PWM INVERTER CONTROL DEVICE AND CONTROL METHOD

摘要

A multi-level PWM inverter control device capable of safely switching from normal operation to protection operation and safely and smoothly returning to the normal operation from the protection operation without requiring a complicated algorithm. When the measured current value I is equal to or greater than a first reference value I1 and smaller than a second reference value I2, a zero vector starting from the OOO state at which intermediate potential is output for all the phases is output (step 22). When the current value I is equal to or greater than the second reference value I2 and smaller than a third reference value I3, after the zero vector is output, a base block operation for turning off all the switching elements is performed (step 28). When the current value I becomes greater than the third reference value I3, an emergency stop is performed (step 29). When returning to the normal operation after performing the base block, the zero vector output operation is performed before returning to the normal operation.