The Research On MPPT PV Systems And Z-inverter Control Strategy

Since the beginning of the twenty-first century, the demand of energy for each country energy is increasing.In today’s society,we advocate a low-carbon environment, which makes the development and utilization of new energy to set off a boom.As a green energy of solar energy, with clean, sustainable, non-polluting and high-profile,it gets more attention.The article from photovoltaic power generation system began to overall introduction, and then were on grid inverter controller structure, working principle and control method to do a more detailed description, and maximum power point tracking, main circuit topology has done a more in-depth research.First of all,the development of photovoltaic power generation technology at present, the development trend of the inverter technology and common photovoltaic power generation system structure has been introduced in the paper. And make modular introduction of the grid inverter topology working principle and control system,and then make brief introduction of the photovoltaic array phototropism research and inverter system control method.Secondly, comparative analysis of several inverter, selected the inverter main circuit topology of network control systems, and the various parts of the hardware circuit has designed.In the main circuit,the Z type impedance source network as the circuit topology, with its own unique topological structure can work at through state, greatly improve-the overall efficiency, so the detailed analysis of formula deduction and modeling has carried on.Through the detailed deduction and calculation to determine various related parameters of the device.Again,the control of the significance of the orientation of the PV array and simple control strategy has taken a brief description.Then,on the basis of analysis and comparison of several traditional method of maximum power point tracking a method has designed which based on the perturbation observation and the gradient method. According to the mathematical model of PV array, in Matlab/simulink software photovoltaic array simulation model has set up, the corresponding track circuit has designed and set up, and according to the real-time simulation environment the first try parameters and performance Matlab/simulink has set, the simulation waveform verified the feasibility of the algorithm.Finally, in the main loop control,a combination of PID control and repetitive control mode has been used, to realize the accurate control of the inverter output, the inverter control system for the Matlab/simulink simulation results from the simulation waveform control effect and harmonic analysis is ideal to see.The phase lock control has a author briefly introduced, the system for the on-line debugging and through the oscilloscope to test the waveform.Experimental results is good, the purpose of the grid could realize.