The inverter output filter is installed between the inverter and the motor to reduce the DV/dt of the motor side, mainly for protecting the motor; the incoming reactor is installed on the incoming side of the inverter, which will increase the impedance of the line and is mainly used to suppress the harmonic impact of the inverter on the grid.

The cycle is the period, 1 cycle of a 50Hz grid is 0.02 seconds, and 0.5 cycle is 0.01 seconds.

The boundary energy meter is the power meter installed and operated in the gate power metering devices of power generation enterprises' online, inter-district liaison line, provincial network liaison line, and provincial off-grid, which is used for trade settlement and assessment of internal economic indexes and plays an important role in the power metering of the whole power grid.