SVPWM Control Algorithm Of Three-Phase Voltage-type Reversible Converter

In modern industrial production, a large number of converter device injected a large amount of harmonic and reactive power to the grid, causing poor power quality. In order to ensure the normal operation of the power grid and electrical equipment, eliminating harmonic pollution becomes particularly important. The three-phase voltage-type reversible converter just with low harmonic content, can be run on unity power factor, and can eliminate harmonics from the source, which can be used to solve the harmonic pollution problem.Firstly, universal mathematical model and dq model of the three-phase voltage-type reversible converter are set up in three-phase stationary abc coordinate and the synchronous rotating dq coordinate respectively. And a method of obtaining space vector pulse width modulation (SVPWM) signal is proposed.Secondly, the grid voltage oriented vector control strategy is adopted to achieve harmonic suppression and unity power factor operation. It gives detailed design processes of current inner loop and DC voltage outer loop. The system transfer function and the PI controller parameters are obtained. To further reduce the harmonic effect and reject periodical disturbance, The improved repeat PI composite control algorithm is used to achieve no static error tracking. Simulation results show that the proposed control strategy can effectively restrain the grid current harmonics.In addition, the virtual flux oriented vector control strategy is put forward to suppress the grid voltage harmonic and improve control performance. The grid voltage is estimated by the DC voltage, AC current and switch signal based on the virtual flux. Simulation results show that the converter can be controlled in this strategy without any grid voltage sensor, and realize the unity power factor running and harmonic suppression.Finally, an experimental platform of three-phase voltage-type reversible converter, using the TMS320F2812as the core control, is been made. The grid voltage oriented vector control is realized on the platform. Experimental results verify that using the proposed control strategy can effectively restrain the grid harmonic effect and the total harmonic distortion is less than2%. Limited by experimental conditions, experimental demonstration of virtual flux oriented vector control strategy is not given in this paper, and it will be completed in the future work.