Abstract: Abstract: This paper initial on the importance of photovoltaic power generation, its development process and the current research status at home and abroad.Then it involves the composition and system classification of the whole PV grid connected power generation system, and the principle of photovoltaic cell power generation. Finally, the model of photovoltaic power generation system is built through the Simulink simulation experiment in MATLAB. Then, a photovoltaic power generation system with SVG is built, which verifies that it can perform reactive power compensation quickly and accurately, which is the best choice of reactive power compensation device. 1.Photovoltaic power generation technology and reactive power compensation technology brief At present, solar power generation can be divided into two types: optical power generation and thermal power generation. Photovoltaic power generation directly transforms solar light into electricity instead of thermal conversion, also known as photovoltaic power generation. 1.1 Development of photovoltaic power generation technology and development status at home and abroad 1.2 Development of reactive power compensation technology and current development status at home and abroad 2.Overview of photovoltaic grid connected power generation system 2.1 Brief introduction of photovoltaic grid connected power generation system 2.2 Characteristics of photovoltaic cells 2.2.1 Brief introduction of photovoltaic cells 2.2.2 The generation principle of photovoltaic cells 2.2.3 Output characteristics of photovoltaic cells 2.3 Battery 2.4 Inverter 2.5 Classification of photovoltaic power generation system 3.Reactive power and voltage characteristics of photovoltaic power generation system Considering the characteristics of photovoltaic generation, giving full play to its own reactive power regulation ability, coordinating other reactive power and voltage sources in the grid to participate in voltage adjustment is an important technology link to develop large-scale photovoltaic power generation. 3.1 Overview of reactive power and voltage characteristics of photovoltaic power generation system 3.2 Research on reactive power and voltage control of distributed photovoltaic power generation system 3.3 Research on reactive power and voltage control of large photovoltaic power station 4.Reactive power compensation of photovoltaic power generation system 4.1 Basic theory of reactive power control in distribution network 4.1.1 Reactive power loss and its characteristics in distribution network 4.1.2 Harmonic and its harm in distribution network 4.1.3 Basic principle of reactive power control in distribution network 4.2 Basic principle of reactive power compensation in photovoltaic power generation system 4.3 Technical requirements for reactive power compensation of photovoltaic grid connected power station 4.4 Common reactive power compensation methods and devices 4.5 Control method of reactive power compensation 5.Photovoltaic power generation system and reactive power compensation simulation model 5.1 Model of photovoltaic power generation system under Simulink 5.1.1 Output characteristics and model of photovoltaic array 5.1.2 Maximum power point tracking control model 5.1.3 Three phase inverter 5.1.4 Integrated photovoltaic power generation model 5.2 Simulation model of reactive power compensation equipment for photovoltaic power generation system under Simulink 5.2.1 Selection of reactive power compensation equipment for photovoltaic power generation system 5.2.2 SVG control strategy 5.2.3 SVG simulation model under Simulink 5.3 Simulation results 6.Conclusion Finally, the simulation results verify that the new PV grid-connected system with reactive power compensation not only provides power to the large grid, but also can help the large grid to compensate reactive power.