Method for solving unbalance of three-phase currents and handling negative sequence

The invention relates to a method for solving the unbalance of three-phase currents and handling the negative sequence. According to the method, the variable quantity of a current signal of a power grid serves as a control quantity, filtering, phase shift, proportional amplification and operation processing are performed on the variable quantity of the current signal of the power grid through a controller to obtain a current with the magnitude equal to that of the negative sequence current of the power grid but the direction opposite to that of the negative sequence current of the power grid, a power unit of an SVG device is made to generate a current counteracting the negative sequence current of the power grid, and thus the purpose of handling the negative sequence is achieved. The method for solving the unbalance of three-phase currents and handling the negative sequence is characterized in that a power grid current acquisition point with the negative sequence current eliminated obtains a current value, needing further fine adjustment, of the SVG device, and finally a control current is output to make the adjusted negative sequence voltage in the power grid zero through calculation of the SVG device. The method can effectively solve the problem of unbalance of the three-phase currents and the negative sequence of the power grid, is high in response speed and tracking precision and can greatly improve the stability and the reliability of the power grid.