| 摘要 |
<p>An apparatus and method for detecting a ground fault occurring on an output side of an inverter circuit, which includes a converter circuit for rectifying an alternating current into a direct current, a capacitor (3) for smoothing the direct current, an inverter circuit for converting the smoothed direct current into a predetermined frequency and voltage through the on/off operation of switching elements (4a - 4f) connected in parallel with diodes (5a - 5f), and a PWM signal generator for controlling the on/off of the switching elements (4a - 4f). The ground fault detector includes current detectors for detecting current flowing in the switching elements (4a - 4f), a device (24a - 24f) for detecting an overcurrent flowing from one of the switching elements (4a - 4f) and for outputting an overcurrent signal when the output of any of the current detectors exceeds a predetermined value (22a - 22f), a device for detecting a zero vector signal transmitted by the PWM signal generator, and a ground fault detector circuit (21) for detecting a ground fault condition in accordance with the overcurrent signal and the zero vector detection signal. <IMAGE></p> |
