Fault-tolerant control system and method for four-direct-current motor series system

Abstract

The invention discloses a fault-tolerant control system and method for a four-direct-current motor series system. The method is characterized in that whether four direct-current motors have faults ornot is judged by utilizing a current value of an output end of a five-phase voltage source type fault-tolerant inverter module through an actual current reconstruction, fault detection and fault-tolerant control module, and a reference torque value of the motor corresponding to the fault is set to be zero; the motor reference torque is obtained by calculating the difference between the reference rotating speed and the actual rotating speed through a PI regulator and a reference torque calculation module; the difference between the calculated torque and the reference torque is sent to a hysteresis comparator module; an output voltage of the hysteresis comparator is sent to a PWM module, a control signal capable of driving an inverter working bridge arm to work is generated and sent to a corresponding bidirectional thyristor, if the motor breaks down, the corresponding bidirectional thyristor is turned off so that the flowing torque is zero, the pulsation of the electromagnetic torque isoutputted in a minimum mode, normal work of other motors of the system is guaranteed, control performance is improved, and protection on the motor system is achieved.

Description

technical field [0001] The invention belongs to the technical field of DC motor fault-tolerant control, and in particular relates to a fault-tolerant control system and a control method of a series system of four DC motors. Background technique [0002] Direct torque fault-tolerant control has the characteristics of instantaneous torque control, and realizes direct control of motor torque; traditional direct torque fault-tolerant control uses more zero-voltage vectors continuously at low speed, which makes the switching frequency very low and the torque ripple large , it is impossible to obtain a more accurate mathematical model of the diagnosed object, and the robustness is poor; the fault diagnosis method based on the mathematical model is inaccurate and has a lot of interference. Fault diagnosis is also a difficult point. [0003] At the same time, due to the high power and high energy density of the power switch tube on the working bridge arm of the inverter, the failur...

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Problems solved by technology

[0004] Aiming at the technical problems existing in the prior art, the object of the present invention is to provide a fault-tolerant control system and control method for a series system of four DC motors, so as to solve the problems in the prior art that the torque ripple is large and accurate fault diagnosis cannot be realized, and the working inefficient technical issues

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