Design And Implementation Of The Photovoltaic Inverter System

The solar photovoltaic power will play an important role in alleviating the energy crisis and reducing the environmental pollution and have a bright prospect of applications. Inverter is the most important component of the photovoltaic power system. This dissertation is dedicated to the design of the photovoltaic inverter system. After the theoretical analysis and simulation of the topology and control strategy, a 5kW photovoltaic inverter system with abundant extended functions which based on full-bridge topology and controlled by DSP is designed. It meets all the demands of this issue. The essence of this issue can be concluded as follows.Firstly, the total solutions for the photovoltaic inverter system are proposed. The full-bridge topology is adopted. The system is proved to be with good steady-state characteristics and dynamic performance by analyzing the transmission function of the dual-loop control strategy. The hybrid SPWM modulation is chosen by comparing several classic modulation methods. The system solution is verified to be practicable through the Saber simulation.Secondly, the detail designs of the inverter are carried out, including the hardware designs such as main circuits, driver circuits, sample and signal conditioning circuits, protecting circuits and the software designs such as the realization of PI control strategy and the rectification of the ADC precision in TMS320F2812.Thirdly, the function extending system is designed. The hardware and software designs are done. The communication protocol between the inverter controller and the extending system controller is fixed. The algorithm of the working parameters of the inverter is provided.Finally, the experiments based on the 5kW photovoltaic inverter system with abundant extended functions are conducted. All the performance including the output power, the efficiency, the THD of output waveform and load regulation of the experimental prototype proves to be qualified. The PV inverter system has excellent steady-state characteristics and dynamic performance.