Research On Phase Compensation Resonant Control Of Single-phase Photovoltaic Grid-connected Inverter

With the rapid economic development and improvement of people’s quality of life,human demand for energy is growing.However,the excessive development and use of fossil fuels bring two major global problems of energy tensions and environmental pollution.In the double restriction of economic development and natural environment,the development and utilization of new energy is particularly important.Among them,the solar energy with its widely distributed,endless and other advantages has a pivotal position in the application of new energy.As one of the most popular applications of solar energy,grid-connected photovoltaic generation is being developed rapidly.Under this background,this paper studies the grid-connected inverter of the core equipment of photovoltaic grid-connected inverter system.Because inverter is a main interface device between PV array and grid,its performance determines the performance of the whole PV system.In order to maximize the energy output from the PV array into the grid and maintain the stable operation of PV grid-connected system.This paper has carried on the deep discussion from two important aspects of the topology and control strategy.First of all,this paper gives the background of the solar power,the current development status and good prospects for development.It analyzes and compares the various topologies of grid-connected inverter.The main circuit topology of the two-stage single-phase grid-connected inverter is established.The energy in the grid-connected system is transferred back and forth between the DC side and the AC side,the higher order even harmonics of the DC side of the inverter will affect the output current of the inverter.So that the grid current contains a large number of odd harmonics.Even with the more advanced current control method,it is still difficult to eliminate.Through the analysis and comparison of various control strategies,the phase compensation resonant control technology is selected as the control method of inverter current in this paper.The phase compensation resonant control strategy can compensate for the phase at any of the harmonic frequencies in the system.So that the odd harmonics can be suppressed to reduce the total harmonic content of the grid current.And compared with the ordinary ratio resonance control technology,the advantages of the control method are described.Then,the mathematical model of the two-stage and two-phase grid-connectedinverter is established.The overall control scheme of PV grid-connected system is given,and its principle is discussed in detail.The signal acquisition part is mainly through the voltage,current sampling circuit to obtain the system DC and AC real-time signal.And the single phase phase locked loop technology is used to track the phase of the grid voltage.The signal processing is completed through the DSP chip TMS320F28335.The simulation model of the system is established in MATLAB/ SIMULINK environment.Experiments have been carried out with DSP chip programming.The simulation results and experimental results show the effectiveness of the phase compensation resonant control strategy used in this paper.Finally,the paper summarizes the whole paper,analyzes the key points and their shortcomings,and looks forward to the future research work of this subject.