The disclosure relates to an active damping control method and system for sub-synchronous oscillation of DFIG, and storage medium. The method comprises the following steps: collecting oscillation components of stator current and/or stator voltage; determining each energy branch in DFIG converter according to the flow path of the oscillation component(s) of the stator current and/or the stator voltage in DFIG converter; determining the corresponding function of each energy branch according to oscillation component(s) the stator current and/or the stator voltage; determining the energy compensation branch and its corresponding energy compensation function in DFIG converter according to the corresponding function of each energy branch and converter parameters; controlling the sub-synchronous oscillation of DFIG by controlling the energy compensation branch according to the energy compensation function.

Apparatus and associated methods relate to active damping of mechanical oscillations of a synchronous generator's drivetrain by modulating an excitation signal provided to the synchronous generator in proper phase relation with detected mechanical oscillations so as to dampen these oscillations. The excitation signal includes a superposition of a voltage-regulation signal and an active-damping signal. The voltage-regulation signal is configured to regulate an output voltage of electrical power provided by the synchronous generator, and the active-damping signal is configured to provide active damping to the drivetrain of the mechanical system that includes the synchronous generator. The active-damping signal is generated by detecting mechanical oscillations of the drivetrain, filter such detected mechanical oscillations such that the active-damping signal has a proper phase relationship with the mechanical oscillations over a predetermined range of frequencies. This proper phase relationship is maintained over the range of frequencies using a second order lag/lead filter.

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.

The hybrid power generation system includes a renewable energy power generation device and a rotary power generation device connected to a common alternating-current power system. In the system, if renewable energy or an output fluctuates, a correction value calculated based on the fluctuation amount is added to a control parameter as a feedforward component, controlling the rotary power generation device.

An aircraft propulsion system includes a gas turbine engine; a generator; a storage battery; a motor which drives a rotor, using at least one of the electric power which is output from the generator and the electric power which is output from the storage battery; a detection unit which detects the number of revolutions of the engine shaft; an engine control unit which controls at least a fuel flow rate of the gas turbine engine; and a generator control unit which controls the operation of the generator. When the number of revolutions satisfies a predetermined condition, at least the generator control unit executes a control for reducing a sudden change in the number of revolutions.

The application relates to a stability-control method and system for grid-connected system of double-fed wind farm, which belongs to the technical field of wind power generation system. The method comprises: collecting operation state parameters of each unit in the system; according to the operation state parameters of each unit, determining a mutual voltage between the units, an interlocking phase angle between the units, and a sub-synchronous current of each unit; according to the mutual voltage between the units, the interlocking phase angle between the units and the sub-synchronous current component of each unit, determining an energy coefficient of each unit, and then obtaining a total energy coefficient; according to the total energy coefficient, regulating the operation state parameters of each unit.

A system includes a generator control unit (GCU). The GCU includes a saturable reactor and a rectifier. Each of the saturable reactor and the rectifier has a separate input to receive AC power from a separate respective permanent magnet generator (PMG). A method includes supplying AC power from a first permanent magnet generator (PMG) of a generator to a saturable reactor of a generator control unit (GCU) that is operatively connected to control the generator. The method includes supplying AC power from a second PMG to a rectifier of the GCU, wherein the first PMG supplies a lower AC voltage to the saturable reactor than the second PMG supplies to the rectifier.

A method and system of subsynchronous oscillations and interactions damping integrated in in a rotor converter based on an adaptive state feedback controller with two spinning vectors, and a Kalman filter whose parameters are optimized by minimizing maximum sensitivity under a constraint of positive damping for a plurality of sensible scenarios is provided. The damping signal generated by the damping module is applied either to a power proportional integer controller or to a current proportional integer controller.

A solution to optimally manage those requirements ensuring on the one hand, that the requirements set by the grid operators are appropriately and accurately accomplished at a point of interconnection (POI) and on the other hand, preventing the wind turbines from over fulfilling the requirements, for example, by remaining connected at voltages levels higher or lower than the ones required which, although possible, may cause higher loads and currents in the wind turbines than needed to fulfill the requirements.

A method for operating an electric machine (in particular a wind turbine) having a generator with a rotor and a stator is provided. The method includes: i) evaluating an active damping applied to the electric machine, ii) estimating a damping criterion from the evaluated applied active damping, and iii) shifting a dynamic capacity curve towards a maximum allowed level. The maximum allowed level is based on the damping criterion and a first operation criterion and/or a second operation criterion. Furthermore, the dynamic capacity curve is a dynamic power capacity curve or a dynamic torque capacity curve.