Detection And Improvement Study On Power Quality Of Grid-Connected Inverters

Nowadays,the development of new energy likes a raging fire,and the prospect of grid-connected inverter market is broad.It is essential to guarantee indicators of inverter power in line with the national utility grid quality standards and into the grid smoothly.Power quality is complex and changeable,the conditions of evoked accident are also complex,and the quality decline will cause damage to the electrical equipment of the system.So it is necessary to grid inverter testing and improving power quality disturbance signal.Mainly as follows:1.For detecting the harmonics and inter-harmonics,an atomic sparse decomposition algorithm is put forward.This algorithm decompose the signal into a set of optimal linear combination of the matching atom in the redundant complete atomic library,and it can find the best match of atoms and their parameters adaptively by using the matching pursuit algorithm.2.In view of the voltage fluctuation and flicker detection and analysis of the filter design principle of the IEC recommendation algorithm,the simulation in MATLAB,the separation flicker package,and statistical evaluation of the flicker value.3.According to the transient signal detection,adopt Mallat algorithm to decompose signals,determine various modulus maxima in the spectrum of singular point positioning begin-end time disturbance signal.This method can accurately and quickly locate the inverter output signal transient disturbance.4.On grid inverter harmonic of power quality,mainly from the selection of the output filter,the control of net current technology and grid inverter controller three aspects to improve,through theoretical analysis and simulation comparison,selected the LCL filter and the net current and capacitive current double closed-loop active damping control,proportional resonance integral(PRI)control,can effectively improve the power quality.5.Design a single-phase grid inverter,3kVA on grid inverter side and into the net current harmonic detection,the experimental results show that the proposed grid inverter and improve power quality detection method has a good effect...