Design And Realization Of Hybrid Wind/Photovoltaic Intelligent Generation System

Due to ever increasing energy crisis and environment degradation, there is a rising public awareness of environmental protection and progress in power deregulation. Wind and photovoltaic power generation are two of the most promising renewable energy technologies owing to many merits they have, such as zero or low emission and inexhaustibility. With the declining of cost, upgrading of industry technology and the support from government financial and policy, hybrid wind and photovoltaic intelligent power generation system (HWPIPG) will be the new hot spots of research and application of renewable energy, as a flexible and stable energy supply system.With the complementary characteristics between wind and photovoltaic, HWPIPG make the intermittent wind and solar energy adapt to daily application by the control of transformation, charging and storage. HWPIPG is composed of control system, storage system and related facilities. Because of the separated design of generation system, control system and storage system, the integrated system may not work stably. It also is a technology barrier in this area. Aiming at the realization of the practical HWPIPG that can control the generation and manage the whole systems, after the survey and analysis of the current research work, we present in this thesis our research on the problems of HWPIPG development and the maximum power point tracking(MPPT). The main contributions of this thesis are:1) The architecture and implementation of an intelligent control system is presented in this thesis. Firstly, a hybrid flexible modular structure is proposed, composed of generation control section, charging and discharging section and system monitor section. Secondly,the controller is implemented based on the function modules, making the system more flexible. Based on the modules design, an intelligent monitor system is developed to solve the compatibilities among the modules. Software modules are developed on microchip , performing some functions that hardware can do. The designed HWPIPG has properties of openness, reliability and flexibility.2) A highly efficient MPPT strategy for photovoltaic is presented. Based on the unchanged equivalent resistance, the relationship between solar power and voltage is deduced. It can be implemented only by voltage sensor by improving the traditional perturb and observe method. The simulation and experimental results show that the proposed control strategy can withstand rapid irradiation, and the system tracks the maximum power point very well.3) The charging and discharging strategies of the battery is studied. A circuit is developed that can performing charging and discharging currently. The flexible circuit modules make it possible to resize the HWPIPG without any adjustment, effectively extend the life of the battery.4) The switching power supply (SPS) with two-transistor forward is studied as well. Applying feedback control in SPS design, a method of developing the feedback of precision SPS using TL431 is developed, and an example is addressed to show the adaptability.