Abstract: A method for controlling a power converter of a wind turbine power system connected to an electrical grid. The wind turbine power system has a generator and the power converter has rotor-side converter and a line-side converter. The method includes monitoring an electrical parameter of at least one of the wind turbine power system or the electrical grid. In response to detecting a transient event in the electrical grid, the method includes temporarily disabling the line-side converter of the power converter from the electrical grid. Either during the transient event or after the transient event is over, the method includes implementing a control action for the line-side converter of the power converter. Further, the method includes enabling the line-side converter of the power converter to the electrical grid.

Abstract: A fault inrush transient current restraining type virtual synchronous inverter and thereof is disclosed. The invention solves the problem that a virtual synchronous inverter will be burned due to inrush transient current in an extreme situation of a symmetrical fault occurring on the grid side by setting an information collection module for inverter output voltages and currents, a virtual synchronous inverting control module, a fault detection and synthesize module, a hysteresis comparison control module and a post fault clearing switch back grid-tie control module.

Abstract: A portable generator is disclosed including a mounting arrangement for positioning a wireless communication device on a control panel of the portable generator. The mounting arrangement includes a mounting platform formed from a composite material where the mounting platform is secured to a rear surface of a front panel of the control panel assembly. The front panel includes a transmission cutout. The mounting platform includes a transmission window such that a wireless antenna of the wireless communication device can be aligned with the transmission cutout. The portable generator further includes a fuel sensing device that generates both a visual indication and an output signal indicative of the level of fuel in a fuel tank. The output signal can be transmitted by the wireless communication device to a remote location for remote fuel monitoring.

Abstract: A power generation system includes a generator mechanically coupled to an engine to generate electrical power and a fault ride through system connected between the generator and a power grid. The fault ride through system includes a mechanical switch connected in parallel with a solid state switch and a controller for controlling the mechanical switch, the solid state switch and ignition of the engine in coordination.

Abstract: A power generation system includes a generator mechanically coupled to an engine to generate electrical power and a fault ride through system connected between the generator and a power grid. The fault ride through system includes a mechanical switch connected in parallel with a solid state switch and a resistor to absorb power from the generator during a grid fault condition. The mechanical switch and the solid state switch are controlled in coordination with the engine.

Abstract: A vehicle-mounted electric rotating machine includes a field winding wound on a rotor for magnetizing a field pole of the rotor, a stator winding for generating an AC voltage in accordance with a rotating magnetic field generated by the field pole, a power converter for converting the AC voltage to a DC voltage and outputting the DC voltage through a first power supply line connected to an output terminal thereof, and a load dump handling section for performing a load dump protection operation when a voltage of the output terminal of the power converter exceeds a threshold voltage. The load dump handling section is supplied with operating power through a second power supply line provided separately from the first power supply line.

Abstract: This disclosure is directed to a fault-tolerant energy conversion system. A fault-tolerant doubly-fed induction generator (DFIG) for use with a wind energy conversion system (WECS) consistent with the present disclosure may allow for seamless operation during all kinds of grid faults. In one embodiment, a six-switch grid side converter (GSC) commonly used with such systems may be replaced with nine-switch converter circuitry. With three additional switches, the nine-switch converter can provide two independent three phase outputs. For example, one three-phase output may be coupled to the grid through interfacing inductors to realize normal GSC operation, while the other three-phase output may be coupled to neutral side of the stator windings to provide fault ride-through (FRT) capability to the DFIG. A control algorithm may be employed that both achieves seamless fault ride-through during any kind of grid faults and strictly satisfies grid codes requirements.

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: An energy production plant has a drive train including a differential gear (14) with three drive and power take-off assemblies, a first drive assembly being connected to a drive shaft, a power take-off assembly being connected to a generator (13) and a second drive assembly being connected to a differential drive assembly (16). The differential gear (14) is a planetary gear. Both an emergency brake (4) and a service brake (20) are located in the drive train. In the event of a power failure, grid fault or an emergency shutdown, the service brake (20) is activated such that the torque acting on the rotor (1) supplied by the drive train remains substantially constant for a period of at least 0.5 seconds.

Abstract: A braking system includes a converter, a capacitor coupled to an output of the converter, a bridge coupled in parallel to the capacitor, and at least one inductor coupled to the bridge, an electrically conductive disc disposed proximate to the at least one inductor, and a switching unit controller for commanding the converter to convert a level of voltage supplied therefrom from a first voltage level to a second voltage level and thereby increase energy stored in the capacitor, and, upon receiving a brake command, commanding the bridge to ramp-up electrical current in the at least one inductor so as to induce an electromagnetic force on the electrically conductive disc.

Abstract: A load bank comprises one or more load resistors connected to an engine-generator and a control system for maintaining a minimum generator load when necessary for optimal operation. The control system operates the load bank to mitigate harmful effects of generator neglect and maintains loading for efficient DPF regeneration while allowing the generator to quickly dump the load bank when real load increases.

Abstract: A load bank comprises one or more load resistors connected to an engine-generator and a control system for maintaining a minimum generator load when necessary for optimal operation. The control system operates the load bank to mitigate harmful effects of generator neglect and maintains loading for efficient DPF regeneration while allowing the generator to quickly dump the load bank when real load increases.

Abstract: Fault Ride Through (FRT) transient management system configured to enhance the FRT capability doubly-fed induction generator (DFIG)-based wind turbines. A grid side converter (GSC) introduces shunt and series compensation for normal operation and voltage dips, respectively. A braking resistor may be added to smooth switching transients from shunt to series interfaces and dissipate excessive power from the GSC. To attain a flexible control solution for balanced and unbalanced fault conditions, the transient management scheme may employ positive and negative sequence controllers. The system dynamics for the series compensation topology may be analyzed using small-signal linear model. Based on the mathematical model, the controller may be tuned to balance voltage regulation performance and transient stability margins with consideration of various operating conditions.

Abstract: A turbine array including: a plurality of turbines; an electrical machine connected to each of the turbines and to an electrical grid; wherein at least one of the electrical machines is a motor-generator which can operate in a motor mode or a generator mode, and wherein the other electrical machines are generators; and a controller for detecting a loss-of-grid event; wherein the controller sets the motor-generator to the motor mode when a loss-of-grid event is detected, the motor-generator being driven by the generators and thereby providing a load to the generators.

Abstract: A braking system for a wind turbine is disclosed. The braking system may include a DC chopper connected to a DC bus and a super capacitor capable of being connected to the DC chopper through a switch. The DC chopper may be controlled by a control system to enable one of charging, discharging, idle or system off modes of the super capacitor.

Abstract: In a rotary electric machine, a load-dump protector turns on a switching element as a low-side rectifying element for at least one of plural-phase stator windings when the output voltage exceeds a first threshold voltage due to load dump. The load dump protector determines a turnoff timing of the switching element as the low-side rectifying element for the at least one of the plural-phase stator windings after the output voltage, which exceeded the first threshold voltage once, falls below a second threshold voltage. The second threshold voltage is set to be lower than the first threshold voltage. The load dump protector turns off, at the determined turnoff timing, the switching element as the low-side rectifying element for the at least one of the at least two-phase stator windings.

Abstract: A double fed induction generator (DFIG) converter method are presented in which rotor side current spikes are attenuated using series-connected damping resistance in response to grid fault occurrences or grid fault clearances.

Abstract: A rectifying unit rectifies an alternating current voltage induced across each of at least two-phase stator windings. A turn-on unit monitors an output voltage of the rectifying unit, and turns on a switching element as a low-side rectifying element for at least one of the at least two-phase stator windings when the output voltage exceeds a first threshold voltage due to load dump. After the output voltage, which exceeded the first threshold voltage once, falls below a second threshold voltage, a turnoff unit waits for turnoff of the switching element until a turnoff time suited for preventing occurrence of a surge across the at least one of the at least two-phase stator windings appears. The second threshold voltage is set to be lower than the first threshold voltage. The turnoff unit turns off, at the appearance of the turnoff time, the switching element.

Abstract: A power transmission system may include a plurality of renewable-energy devices such as wind turbines or subsea turbines. The devices are connected together in parallel to a subsea cable that carries an ac transmission voltage. Each device includes a turbine assembly that is rotated by wind or water current flows, and a variable speed ac induction generator. A power converter is connected to the subsea cable and is used to interface the generators to a supply network or power grid. The power transmission system is operated such that an indicated operating speed of one or more of the devices is used to control the power converter (e.g. the PWM strategy that is used to open and close the power semiconductor devices) to achieve desired stator electrical quantities at each generator.

Abstract: A DC chopper comprising a control unit and a power circuit and a DC chopping method for a DFIG (doubly fed induction generator) system are provided. The input terminal of the control unit is coupled to a DC capacitor of a converter to detect a DC voltage. The power circuit includes input terminals, an overvoltage protection module, a rectifier module and output terminals. The overvoltage protection module comprises at least one discharge unit formed from a discharge resistor and a switch element, and the rectifier module is coupled in parallel to the overvoltage protection module. When a grid voltage drops, the control unit outputs a corresponding control signal to drive the switch element to be ON or OFF, and the output terminal of the power circuit absorbs a portion of rotor inrush current, so as to impose over-current protection.

Abstract: A wind turbine connected to a power grid is provided. The wind turbine is selectively activated to operate at a high-voltage ride through (HVRT) mode. The wind turbine includes a grid voltage circuit, a DC bus, a voltage source, and a dynamic brake. The grid voltage circuit monitors a fundamental voltage of the power grid and activates the HVRT mode if the fundamental voltage is at least about equal to a threshold voltage value. The DC bus has a DC bus voltage. The voltage source provides a DC bus rated voltage. The dynamic brake has a brake chopper and a resistive element. The dynamic brake is connected to the DC bus. The dynamic brake is connected to the voltage source if the HVRT mode is activated.

Abstract: A wind turbine generator includes a synchronous generator that generates electric power via rotation of a rotor provided with blades that receive wind and that supplies the generated electric power to a utility grid, and a sea water resistor in which sea water serves as a resistive element. When the output power of the synchronous generator drops suddenly because of a momentary power interruption caused by a fault occurring on the utility grid, thus producing surplus energy, the sea water resistor consumes, in the form of electric power, the surplus energy that cannot be supplied to the utility grid from among the electric power generated at the synchronous generator. Because the sea water resistor uses sea water as the resistive element, the problem of heat generation hardly ever arises, and because the sea water can be easily exchanged, it is not affected by lifetime or on-time limitations.

Abstract: A power generation system that includes a prime mover configured to generate mechanical energy. The power generation system also includes a power generator configured for generating electrical power from the mechanical energy received from the prime mover. The power generation system further includes a fault ride-through switch electrically coupled in series between the power generator and a power grid. The fault ride-through switch includes a first branch configured to carry the electrical power during normal operating conditions and includes an LC resonance circuit. The fault ride-through switch also includes a multiphase transformer configured for providing voltage phases of different polarities to the LC resonance circuit.

Abstract: A rectifying unit rectifies an alternating current voltage induced across each of at least two-phase stator windings. A turn-on unit monitors an output voltage of the rectifying unit, and turns on a switching element as a low-side rectifying element for at least one of the at least two-phase stator windings when the output voltage exceeds a first threshold voltage due to load dump. After the output voltage, which exceeded the first threshold voltage once, falls below a second threshold voltage, a turnoff unit waits for turnoff of the switching element until a turnoff time suited for preventing occurrence of a surge across the at least one of the at least two-phase stator windings appears. The second threshold voltage is set to be lower than the first threshold voltage. The turnoff unit turns off, at the appearance of the turnoff time, the switching element.

Abstract: In a rotary electric machine, a load-dump protector turns on a switching element as a low-side rectifying element for at least one of plural-phase stator windings when the output voltage exceeds a first threshold voltage due to load dump. The load dump protector determines a turnoff timing of the switching element as the low-side rectifying element for the at least one of the plural-phase stator windings after the output voltage, which exceeded the first threshold voltage once, falls below a second threshold voltage. The second threshold voltage is set to be lower than the first threshold voltage. The load dump protector turns off, at the determined turnoff timing, the switching element as the low-side rectifying element for the at least one of the at least two-phase stator windings.

Abstract: Switching control systems and methods are presented for controlling power conversion systems to provide electrical power to a grid or other load in which a synchronous machine is driven by a wind turbine or other prime mover to provide generator power to a switching type current source converter (CSC), with a current source rectifier (CSR) of the CSC being switched to provide d-axis control of the synchronous machine current based on grid power factor feedback, and with a current source inverter (CSI) of the CSC being switched to provide leading firing angle control and selective employment of dumping resists to dissipate excess generator energy in a fault mode when a grid voltage drops below a predetermined level.

Abstract: A method for the operation of a wind energy plant with a rotor, which transfers a driving moment to a generator via a drive train, wherein the generator provides a pre-settable generator moment acting opposite to the driving moment and is connectable to a grid, characterised in that after a sudden voltage change in the grid, the generator moment is controlled depending from the phase position of a torsional vibration of the drive train.

Abstract: The invention discloses a power grid fault ride-through device and a method for a doubly fed induction generator.

Abstract: A power generation system includes a generator mechanically coupled to a turbine to generate electrical power. The system includes a fault ride through system having a variable resistor and a variable inductor. The variable resistor is connected in parallel across output terminals of the generator to absorb power from the generator during a grid fault condition, and the variable inductor is connected between an output terminal of the generator and a power grid.

Abstract: Method and system are provided for operating a generator using a dynamic capability curve. In one embodiment, the method allows providing a family of static capability curves corresponding to nominal reference levels of pressure of a fluid for cooling the generator. The method further allows acquiring data indicative of the actual pressure of the cooling fluid. A dynamic capability curve is generated to be responsive to the actual pressure of the cooling fluid. The family of static capability curves may be displayed relative to the dynamic capability curve, thereby allowing the operator to monitor and control the operation of the generator based on the actual pressure of the cooling fluid and further in view of at least one of the nominal reference levels of pressure for the cooling fluid.

Abstract: A reference voltage of an output terminal of a synchronous machine is set according to a reactive current output from the synchronous machine, a reference voltage of the high voltage side of a transformer, and a phase compensation transfer function to quicken attenuation of an electric power fluctuation.

Abstract: An excitation controller controls excitation of a synchronous machine, which is connected to a power transmission system through a transformer, so that a high-side voltage of the transformer is maintained at a target voltage with high accuracy. An output terminal target voltage of the synchronous machine is set to precisely compensate for a voltage drop in the transformer, corresponding to the transformer phase angle variation. To achieve this result, the excitation controller detects an output terminal voltage and an output current of the synchronous machine and calculates active and reactive currents of the output current, sets the output terminal target voltage of the synchronous machine from the active and reactive currents, the high-side voltage of the transformer, and the reactance of the transformer, and controls excitation of the synchronous machine to compensate for the voltage drop in the transformer corresponding to phase angle variation of the transformer.

Abstract: Method and system are provided for operating a generator using a dynamic capability curve. In one embodiment, the method allows providing a family of static capability curves corresponding to nominal reference levels of pressure of a fluid for cooling the generator. The method further allows acquiring data indicative of the actual pressure of the cooling fluid. A dynamic capability curve is generated to be responsive to the actual pressure of the cooling fluid. The family of static capability curves may be displayed relative to the dynamic capability curve, thereby allowing the operator to monitor and control the operation of the generator based on the actual pressure of the cooling fluid and further in view of at least one of the nominal reference levels of pressure for the cooling fluid.

Abstract: The power supply system includes an alternator that generates electric power according to the number of revolutions of an engine mounted in a vehicle and charges a predetermined battery; an output unit for outputting the electric power from the charged battery to the outside; a power generation control unit that detects the current amount of the electric power transmitted from the battery to the output unit and sets the number of engine revolutions according to the detected current amount; and an engine control unit that controls the number of revolutions of the engine in accordance with the number of engine revolutions set by the power generation control unit.

Abstract: Duty ratio of a power switching transistor connected to the field coil is controlled according to whether or not a high-power load is connected. When the high power load is not connected, the duty ratio is made 60%, for example, so that excessive power not generated. On the other hand, when the high power load is connected, the duty ratio is increased to 100% so that full power is generated by the generator. The power switching transistor is also controlled according to the battery voltage in a well known manner.

Abstract: A vehicular electric power system is composed of a rotating AC machine having polyphase armature coils, a full-wave rectifier for rectifying the generated voltages by a plurality of SiC-MOSFETs to give a rectified output to the battery unit, and a control device for selectively turning on the plurality of SiC-MOSFETs to raise the generated voltages by short-circuiting and open-circuiting the armature coils on the basis of the phases of voltages generated by the rotating AC machine at a predetermined duty factor.

Abstract: A vehicle generator control device comprises a detector adapted to detect whether or not a lamp load has been applied; and a control circuit. When an electric load is applied (i.e., when the terminal voltage of a battery is lowered) under the condition that the application of the lamp load has been detected, the control circuit suspends a load response control operation (increasing the field current of the generator by turning the field current switch on and off), and instead increases the field current abruptly by maintaining the field current switch conductive, thereby to increase the terminal voltage of the battery immediately. Thereby, a vehicle generator control device is provided which is free from a difficulty that, when a load response control operation is carried out with lamps with head turned on, the output light of these lamps are decreased or the lamps flicker.

Abstract: In a voltage regulator for an alternator which charges a battery via a charging cable and supplies a vehicle mains with voltage, the output voltage is regulated as a function of the temperature of the battery. The voltage regulator has a power part and a control part, which includes a simulation device for storing data and for determining the temperature of the battery, and hence the optimum charging voltage, by simulation from the stored data. Further, the voltage drop between the alternator and battery can be calculated from the alternator current and the resistance of the charging cable while taking into account correction factors which take into account the different connections of the consuming devices between the alternator and the battery so that the calculated voltage drop and the optimum charging voltage for the battery can be used by the voltage regulator to set the voltage delivered to the battery.

Abstract: The power supply system for a motor vehicle, includes a battery; a three-phase generator; a connecting line connecting the terminals of the generator and the battery; a rectifier connected electrically to the generator; a voltage regulator for switching an exciter field of the generator on and off to control a voltage actual value at the generator terminals and producing an average field current in the exciter field to maintain a power supply voltage substantially constant regardless of load and speed; and a circuit device for determining and for partially compensating an undesirable direct voltage drop at the generator terminals resulting from a voltage drop in the connecting line caused by load current. The device for determining and for partially compensating is structured to determine an alternating voltage at the generator terminals produced by an alternating current component in the connecting line.

Abstract: A system for charging a battery from a generator including a rectifier regulator wherein the regulated voltage is stepped up to compensate for voltage drops in the cable connecting the rectifier regulator to the battery.

Abstract: An electric power system having line drop compensation includes a controllable electric power source having an output for supplying voltage to a power bus, a local voltage regulator for monitoring the output voltage of the power source and for producing a control signal representative of a desired nominal output voltage of the power source, and a remote voltage regulator for sensing voltage on the power bus at a point of regulation located away from the power source. The remote voltage regulator produces a pulse width modulated signal having a duty cycle representative of the voltage at the point of regulation. A pulse width to trim bias converter receives the pulse width modulated signal and produces the trim signal having a magnitude representative of the duty cycle of the pulse width modulated signal.

Abstract: A charging generator charges a battery by a voltage output from a generating unit having an armature coil and a field coil. The generator comprises a voltage boost/drop circuit connected between the output of the generator unit and the battery; a first control circuit connected between the field coil of the generating unit and the battery for controlling a field current flowing through the field coil to regulate a voltage generated in the armature coil of the generating unit in response to a voltage across the battery; and a second control circuit connected to the voltage boost/drop circuit for controlling the boost/drop ratio of the voltage boost/drop circuit.

Abstract: A regulator is responsive to an input signal proportional to the system supply voltage for adjusting the current flowing in the field windings of an electrical alternator which controls the output power thereof. The primary regulation loop of the regulator generates a pulse train having a duty cycle inversely proportional to the amplitude of the input signal while an oscillator provides a sawtooth signal at a predetermined frequency which controls the response frequency of the regulator. The regulator limits the rate of increase in the duty cycle of pulse train upon detecting a decrease in the system supply voltage by converting the duty cycle of the pulse train to a charging signal for developing a voltage across a capacitor proportional to the duty cycle of the pulse train. The voltage across the capacitor is compared to the sawtooth signal and triggers a latch which disables the output signal of the regulator as the duty cycle lengthens in response to the decrease in the system supply voltage.

Abstract: The power system stabilizer is provided at an individual power system to be separated due to an accident cutting off a link line which interconnects a number of power systems to form a large-scale power system. The power systems include power stations such as power plants and transformer substations. A simplified arithmetic processing unit of the stabilizer performs an arithmetic processing by a simple linear equation using an output frequency of a representative power station belonging to the separated power system immediately after the accident has been cleared, so that a total load drop of the separated power system can be assumed. Based on the assumption amount, balance control of demand and supply in the separated system is made.

Abstract: There is provided a static VAR generator having voltage regulation in combination with the capability to damp subsynchronous resonance should it occur. A novel method for controlling subsynchronous resonance is provided by monitoring the frequency of the electrical generating system and controlling the insertion of compensating inductance in response to disturbances that may result in voltage and frequency pulsations.

Abstract: A generator system which is self-excited even during a fault condition includes a main generator having armature windings and a main field winding which is excited by a rotary transformer. The rotary transformer includes a stationary primary winding and a rotating secondary winding, with the primary winding receiving a controlled portion of the main generator armature output. The current through the primary winding of the transformer is controlled by silicon controlled rectifiers which are gated by a voltage regulator circuit. The voltage regulator circuit in turn receives signals from the voltage delivered to the load, the highest phase current delivered to the load and the voltage at the main generator armature output. The voltage regulator controls the current through the primary winding of the transformer in accordance with the voltage delivered to the load if that voltage is greater than a predetermined value.

Abstract: There is provided a static VAR generator having a novel method for controlling subsynchronous resonance by monitoring the frequency of the electrical generating system and controlling subsynchronous resonance by phase-firing thyristor controlled inductance.

Abstract: A control circuit for a self-excited AC generator including an automatic voltage regulator, a fly-wheel capacitor which is charged normally by part of the generator output during a no-load operation or small-load operation of the generator, a detection circuit which detects a drop of the generator output voltage when said output voltage drops below the predetermined value, and a field current control circuit which operates on the fly-wheel capacitor to discharge the stored electric energy to the field winding of the generator or an exciter equipped with the generator when the detection circuit detects a drop of the generator output voltage. The control circuit provides additionally with the second field current control circuit which supplies a current from the generator output terminal to the field winding through a rectifier when the detection circuit detects a drop of the generator output voltage.