Method and system for controlling zero-sequence IV section protection of 220 kV circuit

The invention provides a method for controlling zero-sequence IV section protection of a 220 kV circuit. The method comprises the steps that a locking curve in a preset time period is constructed according to the inherent characteristics of the amplitude of a zero-sequence current of an excitation surge current, and time integration is carried out to obtain a current theoretical amplitude integralvalue; a curve, in which the amplitude of the actual zero-sequence current in the preset time period is changed along with time, is obtained, and time integration is carried out to obtain a current actual amplitude integral value; the current actual amplitude integral value is compared with the current theoretical amplitude integral value so as to determine the conditions of the current and actually generated zero-sequence current on the zero-sequence IV section protection of the 220 kV circuit, and the corresponding control, wherein when the actual zero-sequence current generation is in a high-resistance grounding f