A direct torque control method for hidden pole hybrid excitation motors for electric vehicles

Abstract

The invention discloses a direct torque control method for a non-salient pole type hybrid excitation motor for an electric vehicle. According to the method, on the basis of a partition control strategy for the hybrid excitation motor, set values of a stator magnetic chain and excitation current are calculated by a maximum torque current ratio algorithm in different running regions; a switch table is inquired according to the set value of the torque, the set value of the magnetic chain and difference values of respective feedback values to select a voltage vector, thus a switching state of a PWM (pulse width modulation) inverter is controlled and the direct torque control over the hybrid excitation motor is realized. According to the direct torque control method, on the premise of guaranteeing the basic running characteristic of the hybrid excitation motor, the direct torque control over the hybrid excitation motor is realized, the control system algorithm is simplified, and the torque response speed of the motor is increased. Compared with the conventional direct torque control method, the method has the advantages that in different running regions, the set value of the stator magnetic chain is calculated according to the maximum torque current ratio algorithm, the reactive component of armature current is reduced, and the efficiency of the motor and the torque output capacity are improved.

Description

technical field [0001] The invention relates to a direct torque control method of a hidden pole type hybrid excitation motor for an electric vehicle, belonging to the technical field of motor control. Background technique [0002] Hybrid excitation motor (HESM) has two excitation sources of permanent magnet and electric excitation winding, which inherits the advantages of high efficiency and power density of permanent magnet synchronous motor. Compared with permanent magnet synchronous motor, it has stronger magnetic field adjustment ability and torque The advantages of strong output capacity and wide speed range. [0003] At present, the vector control method based on partition strategy is generally used in the control of hybrid excitation motors. The vector control algorithm is complex and has a great dependence on the motor parameters, and the change of the parameters during the operation of the motor will cause a large error. Direct torque control (DTC) is a high-perfo...

AI Technical Summary

Problems solved by technology

In the traditional direct torque control method, the given value of the flux linkage is the rated value of the stator flux linkage. The advantage is that the stator core can be fully utilized. However, the reactive current component of the d-axis is relatively large under light load, which will increase the generation of the armature resistance of the motor. heat, resulting in a decrease in overall efficiency

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