Dead Time Reduction Control of a Series Slave Drive Type Discharge Circuit in High Voltage Power Supply for ERF Dampers

This paper explores, the adoption of a series slave drive for discharge switches to reduce the costs of discharge circuits in high-voltage power supplies for ERF dampers. With this driving method, the charging period of the voltage divider capacitor after the turn-off of the discharge switch is a dead time, which reduces the responsiveness of the system. Thus, a control method to reduce the dead time by turning-off the discharge switch at a higher output voltage than the target was proposed. This method is based on the estimated charge energy of the voltage divider capacitor and the estimated energy consumption of the load with high temperature dependence of the parameters. The circuit was simulated to verify the effectiveness of the proposed control for reducing dead time in the range of discharge voltage amounts from 1kV to 4kV. As a result, the switching cycle of the discharge circuit was reduced by up to 23% at an ERF temperature of 20°C and up to 38% at an ERF temperature of 50°C by reducing the dead time with the proposed control. This confirmed the effectiveness of the proposed control.