Rotor position detecting method for permanent magnetic brushless direct current motor (DC motor)

Abstract

The invention discloses a rotor position detecting method for a permanent magnetic brushless direct current motor (DC motor), which detects the rotor position of the permanent magnetic brushless DC motor by a state observer and a Kalman filter, wherein, the state observer respectively observes the speed and torque fluctuation of the motor, and establishes a motor mathematical model with convenient linearization for observation when observing; and the Kalman filter adopts a linearization method surrounding the latest state estimation value, i.e. expanding Taylor series near the predicted estimation value and taking a linear term thereof to obtain an approximate expression. The rotor position detecting method for the permanent magnetic brushless DC motor of the invention has good reliability, high efficiency, high accuracy and flexible control, and can realize control of the motor without a position sensor.

Description

technical field [0001] The invention relates to a detection method, in particular to a rotor position detection method for a permanent magnet brushless DC motor. technical background [0002] Modern industry has higher and higher requirements for motor performance, and the improvement of motor performance is achieved through the following two ways. One is the research on the motor body, which mainly uses a special structure to improve the performance of the motor; the other way is Adopt advanced control strategies. Traditionally, the research on brushless DC motors mainly focuses on the motor itself and the hardware circuit of the controller, but there is little research on various advanced automatic control strategies. [0003] The reason why the permanent magnet brushless DC motor can run synchronously and has the good speed regulation performance of the brushed DC motor is that the on and off of the inverter power device (corresponding to the conduction state of the moto...

AI Technical Summary

Problems solved by technology

[0006] 1. The volume of the motor is increased to install the sensor, which increases the cost of the motor;

[0007] 2. There are too many connecting wires for the sensor

When the motor needs to be sealed for operation, these connecting wires are a disadvantage;

[0008] 3. The output signals of the sensors are all weak electric signals, so too many and too long connecting lines are easy to introduce interference;

[0009] 4. Working environments such as high temperature, low temperature, dirty air and easy corrosion, as well as working conditions such as vibration and high-speed operation will reduce the reliability of the sensor

If the sensor is damaged, it may also cause damage to other components such as the inverter;

[0010] 5. The installation accuracy of the sensor directly affects the performance of the motor operation, so it also relatively increases the difficulty of the production process;

[0011] 6. The existence of the sensor reduces the operational reliability of the motor and increases the difficulty of maintenance

[0012] In summary, the external rotor position sensor limits the popularization and application of permanent magnet brushless DC motors to a certain extent.