| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a three-phase voltage type PWM inverter device which can detect each phase current based on the detected value of a DC bus line current by a simple and inexpensive constitution. <P>SOLUTION: A current detection circuit 8 detects the DC bus line current applied to a shunt resistor 1 of an inverter main circuit 2. A sample hold circuit 9 samples and holds a current value detected by the current detection circuit 8. A micro computer 4 detects the current value held by a capacitor 9c of the sample hold circuit 9 as a phase current of a particular phase determined by switching patterns of switching elements 2u to 2z, at the timing of the mountain vicinity or the valley vicinity of a PWM carrier signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
