Method for regulating a bank of alternators comprising at least two alternators that deliver their output in parallel to a load (C), said alternators each being provided with a regulator (12, 13) that is configured to deliver an output signal representative of the reactive power level of the corresponding alternator divided by its nominal reactive power, and a control law allowing the reactive power level of the alternator to be modified depending on an input signal, method wherein a weighted signal employed as the input signal of these regulators is generated from the output signals representative of the reactive power level of each of the alternators, i.e. the signals delivered by the corresponding regulators, so as to make each of the alternators converge to a predefined reactive power level (T.sub.rp).

A system contains a double fed induction machine having a stator and a rotor, a fly wheel coupled to the rotor, and a control device for providing a rotor voltage and a rotor current to the rotor. The control device is connected to the rotor and the stator and is capable of generating the rotor voltage and rotor current in response to an electrical signal that is applied to the stator. The control device has a multilevel converter and a control unit for controlling the multilevel converter.

A hybrid power generation unit and synchronous condenser system connectable to a power grid includes a combustion turbine coupled to a first shaft and operable to provide rotational energy to the first shaft, a gear box coupled to the first shaft, and a first clutch portion coupled to the first shaft. A motor is selectively coupled to the gear box to turn the gear box and the first shaft, a second clutch portion is connected to a second shaft, and a generator is coupled to the second shaft. The generator is selectively connectable to the grid to operate as a synchronous condenser when the first clutch portion and the second clutch portion are disengaged and to convert rotational energy from the first shaft to electrical power when the first clutch portion and the second clutch portion are engaged.

A photovoltaic grid-connected system and a control method therefor. The photovoltaic inverter is connected to the grid through a synchronous motor back-to-back drive system including two synchronous motors. The photovoltaic inverter is controlled to operate in the current source mode after the photovoltaic grid-connected system is started, the synchronous motor back-to-back drive system is controlled to operate in the generator mode, and the excitation current of the first synchronous motor is controlled to maintain the voltage stability of the AC side of the photovoltaic inverter. Therefore, the stability and safety of the power grid is significantly improved and the impact of intermittent new energy on the power grid is reduced by virtue of the characteristics of the synchronous motor, and the maximum power point of the photovoltaic array can be tracked to avoid loss of power generation, and traditional photovoltaic inverters can be used without any modification.

A power system includes a turbine assembly including a turbine and a turbine shaft, a generator assembly including a generator and a generator shaft, an inertia assembly including a flywheel coupled to the generator shaft, and a clutch assembly for coupling the turbine shaft to the generator shaft. The clutch assembly is transitionable between a closed state, in which the turbine shaft is coupled to the generator shaft, and an open state, in which the turbine shaft is decoupled from the generator shaft. The power system is operable in a power generation mode when the clutch assembly is in the closed state and a synchronous condenser mode when the clutch assembly is in the open state.

A configuration for stabilizing an AC voltage grid has a rotating phase-shifter that is configured to exchange reactive power with the AC voltage grid. The configuration is distinguished by a converter which has a grid side for connection to the AC voltage grid and a machine side for connection to the phase-shifter. A method is furthermore taught for stabilizing the AC voltage grid by way of the configuration.

This command generation device generates a control command for a power conversion device which converts DC power outputted by a DC power supply device to AC power and supplies the same to a bus, and which converts AC power from the bus to DC power and supplies the same to the DC power supply device. Said command generation device comprises: a virtual power generation calculation unit which simulates the driving of a virtual power generator and, on the basis of a rotor model that calculates the rotational speed of the virtual power generator, calculates the root-mean-square voltage and phase of the virtual power generator; a bus calculation unit which calculates the voltage and phase at a point of contact between the power conversion device and the bus; a phase difference angle calculation unit which calculates the phase difference angle between the phase of the virtual power generator and the phase at the point of contact; a target power determination unit which determines a target value for the effective power of the power conversion device on the basis of the root-mean-square voltage of the virtual power generator, the voltage at the point of contact and the phase difference angle; and a command generation unit which generates a control command for the power conversion device on the basis of the determined target value for the effective power.

A method of operating a plurality of power sources is provided. The method includes operating a first power source at a first power output and operating a second power source at a second power output. The second power source has a second operational capacity greater than the first operational capacity. First transient zone parameters are determined to operate in a first transient output power range. The first transient zone parameters include a first planned power output and a second planned power output constrained to be less than the first operational capacity.

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.

A method for controlling a power system includes generating, via at least one inverter-based resource, one or more command signals via a regulator of at least one inverter-based resource of the power system. Further, the method includes dynamically estimating, via the at least one inverter-based resource, a reactive power capability of the at least one inverter-based resource based, at least in part, on the one or more command signals. Further, the method includes sending, via the at least one inverter-based resource, the reactive power capability to the system-level controller. Thus, the method includes controlling the power system based on the reactive power capability.