page 1 國立交通大學電力電子晶片設計與 DSP 控制實驗室 Power Electronics IC Design & DSP Control Lab., NCTU, Taiwan 年 10 月 13 日 賴 逸 軒賴 逸 軒 國立交通大學 電機與控制工程研究所 Filename: \PMSM-01 ： Hall-Sensor Control\ 【論文選讀翻譯】 \1997.New approach for high-performance sensorless PMSM drives ( 插圖 ).ppt Sensorless PMSM Drives POWERLAB NCTU 電力電子晶片設計與 DSP 控制實驗室 Power Electronics IC Design & DSP Control Lab. 台灣新竹交通大學 電機與控制工程研究所 J. S. Kim and S. K. Sul, “ New Approach for High-Performance PMSM Drives without Rotational Position Sensors, ” IEEE Trans. Power Electron., vol. 12, no. 5, pp , Sep

page 2 New Approach for High-Performance PMSM Drives without Rotational Position Sensors 電力電子晶片設計與 DSP 控制實驗室 Power Electronics IC Design & DSP Control Lab. 國立交通大學 電機與控制工程研究所 Power Electronics IC Design and DSP Control Lab., NCTU, Taiwan IEEE Trans. Power Electron., vol. 12, no. 5, pp , Sep

page 3 Fig. 1. Space-vector diagram of the PMSM N S B Phase A Phase C Phase Equivalent 2-phase motor model Model on the synchronous reference frame The exact actual rotor angle Δθ r is NOT available in the drives without position sensors!!! The estimation angle Δθ e in adopted.

page 4 Fig. 2. Timing diagram of the electrical steady-State operation k = 12312k = 1 Speed Control Estimation Speed Control Estimation Interval (n = 1) (n = 2) Time Estimation Sampling Current Sampling Current i*[1] i*[2] 0 0 i*[n] The main idea of Electrical Steady-State operation concept is to remove the current dynamics within certain period to find out the back-EMF information.

page 5 Fig. 3. Back-EMF constant compensator PI (estimation) (setting) Idea : The long-term average value of has the same value as the actual rotor speed in steady state.

page 6 Fig. 4. Overall control structure of the proposed sensorless algorithm 1 11 L.F. Eq.(17) L.F. 0Hz 20Hz   L.F. 50Hz Z1Z1 Speed Controller Current Controller (PI+SVPWM)  Compensator 

page 7 Fig. 5. Experimental system setup IGBT inverter TMS320C30 DSP Controller PMSM Dynamo meter Oscilloscope V dc IbIb IaIa

page 8 Fig. 6. Angle-estimation performance of the proposed scheme The d-axis current is not perfect zero because of the nonlinearity of the control scheme: the control angel is fixed to constant value in one estimation interval while the actual rotor angle slightly moves during that period.

page 9 Fig. 7. Step response of the proposed scheme 1.The machine is initially running at constant speed of 50 rpm under full load condition. 2.The speed command is changed instantaneously from 50 rpm to 2000 rpm and back to 50.

page 10 Fig. 8. Speed-reversing response of the proposed PMSM sensorless drives High-Speed Case Low-Speed Case

page 11 Fig. 9. Starting capability of the proposed algorithm  If the initial angular difference is less than electrical 80°, the stable starting performance can be obtained in the case of half-load condition.  If the load tends to increase according to the machine speed, a special start-up algorithm is not necessary.  When the machine is under full-load condition at a standstill, the initial rotor angel should be detected through certain algorithm for stable starting. different initial angular difference

page 12 Fig. 10. Parameter dependency L s is detuned to 50% R s is detuned to 50% As described, the angle estimation is not affected by the parameter uncertainties. However, in the case of the detuned resistance, steady-state error of about 100 rpm occurs in the loaded operating condition with 1000 rpm reference. Small speed estimation error due to slight in accuracy of the parameter can be automatically neutralized by action of the back-EMF constant compensator.

page 13 Fig. 11. Back-EMF compensation performance Compensation ON When the compensating action starts at 1 sec. This error in gradually removed by the proposed algorithm and the actual speed follows the speed command accurately after several seconds.