Research On Three-phase PV Grid-connected Power Inverter

With the situation of global energy crisis and environment pollution becoming more and more severe, it is imperative to exploite and utilize the clean and regeneration energy resource. Solar energy is one of the most clean, practical and large scale regeneration energy resource. The whole world focus on the use of solar energy. Photovltaic grid-cnnected system will be the main utilization of solar energy. So it will be developed rapidly. Furthermore, with the development of high performance Digital Signal Processor(DSP), it is possible that some most advanced control strategies can be used to PV grid-cnnected system. Under this background, the dissertation deeply researches the PV grid-connected power inverter, which is the core of the system, and uses TMS320LF2407A to control the system in order to transform the solar energy into electrical energy maximum. It is significant to research and experiment on the PV grid-connected system.Firstly, the dissertation introduces the model of PV array and its characteristics, and compare some usually maximum power point tracking(MPPT) methods. A MPPT method based on gradient is proposed; secondly, simulations that contrast the rapid current tracking based on deadbeat PWM control method and other used control strategies, the deadbeat PWM control method is more applicable to realize the rapid current tracking. At last, by analyzing and comparing the structures, two stages structure of three-phase PV grid-connected inverter is adopted in the dissertation.By deep analysis and research, the design of the hardware and software of the whole system is introduced in detail: including the design of the main circuit of system and its parameters, the design of the control circuit, the signal process circuit and power module driver, chart of the software of the system.The experimental results demonstrate that the control scheme of the system proposed in this dissertation is doable.