An electric motor drive device with a failure detection circuit and a failure detection method for an electric motor drive device having a failure detection circuit

摘要

An electric motor drive apparatus having a failure detection circuit (1), said electric motor drive apparatus comprising: - a bridge circuit (200) which drives an electric motor (100) and is constructed of high-potential side arms (21) and low-potential side arms (22); A PWM control circuit (502) generating a voltage command for driving the electric motor (100); A PWM signal generation circuit (503) which generates a PWM signal from the voltage instruction; A DC detection circuit (400) which detects DC on a DC side of the bridge circuit (200); A phase current calculation circuit (501) that calculates output phase current of the bridge circuit (200) based on the DC current and the PWM signal; and a failure detection circuit (600) that detects the failure of the DC detection circuit (400), wherein the failure detection circuit (600) that determines the failure of the DC detection circuit (400) from the DC detection values in a zero voltage vector period in which the high potential side arms (21) of the bridge circuit (200) are all ON and in a zero voltage vector period in which the low potential side arms (22) of the bridge circuit (200) are all ON.