Study On The Fault Diagnosis Of Fractional Kalman Filter Inverter

With the ongoing development of power electronics,the application fields of inverter power device are not only in military,transportation,aerospace and other fields with high security demand,but also in some simple electric equipments with low security demand.There can be little doubt that the reliability of inverter power system is quite vital.As the heart of single phase inverter system,the power switch device IGBT is extremely easy to break down.The disable IGBT would have a bad influence on security and reliability of system.Aiming at fault diagnosis method of power switch device IGBT open circuit in single-phase inverter,this paper makes an in-depth study.The main contents of this paper are as follows:Firstly,the object of study in this paper is a single phase grid connected inverter with 500W output power.This paper adopts fractional calculus to describe the capacitor and inductance,afrer considering that the capacitor and inductance in filter circuit may take nonlinear impact into system and calculus can not express the circuit model accuracily.And the fractional capacitor and inductanc are approximated with calculus to build the fractional circuit model.The output waves of fraction circuit model and calculus circuit model are simulated and compared in MATLAB/Simulink.The comparision shows that fractional circuit are more accurate.Secondly,after making analysis on the working principle of single phase inverter,this paper calculates and gets the fractional state space equation of single phase inverter with fractional calculus and state space average method.And the fractional calculus operator is dispersed with direct discretization method.This paper designs the fractional kalman filter to be a state observer,in order to estimate the output voltage and circuit of single phase inverter.After comparing the estimation wave and real wave of single phase inverter to obatin the current residual.In accordance with the fault type of IGBT open circuit in single phase inverter and the inverter symmetry,the current residual is feature extracted and analysed to make sure the fault time position and fault style.This paper form the method of fault diagnosis based on analytical model with fractional kalman filter observer.Eventually,this paper utilizes MATLAB/Simulink to simulate the single tube and double tubes faults.And the simulation result shows that the method has the ability of identifying the fault time,position and type,verifies its effectiveness,has a certain value for engineering application and popularization.