Transient Analysis of Capacitor Switching and Breakdown

Capacitor banks are widely used for reactive power compensation and voltage regulation in systems due to their low capacity cost, flexible operation, and convenient maintenance. Due to the complex operating conditions and long-term impact of various adverse factors, component breakdown faults will inevitably occur inside the capacitor bank. After a certain number of breakdown components reach a certain level, it will cause protection tripping and unplanned shutdown. If the protection fails to act in a timely manner, a large number of component breakdown will lead to a penetrating short circuit fault in the capacitor, and in severe cases, it will lead to malignant accidents such as capacitor explosion and fire, posing a threat to the safe operation of systems and equipment. Existing research and field data show that the breakdown fault of capacitor bank components will cause the three-phase voltage and current at the capacitor bank port to produce transient disturbance waveform. Compared with the steady waveform, it is weak, difficult to capture and has limited bearing information. The transient waveform has unique characteristics and contains rich equipment status information, which has a large space for analysis and application. This article analysis voltage and current transient waveforms from large number of switching/breakdown experiments. It is great of importance the capacitance abnormality detection and location.