Performance Improvement for PMSM Driven by DTC Based on Discrete Duty Ratio Determination Method

Abstract

In order to improve the performance of the servo control system, which is composed ofthe permanent magnet synchronous motor (PMSM) driven by novel direct torque control based on the fixed sector division criterion (FS-DTC) utilizing the composite active vectors, a discrete duty ratio determination method (FS-DDTC) is proposed in this paper. The determination of the accurate duty ratio is the key to obtain the desired error compensational results for PMSM, which is related to the performance of the servo system directly. As the applied master vector and slave vector during each control period are the adjacent vectors, therefore, the direction of the synthetic vector is between the directions of the two applied active vectors. Additionally, the analytical relationship between the sector angle of the synthetic vector and the error rate, which can realize the determination of the discrete duty ratio value without complicated calculations is deduced first. Furthermore, the duty ratio values of the two applied active vectors in FS-DTC are obtained through the selections of the duty ratio scale in the novel discrete duty ratio determination method directly, which can simplify the calculation process of the accurate duty ratio values effectively. The effectiveness of the proposed discrete duty ratio determination method is verified through the experimental results on a 100-W PMSM drive system.

Control of PMSM Based on Switched Systems and Field-Oriented Control Strategy

“…The following equilibrium relation can be written around this operating point: The mathematical model of the PMSM is a nonlinear one, and is presented by the relations in the system (1) [5][6][7][8].…”

“…As a typical example of the static operating point, we can choose a state vector of the PMSM control system defined in the relation (7).…”

“…Common control strategies for PMSM include FOC and direct torque control (DTC) [5][6][7][8]. If the DTC strategy provides acceptable performance but with a relatively simple control system, the FOC strategy provides both superior control performance and a control structure that can be implemented in low-and medium-cost embedded systems.…”

Analysis of Core Loss of Permanent Magnet Synchronous Machine for Vehicle Applications under Different Operating Conditions

“…After considering the magnetic saturation effect, the dq-axis flux linkage of the motor changed nonlinearly with the current, and the harmonic content of the phase current was higher than the harmonic content without considering the magnetic saturation effect. Figure 4 shows the vector control system used in this section to analyze the core loss under different working conditions [24][25][26][27][28].…”

“…shows the vector control system used in this section to analyze the core loss under different working conditions[24][25][26][27][28].…”