Fault Diagnosis Of Dual PWM Frequency Control Systems

The application of a new Dual PWM frequency control system not only make the DCvoltage is adjustable within a certain range, and the rectifier AC side current sinusoidal, unitypower factor operation, two-way transmission and allows electricity.With the development ofDual PWM frequency control system, high sensitivity, high reliability, dual PWM inverter faultdiagnosis become an increasingly meaningful research topic.Study to the three-phase voltage source PWM rectifier (VSR) for the PWM rectifier sectionintroduces the mathematical model of its topology, as well as in different coordinate systems, thedesign of voltage and current double closed loop direct current control system, and brieflyexplore the use of feed-forward solutionthe decoupling module for the current inner loop d,applied to the q-axis component of the decoupling control problem and an outer voltage loop PIregulator parameters selection.Part for the PWM inverter, the PWM inverter induction motor as one as the object of study,based on the Clark transform and Park transform to derive the dynamic mathematical model ofthe induction motor in dq coordinates on the vector frequency control of the basic principles androtorfield oriented vector control, expressed in space vector PWM (SVPWM) control strategy,design the space vector of the double closed-loop induction motor control system with the torque,the inner ring of the flux and speed of the outer ring.For fault diagnosis and online monitoring of the capacitor, the dielectric loss angle and thevoltage across the capacitor current than that is, impedance combined judgment capacitance faultcondition. Introduced the principle of the Relax algorithm to derive the fundamental phasevoltage and current signals through its dielectric loss parameters for capacitive devices, andverified by theoretical analysis and simulation results of the algorithm a higher accuracy.Finally, the Matlab/Simulink platform to build a dual PWM induction motor variablefrequency speed control system, and to explore the fault set.Simulink simulation results, throughthe analysis of the control parameters of the rectifier and inverter side, load the size of the effectof fault diagnosis, and both sides of the fault diagnosis, fault characteristics of indicators that arerobust, reliable, rapid diagnosis.