66 kV变电站并联电容器组故障发展特征研究

Study on Fault Development Characteristics of Shunt Compensation Capacitor Bank in 66 kV Substation

变电站并联电容器组运行过程中,由于电介质绝缘老化等因素的影响,电容器内部可能发生各种故障,产生较大幅值的过电压,威胁电容器组绝缘。通过ATP-EMTP软件模拟了66 kV变电站并联电容器组在发生电容器元件击穿熔丝燃弧、击穿元件可靠熔断、电容器群爆以及群爆重燃等4种故障情况下的电容器组节点电压、电流变化特性。研究结果表明:当发生电容器元件击穿熔丝燃弧、元件击穿可靠熔断时,电容器组节点电压基本不变,完好电容器元件上流过电流略有上升;电容器发生群爆以及群爆重燃时,电容器组节点会出现明显过电压、过电流,威胁电容器组绝缘,应予以防护。

During the operation of the shunt capacitor bank in a substation,various faults may occur inside the capacitor due to the influence of such factors as dielectric insulation aging,the overvoltage with large amplitude may generate and threaten insulation of the shunt capacitor bank.ATP-EMTP is used to simulate the voltage and current variation characteristics of the shunt capacitor bank in the 66 kV substation at such four fault conditions as capacitor component breakdown and arcing,reliable fusing of faulty components,capacitor multi-explosion,capacitor multi-explosion and reignition.It is shown by the study result in case of the first two faults,the node voltage of the shunt capacitor bank is basically unchanged and the current flowing on the healthy capacitor element has a slight increase.While,in case of the latter two faults,the remarkable over voltage and over current will occur on the node of capacitor bank,which threatens the insulation of capacitor bank and shall be protected.