Research On Harmonic Detection And Suppression Of Distributed Photovoltaic Power Generation System

With the energy and environmental problems becoming increasingly prominent,clean and renewable energy is a matter of great concern.Then solar energy become one of the most promising new energy because of the green with abundant resources and other advantages.The photovoltaic power generation also gradually began to occupy the market power,and has become one of the method to solve the energy problem,but there are power electronic devices in photovoltaic power generation system that will bring the harmonic problems in power grid in the process,and will lead to the traditional power quality decline,so how to suppress the harmonics in grid connected photovoltaic system,is one of the important content of research on grid connected photovoltaic system.Based on the composition and working principle of distributed photovoltaic power generation system,this paper analyzes the harmonic generation mechanism of distributed photovoltaic power generation system,and then explores the methods of harmonic detection and suppression of distributed photovoltaic power generation system.Taking the example of a coastal area as the research object,collecting the operation data of the example,analyzing the power generation characteristics of the photovoltaic power generation system combined with the temperature and sunshine,and detecting the harmonic parameters of the system during operation,measuring the power quality by the utility grid standard,its harmonic problem,proposed to build a function with active filter photovoltaic grid-connected system..In the process of research,the Fourier transform and instantaneous reactive power theory based on the harmonic detection method,for the detection of photovoltaic power generation system harmonics exist in the spectrum aliasing,fence effect,spectrum leakage and other issues,Through the addition of Hanning window and All phase fast Fourier transform to improve,for both harmonic detection can compensate for reactive power instantaneous reactive power harmonic detection method,compared with the two harmonic detection method,select the voltage Detection of high accuracy in the case of distortion.According to the similarities and differences between the structure and working principle of active power filter and PV grid-connected power generation,it is proposed to combine the distributed photovoltaic power generation system with the active power filter to construct a photovoltaic grid-connected system with active filter function.The realization of photovoltaic grid and harmonic and reactive power compensation,for the system in the DC side voltage,command current synthesis and current tracking inverter and other three main components of the control method to select and design,and in MATLAB/Simulink simulation platform To build a simulation model to verify its feasibility and correctness.