CIRCUIT FOR DETECTING DISCONNECTION OF POWER LINE OF AC SERVO DRIVE

摘要

PURPOSE: A circuit for detecting disconnection of a power line of an AC servo drive is provided to control a driving operation of a motor by performing a disconnection detection process using the test current. CONSTITUTION: A test current generation unit(103) generates a test current signal. A switching unit(105) switches selectively a driving current signal and the test current signal by using a switching control signal. A current control unit(131) amplifies the driving current signal and the test current signal. A second three-phase converter(142) is used for converting the amplified current signal to a three-phase current signal. A PWM converter(151) is used for performing a PWM process for the three-phase current signal. A current feedback unit(161) feeds back the current signal of the PWM converter to the current control unit. A first three-phase converter(141) is used for converting the test current signal of the switching unit to the three-phase current signal. A disconnection detector(190) is used for generating the switching control signal and deciding the disconnection of the power line by comparing the current signal of the first three-phase converter with the current signal of the current feedback unit.