Controlling device of permanent-magnet synchro motor

Abstract

The invention provides a controller of a permanent magnet synchronous motor in which smooth start can be realized in a short time without using an absolute position detector. The controller comprises a detection mode setting means (18) outputting a magnetic pole detection command for detecting the magnetic pole position of a permanent magnet synchronous motor; a magnetic pole detection current command means (19) outputting a plurality of different values as electric phase angle and current commands for detecting initial magnetic pole phase in response to the magnetic pole detection command; signal switch sections (21a-21c) outputting the electric phase angle and current commands for detecting initial magnetic pole phase being delivered from the magnetic pole detection current command means to a current control section when the magnetic pole detection command is inputted; and a magnetic pole phase judging means (20) for detecting oscillation phenomenon by extracting a high frequency component from a feedback current for a plurality of different values outputted from the magnetic pole detection current command means (19) in response to the magnetic pole detection command, and specifying an electric phase angle for maximizing oscillation as the initial magnetic pole phase.

Description

technical field [0001] The present invention relates to a control device for a permanent magnet synchronous motor that detects the magnetic pole position of the synchronous motor. Background technique [0002] Patent Document 1: Japanese Unexamined Patent Publication No. 2003-143894 (page 1, figure 1 ) [0003] An elevator traction machine using a permanent magnet synchronous motor generally has a sensor for detecting the rotor magnetic pole position of the motor, and this function is often embedded in a speed detector directly connected to the rotating shaft of the motor. The detection accuracy of the rotor pole position determines the control performance of the motor torque. If the electrical angle deviates by 60 degrees, the torque will be halved, and if it deviates by 90 degrees or more, the torque in the opposite direction will be generated. [0004] Therefore, not only the detection accuracy of the sensor itself is important, but also the positioning accuracy of the ...

AI Technical Summary

Problems solved by technology

Therefore, it is easy to generate torque in the opposite direction to the command, or the torque is not enough, etc.

In this case, since the elevator cannot be operated normally, there is a problem that it is not suitable to apply the conventional method of performing excitation correction while running.

[0008] However, considering the manufacturing cost, it is not practical to install an absolute position detector to ensure an electrical angle accuracy of several orders of magnitude

Therefore, in the case of using an absolute position detector in a multi-pole permanent magnet synchronous motor, the correction of the electrical phase angle is a big problem

Also, there is the problem that absolute position detectors are prohibitively expensive compared to enhanced encoders typically used in induction motors

[0009] In addition, in the magnetic pole position estimation method of Patent Document 1, since the axis discrimination and pole discrimination must be performed when setting the initial value, and the convergence calculation is also performed, it may take time to estimate the magnetic pole position, and it may take time before the actual start. Spend time

Images