A new switching control approach to reduce capacitor bank inrush current

Abstract

This paper presents the results analysis of switching’s effect when capacitor bank operation against the amount of inrush current on the circuit breaker. The capacitor bank switching causes inrush current and high-frequency oscillation if there are two or more capacitor banks connected on the same bus. When it occurs repeatedly, the insulation from the electric equipment will weaken and breakdown. For this reason, we propose a method to reduce the inrush current using new controlled switching. Switching control is used to find the time (t) of circuit breakers’ switching. So it can be seen the configuration of capacitor banks’ switching causes minimal inrush current. We have done a case study 3 capacitors using Simulink. Variables used are inrush current (ii), controlled switching time (t), and damping reactor (Lreactor). Inrush currents can be reduced by 99.8% using the proposed switching control method. The amount of inrush current is below the capability of the power breaker rating so that it does not cause a power breaker to interrupt and also does not cause overcurrent in the system. If the circuit breaker does not trip when there is a high inrush current in a short time, it can be dangerous for the electrical system equipment.