外文翻譯---關于交流伺服驅動器的死區(qū)效應的分析與補償

1、外文資料原文 外文資料原文Analysis And Compensation Of Dead TimeEffectsFor The AC Servo DriverHaitao Qin1, Anwen Shen2, Qiao Zhang3,Wenyu Wang4Department of Control Science and Engineering, HuaZhong University of Science and Technolo

2、gy, ChinaAbstract—A on-line dead time compensation method for the alternating current (AC) servo is proposed. By apply the Fast Fourier Transform (FFT) to the compensating voltage in one period of three phase output cur

3、rent, without any additional hardware, the dead time effects is eliminated by compensate the 1th, 5th, 7th harmonic components only. The results of simulations and experiments well demonstrate the effectiveness of the pr

4、oposed method.Index Terms--AC-Servo, Dead-Time Compensation,Permanent magnet synchronous motor (PMSM).I. INTRODUCTIONFor the storage effect of power device, it’s very necessary to set a dead-time on both switches in

5、 an inverter leg to avoid the shoot-through in the dc-link. According to the Insulated Gate Bipolar Transistor’s (IGBT) performance, we usually set the dead time as 2~5us, this distorts the voltage source inverter’s (VSI

6、) output voltage, resulting in phase current distortions, torque ripples and degradations of control performance. To overcome the dead-time effect, various approaches have been studied and applied. Conventionally, erro

7、r voltage due to the dead-time effect can be pre-calculated and compensated by adding them to the 3-phase reference voltage according to the phase current polarity[1-2]. A on-line compensation method is presented in [3]

8、, compute the error voltage by compare the reference voltage with the real voltage, and then add this to next reference voltage as the new reference. In this approach, the error voltage which caused by many reasons suc

9、h as dead-time, dc-link voltage drops, etc can be eliminated. However, estimation of the real voltage should use the parameter of motor which are not fixed value but varying while at working. In [4], dead-time effect is

10、 compensated by modified PWM gate signals with hardware circuits. In [6], a method which change the PWM gate signal on-line based on the polarity of phase current is presented. All the approaches mentioned above can el

11、iminate the deadtime effect greatly and have a good performance, however, with the increase of complexity of the software and hardware, which restrict the practicability.Thus, In the paper, a method based on the 2-phase

12、 stationary frame is proposed. The proposed method produces the compensating signal by use the phase of the current only, does not need any additional hardware circuits.Figure.2. practical switching pattern considering

13、 the dead-time and turnon/off time of switching devices. (a) ideal gate signal patterns. (b)practical signal patterns considering the dead-time. (c) actual outputvoltage considering the dead-time and switching timeThe av

14、erage error voltage can be calculated from Figure.2 as in (1):(1)d ad aU if i 0 U U if i 0 ? ?? ? ? ? ??? ? ?，，Where , . d dcsT U U T? ? ? d on off T T t t ? ? ? ?According to (1) , the most obvious impact of de

15、adtime effect is lower the output voltage, resulting in harmonics in phase current, torque ripple and speed fluctuation, especially in low speed.II. COMPENSATION OF DEAD-TIME EFFECTThe main principle of the compensation

16、is produce a same amplitude and opposite sign voltage with the error voltage to decrease or eliminate the effect of dead-time. From (1), amplitude of the error voltage which depend on dead-time, switch period, switching

17、 time and dc-link mvoltage is fixed for off-line compensation. The key of compensation is to judge polarity of the phase current. It’s difficult to judge the polarity of phase current accurately in the real control syst

18、em, however, and the ambiguity at the zero point of phase current will deteriorate the compensation effect. Thus, in this paper, a compensation method which depend on the phase of current only in the 2-phase stationary (

19、α /β ) frame is proposed. The error voltage depend on the polarity of phase current, so three phase current will have six different combinations of the error voltage vector. Table.I shows ,the error voltage and it’s ve

20、ctor at different polarity of three phase current, where . 1 , 2 2 3 2 3 d d K U K U ? ? ? ?TABLE IERROR VOLTAGE VECTOR ACCORDING TO THE POLARITY OF THREEPHASE CURRENTFigure.3 shows the compensation voltage vecto