PWM Rectifier with DC Reverse-Blocking Diode for High-Reliability Generating Apparatus and Its Application to Gas Heat Pump System

摘要

High reliability generating apparatus with a PWM rectifier equipped with a DC reverse-blocking diode is proposed. The PWM rectifier adjusts the power from a permanent magnet synchronous generator by means of position sensorless control. Due to the DC diode, the PWM rectifier is shoot-through free, I.e. the switches in one arm are not broken with their simultaneous turning-on caused by electromagnetic interferences, etc. The apparatus is applied to the Gas Heat Pump system (GHP), which is an efficient air-conditioning system powered by fueling gas, to satisfy its requirement of high reliability to the electrical equipment. There is a control issue in the proposed circuit, that is the DC bus capacitor is electrically separated from the switches when the DC diode is reverse-blocking, which results in the voltage fluctuation at the switches side. This is overcome by adding a stabilization control. The system is tested with a 1.5kW-class experimental setup, which demonstrates desirable performances as expected, and it is confirmed that the rectifier is durable to the simultaneous turning-on of the switches in one arm.