A method for controlling a wind farm, which is operated by means of a wind farm control unit and comprises a multiplicity of wind power installations having wind power installation controllers and being connected to one another via a common wind farm grid, which is connected to an electrical power supply grid of a grid operator by means of a wind farm transformer, comprising the following steps: reception of at least one fault bit at the wind farm control unit, in particular at least one fault bit of the grid operator, deactivation of all external setpoint value specifications at the wind farm control unit apart from those of the grid operator after reception of the fault bit, activation of a closed-loop fault case control implemented in the wind farm control unit after successful deactivation of all external setpoint value specifications apart from those of the grid operator.

A power supply system includes a plurality of power conversion devices connected in parallel with each other, a load state detector to detect an operating state of a load connected to the DC system, and a command generator to generate a distribution voltage command Vref Each of the power conversion devices includes a DC voltage controller to generate an output power command Pdc_ref based on a voltage of the DC system and the distribution voltage command Vref, and an AC/DC converter to convert AC power received from the main power source based on the output power command Pdc_ref and output the converted power to the DC system. The command generator generates the distribution voltage command Vref such that loss of the load connected to the DC system is reduced, based on a detection result of the load state detector.

A power supply system includes a plurality of power conversion devices connected in parallel with each other, a load state detector to detect an operating state of a load connected to the DC system, and a command generator to generate a distribution voltage command Vref Each of the power conversion devices includes a DC voltage controller to generate an output power command Pdc_ref based on a voltage of the DC system and the distribution voltage command Vref, and an AC/DC converter to convert AC power received from the main power source based on the output power command Pdc_ref and output the converted power to the DC system. The command generator generates the distribution voltage command Vref such that loss of the load connected to the DC system is reduced, based on a detection result of the load state detector.

A plurality of generators redundantly supply power to AC motors via a main DC bus system having a pair of buses, each of which is connected to each generator by an active front end (AFE) inverter containing an insulated-gate bipolar transistor. Isolated DC/AC inverters are connected to the pair of main buses in pairs, respectively. Each pair of the isolated DC/AC inverters is connected to one of the AC motors with a filter of capacitors and inductors between each inverter and the motor. The AFE inverters and isolated DC/AC inverters galvanically isolate the main buses and enable load sharing among the generators.

A plurality of generators redundantly supply power to AC motors via a main DC bus system having a pair of buses, each of which is connected to each generator by an active front end (AFE) inverter containing an insulated-gate bipolar transistor. Isolated DC/AC inverters are connected to the pair of main buses in pairs, respectively. Each pair of the isolated DC/AC inverters is connected to one of the AC motors with a filter of capacitors and inductors between each inverter and the motor. The AFE inverters and isolated DC/AC inverters galvanically isolate the main buses and enable load sharing among the generators.

A power control apparatus of an embodiment controls power to be output to a power system from a power station including a power generation unit, and a power storage unit. The power control apparatus includes a power generation control unit, a power storage control unit, and a cooperation control unit. The power generation control unit controls an output of the power generation unit based on a power generation set value. The power storage control unit controls an output of the power storage unit based on a power storage set value. The cooperation control unit outputs the power generation set value to the power generation control unit and outputs the power storage set value to the power storage control unit based on a power demand amount of the power system so as to make the power generation unit and the power storage unit operate in a cooperative manner.

A power control apparatus of an embodiment controls power to be output to a power system from a power station including a power generation unit, and a power storage unit. The power control apparatus includes a power generation control unit, a power storage control unit, and a cooperation control unit. The power generation control unit controls an output of the power generation unit based on a power generation set value. The power storage control unit controls an output of the power storage unit based on a power storage set value. The cooperation control unit outputs the power generation set value to the power generation control unit and outputs the power storage set value to the power storage control unit based on a power demand amount of the power system so as to make the power generation unit and the power storage unit operate in a cooperative manner.

A gas engine power generating system includes an electricity generating component including a gas engine, an alternating-current electricity generator, a cooling system portion, an exhaust system portion, an engine control unit, a battery, and an alternating current/direct current inverter, and a housing. A plurality of the electricity generating components are provided as electricity generating units, and are accommodated in the housing. Each electricity generating unit is configured to be capable of generating electricity independently, the plurality of electricity generating units are electrically connected together in parallel, operation, shut-down, and the amount of generated electric power for all the electricity generating units are managed by a total control unit, and direct-current power from each electricity generating unit is aggregated and converted to alternating-current power, and is supplied to the load side.

A distributed power harvesting system including multiple direct current (DC) power sources with respective DC outputs adapted for interconnection into a interconnected DC power source output. A converter includes input terminals adapted for coupling to the interconnected DC power source output. A circuit loop sets the voltage and current at the input terminals of the converter according to predetermined criteria. A power conversion portion converts the power received at the input terminals to an output power at the output terminals. A power supplier is coupled to the output terminals. The power supplier includes a control part for maintaining the input to the power supplier at a predetermined value. The control part maintains the input voltage and/or input current to the power supplier at a predetermined value.

The present disclosure provides a system-level protection system and method for sub/super-synchronous resonance/oscillation. The system includes a centralized protection coordinator arranged in a control center and a plurality of distributed protection relays arranged in a plurality of transformer substations or wind farms. Each distributed protection relay is configured to acquire a sub/super-synchronous impedance of the wind farm. The centralized protection coordinator is configured to acquire the sub/super-synchronous impedances measured by the plurality of distributed protection relays, to obtain a sub/super-synchronous aggregate impedance of the system according to a preset circuit topology and the sub/super-synchronous impedances, and to generate a system-level protection signal when the sub/super-synchronous aggregate impedance does not meet a stable condition. Each distributed protection relay is further configured to initiate a system-level protection according to the system-level protection signal.