PMSM vector control system is widely used in servo systems and speed regulating systems. In this paper, the application problems of PMSM vector control system are discussed. The AC parameters in the three-phase static coordinate are transformed into DC value in the two-phase rotated coordinate by coordinating transformations. The control process is simplified. The PMSM is virtualized as a separately excited DC motor using the control method of i d = 0. Six PWM signals are generated to control IPM module using SVPWM algorithm. Finally, the PMSM vector control system is realized, which is composed of TMS320F2812, photo-electricity encoder, hall current sensors and IPM module. It is demonstrated that the system has a good dynamic performance and steady-state precision.

and the US-based Prime Group, both sponsored by the China-United States Exchange Foundation (CUSEF), conducted parallel public opinion surveys on how Chinese view the United States and how Americans view China, respectively. The Chinese study divided the respondents into two groups-the Chinese public and Beijing experts, and the US polls also sent questionnaires to both the US public and Washington experts. This article highlights the findings of Chinese and US surveys, compares the perceptions of individuals in China and the US of each other and bilateral relations, and explores the background of and reasons behind those perceptions.

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