Novel low-voltage hybrid compensation method and system

The invention provides a novel low-voltage hybrid compensation method. One SVG is used as a host, and the rest SVG and APF are used as slaves; intelligent capacitors send own state information to thehost SVG; the host SVG obtains the compensation condition of each intelligent capacitor according to the sent state information; and the host SVG samples a power grid and implements control. The method comprises the following steps: 1) if the capacity of a first APF cannot meet the harmonic current compensation capacity, a second APF executes residual harmonic current compensation, and so on; 2) afirst control unit of the host SVG uses a DFT algorithm to calculate the effective value of the current according to the acquired current waveform, and further derives the reactive current; in the input process, the reactive current needing to be compensated is recorded as Q input sum, and the host SVG distributes the compensation capacity of the intelligent capacitors and the compensation capacity of the host and slave S