An analysis of permanent magnet synchronous motor drive

Abstract

Permanent magnet (PM) excited synchronous machines have shown increasing popularity in recent years for the industrial drive applications due to the recent developments in magnetic materials, power converters, and digital signal processors. The control of a high performance permanent magnet synchronous motor drive for general industrial application has received wide spread interest of the researchers. Interior permanent magnet synchronous motor drives are widely used in high performance applications. In these applications, the drive speed should follow accurately a certain command trajectory and recover from sudden load disturbances very fast. The precise control of the permanent magnet synchronous motor is necessary where the dynamic responses greatly affect the quality of the products. -- In this thesis, a complete permanent magnet synchronous motor (PMSM) drive system fed by a PWM voltage source inverter is developed. The design of multi-loop control for the interior permanent magnet synchronous motor drive for high performance application is introduced. Speed controller using synchronous reference frame proportional integral (PI) regulator is employed as an outer loop. Moreover, two synchronous frame PI regulators are employed as inner loops to control the direct and quadrature axis current components of the motor. Implementation of the current controllers in the synchronous reference frame ensures independency of the controllers on the cross coupling between the d-q axis and gives superior performance. The controllers are based on the indirect field oriented control. A systematic mathematical formulation is presented for designing motor controllers. The control scheme is implemented using a high speed digital signal processor (DSP). The experimental results validate the theoretically simulated speed responses with different dynamic operating conditions. These results illustrated the efficacy of the proposed multi-loop control of the PMSM drive.