Research On Reactive Power Compensation And Harmonic Suppression Of Converter Power Supply Systems

First of all, this paper analyzes the theory about reactive power compensation of electrical machines system with converter power supply through AC voltage regulation. By using state variable method and SIMULINK, 3-phase thyristor voltage regulating system and motor soft-starting are simulated. In order to acquire optimal reactive power compensation effect when motor runs at no load or light load, the control strategy of the maximum combined energy-saving index is put forward. The application of AC voltage regulation in oil-pumping motor is analyzed, and the intelligent control strategy is set forth. A 3-phase thyristor voltage regulating system is implemented. The experiment results validate the simulation results.Secondly, the applications of controllable reactor in the reactive power compensation of converter power supply systems are studied.The structure and operation principle of a novel controllable reactor are analyzed. Based on the theoretical analysis, the state equations are derived by using magnetic density as the state variable, and the system performance is simulated. The simulation results are confirmed by the experiments. The reactive power compensation principle and method of constant power factor control are studied theoretically .and experimentally. The simulation and experiment results show that the reactive power compensation effect by using the controllable reactor is quite well.At last, harmonic suppression methods of converter power supply systems are discussed. Taking twelve-phase rectifier as an example, the harmonic suppression principle of multi-phase rectifying system is analyzed. The harmonic suppression principle of the phase-shifting transformer specially the phase-shifting reactor, are studied. The selection of optimal phase-shifting angle, structure and connection of phase-shifting windings of the phase-shifting reactor are analyzed. A six-phase rectifying system with the phase-shifting reactor is simulated and tested. Both the simulation and the tested results shows that the harmonic suppression of the phase-shifting reactor is effective.