| 摘要 |
PURPOSE: An inverter and a controlling method thereof are provided to prevent a switching of a switching device from occurring in an area where a load current is small. CONSTITUTION: A zero detecting part(61) detects a zero crossing point of a load current. A control signal adjusting part(51) controls a three-phase AC power by adding a predetermined control voltage with a control voltage generating part and three adders(53). A pulse width modulating part(46) generates six switching control signals(C1,C2,C3,C4,C5,C6) with three comparators(48), three inverters(49), and a dead time applying part(47). A three-phase sine wave AC power(Va,Vb,Vc) are supplied from a source of supply of the three-phase AC power, and a pyramidal wave is supplied from a source of supply of the pyramidal wave. The zero detecting part(61) connected to a load calculates an angle of power factor of a load current and detects a zero crossing point.
|
