Research on Harmonic Overvoltage Suppression Technology of Single-core Cable Shielding Layer

Traditional shielding layer protector of single-core cable can only suppress lightning and fault overvoltage, and can not solve the induced overvoltage and harmonic overvoltage caused by harmonics. When a discharge damping technology for shielding layer of single-core cable is proposed. Firstly, establish the coupling model of shielding layer by analyzing the mechanism of shielding layer induced voltage; then, study the induced overvoltage and resonance overvoltage caused by harmonics based on the model; furthermore, a technical scheme of reducing the overvoltage caused by harmonics by grounding the cable shielding layer through discharge capacitance and damping resistance in series is proposed; finally, give the method of choosing parameters of discharge capacitance and damping resistance. Theoretical results and simulated analysis confirm effectiveness of this method.