光伏

Absfrmf-Distributed generation (DG) system ranging in s h e from a few kilowatls up lo 50 M W refers lo a variety of small, modular power-generating technologies connected to the electric grid which combined with enerw management and storage systems to improve the operation of electricity delivery systems. DG provides solutions to two long standing problems of power non-availability Bt all times of sumcient system nower eeoeration lo meet neak demands and the lack of ispacityof existing transmission Lines IO carry SII the electricity needed by consumers. Installing DG at or near II customer load can eliminate the need to upgrade existing transmission and distribution networks lo handle the extra power requikneot. The paper presents a model of the photovoltaic fuel generator (PVFC) for locaked load management. Results obtained for dynamic and steady-state characteristics are presented and discussed. Photovoltaic systems employ direct current motors; therefore understanding of the system operation and the matching of the system components for a particular PV system, de motor type, sod load lype are important factors of this system design. The performance of de motor powered by PV generator connected the load, were analysed with respect to the transient (starting) and steady state operation. Since the PV generator is a non-linear and time dependent power supply with output that varies with the insolation (hourly and daily). In all cases the de motor load is more compatible with the PV generator.
IEEE AFRICON 2004
735
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Model of a Photovoltaic Fuel-Cell Generator
Elias F.M. Kheswa and Innocent E. Davidson, Senior Member, IEEE PV generators are modular power-generating technologies which has the advantage that more units can he added if the load increases. More recently, the PV generator systems are behe used to suonlement the conventional vower eeneration. Their advantage is that they can be locatedclose ; the sites o located near the where electricity is to be consumed. end-user, they can reduce transmission and distribution costs and, under Some cucumstances3 provide with peak load high quality power and increase reliability of electrical Services delivered. Several authors have discussed various aspects of the steadystate performance of dc motors operated from a PV generator. Maltin [I] already demonstrated the feasibility of using a solar PV IO drive water pumping units for irrigation and drinking water in remote areas. [2] analyzed a water pumping system driven by a permanent magnet d.c. motor. Fam and Balachander [3] examined the dynamic performance of a d.c shunt motor connected to a PV array. Appelbaum and Bany [4] presented the case of a separately excited motor driving a mechanical load. Braustein and Komfeld [5] analysed the problem of a series motor driving a water pump. Roger [6] also compared the steady state performance of various types of dc motors connected to a PV array. There is however limited information about the modeling and dvnamic oerformance of a ohotovoltaic fuel cell IPVFC) generator system coupled to a universal motor. This paper examined and describes a mathematical model of a PVFC eenerator couoled to a load. which is a dc universal motor. A comparative analysis for the dynamic response of this motor under dc and Photovoltaic generator are presented. A detailed study model has been proposed and the design for PV generator. Experimental studies can be found in literature [1-6]. The system (see figure3) consists of a PV system generator, a dc motor and a mechanical load. In this arrangement the PV generator is directly connected to the motor load without batteries. The operation of the lype of the motor was also analyzed. The study also addresses itself to the PV generator current and voltage, and load. The I-V and P-V characteristics of the generator were determined for various insolation levels (in percentages). It should mention that the PV generators is nonlinear and time dependent current s o m e , therefore it is expected that supplied constant voltage. Figure 1, illustrates the PV panels on the roof of University of Natal, and figure 2, shows a schematic block diagram of a photovoltaic fuel cell hybrid energy system.
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Inder Terms-Photovoltid Energy systems, Dynamic modelling. Distributed Generation
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1. INTRODUCTION LECTRICITY demand by domestic and commercial loads continues to experience growth. These categories and types of load require more efiicient load control and energy management techniques to optimize energy costs. With the deregulation of the electricity industry (ESI), new approaches to electricity delively and demand side management @SM) need to be investigated to satisfy customer demand for localized control of energy services. With ESI deregulation, new opportunities arise for distributed generation @C) integration and distributed energy management @EM) to cater for increasing customer demands for custom-power solutions. There are a variety ways to generate power; another option is the photovoltaic fuel cell which can be proposed as solution to generate power to meet the demand. These power sources are able to supply the energy needs of homes, communities reliably when accessed and designed correctly.