| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect abnormality of an optical sensor of an encoder before starting operation of a motor. <P>SOLUTION: A power conversion apparatus includes a controller which generates a driving signal for a semiconductor switch, and feeds the rotational speed calculated from a two-phase output signal of an encoder back to the controller, for generating the driving signal. It includes a safety function device 40 which, upon detecting abnormality of a distribution system or the like based on the output signal of an encoder 10, sends a safety shielding signal which stops a motor 200 to a controller 50. The controller 50 includes a control calculator 51 which, upon inputting of a test start command from the safety function device 40 before the start of operation, applies a DC voltage only during a short period between wires of a stator winding of the motor 200, for generating a torque at a rotor. The safety function device 40, if the output signal of the encoder 10 does not change within an application period of the DC voltage, determines that there is an abnormality with an optical sensor inside the encoder 10, and outputs the safety shielding signal. <P>COPYRIGHT: (C)2012,JPO&INPIT |
