Study On Technology Of The Back To Back Double PWM Converter For Wind Power Generation

As problems of energy shortage and environmental deterioration becamemore serious, it had attached attention to many countries as a green wind energyresources, the technology of wind power generation is constantly developing.Because direct-drive wind turbines had many advantages, such as simpleconstruction, high reliability and so on, it became the hot of the research of thetechnology of wind power generation. The traditional direct-drive wind turbinehad a set of double-PWM converter, as a result, the system became morecomplex and the system cost was added. Used this as a starting point, the articlestudied on a new model for direct-drive permanent magnet wind powergeneration system. The double PWM converter is made up of two voltage-sourceconverters and use the capacitor as voltage support. The equipment has manyadvantages, such as controllable reactive power, adjustable power factor, smalloutputting harmonic content, bidirectional energy flow and secure DC voltageand so on, so it was applied to many fields. The main content of this article ishow to control double PWM converter to improve efficient utilization of thewind power generation.In this thesis, the working principle of wind power generation using doublePWM converter was analysed and the advantages during application werecontrasted and summaried, mathematical models of three-phase static coordinatesABC and two-phase synchronous rotating coordinate system dq were established.The control strategies of current inner-loop and power outer-loop were designed,and used the SVPWM as the method of pulse width modulation. To prove that thecontrol policies are correct, the simulation model of the double PWM converterfor wind power generation was established using Matlab/Simulink, and unitypower factor rectification of the motor-side PWM converter and regenerativeinversion of the grid-side PWM converter were simulated.At the same time, the control circuit was designed using TMS320F2812DSP as the main control chip, the double PWM converter of wind power generationand its control method were verified. The experimental result shows that thecontrol program achieving high power factor implementation of PWM converteris viable and the theory analysis is correct in this paper.