Research On The Integration Control Strategy

With the rapid development of human economy and the explosive growth of population in modern society,the demand for energy in the world keeps high with the development.Fossil energy,the basic energy that human beings rely mainly on,is facing the danger of exhaustion.In this situation,the solar power industry came into being,and soon became an important topic of discussion in the world energy industry.This paper mainly discusses the photovoltaic inverters system.Based on the mathematical model,the analysis and modeling of the solar GTI system can reach the MPPT,GTI,and the PLL.when the system voltage is unbalanced.The maximum power algorithm of solar cell,the control strategies of inverter,so the same with the research status of PLL is introduced.This paper introduces the calculation method of MPP of solar battery,the research status of PLL control technology and the control method of inverters.Based on the analysis of disturbance observation method and conductance increment method,the applicability of the system is simulated and compared by using MATLAB and Simulink.The mathematical model and data analysis of the voltage inverters are carried out.The vector control method and instantaneous power control method for determining the voltage direction are discussed.Double-loop control is applied to realize vector control of voltage direction determination.Space Vector Pulse Width Modulation(SVPWM)and maximum power point tracking(MPPT)are used to design grid-connected inverters.Models and simulations are established in the environment of MATLAB and Simulink.phase-locked loop must be used to make the grid voltage tracking without static error.In the case of unbalanced grid voltage,this paper emphatically introduces how to build phase-locked loop and frequency-locked loop models of double quadratic generalized integrator in the situation of Matlab and Simulink,and makes simulation comparison and analysis.Different from the disadvantages of the traditional double quadratic generalized integrator,such as too long operation time and too largeovershoot,this paper presents a method of phase-locked loop based on discrete Fourier transform.Discrete Fourier transform can ensure that the output frequency does not change.With this method,when the system voltage is unbalanced,the output frequency and phase angle errors can be corrected effectively,and the voltage of the power system can be tracked quickly and sensitively.According to the DC bias of single-phase voltage,this paper presents the phase-locked loop method using improved generalized integrator and the phase-locked loop method using discrete Fourier transform.The two methods are simulated and verified in the environment of MATLAB and Simulink,which proves the theoretical feasibility of the two methods.