Protection Against One-Point Grounding Misoperation in Tripping Circuit Based on Damping Characteristics Analysis
Due to the influence of the resistances and inductances of the tripping coil and relay,as well as the grounding capacitance of DC system,the tripping circuit of the substation circuit breaker forms an RLC second-order circuit after a single point of grounding occurs.The oscillation of the grounding current at one-point may cause the coil or relay to trip incorrectly and cause the circuit breaker to trip.The composition of the tripping circuit and the risk of one-point grounding are analyzed,the influences of the resistance,capacitance and inductance of the tripping circuit on the grounding current within the conventional value range are also analyzed,and the value ranges of the resistance,capacitance and inductance of the tripping circuit are proposed under the condition of ensuring that one-point grounding does not misoperate through methods such as particle swarm optimization and multi-dimensional variable analysis.The necessity of further standardizing the resistance and inductance values of relays,optimizing the operating cur-rent of relays,and controlling the equivalent grounding capacitance of DC systems is demonstrated,which provides the guidance and reference for the selection of substation equipment components and the normalized control of DC system grounding capacitance.
万方数据
维普
