A power generation system includes a plurality of photovoltaic cell panels for outputting DC power, a plurality of inverters for converting DC power into AC power, and a high-order device for communicating with the plurality of inverters. The high-order device is configured to acquire a predetermined power factor, and transmit a command value to each of the plurality of inverters so that the power factor corresponding to the predetermined power factor is achieved by a total output of the plurality of inverters. The high-order device is configured so as to determine a specific inverter that has room to increase the amount of reactive power output from among the plurality of inverters, to transmit a reactive power increasing command value for increasing reactive power to the specific inverter.

System for controlling voltage supply to a portion of a distribution grid. The portion of the grid including a substation providing one or more transformers operable to increase or decrease the voltage supplied to consumers within the portion of the grid. The voltage control system includes: a data set including a previously measured power consumption associated with previously measured values of a property(ies) being one of voltage, current, frequency or load, or a combination thereof, a measuring device to measure the property(ies) within the portion of the grid, a processing device to determine a most likely effect of altering the value(s) of the property(ies) from a first value to a second value, a storage device for storing one or more rules associating a trigger event with a response action associated with the substation, and a control device to receive a measurement of the property(ies) within the portion of the grid.

A power generation system includes a plurality of photovoltaic cell panels for outputting DC power, a plurality of inverters for converting DC power into AC power, and a high-order device for communicating with the plurality of inverters. The high-order device is configured to acquire a predetermined power factor, and transmit a command value to each of the plurality of inverters so that the power factor corresponding to the predetermined power factor is achieved by a total output of the plurality of inverters. The high-order device is configured so as to determine a specific inverter that has room to increase the amount of reactive power output from among the plurality of inverters, to transmit a reactive power increasing command value for increasing reactive power to the specific inverter.

A method, an apparatus and a device for suppressing a first HVDC commutation failure under an AC system fault are provided. The method includes: obtaining a three-phase voltage of a converter bus, and calculating a zero-sequence component amplitude and an ?? component amplitude; calculating a first trigger-angle command for a single-phase fault and a second trigger-angle command for a three-phase fault selecting a smaller one of the first trigger angle command and the second trigger angle command as a trigger-angle command for an extinction-angle controller; and adjusting a trigger angle of the HVDC transmission system by using the trigger-angle command as an upper limit value for an output of the extinction-angle controller of the HVDC transmission system.

System for controlling voltage supply to a portion of a distribution grid. The portion of the grid including a substation providing one or more transformers operable to increase or decrease the voltage supplied to consumers within the portion of the grid. The voltage control system includes: a data set including a previously measured power consumption associated with previously measured values of a property(ies) being one of voltage, current, frequency or load, or a combination thereof, a measuring device to measure the property(ies) within the portion of the grid, a processing device to determine a most likely effect of altering the value(s) of the property(ies) from a first value to a second value, a storage device for storing one or more rules associating a trigger event with a response action associated with the substation, and a control device to receive a measurement of the property(ies) within the portion of the grid.

A method, an apparatus and a device for suppressing a first HVDC commutation failure under an AC system fault are provided. The method includes: obtaining a three-phase voltage of a converter bus, and calculating a zero-sequence component amplitude and an component amplitude; calculating a first trigger-angle command for a single-phase fault and a second trigger-angle command for a three-phase fault; selecting a smaller one of the first trigger angle command and the second trigger angle command as a trigger-angle command for an extinction-angle controller; and adjusting a trigger angle of the HVDC transmission system by using the trigger-angle command as an upper limit value for an output of the extinction-angle controller of the HVDC transmission system.