A power conversion system includes plural power conversion apparatuses and a server connected to each of the plural power conversion apparatuses. Each of the plural power conversion apparatuses includes a power conversion circuit interconnected with a power system, a calculating unit configured to calculate, based on an output current and an output voltage of the power conversion circuit, at least one information of reactive power and a reactive current output by the power conversion circuit, a storing unit configured to accumulate, in a storage device, time-series reactive power information which is information associating time and the at least one information calculated by the calculating unit, and a communication interface configured to transmit the time-series reactive power information stored in the storage device to the server. The server is constructed to collect the time-series reactive power information of each of the plural power conversion apparatuses via the communication interface.

A stability control method for a virtual synchronous generator (VSG) in a strong grid based on an inductance-current differential feedback is provided. A grid-connected topological structure of a VSG using the control method includes a direct-current (DC)-side voltage source, a three-phase inverter, a three-phase grid impedance and a three-phase grid. By controlling the VSG and controlling the inductance-current differential feedback, the method suppresses the oscillation of the output power from the VSG in the strong grid and implements the stable operation of an inner-loop-free VSG in the strong grid, without adding the physical inductance, increasing the cost of the filter and additionally providing a grid-side current sensor.

A system and method are provided for controlling a power generating facility. Accordingly, the facility-level controller determines a reactive-power-delivery coefficient for each power generating asset of the power generating facility. The reactive-power-delivery coefficient includes at least one of a reactive-power-generation coefficient and a reactive-power-transmission coefficient. The reactive-power-delivery coefficient is indicative of an impact on the active power production capability of each of the power generating assets due to a change in an amount of reactive power delivered to a point of interconnect. Based at least in part on the reactive-power-delivery coefficient, the facility-level controller determines a portion of a demand signal to be satisfied by each of the power generating assets.

A wind farm for supplying electrical power into a supply grid. The farm includes wind power installations, a farm grid connecting the installations, and a power flow control device. The power flow control device is configured to connect the farm grid and the supply grid such that an electrical power generated by the installations can be supplied into the supply grid. The power flow control device has at least: a DC link configured to conduct at least the electrical power generated by the installations, an electrical energy store connected to the DC link, an inverter connected to the DC link and configured to inject at least the electrical power generated by the installations into the supply grid, and a controller configured to drive the inverter in such a way that the farm, at the supply grid, in the steady state appears to be dynamic like an electromechanical synchronous machine.

This application discloses a photovoltaic station and a power coordination method for a photovoltaic station. Sample inverters are disposed in arrays requiring power adjustment in the photovoltaic station. Real-time active power of sample inverters in each array is obtained. Then, an available active capacity and an available reactive capacity of the array and available active capacities and available reactive capacities of all the arrays requiring power adjustment are obtained based on the real-time active power of the sample inverters. Finally, active power and reactive power of the photovoltaic station are separately allocated to the N arrays based on the available active capacities and the available reactive capacities respectively corresponding to the N arrays. Because the sample inverters come from the arrays requiring power adjustment, differences between inverters and differences between the arrays can be fully exploited, and the available active capacities of the arrays can be more accurately obtained by using the sample inverters. Therefore, a more accurate available power capacity of the photovoltaic station is obtained by using relatively accurate available active capacities.

Techniques for detailed monitoring and evaluation of individual subsystems within solar photovoltaic power generation systems are provided. In one aspect, a method for monitoring a photovoltaic system having at least one array of photovoltaic panels and at least one inverter system configured to convert output from the panels from DC to AC includes the steps of: obtaining sensor data from the photovoltaic system; computing an efficiency of the panels and an efficiency of the inverter system using the sensor data; computing an aging parameter for the panels using the efficiency of the panels; computing an aging parameter for the inverter system using the efficiency of the inverter system; determining whether the aging parameter for the panels or for the inverter system exceeds a predetermined threshold level; and taking action if either the aging parameter for the array or for the inverter system exceeds the predetermined threshold level.

Techniques for detailed monitoring and evaluation of individual subsystems within solar photovoltaic power generation systems are provided. In one aspect, a method for monitoring a photovoltaic system having at least one array of photovoltaic panels and at least one inverter system configured to convert output from the panels from DC to AC includes the steps of: obtaining sensor data from the photovoltaic system; computing an efficiency of the panels and an efficiency of the inverter system using the sensor data; computing an aging parameter for the panels using the efficiency of the panels; computing an aging parameter for the inverter system using the efficiency of the inverter system; determining whether the aging parameter for the panels or for the inverter system exceeds a predetermined threshold level; and taking action if either the aging parameter for the array or for the inverter system exceeds the predetermined threshold level.

A wind farm comprises a plurality of wind turbines connected to a network internal to the wind farm, a network feed-in point in the network internal to the wind farm for feeding electrical power into a supply network, a control device associated with the network feed-in point designed to control the wind turbines feeding power into the supply network by the network feed-in point on the basis of measured values recorded at the network feed-in point, and at least one additional network feed-in point having an additional control device designed to control the wind turbines feeding power into the supply network by the additional network feed-in point on the basis of measured values recorded at the additional network feed-in point, wherein the network internal to the wind farm is designed to variably connect at least one wind turbine to one of the plurality of network feed-in points.

A power station assembly includes two inverter power stations configured to provide respective power outputs at a voltage and at respective currents. The power station assembly additionally includes a linking module configured to electrically connect to the two inverter power stations to receive the respective power outputs therefrom, combine the respective power outputs into a combined power output, and provide the combined power output to a load.

A power station assembly includes two inverter power stations configured to provide respective power outputs at a voltage and at respective currents. The power station assembly additionally includes a linking module configured to electrically connect to the two inverter power stations to receive the respective power outputs therefrom, combine the respective power outputs into a combined power output, and provide the combined power output to a load.