Online fault tolerance control device of speed sensor of permanent magnet motor

Abstract

The invention discloses an online fault tolerance control device of a speed sensor of a permanent magnet motor. A high rotation speed estimation module and a low rotation speed estimation module are used for respectively obtaining two estimated rotation speeds omega 2 and omega 3, a rotation speed accuracy calculation module is used for receiving the rotation speed omega 1 collected by the motor and the estimated rotation speeds omega 2 and omega 3 from the two rotation speed estimation modules through the speed sensor, a prior probability is obtained by a prior probability calculation method based on the maximum likelihood estimation, and a posterior probability is calculated by a fault tolerance control module according to the prior probability. When the posterior probability f(x1) is greater than the preset threshold, the speed sensor normally works, and the collected rotation speed omega 1 is directly used as the feedback rotation speed for outputting. Or else, the feedback rotation speed is calculated according to the collected rotation speed, the estimated rotation speed and the posterior probability. The device has the advantages that a motor driving system can realize the closed loop control within wide speed adjusting range under the condition of faults of the speed sensor, the rotation speed of the motor is smoothly switched in the fault tolerance control process, and the fault tolerance control effect is improved.

Description

technical field [0001] The invention belongs to the technical field of permanent magnet synchronous motor drive control, and more specifically relates to an online fault-tolerant control device of a permanent magnet synchronous motor speed sensor. Background technique [0002] At present, in the drive control system of the permanent magnet synchronous motor, the vector control algorithm is usually used. The input of the algorithm is the expected speed, the feedback acquisition speed and the current value of the three-phase line, and the expected control voltage is output. The expected control voltage is passed through the space vector pulse width Modulate SVPWM ((Space Vector Pulse Width Modulation) to obtain six PWM (Pulse Width Modulation, pulse width modulation) driving signals, which are used to drive 6 switching tubes in the three-phase inverter circuit, and the switching tubes output three-phase AC to realize the permanent magnet Synchronous motor control. [0003] Th...

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Problems solved by technology

[0006] (1) The prior probability involved in the fault-tolerant control algorithm based on the posterior probability is derived from empirical values, which affects the fault-tolerant effect of the system when it operates at different speeds;

[0007] (2) The speed range estimated based on the reactive power model reference adaptive method is narrow, which is only suitable for low-speed and medium-speed speed estimation, and there is a steady-state error that makes the off-line speed estimation inaccurate

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