Abstract: A microgrid troubleshooting method entails, connecting a first trouble simulating unit between a utility electricity and an AC load, wherein an AC end of a second trouble simulating unit connects with the AC load, and a DC end of the second trouble simulating unit connects with a solar power generating unit, an energy-storing unit, a fuel cell unit, and a DC load; switching the second trouble simulating unit to a short-circuit state, measuring a microgrid earth potential rise, short-circuit current of the solar power generating unit, and short-circuit current of the energy-storing unit, and checking whether the microgrid is damaged; and switching the first trouble simulating unit to a short-circuit state, measuring a microgrid earth potential rise, and checking whether the microgrid is damaged. The method is effective in simulating troubles with the microgrid, measuring the microgrid's short-circuit current, and testing whether the microgrid's protection mechanism is functioning well.

Abstract: The invention provides a DC to DC converting circuit, comprising: a transforming unit with a primary winding and a secondary winding; a bridge rectifier unit coupled to an input voltage, having a first output terminal and a second output terminal coupled to both side of the primary winding respectively; a first switch coupled between the input voltage and the first output terminal; a second switch coupled between the first output terminal and a ground terminal; a third switch coupled between the input voltage and the second output terminal; and a fourth switch coupled between the second output terminal and the ground terminal; an output unit paralleled to the secondary winding; and a clamping unit coupled to the input voltage and paralleled to the bridge rectifier unit, having an auxiliary switch coupled to the input voltage; and a clamping capacitor coupled between the auxiliary switch and the ground terminal; wherein the auxiliary switch is turned on when operation statuses of the first switch and the fourt

Abstract: The invention provides a DC to DC converting circuit, comprising: a transforming unit with a primary winding and a secondary winding; a bridge rectifier unit coupled to an input voltage, having a first output terminal and a second output terminal coupled to both side of the primary winding respectively; a first switch coupled between the input voltage and the first output terminal; a second switch coupled between the first output terminal and a ground terminal; a third switch coupled between the input voltage and the second output terminal; and a fourth switch coupled between the second output terminal and the ground terminal; an output unit paralleled to the secondary winding; and a clamping unit coupled to the input voltage and paralleled to the bridge rectifier unit, having an auxiliary switch coupled to the input voltage; and a clamping capacitor coupled between the auxiliary switch and the ground terminal; wherein the auxiliary switch is turned on when operation statuses of the first switch and the fourt