Research On Variable Speed Constant Frequency Wind Power Generation System Excited By Matrix Converter

The doubly-fed induction generator (DFIG) has become the mainstream in thefield of variable speed and constant frequency (VSCF) wind power generationsystems.In this paper, the matrix converter is as excited,studying VSCF doubly fedwind power generator. Combined with the researchstatus and developmenttrend of thesociety, described the workingprinciple of the windmachine,at the sametime,themathematical modelof wind turbine is also deduced.When we analyze DFIGoperating principle of steady-state mathematical model, DFIG dynamic mathematicalmodel of two-phase synchronous rotating coordinate system is derived. the model ofthe doubly-fed motor S-function is built. Combined with the stator flux of orientationand vector control, generator operation subsystem of DFIG simulation model is setup.This paper briefly introduces the topology of matrix converter, and expounds theprincipleof work on matrix converter, to understand various modulation strategies ofmatrix converter.Itfocuses on the analysis of research on the double space vectormodulation method of the space vector modulation,building a matrix convertersimulation models. To solve the problem of the low rate of utilizationvoltage, thepaper uses harmonic injection PWM method in virtual inverter link. For the DCvoltage fluctuation in output virtual rectifying process, the compensation function ofvirtual inverter HIPWM modulation wave compensation is derived. This paperresearches the control strategy of non normal work condition, analysis of modulationstrategy under symmetric voltage when the input voltage is under asymmetricinformation,andthe influence on the output voltage and input current, and proposes ankind of improving modulation strategy in the rectifier stage of duty cycle addingnegative sequence voltage component.Under unbalanced input voltage condition, thecontrol method of matrix converters of AC excitation is verified. Combined with matrix converter, the double-fed conversion technology and theadvantages ofvector control, a system model of matrix converter excitation andthecontrol of stator flux orientation of DFIGis built. The simulation results show theexcellent characteristics of the system, to verify the correctness and effectiveness ofthe proposed scheme.