Abstract: A source-network-load-storage coordination dispatching method in a background of a coupling of renewable energy sources, including: taking an expectation of a minimum grid operating cost in a dispatching cycle as an objective function; generating an approximate value function of an output of a set for generating electricity from renewable energy sources and a user load, and constructing a source-network-load-storage coordination dispatching model with combination of the objective function; obtaining forecast data of the output of a set for generating electricity from renewable energy sources and the user load, and inputting the forecast data into the dispatching model for solving; performing iterative updating on the approximate value function, importing the approximate value function after the iterative updating into the dispatching model for iterative solving, and terminating an iterative process until a solving result satisfies a preset convergence condition; and using a solving result of a last iteration

Abstract: Disclosed are a net load forecasting method and apparatus for a new energy electric power market. The method includes: obtaining and performing data preprocessing on new energy output data and external environmental data, and extracting strongly correlated features from the new energy output data and the external environmental data after the data preprocessing; performing feature expansion on the strongly correlated features, and inputting the strongly correlated features after the feature expansion into a preconstructed regression forecasting model, to obtain a first forecast value; obtaining and performing data preprocessing on user load data and load influencing factor data, and inputting the user load data and the load influencing factor data after the data preprocessing into a FNN-LSTM hybrid model, to obtain a second forecast value; and calculating a difference between the second forecast value and the first forecast value, to obtain a net load forecasting result.

Abstract: Provided is a determination method of differential protection suitable for an electricity transmission line with multi-terminal T-connection.

Abstract: Provided are a ground fault protection method and apparatus for a photovoltaic station output transmission line. A circuit breaker on a photovoltaic side is controlled by a control element. Whether measured zero sequence impedance on the photovoltaic side of a segment line has a large variation before and after an action of power grid side distance protection is determined, the variation of the measured zero sequence impedance is inputted into the control element, in condition that the variation of the measured zero sequence impedance is less than a setting value, a tripping signal is outputted to the circuit breaker on the photovoltaic side to isolate the fault; and in condition that the variation of the measured zero sequence impedance is greater than the setting value, photovoltaic side distance protection is not started.

Abstract: Provided are a ground fault protection method and apparatus for a photovoltaic station output transmission line. A circuit breaker on a photovoltaic side is controlled by a control element. Whether measured zero sequence impedance on the photovoltaic side of a segment line has a large variation before and after an action of power grid side distance protection is determined, the variation of the measured zero sequence impedance is inputted into the control element, in condition that the variation of the measured zero sequence impedance is less than a setting value, a tripping signal is outputted to the circuit breaker on the photovoltaic side to isolate the fault; and in condition that the variation of the measured zero sequence impedance is greater than the setting value, photovoltaic side distance protection is not started.

Abstract: Provided is a determination method of differential protection suitable for an electricity transmission line with multi-terminal T-connection.

Abstract: Provided is an anti-islanding protection system. The system is applied to a low-voltage distributed generation resource (DGR) and includes a box, a reverse power protector, a protection module and an output controller. The reverse power protector has an end connected to a first current transformer and has another end connected to the output controller. The reverse power protector is configured to provide reverse power protection for the low-voltage DGR. The output controller has an end connected to the protection module and the reverse power protector and has another end connected to a grid-connection switch of the low-voltage DGR. The output controller is configured to control the grid-connection switch to turn off when reserve power is detected. The protection module has an end connected to a second current transformer and has another end connected to the output controller.

Abstract: Provided are a differential protection method and system, applied to a multi-terminal T-connection transmission line. The method includes: selecting two slaves without a connection and connecting the two slaves to construct a slave group; determining a target slave and an auxiliary slave in the slave group, where a first communication path is connected along a channel one, a channel two and a channel three, and a second communication path is connected along the channel three, the channel two and the channel one; transmitting, by the target slave, two frames of messages, and acquiring a delay difference between a transceiving delay of the first communication path and a transceiving delay of the second communication path, where a first frame of messages is transmitted to the target slave via the first communication path, a second frame of messages is transmitted to the target slave via the second communication path.

Abstract: Provided are a differential protection method and system, applied to a multi-terminal T-connection transmission line. The method includes: selecting two slaves without a connection and connecting the two slaves to construct a slave group; determining a target slave and an auxiliary slave in the slave group, where a first communication path is connected along a channel one, a channel two and a channel three, and a second communication path is connected along the channel three, the channel two and the channel one; transmitting, by the target slave, two frames of messages, and acquiring a delay difference between a transceiving delay of the first communication path and a transceiving delay of the second communication path, where a first frame of messages is transmitted to the target slave via the first communication path, a second frame of messages is transmitted to the target slave via the second communication path.

Abstract: Provided is an anti-islanding protection system. The system is applied to a low-voltage distributed generation resource (DGR) and includes a box, a reverse power protector, a protection module and an output controller. The reverse power protector has an end connected to a first current transformer and has another end connected to the output controller. The reverse power protector is configured to provide reverse power protection for the low-voltage DGR. The output controller has an end connected to the protection module and the reverse power protector and has another end connected to a grid-connection switch of the low-voltage DGR. The output controller is configured to control the grid-connection switch to turn off when reserve power is detected. The protection module has an end connected to a second current transformer and has another end connected to the output controller.