IMPROVING PERFORMANCE OF GRID-CONNECTED PHOTOVOLTALC SYSTEMS USING ROBUST ADAPTIVE SLIDING MODE CONTROLLER

Recently operation of photovoltaic resources has been increased in developed countries. Network connected Photovoltaic inverters are widely used in order to deliver the energy to power system. These inverters are optimally operated by control of active and reactive power injection to network. One of the most useful connection of multlevel inverters is the cascaded inverters which needs independent dc supply. This structure of DC sources is suitable for renewable energy resources like photovoltaic systems. In this research the loop control of multilevel cascaded inverters of photovoltaic systems is proposed by using robust adaptive Sliding mode control. The main features of this controller are: robustness are adaptivity to system dynamics. In this research the adaptive part of controller is implemented by using neural network which is used for factor adjustment. This neural network needs an update rule which should be determined by lyapunov theory. The sliding mode is designed so that the maximum power could be obtained under different condition. Simulation results proved the verification of the proposed method.