光伏發(fā)電外文翻譯--光伏發(fā)電控制電路模塊（原文）

1、IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 16, NO. 3, MAY 2001 293Generation Control Circuit for Photovoltaic ModulesToshihisa Shimizu, Member, IEEE, Masaki Hirakata, Tomoya Kamezawa, and Hisao WatanabeAbstract—Photovo

2、ltaic modules must generally be connected in series in order to produce the voltage required to efficiently drive an inverter. However, if even a very small part of photovoltaic module (PV module) is prevented from recei

3、ving light, the genera- tion power of the PV module is decreased disproportionately. This greater than expected decrease occurs because PV modules which do not receive adequate light cannot operate on the normal oper- at

4、ing point, but rather operate as loads. As a result, the total power from the PV modules is decreased if even only a small part of the PV modules are shaded. In the present paper, a novel circuit, re- ferred to as the ge

5、neration control circuit (GCC), which enables maximum power to be obtained from all of the PV modules even if some of the modules are prevented from receiving light. The pro- posed circuit enables the individual PV modul

6、es to operate effec- tively at the maximum power point tracking, irrespective of the se- ries connected PV module system. In addition, the total generated power is shown experimentally to increase for the experimental se

7、t-up used in the present study.Index Terms—AC interactive inverter, multistage chopper, pho- tovoltaic module.I. INTRODUCTION RECENTLY, awareness of the importance of protecting the global environment has been growing, l

8、eading to calls for progress in the effective use of energy in various fields. As a result, not only methods for saving energy, but also the devel- opment of the new energy sources has been investigated. PV cells are cur

9、rently considered to be a new energy source, and a great deal of research has been conducted in this field over the last few decades. As a result, the major disadvantages pre- viously associated with the application of P

10、V power genera- tion, such as initial cost, generation efficiency, and reliability, no longer present such a significant problem. PV generation is a flexible power generation method which is applicable in both small and

11、large power generation plants, i.e., plants that gen- erate anywhere from less than 3 kVA to over 100 kVA. In recent years, interest in small PV power generation systems designed to be installed and used in the house has

12、 grown. However, es- pecially in urban areas, various problems limit the effectiveness and economic feasibility of PV power generation. When a typ- ical urban home is equipped with a PV power generation system,Manuscript

13、 received November 15, 1999; revised February 3, 2001. Recom- mended by Associate Editor K. Smedley. T. Shimizu is with the Department of Electrical Engineering, Tokyo Metropolitan University, Tokyo 192-0397, Japan (e-ma

14、il: shimizu@eei. metro-u.ac.jp). M. Hirakata is with the Fuji Electric Company, Ltd., Mie 513-0816, Japan (e-mail: hirakata-masaki@fujielectric.co.jp). T. Kamezawa is with the Hitachi Company, Ltd., Chiba 275-8611, Japan

15、 (e-mail: kame@gm.narashino.hitachi.co.jp). H. Watanabe is with the Toshiba Company, Ltd., Tokyo 183-0043, Japan (e-mail: hisao@wta.att.ne.jp). Publisher Item Identifier S 0885-8993(01)04043-1.Fig. 1. Series and parallel

16、 connection of photovoltaic modules. (a) Series connection. (b) Parallel connection.the PV modules are normally installed on the roof. Thus, in ad- dition to shadows created by clouds, those created by neigh- boring home

17、s, trees, utility and/or telephone poles, and power line cables sometimes partially cover these PV modules. In con- ventional PV power systems, these shadows lower the overall generation power to a larger degree than was

18、 initially expected. Thus, the construction cost is increased, because the number of PV modules installed on the roof must be increased, and as a result, PV power generation will be less attractive. Therefore, the presen

19、t authors developed a new circuit, called the genera- tion control circuit (GCC), which maintains generation power even when some of the PV modules are shaded from light. In this method, GCC controls individually the ope

20、ration point of each of the PV modules, including the shaded PV modules, so as to generate the maximum power for each of the modules. As a result, the decrease in the total generation power is minimized. In the present p

21、aper, the characteristics and problems associ- ated with parallel-connected and series-connected PV modules are discussed. Next, the principle by which the generation con- trol circuit operates is presented in relation t

22、o solving the above mentioned problems. Two types of practical circuit configura- tions for GCC are proposed and the control schemes of these configurations are described. In addition, the effectiveness of the proposed c

23、ircuit is confirmed experimentally [1]–[4].II. CONNECTION METHODS OF PV MODULES AND ASSOCIATED PROBLEMSA. Connection MethodsIn the PV power generation system, multiple PV modules are generally connected in series, as sho

24、wn in Fig. 1(a), in order to0885–8993/01$10.00 © 2001 IEEESHIMIZU et al.: GENERATION CONTROL CIRCUIT FOR PHOTVOLTAIC MODULES 295the -axis (for example, , and ), and the – curve of each PV module. When the output cur

25、rent of the PV system is increased from zero to the maximum current, the operation point of each PV module moves as indicated in Fig. 3(b),for PV and for PV . This opera- tion characteristic reveals that not only the non

26、shaded modules, but also the shaded module, can operate in the area where each PV module can generate power. Hence, the total output power characteristics of these PV modules, the – curve, is obtained as shown in Fig. 3(

27、b). Then, the total output power, , is given by(1)where, : generation power on PV , : generation power on PV . If each voltage is equivalent at the maximum power point, the output power, , obtained at the maximum power p

28、oint, in this case point , becomes(2)where, and are the maximum power on PV and PV , respectively.C. Operation in Series-Connected PV ModulesFig. 4(a) shows the typical – curve for PV modules con- nected in series for th

29、e same conditions shown in Fig. 3(a). In series connection the generation current is the same for each PV module. Therefore, the operating point of each PV module is given by the point of intersection of the operation li

30、ne, parallel to the -axis (for example, , and ), and the –curve of each PV module. When the output current of the PV system is increased from zero to the maximum current, the op- eration point of each PV module moves as

31、indicated in Fig. 4(a),for PV andfor PV . On operation line , the shaded PV module, PV , gener- ates its maximum power, but the nonshaded module, PV , does not generate its maximum power yet. When the operation line move

32、s to , the operation points of each module PV and PVmove to and , respectively, and the generation power on PV increases. However, the operation point of PV , , moves to the negative voltage region because the current ge

33、n- erated from PV flows through the bypass diode connected in anti-parallel with PV , and the resultant generation power on PV becomes negative. This means that the shaded PV module cannot generate any power and causes a

34、 power loss. On oper- ation line , the nonshaded PV module, PV , generates the maximum power, , but the shaded module, PV , cause a power loss . Hence, the output power, , on this system is decreased to(3)The total outpu

35、t power characteristic of this PV system, the – curve, is obtained in the same manner and is shown in Fig. 4(b). Two peaks in power exist, but the output powers atFig. 4. Generation characteristics for two series-connect

36、ed PV modules. (a) I–V characteristics. (b) P –V characteristics.these peak points are much smaller than that of the parallel con- nected condition shown in Fig. 3(b). Although only two-PV module connection is described

37、in the present paper, the mechanism by which power reduction occurs for multiple PV modules that are connected in series is similar to that for two-PV module connection.III. GENERATION CONTROL CIRCUIT (GCC)A. Operation P

38、rinciples of the Generation Control Circuit (GCC)Fig. 5(a) and (b) show the operation principles of the pro- posed generation control circuit, in which PV modules are connected in series. The GCC has multiple voltage sou

39、rces, to , and the sum of these voltage, to , is equivalent to the output voltage, , on the system. Also, voltage sourcesthrough are connected in parallel to PV modules PVthrough PV , respectively. For the circuit shown

40、in Fig. 5(a), not only the output power of this system but also the power for GCC are always supplied from the output terminal on the se- ries connected PV module. However, for the circuit shown in Fig. 5(b), the voltage

41、 source, from to , on GCC gener- ates the positive or negative output power in two ways because input terminals, such as and in Fig. 5(a), do not exist. Therefore, while some of these voltage sources generate pos- itive