Research On Repetitive Control Based Thyristor Switch Filter

This thesis introduces the application of TSF (Thyristor Switch Filter) oninjection modeling machine. TSF is able to rapidly track the dynamic behavior ofimpact load, filter out harmonics and compensate for reactive power. To improve thepractical situation of a rubber factory’s injection modeling machine with harmoniccurrents and low power factor, this thesis proposed repetitive controlled TSF controlstrategy, and improved the power quality through adjusting the angle of the thyristortrigger delay control continuously into the grid reactive power.To accurately track the system required compensation of reactive power, and toensure the TSF input reactive power infinitely approach to the system requiredreactive power, repetitive control strategy was adopted. In order to design the TSFrepetitive control system, analysis has been done for the property and format ofrepetitive control model, repetitive controller and compensator. With thecombination of ideal structure of repetitive control model, the TSF repetitive controlsystem was developed.Through controlling the TSF reactive power input to the system by adjustingthe angle of the thyristor trigger delay. This research analyzed the TSF admittanceand thyristor trigger delay angle relationship formula, derived the reactive power-thyristor trigger delay angle relationship table, thyristor control angle underdifferent reactive power can be obtained with this look-up table. This paperresearched on harmonic current produced by non-zero-voltage triggering, proposedand validated the strategy used to suppress the negative effects of harmonic current.According to the lower power factor and harmonic current of the rubber factory,practical data has been detected to design a TSF reactive compensat ion harmonicsuppression system. This system contains three sets of fifth TSF channels and oneset of seventh TSF channel. In order to analyze the effects of parameterperturbations to TSF systems, TSF system dynamics model was established duringthis research. To simplify the adjustment and improve the model integration ofcompensating devices, a TSF dynamic reactive power compensation device wasdesigned. This thesis provides the design graph of primary and secondary wiringside hardware structure.To verify the effectiveness of the designed TSF system to compensate reactivepower and suppress harmonics, TSF system simulation model was established andTSF software and hardware control system was designed. In this research, circuitcurrent and voltage waveforms, power factor and harmonic current, waveformFourier analysis simulation results before and after compensation has been obtained, and the experimental waveforms of zero-voltage triggering and non-zero-voltagetriggering. The results of simulation and experiment both verified the reliability andfeasibility of the strategy.