Patent ID: 7710053
Filing Date: 2010-05-04
Classification: H02P

Abstract:
1. A motor driving apparatus, comprising: inverter apparatuses each of which including a rectifier and an inverter; inverter control units for controlling said inverter apparatuses; a unit formed by connecting a plurality of inverter control apparatuses in parallel to each other, said plurality of inverter control apparatuses performing variable-speed driving of a motor; and breakers each of which being provided between each of said inverter apparatuses and said motor; each of said inverter control units, further comprising: a failure detection unit for detecting a failure of each of said inverter apparatuses; an inverter start frequency/phase setting unit for setting frequency/phase at an inverter-apparatus starting time; a motor rotation frequency/phase detection unit for detecting frequency and phase of a terminal voltage at said motor; a failure-time input frequency/phase setting unit for performing a computation based on said values detected by said motor rotation frequency/phase detection unit, and outputting said computed output to said inverter start frequency/phase setting unit; and a failure-occurrence-signal reception unit for receiving a failure occurrence signal outputted from a failure detection unit of the other inverter control apparatus, inputting said output of said failure-time input frequency/phase setting unit into said inverter start frequency/phase setting unit, and instructing said inverter start frequency/phase setting unit to start said inverter; wherein, at a failure occurrence time of each of said inverter apparatuses for driving said motor, each of said breakers is switched to said other inverter control apparatus based on a failure occurrence signal outputted from said failure detection unit of said inverter control apparatus, and said inverter is started by controlling said frequency and said phase at said inverter-apparatus starting time by using said failure-time input frequency/phase setting unit of said inverter control apparatus which is to be newly started by said switching.