Vehicle built-in permanent magnet synchronous motor controlling method

Abstract

The invention provides a vehicle built-in permanent magnet synchronous motor controlling method. The method comprises steps of 1, establishing permanent magnet synchronous motor mathematic models including a voltage equation model, an electromagnetic torque equation model and a torque balance equation model; 2, designing a sliding mode surface and a sliding mode control law, so as to achieve sliding mode control of the electromagnetic torque of a motor; 3, based on the electromagnetic torque value Te, performing decomposition to obtain a quadrature-axis current iq and a direct-axis current id; 4, based on iq, id, Udc, quadrature-direct axis voltage references U'q and U'd, obtaining quadrature-direct axis current reference values i<*>[q] and i<*>[d] by decomposition; 5, decomposing i<*>[q] and i<*>[d] to obtain the quadrature-direct axis voltage references U'q and U'd; and 6, based on the U'q and U'd, obtaining two phase stationary voltages U[alpha] and U[beta] by coordinate conversion, taking the U[alpha] and U[beta] as the input, and obtaining three phase reference voltages Ua, Ub and Uc after modulating the models to drive an inverter and the motor to work. The control method can ensure stable operation of the motor under any working condition.

Description

technical field [0001] The invention relates to the field of electric vehicle control, in particular to a control method for a vehicle-mounted built-in permanent magnet synchronous motor. Background technique [0002] The built-in permanent magnet synchronous motor has the advantages of wide speed range, high torque current ratio, high power density, high efficiency, high power factor and low noise, and is currently widely used in industrial fields such as electric vehicles. The basic requirements of the vehicle built-in permanent magnet synchronous motor drive system are: at low speed, it is required to output large torque to meet the performance requirements of starting, acceleration and climbing; , Overtaking and other performance requirements. [0003] The common maximum torque-to-current ratio control methods for vehicle built-in permanent magnet synchronous motors in the low-speed constant-torque operation stage include table look-up method and curve fitting method. ...

AI Technical Summary

Problems solved by technology

However, this method does not consider the current reverse situation. When the speed or load torque is negatively given, the system will be out of control when the motor current is reversed; and the current amplitude is not limited. When the voltage rise causes the current adjustment System performance will degrade rapidly when the controller goes into saturation

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