| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor driving device that can adjust an output voltage of an inverter depending on load torque, based on a current detected from a DC bus. <P>SOLUTION: A motor driving device drives a permanent magnet synchronous motor without means of detecting a rotor position, by an inverter that converts DC power into AC power. The motor driving device that controls a ratio of an output voltage level of the inverter and a frequency of the same to be substantially constant has: a low-pass filter 16 that detects an average value of a current flowing in a DC bus 30 of the inverter 32; torque current detection means 17 that detects a torque current, which is a q-axis component of a current in a d-q coordinate system, from the average value of the current, which is detected by the filter 16; and subtractors 18 and 20 and PI adjustment means 19 that adjust the output voltage level of the inverter 32 so that the detected torque current coincides with a torque current command value. <P>COPYRIGHT: (C)2012,JPO&INPIT |
