Patent ID: 6465911
Filing Date: 2002-10-15
Classification: H02J,Y02E,Y04S

Abstract:
A power supply system switching device comprising:a first mechanical bypass switch connected in series with a first power supply system, a second mechanical bypass switch connected in series with a second power supply system, a semiconductor switch; a circuit-changing switch for switching and selectively connecting the semiconductor switch in parallel with the first and second bypass switches, a load connected to a connection point of the first bypass switch, the second bypass switch, and the semiconductor switch, and a controller for on-off controlling the first and second bypass switches and the semiconductor switch so that one of the first and second power supply systems is selected to supply power to the load by switching of the first and second bypass switches, the semiconductor switch being switchably connected in parallel with the one of the first and second bypass switches connected to the first and second power supply systems not supplying power to the load, the controller, when switching from power being supplied to the load from the first power supply system to power being supplied from the second power supply system, causing the first bypass switch to open and the semiconductor switch connected in parallel with the second bypass switch to conduct, whereby current formerly flowing through the first bypass switch is initially commutated to flow through the semiconductor switch, causing the second bypass switch to close, whereby the load is switched and connected to the second power supply system, and, thereafter causing the semiconductor switch to be connected in parallel with the first bypass switch.