Real-time Control Research Of Three Phases Grid Connected PV Inverter Based On Ucos-Ⅱ

In the background of energy crisis which is getting closer and closer, the energy structure whose main body is fossil energy need to be changed, so it is imperative to develop new energy, of which solar energy is an important choice. From the economics angle, China has become one of the most important markets, the Chinese government has ever been and will be supporting the photovoltaic industry strongly in spite of the anti-dumping cases. So whether for the sustainable development of human society or for economic benefits, photovoltaic technology research should be promoted strongly.The research object is a three phases photovoltaic grid-connecting inverter of this paper, of which the mathematical model in the synchronous rotating reference frame is established, basing the model the Feed forward decoupling dual closed loop control strategy is established. The most two important modules in the control system SVPWM (space vector pulse width modulation) and PLL (phase locking loop) is comprehended in detail.First of all the uCOS-II kernel is transplanted on the main controlling chip TMS320f2812before the application programming based on the real time operation system kernel uCOS-II. An experiment is designed to check out the correctness, the critical problem of SP adjustment is solved well.The whole set of the photovoltaic grid-connecting embedded operation system is developed based on the real time kernel uCOS-II, the grid-connecting algorithm which requires critical real-time is dovetailed into interrupt service routine, the other functions which is not critical real-time required are packaged into several tasks. The operation process and the timing sequence during one period of grid-connecting algorithm were analyzed.The photovoltaic grid-connecting embedded operation system runs on the hardware platform, it is shown that the system performances well in grid voltage phases tracing, SVPWM, Unit power factor operation and task scheduling, which proves the reliability of uCOS-II and the correctness of grid-connecting algorithm.