Research Of Low-Power Photovoltaic Inverter For BIPV System

As the world's energy shortage and environmental pollution problems have get more obviously, the rational utilization of solar energy becomes a global concern with the meaning of sustainable development strategies. Building Integrated PV (BIPV) as one of the main areas of solar applications can improve building energy efficiency, and becomes an important indicator of a "green building", so it has important significance to solve environmental pollution and the energy crisis. In remote areas without electricity or isolated island, stand-alone PV systems become an important research field for BIPV technology.In order to improve the efficiency of BIPV power system, it is explored from the BIPV power system structure and control-strategy two angles and then the new BIPV system architecture is presented. In BIPV system, PV as building materials is easy to form shadow due to its installation angle of orientation and other buildings, resulting in lower system energy conversion efficiency. In this paper, the proposed single-stage inverter system adopt AC modular structure of BIPV system and can effectively improve the anti-shadow BIPV power systems, electrical parameter adaptive capacity and system energy efficiency.In this paper, a theoretical analysis and control strategy is researched about BIPV system based on the AC-module-based BIPV system. The characteristics of the PV modules are studied in detail and also emphatically analyzed the PV power point tracking (MPPT) principle of work. Several kinds of MPPT control methods have been compared, and combined with constant voltage method (CVT) and variable step incremental conductance method (INC), an improved composite MPPT control algorithm is proposed and has been done a simulation research.Inverter circuits use SPWM modulation, combined common inverter control scheme, the PI adjustment and voltage close-loop feedback control technology is used. Based on the research of these two theories, a detailed hardware and software system has been designed and then the paper designs an experimental prototype using a high-speed digital signal processor core controller TMS320LF2407 and has done experimental studies.This paper has done a simulation and experimental study about the output characteristics of PV modules, system performance and the inverter MPPT working process. According to experimental results, the paper gets the efficiency curve of the system. Experimental results show the feasibility of the system control program, and it can provide some reference for practical application and theoretical studies.