The Research On The Suppression Of Power System Harmonic And Reactive Power Compensation Based On PWM Rectifier

With the wake of developments in technology, various of electronics andelectric devices spread at high speed. But the pollution of public supply networkharmonic wave and reactive power problem are getting worse, electric quality is in acontinuously accelerating decrease. The research and solution about harmonic waveand reactive power problem in grid have been focused on all along. And how tosolve the problem about harmonic wave and reactive power based on reducing thecost and the achieving the goal is the hotspot in the last years.The main way to solve the problem of harmonic wave is using filter with sauceor not and about the reactive power issue, STATCM or static var compensator iswidespread used. Dealing with the two problems, PWM rectifier is used to solve thetwo problems at one time and it not only achieves the goal but also reduces the cost.First of all, this thesis explains the principles of the PWM rectifier and static varcompensator. As comparison, two models are built with the matlab/simulinksimulation software and based on the two models, the performances of the twocomponents are analysed in supply network, meanwhile, the ability of static varcompensator fixing reactive power is formulated and the harmonic wave frequencyspectrum of PWM rectifier is analysed. It proves through computed result that bothof them are able to do a good job when solving the problem alone.After that, a simulation model that could achieve the harmonic suppression andreactive power compensation is built with the characteristic of PWM rectifier.Several operating condition are been calculated like when the rectifier works in thehigh-power factor rectification mode, namely, without the function of reactive powercompensation and harmonic wave suppression, rectification and reactive power compensation mode, rectification and harmonic wave compensation mode,rectification, reactive power compensation and harmonic wave suppressionmode,then the results in the several modes are analysed.At last, the specific examples using the parameter in a power grid of somefactory through the established model are analysed, it proves the performance of thismethod used in actual conditions and also the effect in practical application. Thecorrectness of this method is proved and settles the theoretical basis for the futureresearch.