Mixed excitation synchronous motor current optimization method based on zone control

Abstract

The invention discloses a mixed excitation synchronous motor current optimization method based on zone control. The method includes a control method in which in a starting and accelerating process, output torque of a low-speed zone is controlled to be maximum, and after a steady state is entered, copper loss is minimized; and a control method in which given values of currents i<d>, i<q> and i<f> of a high-speed flux weakening zone are controlled in a coordinated manner, and improvement of a maximum speed of the motor and minimum copper loss are taken into account. The mixed excitation synchronous motor current optimization method based on zone control designed by the invention substantially solves the problem that in a traditional control method of a low-speed zone, in starting and stable operation, output torque is limited when copper loss is controlled to be minimum, and copper loss is increased when output torque is maximum; solves the difficulty of simultaneous realization of improvement of a maximum rotating speed and reduction of copper loss in a high-speed flux weakening zone; and solves the problem that a coordination control algorithm of the given values of the currents i<d>, i<q> and i<f> of the high-speed flux weakening zone is complicated, simplifies an algorithm of given optimized current, and omits a large number of equation solving operations.

Description

Technical field: [0001] The invention relates to a hybrid excitation synchronous motor current optimization method, which belongs to the hybrid excitation synchronous motor control technology. Background technique: [0002] Permanent magnet synchronous motor (PMSM) uses permanent magnet as a single source of magnetic potential, which makes it difficult to adjust the air gap magnetic field in the motor. Hybrid excitation synchronous motor (HESM) introduces a set of excitation windings on the basis of PMSM, which makes it have permanent magnet synchronous motor. Advantages of high motor power density and easy field adjustment of electric excitation motors. Coordinating the control of armature current and excitation current can achieve the goals of low-speed large torque output and high-speed wide speed regulation range, which has broad application prospects in the field of electric vehicles. Therefore, the research on HESM current coordinated optimal control can improve the r...

AI Technical Summary

Problems solved by technology

In the high-speed area, the maximum output torque is the maximum target, i d = 0, under the premise of satisfying the voltage and current equation, the excitation current and the quadrature axis current i q is the maximum value, so that the output torque is maximized, but this method ignores the copper loss control of the motor, and does not use the direct axis current i d In the high-speed area, keep the quadrature axis back electromotive force unchanged, and use the incomplete copper loss formula to control the copper loss to the minimum. However, this method involves a large number of formula calculations, is greatly affected by parameters, and the output torque is reduced.

[0004] Therefore, in the existing control strategies, the coordination between the minimization of copper loss and the improvement of dynamic performance is ignored in the low-speed region, and the i d with i f Coordinated field weakening, or there are a large number of formula calculations to achieve a single goal of maximum torque or loss reduction, which fails to maximize the performance of the motor

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