adjusts blade pitch of the wind turbine to reduce the rotor power coefficient. The captured wind power is thereby reduced to be approximately equal to the requested electrical power, which is less than either the available power or the rated power of the wind turbine generator. This reduction in captured power provides the controller with an additional degree of freedom that allows the controller to increase the electrical power output of the wind turbine in response to wind fluctuations without damaging the wind turbine. By allowing increases in power under de-rated conditions, the controller may reduce the amount of pitching necessary to prevent the turbine from exceeding its rated power output level.

Abstract: Systems and methods for providing generated power to a power grid subject to reactive power requirements. A reactive follower includes a reactive power generator coupled to a distributed power plant via a series impedance such as a step-up transformer. A reactive follower controller controls the reactive power generator on the basis of an estimated reactive power commanded by a reactive power management system and includes multi-variable control logic to determine when to increase reactive power produced by the reactive power generator based on the reactive power commanded by the distributed reactive power management system and point-of-interconnection measurements of power, reactive power, and voltage.

Abstract: Method for protecting an electrical energy distribution box, the electrical energy distribution box comprising a set of distribution bars intended to be connected between a generator and loads, each of the bars being able to transfer at least a part of the electrical energy passing through it to at least one other bar of the set of bars. According to this method, the incoming and outgoing currents of a single distribution bar are measured and a fault in the set of bars is detected on the basis of the currents measured in the said bar.

Abstract: A power conversion and distribution system detects faults by monitoring differential current and differential power at certain locations in the system. Current loss faults are detected based on the monitored differential current, and series arc faults are detected based on the monitored differential power. A system controller may make the fault determinations and disable a power converter circuit of the power conversion and distribution system in response to detection of a fault.

Abstract: A method, system, and computer program product for detecting and interrupting a ground fault in a direct current (DC) power circuit are provided in the illustrative embodiments. A first value of a first current flow over a first part of the DC power circuit is compared with a second value of a second current flow over a second part of the DC power circuit. A voltage is generated, wherein the voltage is proportional to a difference between the first and the second values. Responsive to the voltage exceeding the threshold voltage for a threshold time, a signal output is produced, the signal configured to cause a short-circuit in the first part of the DC power circuit. The first part of the DC power circuit is interrupted responsive to the short-circuit.

Abstract: A transfer switch configured to detect a ground current is configured to selectively connect a first power source or a second power source to a load. Each of the power sources includes at least one “hot” lead and one neutral lead, and the transfer switch is configured to switch both the “hot” and the neutral leads. If the neutral switching portion of the transfer switch fails, current may be supplied to the load via the “hot” lead of one of the power sources and return from the load via a ground conductor and the neutral lead of the other power source. The transfer switch includes a current sensor, detecting current on the ground conductor, in order to detect such a condition. The signal from the current sensor is provided to a control circuit, which, in turn, activates an indicator if the current on the ground conductor exceeds a predefined level.

Abstract: A collector monitoring system is disclosed. In one embodiment, the collector monitoring system includes: a sensor connected to an interior surface of a dynamoelectric machine housing, the sensor for sensing a condition of a collector during operation of a dynamoelectric machine; and a diagnostic system operably connected to the sensor, the diagnostic system configured to: obtain data about the condition of the collector from the sensor; compare the data about the condition of the collector with a predetermined condition threshold; and provide an indicator of a collector fault in response to the data about the condition of the collector exceeding the predetermined condition threshold.

Abstract: An arc flash mitigation system for use with a generator excitation system is provided. An exemplary arc flash mitigation system includes three semiconductor fuses, three current transformers, an overcurrent detection circuit, a gate firing circuit, and three pairs of thyristors respectively arranged in an anti-parallel phase-to-phase configuration. An exemplary method includes detecting an overcurrent and providing a gate signal to each of a plurality of thyristors included in a crowbar circuit.

Abstract: One embodiment of the present application is directed to a protection technique for an electric power generation system. In one or more implementations, an electric power generator, generator control circuitry, electrical output sensors to provide one or more corresponding signals, electrical switching equipment to selectively couple the generator to an electrical load, and electric power feeder or branch circuit conductors, to route electric power from the generator to the switching equipment, are provided. The control circuitry is responsive to the sensor signals to determine if a shutdown condition exists as a function of a protection profile determined for the system. This profile may account for damage thresholds of the generator, the feeder or branch circuit conductors, the electrical switching equipment for each of a number of different combinations of level and duration of electrical output as represented by the sensor signals.

Abstract: A mobile generator for generating a direct voltage for a tool supplied with direct current includes an alternating-voltage generator (1), an electronic control unit (3), a rectifier unit (2), which has a direct-voltage output (6) with live conductors (9, 10) for connecting the tool (11), and a protective device (14). The protective device is between the live conductors (9, 10) and a protective potential (18), especially ground or a protective wire. The protective device (14) has an insulating spark gap (15) responding in the case of an error with a defined response voltage (UT) for grounding the live conductors (9, 10).

Abstract: An overcurrent fault protection method includes detecting an overcurrent fault in a variable frequency electric power generation system having a first main generator connected to a first alternating current bus through a first generator line contactor, a second main generator connected to a second alternating current bus through a second generator line contactor and an auxiliary power generator connected to a plurality of bus tie contactors, through a third generator line contactor, and connected to at least one of the first and second alternating current buses through the plurality of bus tie contactors, in response to detecting the overcurrent fault, locking out one or more of the plurality of bus tie contactors and in response to a continued detection of the overcurrent fault, opening at least one of the first second and third generator line contactors.

Abstract: The proposed system has a plurality of generator systems, each generator system having an alternating current generator directly connected to a rectifier. The alternating current generator is rotationally coupled to a prime mover, wherein, upon operation of the prime mover, the alternating current generator produces an alternating current output , is de-synchronized to further ones of the plurality of generator systems and has a variable generator speed. The rectifier directly connected the alternating current generator is adapted to convert the alternating current output of the alternating current generator into a direct current output. A direct current distribution bus is coupled to the direct current outputs from each of the rectifiers. The system further has a plurality of inverters adapted to receive power from the direct current distribution bus, the output of each inverter being adapted to drive an alternating current motor.

Abstract: An example method of detecting a generator overvoltage condition includes predicting a primary control current to provide a predicted control current, monitoring the primary control current, and detecting a generator overvoltage condition based on a comparison of the predicted control current to the primary control current. The method interrupts the primary control current based on the comparing.

Abstract: A rotary electric machine for a vehicle is provided. The rotary electric machine includes a power system circuit which has a power element and is grounded via a first ground terminal and a first connecting line and a control system circuit which controls the power system circuit and is grounded via a second ground terminal and a second connecting line.

Abstract: An autonomous breaker can apply a current through a high impedance source to a bus coupled to either end of a breaker in order to measure an impedance of the bus. The status of the bus can be determined from the measurement. Based on the determined status, a fault detection procedure can be selected and implemented to determine if a fault exists on the bus. When the fault detection procedure has been implemented and no fault has been detected, the breaker can close, and thus couple the bus to another bus.

Abstract: An electric vehicle is provided having an electric generator and a motor. Generated electrical energy may be routed to a DC bus of an inverter system. The inverter system may be configured to provide the electrical energy to the motor. A controller may detect a fault based on the voltage level of the DC bus.

Abstract: Various embodiments disclosed herein provide protection to monitored equipment at both a local level and a system level, in order to offer more comprehensive protection. In one particular embodiment, the protected equipment may include one or more generators. The protection system may utilize time-synchronized data in order to analyze data provided by systems having disparate sampling rates, that are monitored by different equipment, and/or equipment that is geographically separated. Various embodiments may be configured to utilize a variety of sampling rates.

Abstract: A power system that supplies electrical power to at least one load is disclosed. The power system may include an electrical power generator, current sensors configured to provide current signals representative of currents output from the electrical power generator to the load, and voltage sensors configured to provide voltage signals representative of voltages output from the electrical power generator to the load. The power system may also include a controller configured to receive the current signals and the voltage signals, compare the current signals and the voltage signals to a predetermined map, determine whether a short circuit exists inside the electrical power generator based on the comparison, and send a command to turn off the electrical power generator when the short circuit exists inside the electrical power generator.

Abstract: An apparatus and method for protecting a power system comprising a generator providing power to an alternating current bus, a power converter for converting alternating current power on the alternating current bus to direct current power on a direct current bus, and a direct current load powered by the direct current power on the direct current bus. An undesired condition is identified at the input to the power converter from the alternating current bus. The undesired condition is caused by at least one of the power converter, the direct current bus, or the load. The power converter is disconnected from the alternating current bus in response to identifying the undesired condition for at least a time delay. The time delay is selected such that the power converter is disconnected from the alternating current bus before the alternating current bus is disconnected from the generator due to the undesired condition.

Abstract: To prevent disconnection of wind turbine generators due to changes in wind conditions even if the wind turbine generators is operated to limit the power output. A plurality of wind turbine generators that generate electric power by the rotation of rotors are provided in a wind farm are interconnected and are operated while the power outputs are limited in advance so as to be able to further supply electric power to a utility grid in response to a decrease in the frequency or voltage of the utility grid. The rotational speed of the rotor, which is a physical quantity related to increase and decrease in the power output of the wind turbine generator, is measured for each of the wind turbine generators by a wind-turbine control system, and the limitation amount of the power output of the wind turbine generator is set for each of the wind turbine generators by a central control system on the basis of the rotational speed of the rotor measured.

Abstract: A switching assembly includes a first terminal and a second terminal, a first switch connected to the first terminal, and a second switch connected to the second terminal. The switching assembly further includes a rectifier bridge connected between the first switch and the second switch, and a third switch connected between the first terminal and the second terminal. The switching assembly also includes a control unit that selectively opens and closes the first switch, the second switch and the third switch, and selectively turns on and off the rectifier bridge.

Abstract: A wind energy plant and method for operating it, the plant having a doubly-fed asynchronous machine, a grid-sided converter and a generator-sided converter both being controlled by a control means. In case of a grid fault the converters are controlled by at least one control module which (i) controls the torque and/or the active power and (ii) controls the reactive current and/or the reactive power.

Abstract: A wind-turbine control system is provided for each of a plurality of wind turbine generators constituting a wind farm, sends wind-turbine data about a controlled wind turbine generator to the wind-turbine control systems provided for the other wind turbine generators, and receives wind-turbine data about the other wind turbine generators from the wind-turbine control systems provided for the other wind turbine generators. Then, the wind-turbine control system controls the controlled wind turbine generator based on the wind-turbine data about the controlled wind turbine generator and the wind-turbine data about the other wind turbine generators. Therefore, the control of the wind turbine generators constituting the wind farm can be changed more swiftly according to the operational condition of the wind farm.

Abstract: A circuit for regulating a DC voltage is provided. The circuit includes: a controllable switch system, a resistor, a first control circuit and a second control circuit. The controllable switch system includes a first terminal, a second terminal, a first control terminal, and a second control terminal. The controllable switch system is configured to establish an electrical connection between the first terminal and the second terminal, if a first control signal applied to the first control terminal satisfies a first criterion or if a second control signal applied to the second control terminal satisfies a second criterion; A method for regulating a DC voltage and an AC-to-AC-converter are described.

Abstract: Method for protecting an electrical energy distribution box, the electrical energy distribution box comprising a set of distribution bars intended to be connected between a generator and loads, each of the bars being able to transfer at least a part of the electrical energy passing through it to at least one other bar of the set of bars. According to this method, the incoming and outgoing currents of a single distribution bar are measured and a fault in the set of bars is detected on the basis of the currents measured in the said bar.

Abstract: A system and method for subtransient current suppression in a power system. A generator is configured to provide an output current to a power distribution system. A current sensor is configured to sense the output current. A switch is configured to direct the output current to ground when the switch is closed. A controller is configured to close the switch for a time delay in response to identifying a level of the output current that is greater than a threshold level and to automatically open the switch in response to identifying an end of the time delay.

Abstract: An electrical power protection system, includes a generator configured for supplying Direct Current (DC) power to a load bus, the load bus in electrical communication with a bus circuit; a generator control unit being configured for regulating the output voltage supplied by the generator; a bus contactor in serial communication with the bus circuit, the bus contactor including logic circuits configured for detecting an overcurrent in the bus circuit, the overcurrent representative of a ground fault in the bus circuit; and a capacitor bank coupled to the generator for selectively supplying an excitation voltage through a diode switch to the generator during the ground fault in the bus circuit.

Abstract: An overcurrent fault protection method includes detecting an overcurrent fault in a variable frequency electric power generation system having a first main generator connected to a first alternating current bus through a first generator line contactor, a second main generator connected to a second alternating current bus through a second generator line contactor and an auxiliary power generator connected to a plurality of bus tie contactors, through a third generator line contactor, and connected to at least one of the first and second alternating current buses through the plurality of bus tie contactors, in response to detecting the overcurrent fault, locking out one or more of the plurality of bus tie contactors and in response to a continued detection of the overcurrent fault, opening at least one of the first second and third generator line contactors.