| 摘要 |
A protection apparatus for an inverter is provided to prevent power semi-conductor switch from being damaged by detecting over-current and shielding PWM(Pulse Width Modulation) signal output at the same time. In a protection apparatus for an inverter, a PWM buffer(43) outputs a PWM signal to a power semi-conductor switch of the inverter as a driving signal. A main controller provides the PWM signal. A PWM short-circuit detector(45) is connected between the PWM buffer(43) and the main controller. The PWM short-circuit detector(45) shields an output of the PWM buffer during short-circuit detection by detecting generation of short circuit in the PWM signal of the main controller. A parallel resistance(41) is connected to a current loop passed by the power semi-conductor switch to detect a voltage for current quantity. A comparator(42) outputs over-current detecting signal by comparing a voltage detected by the parallel resistance to a prescribed voltage level. A latch(43) is connected to a output stage of the comparator(42) and the PWM buffer. The latch(43) outputs a signal controlling to shield an output of the PWM buffer by latching the over-current detecting signal if the comparator(42) outputs the over-current detecting signal.
|
