A composite speed controller based on a second-order model of permanent magnet synchronous motor system

Abstract

The speed-regulation problem for a permanent magnet synchronous motor (PMSM) servo system is studied in this paper. In traditional control design for a speed loop, a first-order model is used to approximately describe the relationship between the reference quadrature axis current and the speed output, i.e. the reference quadrature axis current is regarded as the same as the quadrature axis current. This approximation degrades the closed-loop performance of PMSM system when using a vector control scheme. To this end, a second-order model is built to describe the relationship between the reference quadrature axis current and the speed output for a PMSM system. Based on this second-order model, a standard sliding mode controller is designed for the speed loop. Then, to reduce the chattering and improve the performance of the system, a composite controller consisting of a sliding mode feedback part and a disturbance compensation part based on an extended state observer are developed. Simulation and experiment results and comparisons are given to show the effectiveness of the proposed method.

Robust Speed Control of PMSM Using Sliding Mode Control (SMC)—A Review

“…The dynamic response of a closed loop system can be improved by using nonlinear sliding surfaces. For PMSM speed control, several works have been executed using linear SMC, but the drawbacks of linear SMC were overcame by means of hybridization to develop a composite SMC controller [8,43,44] or modification of the reaching law [11].…”

“…However, in practical applications, the upper bound of disturbances is hard to obtain. Hence, a high value of the switching gain is normally chosen to ensure disturbance rejection, which case will result in unwanted large chattering [8]. Several methods have been proposed to deal with this issue.…”

“…In the speed-current cascaded control structure, the relationship between the speed output and the reference quadrature axis current are usually described by a first-order model. However, considering the possibility that the closed-loop performance might degrade due to vanishing relative differences in control periods between both loops, second-order model relationships were also proposed [8]. For high speed applications of PMSMs, integrated speed and current controllers were used to solve the problem of nonlinear coupling between speed and current [9].…”

“…Various nonlinear control methods have been proposed to enhance the speed control performance of PMSMs in different aspects. These methods include sliding mode control [1,4,8,11,12], predictive control [13,14], backstepping control [15], adaptive control [15][16][17][18][19], H∞ control [20], automatic disturbance rejection control [21] and artificial intelligence incorporated controllers [12,22].…”

Direct torque controlled space vector modulated method for line start permanent magnet synchronous and induction motors

“…For this reason, a typical Direct Torque Controlled Space Vector Modulated (DTC-SVM) scheme, providing a fixed switching frequency, is hereby designed for both LSPMSM and induction motors. However, this popular method has also been analyzed, developed, and improved during the past decades (Arab Markadeh et al, 2011;Jidin et al, 2012;Shihua et al, 2011;Uddin and Hafeez, 2012;Vas, 1998;Yongchang and Jianguo, 2011;Yongchang et al, 2012). For example, in Arab Markadeh et al (2011), brain emotional learning based intelligent controllers have been designed for controlling torque and flux parameters.…”