High-Voltage Driver Pre-Charge Circuit for Inrush Current Control

The pre-charge circuit is activated before the main charge circuit to initially charge the energy storage capacitor. This preliminary charging action limits the inrush current that would otherwise damage the electronic switch and battery pack, while still achieving the necessary charging function. The pre-charge circuit includes a pre-charge switch and current limiting components that control the charging current during this initial phase.

The charging process is divided into two distinct stages: pre-charging and main charging. The pre-charge circuit and main charge circuit are separated into independent modules with different functions. The pre-charge circuit handles the initial charging with current limiting, while the main charge circuit handles the subsequent charging at full capacity, thus avoiding the harmful effects of direct full-power charging.

A discharge circuit is introduced as an intermediary component between the energy storage capacitor and the external environment. This discharge circuit includes a discharge switch and discharge resistor that can safely dissipate the residual charge in the capacitor after shutdown. The discharge circuit acts as a mediator that eliminates the harmful residual charge while maintaining the beneficial power retention during operation.

The system implements periodic control of the discharge circuit based on operational states. During normal operation, the discharge circuit remains inactive to allow power retention. After shutdown is detected, the discharge circuit is activated in a periodic manner to safely discharge the capacitor, thus eliminating residual charge risks at appropriate intervals following power-off events.