Output power protection apparatus and method of operating the same

A method of operating an output power protection apparatus comprising following steps:

• (a) providing a DC conversion unit, the DC conversion unit configured to convert an input DC power into an output DC power;
• (b) providing an output protection unit, the output protection unit connected in series to the DC conversion unit, and having a plurality of protection circuits connected in parallel to each other;
• (c) providing a high-voltage battery and a low-voltage battery, the high-voltage battery being charged by the input DC power, and the low-voltage battery connected between the DC conversion unit, the output protection unit, and a low-voltage device, and being charged by the output DC power;
• (d) providing a control unit;
• and
• (e) generating a control signal by the control unit to control the protection circuits to disconnect the connection between the low-voltage battery and the low-voltage device, and the DC conversion unit when a short-circuit condition occurs between the high-voltage battery and the low-voltage battery or the low-voltage battery is reversely connected in polarity.