Abstract: A system and method are provided for controlling a wind turbine. Accordingly, a controller of the wind turbine detects a transient grid event and generates a torque command via a drive-train-damper control module. The torque command is configured to establish a default damping level of a torsional vibration resulting from the transient grid event. The controller also determines at least one oscillation parameter relating to the torsional vibration and determines a target generator torque level based thereon. The target generator torque level corresponds to an increased level of damping the torsional vibration relative to the default damping level.

Abstract: A system and method are provided for controlling low-speed operations of a wind turbine electrically coupled to an electrical grid. The wind turbine includes a generator and a power converter. The generator includes a generator rotor and a generator stator. An operating parameter of the generator rotor is indicative of a low-speed operation of the generator. Accordingly, the crossing of a first threshold by the operating parameter is detected. In response, at least a portion of a required reactive power generation is developed via the generator rotor. The portion is then delivered to the electrical grid via the grid side of the power converter.

Abstract: A method for operating a multi-level bridge power converter of an electrical power system includes connecting a plurality of phases of the power converter to a common terminal at a DC side of the power converter so as to effectively equate the plurality of phases at a common electrical potential. The method may also include monitoring, via a controller, a plurality of devices of the power converter for faults. Upon detection of a fault in one or more of the plurality of devices, the method includes activating, via the controller, one or more protection devices of a crowbar of the power converter to prevent additional faults from occurring in remaining devices of the plurality of devices by diverting energy away from the remaining devices of the plurality of devices.

Abstract: There is provided a system for use with a set of generators. The system includes a processor and a memory including instructions that, when executed by the processor, cause the processor to perform certain operations. The operations can include receiving a command and receiving a signal indicative of a current of at least one generator in the set of generators. The operations can further include causing, based on the command and the signal, a controller to adjust a voltage level of at least one other generator in the set of generators.

Abstract: The object of the invention is to provide an inverter device and an electric motor device using the same to shorten a dead time. Thus, an inverter device is provided, which includes: a switching element including a control terminal and a pair of main terminals; a control circuit configured to output a control signal which indicates whether to instruct an ON state of the switching element; a decision circuit configured to output a decision signal which indicates a state of the switching element based on a voltage between the main terminals of the switching element; and a drive circuit configured to control the ON state or an OFF state of the switching element based on the control signal and the decision signal.

Abstract: An actuating device including a drive device and a monitoring device. The drive device includes an adjusting assembly which can be moved along a straight movement line and which has an adjusting body and a magnetic adjusting element that can be rotatably mounted on the adjusting body. The monitoring device includes a sensor device which is used to detect at least one position of the magnetic adjusting element along the straight movement line. The monitoring device has a magnetic aligning assembly which is arranged such that the adjusting element assumes a specified rotational position relative to the sensor device on the basis of a magnetic interaction between the adjusting element and the aligning assembly.

Abstract: A generator system, including first and second generators each having an inverter circuit outputting AC, a connection circuit connecting the generators through a power line, a master-slave determining unit determining one of the generators as a master generator, and to determine other of the generators as a slave generator, a data acquiring unit acquiring an output data of the master generator, and a synchronization controlling unit controlling switching operation of the inverter circuit of the slave generator based on the output data of the master generator to synchronize an output data of the slave generator with the output data of the master generator, wherein the master-slave determining unit determines one of the generators that starts earlier as the master generator, and when the generators start simultaneously, to determine one of the generators as the master generator in accordance with a predefined rule.

Abstract: In a variable speed generator-motor apparatus, a power converter includes six two-terminal arms each formed by serially connecting k unit converters that can output arbitrary voltage, an AC rotating electric machine includes an armature winding with 60-degree phase zone formed from a double layer coil, the armature winding being divided into first and second pole sides to form double star connection by binding neutral points and to be drawn out as two sets of three-phase terminals; three-phase terminals on the first pole side are connected to first terminals of three arms, and second terminals of the three arms are star-connected to a first terminal of a DC power supply; three-phase terminals on the second pole side are connected to second terminals of remaining three arms, and first terminals of the three arms are star-connected to a second terminal of the DC power supply.

Abstract: Providing a power system and a method for stabilizing a system, in which the number of generators to be disconnected is reduced to narrow an area influenced by a grid fault in the case where the reliability of the state estimation calculation is judged to be high.

Abstract: In some embodiments described herein, proposed schemes utilize a duty-cycle sensing technique to detect load current imbalance in each individual inductor, and then adjusts the duty cycles for the specific phases through a digital duty cycle tuner.

Abstract: A systematic procedure for the synthesis of hybrid feedforward control architectures for pulse-width modulated (PWM) switching converters is provided. In this hybrid feedforward control architecture selected converter variables are sensed and utilized in a particular way based on the converter open-loop characteristics to determine the duty-cycle needed to achieve a control objective. Compared to standard feedback control techniques, advantages can include simpler controller implementation, more convenient sensing, and improved static and dynamic regulation. An example systematic procedure for developing hybrid feedforward controllers is illustrated by first considering a previously known example of hybrid feedforward control: hybrid feedforward control of a boost power factor correction (PFC) rectifier operating in discontinuous conduction mode (DCM).

Abstract: A power generating apparatus and vector control method thereof are provided. The apparatus includes a rotor with plurality of symmetric phase windings, a stator with a single phase winding, sensors and an excitation control device. Current sensors on the stator side and on the rotor side are configured to measure the amplitudes of the load current and the phase current of the rotor respectively. A position sensor is configured to measure the angle of the rotor. The excitation control device is configured to regulate the engine speed responsive to load power. The excitation control device also generates a modulating signal in accordance with the target voltage vector of the rotor and the slip angle and regulates the excitation current in the phase windings of the stator with the modulating signal.

Abstract: A method for measuring a stator core of an electrical machine includes the steps of winding at least one excitation coil around the stator core, applying a discontinuous voltage to the excitation coil(s) to magnetically excite the stator core, and measuring a quantity of the magnetically excited stator core. Further, a corresponding measuring device is disclosed.

Abstract: A synchronous rectifier alternator and a power allocation method thereof are provided. The synchronous rectifier alternator includes an alternator, a synchronous rectifier circuit and a controller. The alternator converts mechanical energy to alternating current (AC) electrical energy. The synchronous rectifier circuit converts the AC electrical energy to direct current (DC) electrical energy and provides the DC electrical energy to a load. The controller detects a voltage level of the DC electrical energy. When the controller detects that the voltage level is higher than or equal to a first threshold voltage value, the controller controls ONs and OFFs of first transistors and second transistors of the synchronous rectifier circuit, such that at least one of regulator diodes of the synchronous rectifier circuit, a stator of the alternator and the load consume power of the alternator.

Abstract: The present disclosure provides an apparatus with a prime mover coupled to a generator that is directly electrically coupled to an electric motor. A propeller or fan may be coupled to and driven by the electric motor. A bi-directional power converter may be coupled to the generator and further coupled to an energy storage device. The energy storage device may be selectively coupled to the electric motor. Methods of using the apparatus are also provided.

Abstract: A control system includes memory storing instructions and a processor configured to execute the instructions. The processor is configured to receive a first indication of a power grid voltage, receive a second indication of a power grid phase angle, receive a third indication of a generator voltage of power provided by a generator, and receive a fourth indication of a generator phase angle of power provided by the generator. The processor is configured to determine a voltage gap between the generator voltage and the power grid voltage and a time difference between the generator phase angle and the power grid phase angle. The processor is configured to generate a signal to cause the generator voltage and the generator phase angle to synchronize with the power grid voltage and the power grid phase angle, respectively.

Abstract: A reactive power compensation apparatus includes one or more phase clusters each comprising a plurality of cells, and a controller controlling the one or more phase clusters. When at least one cell in a specific phase cluster among the one or more phase clusters is faulty, the controller controls a voltage of each cell in each of the remaining phase clusters except for the specific phase cluster to be controlled, using a modulation index.

Abstract: A grounding resistance measurement apparatus measures a grounding resistance at an AC power terminal, and is electrically connected to an equipment input terminal which provides an AC power source. The grounding resistance measurement apparatus includes a DC power generation circuit and a DC voltage detection circuit. The DC power generation circuit receives the AC power source at the equipment input terminal and converts the AC power source into a DC power source. The DC power source is provided to produce a DC resistance voltage across the grounding resistance. A voltage difference between the equipment input terminal and an equipment grounding point is equal to the DC resistance voltage so that the grounding resistance is calculated according to the zero DC component in an AC power loop.

Abstract: An electric motor control system includes a power inverter and control circuitry configured to control the power inverter either according to a target voltage in a voltage-based control mode or according to a target current in a current-based control mode. A controller is operable to switch operation of the control circuitry between the voltage-based control mode and the current-based control mode. The controller may be configured to operate the control circuitry in the current-based control mode at lower motor operating speeds where stator current margin is of greater significance, and to operate the control circuitry in the voltage-based control mode at higher motor operating speeds where stator voltage margin is of greater significance.

Abstract: A method for operating a power generation system coupled to a power grid during a grid unbalance event, a method for determining an injection current to be supplied into a power grid by a power generation system, and a method for addressing an asymmetric grid fault in a power grid connected to a power generation system are provided. The methods may be carried out based on a reactive or an active power/current priority.

Abstract: An alternating current generation system is provided. In the system, in a rotor, a plurality of detection subject portions are arrayed along a circumferential direction in correspondence to reversal states of the magnetic poles in a plurality of magnetized portions. A detecting unit is disposed opposing the rotor so as to generate an output signal corresponding to passage state of the detection subject portions. A phase control unit outputs, to a power converter, a control signal to perform phase control of switching elements depending on the rotation phase of the rotor, based on the output signal from the detecting unit.

Abstract: The invention relates to a method for regulating the output voltage of the alternator of a generator set, said generator set including a heat engine driving the alternator, the alternator including a rotor having a pole wheel. Said method includes the following step: detection of an increase in the power at the outlet of the alternator, and in the event of a detected increase, the value of the current in the polar wheel is modified in such a way as to temporarily bring the output voltage of the alternator to a value lower than the value before the detection of the increase in power, with the aim of decreasing the level of torque required from the heat engine.

Abstract: In one embodiment, a generator includes a rotor configured to rotate in cooperation with a stator to generate electrical power. A sensor, which is supported by the rotor, is configured to generate a trigger signal indicative of a position of the rotor. A communication interface is configured to receive the trigger signal from the sensor of the rotor and receive data indicative of an output of the generator. A controller supported by the rotor or configured to perform a phase analysis of the trigger signal and the output of the generator and calculate a power angle for the generator based on the phase analysis.

Abstract: A device for suppressing high-voltage electricity is connected to a three-phase circuit of an electric generator, including three up arm semiconductor switches, three low arm semiconductor switches, three reverse breakdown diodes respectively connected to the low arm semiconductor switches in parallel, and a control circuit sending PWM signals to turn on and off the low arm semiconductor switches sequentially to evenly share and absorb the energy of surge voltage. Each of the up arm semiconductor switches has a first terminal and a second terminal, wherein the first terminals are electrically connected together, and the second terminals are respectively electrically connected to one of three coils of the three-phase circuit. Each of the low arm semiconductor switches has a first terminal and a second terminal, wherein the first terminals are respectively electrically connected to the second terminals of the up arm semiconductor switches, and the second terminals are electrically connected together.

Abstract: Energy systems and energy supply methods are described. In one aspect, an energy system includes a bus system configured to conduct electrical energy, a plurality of input adapters electrically coupled with the bus system and configured to electrically couple with a plurality of respective source entities which are individually configured to provide electrical energy, a plurality of output adapters electrically coupled with the bus system and configured to electrically couple with a plurality of respective consuming entities which are individually configured to consume electrical energy, and control circuitry configured to control individual ones of the input adapters to provide electrical energy from respective ones of the source entities to the bus system and to control individual ones of the output adapters to provide electrical energy from the bus system to respective ones of the consuming entities.

Abstract: A method for protecting a synchronous machine (2) against damage caused by pole slipping in a power generating unit or a drive unit (1) in an electric power network is disclosed. The method measures signals of current and voltage of the synchronous machine (2) and assumed constant parameters to determine a disturbance (Trig_start). When a disturbance is detected, an indicator of pole slipping is determined, and the time of rotor operation with the occurrence of pole slipping is totalized. Next, if a threshold value allowed for the rotor operation with slipping proves to be valid, corresponding measures protecting the synchronous machine (2) against slipping are implemented. If the detection process is not fulfilled, the process of sudden disturbance and/or the process of accrued detection is conducted until the criterion of pole slipping occurrence is fulfilled for the generator mode or for the motor mode.

Abstract: The method of controlling a polyphase rotating electric machine, the machine operating as a generator and being linked to an electrical network (1), is of the type of those consisting in short-circuiting at least one phase winding in the event of load shedding. A short-circuit command (SAND) is generated for the phase winding when a first measurement voltage V of a voltage B+ of the network exceeds a first predetermined threshold value V1 and when a phase current (I?) in the phase winding vanishes and changes direction. The first measurement voltage V may be obtained by filtering the voltage B+ of the network with a predetermined time constant TF.

Abstract: A converter arrangement has at least one AC voltage connection, at which an alternating current can be fed in or drawn, and at least one DC voltage connection, at which a direct current can be fed in or drawn. The converter arrangement contains at least two series circuits connected in parallel. The external connections of the series circuits form the DC voltage connections of the converter arrangement. Each of the series circuits is connected in parallel and contains in each case at least two submodules connected in series, each of the submodules containing at least two switches and a capacitor. An energy store is to be connected to the capacitor of at least one of the submodules, wherein a filter is connected electrically between the capacitor and the energy store.

Abstract: A process for increasing the excitation current, particularly when activating the alternator, whose rectified alternator voltage is regulated by way of a regulator, is provided. For regulating the alternator voltage, the regulator sets the excitation current of an excitation winding of the alternator. The regulator further receives a phase signal. A rapid increasing of the excitation current to a defined value takes place, during which the phase signal is analyzed simultaneously. This rapid increasing continues until the phase signal or a quantity derived therefrom meets a defined condition with respect to the alternator voltage. Therefore, a further increasing of the excitation current takes place, preferably at a rate of change reduced with respect to the previous rapid increase.

Abstract: A vibration generating apparatus with high yield, low cost, and can exhibit vibration tactile haptic effects even with variation in the natural frequency of a mechanical vibrator, including a damping system having a damping ratio ?<1 to support a mechanical vibrator to a fastening part, and a magnetizing unit generating a dynamic magnetic field to vibrate the mechanical vibrator by non-contact, the mechanical vibrator generating a beat vibration by making the frequency of a drive voltage applied to the magnetizing unit, from a drive start or middle of drive, to be a non-resonant frequency out of a damped natural frequency of the mechanical vibrator, wherein the apparatus comprises a forced vibration control unit controlling to stop application of the drive voltage, in a beat wave defining an amplitude of the beat vibration, at a second valley part after a first peak part from the side of the drive start.

Abstract: A rectifier bridge circuit is described for rectifying the phase voltage generated by a generator, including a positive half-bridge having multiple rectifier elements and a negative half-bridge having multiple rectifier elements. The rectifier elements each have a controllable switch having a diode connected in parallel. A control circuit is provided for switching the switches on and off. The switch-on time tswitch on setpoint and/or the switch-off time tswitch off setpoint of the switch is/are computed based on a characteristic map or a mathematical function.

Abstract: There is provided a power generation park (100) having a power output (108) for providing electrical output power (150) to an electricity network (128). A power generation device (102a, . . . 102n) has a converter device (106) configured for receiving input power (142) from a power generator (104) and providing, in response thereto, the electrical output power (150) to the power output (112). The power generation park (100) also has a controller (122) being configured for receiving an oscillation indicating signal (126) indicative of a power oscillation in the electricity network (108), the controller (122) being further configured for providing a damping control signal (132) in response to the oscillation indicating signal (126); the converter device (106) being configured for modulating the electrical output power (150) in response to the damping control signal (132) so as to damp the power oscillation in the electricity network (128).

Abstract: A method is employed for operating a wind turbine. Electrical energy is produced by means of a generator and is fed into an electrical power network. The electrical energy is fed to the secondary side of a transformer at a low voltage and is output on the primary side of the transformer at a higher voltage. The potential on the primary side of the transformer is undefined. In the method, a measured value of the voltage between the primary side of the transformer and the earth potential is first recorded. The measured value is compared with a predefined limit value. The electrical energy produced by the generator is changed if the measured value exceeds the limit value. A wind turbine is designed to carry out the method. Faults in the medium voltage network can be reacted to without an additional star point on the primary side of the transformer being required.

Abstract: Systems and methods for reducing current imbalance between parallel bridge circuits used in a power converter of a doubly fed induction generator (DFIG) system are provided. A control system can monitor the bridge current of each of the bridge circuits coupled in parallel and generate a feedback signal indicative of the difference in bridge current between the parallel bridge circuits. Command signals for controlling the bridge circuits can then be developed based on the feedback signal to reduce current imbalance between the bridge circuits. For instance, the pulse width modulation of switching devices (e.g. IGBTs) used in the bridge circuits can be modified to reduce current imbalance between the parallel bridge circuits.

Abstract: An electric power generation plant has at least two synchronous machines and a source of mechanical power (torque), coupleable such that one or more of the synchronous machines can be operated as a generator while one or more is operated as a synchronous condenser. Field exciters, controlled shaft couplings, starters and switching sequences control starting, restarting and switching into simultaneous operation as generators, as condensers, or as one or more generators and condensers synchronously coupled to one another along a drive train. The disclosed configurations include modifications of existing generator installations such as decommissioned plants, such as by controllably coupling a second synchronous machine to a drive train, for use as a condenser for power factor control when needed or as an added source of generator capacity during times of high demand.

Abstract: A method of controlling a generator (110) of an electric drive (104) associated with an engine (102) is provided. The method may determine an operational state of the electric drive (104) based on a speed of the engine (102), and selectively engage one of a map-lookup control scheme (150) and a fixed-theta off control scheme (152) for operating the generator (110) based on the operational state of the electric drive (104).

Abstract: According to an embodiment, a method of operating a wind turbine comprising a DC-to-AC voltage converter is provided, the wind turbine being connectable to a grid via the DC-to-AC voltage converter, the method comprising: determining a line voltage of a power line connecting the DC-to-AC voltage converter to the grid; if the determined line voltage exceeds a predefined voltage threshold value, injecting reactive current into the power line, wherein the amount of reactive current injected is chosen such that an output voltage of the DC-to-AC voltage converter is kept within a predetermined voltage range.

Abstract: A method for operating an electrical machine having a stator 1 with a coil from electrical conductors, which has two coil ends 2 lying opposite each other. The method includes simultaneously recording vibration measurements by means of which the elliptic vibration modes of the two coil ends 2 can be determined as a factor of time; determining the ellipse inclinations and the phase positions of elliptic vibration modes of the two coil ends 2; determining critical operating states of the electrical machine, in which the elliptic inclinations and the phase positions of the elliptic vibration modes of the two coil ends are substantially identical; and operating the electrical machine in such a manner that the critical operating states can be avoided by varying the idle power of the electrical machine.

Abstract: A fault tolerant electrical machine including: a plurality of phases; a detector arranged to detect a fault in at least one of the phases; and a controller arranged to intentionally cause a fault in at least one other of the phases such that the vector sum of the second harmonic power vectors of the remaining phases is zero.

Abstract: A wind power generator generates power through a rotation of a rotor and is interconnected, and operated with its power generation output previously limited in order to be able to further supply the power to a power system in response to a decrease in system frequency. Thus, a concentrated control system derives a required restricted amount corresponding to a power generation output required to respond to the decrease in system frequency, derives a value by subtracting an amount corresponding to a latent power generation output with which the power generation output can be increased, from the required restricted amount, and sets a restricted amount of the power generation output in each wind power generator to perform the operation with the power generation output previously limited to respond to the decrease in system frequency, based on the above value.

Abstract: A method for regulating the reactive power generated or absorbed by a synchronous electric generator includes regulating a quantity of coils disposed in line with a stator winding. Additionally, a generator operating point of the generator is regulated.

Abstract: The control method of a wind turbine generator increases the speed range of wind turbine generators, maximizing the operation and efficiency thereof, in addition to lengthening their service life, on minimizing the extreme and fatigue loads to which the wind turbine generators are subject, and which are due mainly to the stops and disconnections thereof as a result of strong gusts of wind. More specifically, the control method of the present invention stands out essentially for being based on the control of the reactive current circulating through the electric generator, said reactive current control being carried out in accordance with the rotational speed (?g) for the purpose of reducing the voltage at the converter terminals on the generator side, or rotor voltage (VR), which ultimately allows a transitional increase in the speed range of the wind turbine generator.

Abstract: Systems, methods, and a voltage regulator are provided for tuning reactive droop compensation of a generator in a parallel power generation system. The voltage regulator is configured to compute a simulated droop compensation voltage for the generator and control an excitation signal to the generator based at least in part on the simulated droop compensation voltage.

Abstract: A synchronous electrical machine comprises a plurality of phases and detecting means arranged to detect an open-circuit fault in at least one of the phases of the synchronous electrical machine. Isolating means is arranged to isolate the at least one phase of the synchronous electrical machine with the fault. Phase shift means are arranged to produce a controlled phase shift between the voltage and the current within the remaining phases of the synchronous electrical machine so as to adjust the phase angle of the second harmonic powers produced by the remaining phases of the synchronous electrical machine such that the vector sum of the second harmonic power vectors of the remaining phases of the synchronous electrical machine is zero to eliminate torque ripple. The phase shift means is arranged to adjust the phase angle of all the remaining phases by the same predetermined angle to maximize the torque ripple-free power output of the synchronous electrical machine.

Abstract: The present invention relates to a control device for a doubly-fed induction generator in which a feedback linearization method is enabled and further provides a control device for a doubly-fed induction generator in which a feedback linearization method is embedded, characterized in that the control device divides and measures positive sequency components and negative sequency components from stator voltage and current, rotor voltage and current, and signals of stator magnetic flux and rotor magnetic flux of the doubly-fed induction generator.

Abstract: A new method for predicting the rotor angle stability status of a power system immediately after a large disturbance is presented. The proposed two stage method involves estimation of the similarity of post-fault voltage trajectories of the generator buses after the disturbance to some pre-identified templates and then prediction of the stability status using a classifier which takes the similarity values calculated at the different generator buses as inputs. The typical bus voltage variation patterns after a disturbance for both stable and unstable situations are identified from a database of simulations using fuzzy C-means clustering algorithm. The same database is used to train a support vector machine classifier which takes proximity of the actual voltage variations to the identified templates as features.

Abstract: Embodiments according to the present invention provide methods and a system for a control approach that effectively maintains the DC link voltage at a constant set value under variable system conditions and keeps the converter operating within an optimal power factor range.

Abstract: In a wind turbine generator, the rotation of the rotor is speeded up by a hydraulic pump and a hydraulic motor and is transferred to a synchronous generator. In a state in which the wind turbine generator is interconnected to a utility grid, and the synchronous generator reaches a synchronous speed, if no mechanical power is transferred to the synchronous generator, a wind-turbine control system operates the synchronous generator as a synchronous condenser, thus controlling the magnitude of the field current of the synchronous generator. Thus, the wind turbine generator can supply reactive power to the utility grid without adding new equipment, such as a reactive power compensator using a semiconductor switch.

Abstract: In a wind turbine generator, the rotation of the rotor is speeded up by a hydraulic pump and a hydraulic motor and is transferred to a synchronous generator. In a state in which the wind turbine generator is interconnected to a utility grid, and the synchronous generator reaches a synchronous speed, if no mechanical power is transferred to the synchronous generator, a wind-turbine control system operates the synchronous generator as a synchronous condenser, thus controlling the magnitude of the field current of the synchronous generator. Thus, the wind turbine generator can supply reactive power to the utility grid without adding new equipment, such as a reactive power compensator using a semiconductor switch.

Abstract: The vehicle generator includes an armature winding including a plurality of phase windings, a switching section formed as a bridge circuit constituted of a plurality of pairs of an upper arm and a lower arm connected in series to rectify voltages induced in the phase windings, each of the upper and lower arms being constituted of a switching element parallel-connected with a diode, a control section for controlling on/off timings of the switching elements, and a voltage zero-cross detecting section for performing voltage zero-cross detection to detect, as voltage zero-cross points, time points at which at least one of line-to-line voltages among the phase windings of the armature winding changes in polarity. The control section is configured to start on-off control of the switching elements based on the voltage zero-cross points detected by the voltage zero-cross detecting section.