Power Supply Hold-Up Time Extension via Pre-Charging Capacitor

The invention divides the energy storage function into two separate capacitors: a bulk capacitor and a pre-charging capacitor. The pre-charging capacitor is specifically dedicated to extending hold-up time, while the bulk capacitor maintains its original size for normal operation. This segmentation allows the hold-up time to be extended without increasing the bulk capacitor volume, as the pre-charging capacitor provides the additional energy storage capacity needed during power failures.

The pre-charging capacitor is charged in advance to a voltage higher than the bulk capacitor voltage before power failure occurs. This preliminary charging action ensures that when power is lost, the pre-charging capacitor immediately provides energy to extend hold-up time without requiring the bulk capacitor to be oversized. The controller manages this pre-charging process during normal operation, preparing the system for potential power interruptions.

The energy storage function is segmented between two capacitors with different roles. The bulk capacitor can be reduced to a smaller, more practical size for normal power supply operations, while the pre-charging capacitor is specifically sized and charged to provide the necessary energy extension during power failures. This segmentation allows the bulk capacitor volume to be reduced while maintaining or extending overall hold-up time through the coordinated operation of both capacitors.

The invention changes the voltage parameter relationship between capacitors by charging the pre-charging capacitor to a higher voltage than the bulk capacitor. This parameter change allows the pre-charging capacitor to store sufficient energy for hold-up extension in a smaller volume, compensating for the reduced bulk capacitor size and enabling the power supply apparatus to meet size constraints while maintaining adequate hold-up time.