Initial Voltage Change on Capacitor Switching

This letter presents field measurements of capacitor switching transients with initial bus voltage changes different from widely used assumptions. Instead of being pulled toward zero in all three phases, initial voltage changes in both directions are seen in grounded capacitor switchings. Electromagnetic Transients Program simulation shows that the reason could be pole spread in breaker closing and mutual coupling between the three phases. The letter suggests that this transient pattern be considered in capacitor switching research.