Fractional order based control system and control method for direct torque of permanent-magnet synchronous motor for electric vehicle

Abstract

The invention provides a fractional order based control system and a fractional order based control method for direct torque of a permanent-magnet synchronous motor for an electric vehicle, so as to effectively adjust a speed loop of the control system for the direct torque of the permanent-magnet synchronous motor. The control method includes the steps: firstly, detecting three-phase current, voltage and inverter direct-current bus voltage which are outputted by an inverter, obtaining electromagnetic torque, stator flux linkage and a stator flux linkage sector theta at the current state by torque, flux linkage and theta calculation units, comparing the calculated flux linkage and torque with a given flux linkage and given torque signals outputted by a fractional order adjuster respectively, outputting the current flux linkage error and torque error states, determining a selected voltage vector by the states and the sector of the flux linkage together to determine on-off state of the inverter so that the permanent-magnet synchronous motor is controlled, wherein the speed loop adopts fractional order PIepsilon Dmu control. The control system has the advantages of simple structure, novel conception, rapidness in response and the like, and the control method has the advantages of wide control range, high precision, rapidness in response and the like as the speed loop adopts fractional order PIepsilon Dmu control.

Description

technical field [0001] The invention belongs to the technical field of AC motor transmission, and relates to a direct torque control system and method of a permanent magnet synchronous motor for electric vehicles based on fractional order. Background technique [0002] The energy and environmental issues and the financial crisis faced by the automobile industry have made the research on electric vehicles attract extensive attention from all over the world. In addition to showing superiority and strong competitiveness in energy environmental protection and energy saving, electric vehicles also show huge advantages in vehicle performance. The torque response of electric vehicles is fast and the acceleration is fast, which is 2 orders of magnitude higher than that of fuel vehicles. The motor can be configured in a decentralized manner, and the wheel speed can be directly controlled by wire transmission electronic control technology, which can easily realize four-wheel independe...

AI Technical Summary

Problems solved by technology

However, as an emerging control method, direct torque control has the problems of severe flux linkage and torque ripple, and poor low-speed performance.

Images