Control method for directionally correcting rotor field of asynchronous motor

Abstract

The invention discloses a control method for directionally correcting a rotor field of an asynchronous motor, and belongs to the field of motor speed regulation. The method is characterized by comprising the step of: forming a closed loop by dot products of stator flux linkage vectors and stator current vectors to directionally control and correct the magnetic field so as to realize complete uncoupling of torque and flux linkage. The method disclosed by the invention solves the problem of inaccurately directing the rotor filed caused by inaccurate parameters, so that the performance of vector control of the asynchronous motor is improved. A novel asynchronous motor decoupling control method is found, so that the control performance of the asynchronous motor is more approximate to that of a current motor.

Description

technical field

[0001] The invention relates to the application of a vector control system in the field of drive control of asynchronous motors, such as the application of cage-type asynchronous motors in electric vehicles and the like. Background technique

[0002] With the reduction of non-renewable energy sources such as petroleum, it is necessary to find a substitute for petroleum. Electric vehicles use electric drive to solve the impact of the oil crisis on the automotive industry. Asynchronous motors are widely used in the drive field of electric vehicles, which has promoted the vigorous development of new energy vehicles. Asynchronous motors often adopt a vector control algorithm based on rotor field orientation. Vector control decouples the excitation current of the asynchronous motor from the torque current, thereby decoupling the flux linkage and torque, and obtaining the same speed control performance as a DC motor. However, motor parameters change with operatio...

Examples

Embodiment

[0083] In order to highlight the advantages of this algorithm, a comparative experimental study was carried out on a 15kW asynchronous motor. The rated voltage of the motor used is 180V, the rated current is 80A, the rated frequency is 120Hz, and the number of pole pairs is 2. The controller is composed of DSP28335. The switching frequency is 2kHz and the dead time is 6 microseconds. The field-oriented correction method based on reactive power closed-loop and this method are used for experimental comparison.

[0084] first given i sq_ref is 0, given i sd_ref The rated excitation current is 35A, and the motor is controlled to run at different frequencies. Use a voltage probe to record the effective value of the stator voltage of the motor, and draw a curve, such as Figure 6-8 The no-load curve in . because i sq_ref =0, the basic synchronous frequency It can be seen that the motor orientation is not affected by the motor rotor time constant T r The motor terminal volta...

technical field

[0001] The invention relates to the application of a vector control system in the field of drive control of asynchronous motors, such as the application of cage-type asynchronous motors in electric vehicles and the like. Background technique

[0002] With the reduction of non-renewable energy sources such as petroleum, it is necessary to find a substitute for petroleum. Electric vehicles use electric drive to solve the impact of the oil crisis on the automotive industry. Asynchronous motors are widely used in the drive field of electric vehicles, which has promoted the vigorous development of new energy vehicles. Asynchronous motors often adopt a vector control algorithm based on rotor field orientation. Vector control decouples the excitation current of the asynchronous motor from the torque current, thereby decoupling the flux linkage and torque, and obtaining the same speed control performance as a DC motor. However, motor parameters change with operatio...

Examples

Embodiment

[0083] In order to highlight the advantages of this algorithm, a comparative experimental study was carried out on a 15kW asynchronous motor. The rated voltage of the motor used is 180V, the rated current is 80A, the rated frequency is 120Hz, and the number of pole pairs is 2. The controller is composed of DSP28335. The switching frequency is 2kHz and the dead time is 6 microseconds. The field-oriented correction method based on reactive power closed-loop and this method are used for experimental comparison.

[0084] first given i sq_ref is 0, given i sd_ref The rated excitation current is 35A, and the motor is controlled to run at different frequencies. Use a voltage probe to record the effective value of the stator voltage of the motor, and draw a curve, such as Figure 6-8 The no-load curve in . because i sq_ref =0, the basic synchronous frequency It can be seen that the motor orientation is not affected by the motor rotor time constant T r The motor terminal volta...

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