Patent ID: 6278622
Filing Date: 2001-08-21
Classification: H02J,H02M

Abstract:
A method of controlling an electric power source apparatus comprising an electric power converter circuit having on-off controllable switch elements to convert an output of an electric power source into predetermined DC or AC output by switching said switch elements and a pair of load connection terminals across which is applied an output of said electric power converter circuit while said electric power source apparatus is allowed to be driven in the condition that a voltage from another electric power source is allowed to be applied across said load connection terminals and comprising the steps of;detecting a waveform of a voltage across said load connection terminals after said output of said electric power converter circuit is stopped when an overcurrent flows through said load connection terminals from said electric power converter circuit;and judging whether said overcurrent is caused by an increase in a load or by said voltage applied across said load connection terminals from said another electric power source;whereby said output of said electric power converter circuit is kept stopped when it is judged that said overcurrent is caused by said increase in said load exceeding an allowable value and said output of said electric power converter circuit is restored in the condition in which said switch elements are so controlled that said waveform of said voltage applied across said load connection terminals from said electric power converter circuit is consistent with a waveform of said voltage across said load connection terminals detected by said voltage waveform detection step when it is judged that said overcurrent is caused by said voltage applied across said load connection terminals form said another power source, but not by said increase in said load exceeding said allowable value.