Transformer high-voltage side three-phase current transformer secondary side neutral line breakage discrimination method

The invention discloses a transformer high-voltage side three-phase current transformer secondary side neutral line breakage judgment method. The method comprises the steps that transformer high-voltage side three-phase current and high-voltage side neutral point zero-sequence current are collected; calculating a fundamental wave effective value of the self-produced zero-sequence current on the high-voltage side of the transformer; calculating the effective values of the neutral point zero sequence current fundamental wave and each integer harmonic wave at the high-voltage side; in response to the initial empty charging of the transformer, the fundamental wave effective value of the self-produced zero-sequence current at the high-voltage side of the transformer is lower than a fixed value, the fundamental wave effective value of the zero-sequence current at the neutral point at the high-voltage side is higher than the fixed value, and the ratio of the sum of integer harmonics of the zero-sequence current at t