電氣專業(yè)畢業(yè)設(shè)計外文翻譯---快速交直流pwm整流感應(yīng)發(fā)電機系統(tǒng)的高性能控制（英文）

1、High Performance Control of A Boost AC-DC PWM Rectifier-Induction Generator System Jyoti Sastry, Olorunfemi Ojo, Zhiqiao Wu Department of Electrical and Computer Engineering/Center for Energy Systems Research Labor

2、atory for Electric Machines and Power Electronics Tennessee Technological University Cookeville, TN 38505, U.S.A Phone: (931)-372-3869, Fax: (931)-372-3436, E-mail: jojo@tntech.edu Abstract—This paper presents a cont

3、rol methodology for the dc voltage regulation of an induction generator-ac-dc- boost rectifier system in which the copper loss of the generator is minimized. With the aid of an input-output linearization technique, w

4、hich linearizes and decouples the model equations in the synchronous reference frame, a rotor flux vector control type high performance is achieved. Steady-state analysis provides some insights into the operability re

5、gime of the generator. The effectiveness of the control scheme under different load conditions as well as varying rotor speeds has been demonstrated by computer simulations. Some experimental results are include

6、d. Index Words: Induction generator, ac-dc PWM rectifier, excitation, input-output linearization, Butterworth polynomials, magnetizing flux saturation. I. INTRODUCTION Growing research and real application inter

7、ests in alternative energy systems such as wind energy has increased the use of the induction machine as a generator because of inherent advantages of such as low cost, reduced maintenance, rugged and simple construc

8、tion, brush-less rotor (squirrel-cage) and so on. The operation of an induction machine as a motor or generator is determined by the operating slip of the machine. A positive operational slip would indicate the oper

9、ation of the machine as a motor, and a negative slip would indicate the generating mode of the machine. It is well known that an induction machine can be made to work as a self-excited generator, i.e. the generator

10、can be excited by the (a) connection of three capacitors at the stator terminals of the machine (b) by using an inverter/rectifier system [1]. In the case of the inverter/rectifier system, the dc side capacitor appea

11、rs like three phase capacitors due to the switching signals of the inverter, and the single dc capacitor of the rectifier provides the required excitation for the induction generator. An extensive overview illustratin

12、g the vast amount of work done in different areas over the last 25 years such as self-excitation, voltage buildup modeling, steady state analysis of an induction machine has been presented in [2]. Also, in previously

13、 published work, the vector control of the induction generator rectifier system to produce dc power in which the rectifier also provides the excitation has been reported [3]. The system has been studied specifically

14、for applications related to wind energy, thereby studying the controller response for varying rotor speeds. Also the stability of an induction generator-rectifier under field orientation control has been studied in [4

15、], highlighting the possible instability of an induction generator used in high- speed applications. The control method adopted in this paper has been laid out in detail, illustrating the input-output linearization

16、 method used in separating the linear from the non-linear terms in the system model equations. The proposed control scheme has been tested for its effectiveness by varying load conditions as well as varying the rotor

17、speed of the machine. The machine has been operated at a condition of minimum copper loss [5]. The condition of minimum loss is achieved by regulating the command rotor flux using a loss minimization function. The s

18、teady state analysis deals with the operation of the self-excited generator under conditions of saturation [6]. The induction machine has been studied for its output power capability and the effect of the parameters o

19、f the machine on the operation of the machine under different load conditions. The analysis in this paper aims at highlighting the effect of the magnetizing flux on the excitation requirements of the system with the

20、 magnitude of the modulation signal as a measure of the required excitation. By fixing the magnetizing flux linkage the required modulation index for excitation of the machine can be determined. Along with the effect

21、 of saturation, the system has been studied under a condition of minimum copper loss. The organization of this paper is as follows; Sections II and III detail the models of the three-phase boost rectifier and induct

22、ion generator respectively. The model of the combined system has also been included in section III. Section IV deals with the steady state analysis of the IAS 2005 1007 0-7803-9208-6/05/$20.00 © 2005 IEEE IAS 2005

23、 1007 0-7803-9208-6/05/$20.00 © 2005 IEEEThe effect of magnetic air-gap flux linkage saturation is taken into account [6]. The analysis aims at determining the value of the magnitude of the modulation index requir

24、ed for the excitation of the generator, taking into account the effect of saturation and a condition of minimum total copper loss in the machine. Under saturated conditions, the magnetizing inductance varies with t

25、he magnetizing flux as shown in Figure 2 for a 2 hp induction machine. The reference frame transformation angle of the voltage equations assumes the alignment of the q-axis with the magnetizing flux linkage. Hence, th

26、e d-axis magnetizing flux is assumed to be zero, and the d-axis magnetizing inductance is constant. However the q-axis magnetizing inductance is a function of the magnetizing flux, which is approximated by a polynomi

27、al given in (13). 2 68 . 71 15 . 47 54 . 18 1m mmq L λ λ + ? = . (13) ( ) qdr s qds s sdc qds B p j T V M λ λ ω ? + ? = 2(14) ( ) qds r qdr s r B p j T λ λ ω + + ? = 0(15) ( )Ldc qs qds dc RV I M al CpV ? = * Re 23(16

28、) where ωs is the slip frequency defined as r e S ω ω ω ? = . DL r T r s s =DL r B m r r ? =DL r T s r r =DL r B m s s ? =2 m r s L L L D ? =Fig 2. Variation of the reciprocal of the magnetizing inductance with the mag

29、netizing flux. During steady-state, the derivatives, p in (14-16) are zero. Along with accounting for magnetic saturation of the air-gap flux linkage in the machine, the analysis aims at the operation of the machine a

30、t minimum total copper loss. The total copper loss (17) in the machine is minimum, when its derivative with the rotor slip is zero. This condition is achieved by appropriate selection of the operating slip of the mac

31、hine, given by equation (18). The slip is plotted as a function of the magnetizing inductance in Figure 3. Fig 3. Variation of the slip with the magnetizing flux. ( ) ( ) ( ) 2 2 2 2 loss copper 23dr qr r ds qs s I I

32、r I I r P + + + =(17) ( ) 112 222 max? +? =m r r sr sr L r L r r rs ω(18) To obtain a relationship between the magnitude of the modulation index (M) and the magnetizing flux, the stator currents in equation (16) are ex

33、pressed in terms of the stator fluxes. Rearranging equation (15) ( )qdss rr qdr j TB λ ω λ ?? =(19) Substituting equation (19) in (14) ( ) ( )? ?? ? ??? ? ?=s rr s e sdc qdsqdsj TB B j TV Mω ωλ2(20) The stator currents

34、 can be expressed in terms of the stator fluxes as: ( )qdss rm r r qds j T DL BDL I λ ω ? ?? ? ??+ ? =(21) Substituting (20) in (21) and eliminating the stator currents in (16), ( ) ( ) ( )2 3221 Re M Rj TB B j T j T

35、DL BDL alLs rr s e ss rm r r ? =? ? ? ? ???? ? ? ? ???? ?? ? ??? ? ?× ? ?? ? ??+ ?ω ω ω(22) Using equation (22) the effect of the changing magnetizing flux on the magnitude of the modulation index is obtained unde

36、r a condition of minimum copper loss. The magnetizing flux linkage is varied and the corresponding values of magnetizing inductances are calculated. Using the values of the magnetizing inductances, the slip and the c