Motor fault-tolerant control method and device

Abstract

The invention discloses a motor fault-tolerant control method and device. The method includes the following steps: collecting non-fault five phases of currents of a six-phase motor in a current sampling period, and converting the five phases of currents into five current components under a decoupled coordinate system; using a mathematical model of the motor and the five current components to predict the phase current value of each phase of the motor in the next sampling period, and predicting the optimal voltage vector output by a motor controller in the next sampling period according to the instruction value of each phase of current; converting the optimal voltage vector into five voltage components under the decoupled coordinate system, and limiting the amplitude of a voltage vector synthesized from a-axis and d-axis voltage components; and transmitting the a-axis and d-axis voltage components after amplitude limiting back to a phase coordinate system, converting the final optimal voltage vector into the duty ratio per phase, and adjusting the drive signal of each phase of voltage according to the duty ratio per phase to drive the motor. The phase current harmonic of the six-phase motor under the open-circuit fault tolerance condition of one phase of winding is significantly reduced while the dynamic performance of the motor is not affected.

Description

technical field [0001] The invention belongs to the field of electromechanical technology, and more specifically relates to a fault-tolerant fault control method and device for a motor. Background technique [0002] At present, multiphase motors are widely used in the fields of high power density and high reliability, and have broad application prospects in wind farms, electric vehicles, ship propulsion, aerospace and other fields. Compared with three-phase motors, multi-phase motors have more degrees of control freedom, which makes the control of multi-phase motors more flexible. When a multi-phase motor has a phase open circuit fault, the amplitude of each phase current is redistributed through the control algorithm. And the phase can still make the motor run normally, and the rated power of the system is reduced slightly. [0003] For a six-phase motor under fault-tolerant conditions, the spatial distribution of the windings of each phase is no longer symmetrical, and th...

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Problems solved by technology

[0005] Aiming at the defects of the prior art, the purpose of the present invention is to solve the traditional model prediction method, because the algorithm itself is based on the principle of exhaustively enumerating the switch states of the frequency converter, it has a large amount of calculation, high current harmonic content, poor steady-state performance, and large copper consumption. Shortcomings, technical problems that are difficult to meet the needs of long-term fault-tolerant operation

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