Study On Residential Photovoltaic Grid-Connected System And Its Control Method

With the increment of energy consuming and the deterioration of ecosystem environment, many countries around the world are positively looking for a kind of sustainable developing and no pollution new energies. Solar energy is especially concerned by human because of its high efficiency and free pollution. Currently many countries attach great importance to developing roof solar photovoltaic (PV) system. Photovoltaic grid connected generate electricity technology among them have become the main form of the solar application. In the soon future, residential PV grid connected system must enter thousands of families. Based on it, this paper introduces residential PV grid connected system in detail and researches on its control method deeply.Solar array maximum power point tracking (MPPT) control and photovoltaic grid connected inverter control are the two core part of PV grid connected system. The paper researches MPPT algorithm, applies sliding mode variable structure technology in DC/DC converter control and designs the basic model of dynamic control according to the basic operation states of Buck-Boost converter, then testifies the stability of system control. The algorithm's validity is validated by simulation and comparing with other algorithm. In the PV grid connected inverter control aspect, aiming at the shortcoming of PI control, a strategy which combines PI control and repetitive control is put forward. A software phase-locked loop control based on TMS320LF2407 is introduced, which can keep same step with the utility voltage credibly. The corresponding simulation model is set up in MATLAB/ Simulink, related simulation is done. The results show that grid connected current can track the given current...