Research On The Low Voltage Ride Through Performance Of Wind Turbine Generator Based On The Semi-physical Test Bench

With the development of wind power generation technology and advancement of theenergy conservation and emission reduction, wind industry developed fast in recent tenyears. The master control system supervise the whole operation of the wind turbinegeneration system, it is a key component of the whole system. The quality of the mastercontrol system will directly affect the operation of the unit, therefore the design of the testbench related with wind turbine generator system become necessary and important. Withthe rapid development of wind power industry, capacity of wind turbine generation unitwhich merged into grid gradually increase compared with the whole capacity of the gridand the LVRT standard of WTG has been made by many countries of the world. In view ofthis trend, it is necessary to study the LVRT control strategy on the basis of test bench.A kind of overall design scheme of test bench was put forward in view of defects ofexisting bench, then this article completed design of hardware and software of test bench.Operation test display that test bench met design requirements.A kind of improved rotor side control strategy which stator flux dynamic changeprocess was considered was validated in view of defects of existing strategies on the basisof mathematical model of WTG.A kind of improved grid side control strategy whichchanges of DC side load current and grid voltage were considered compared withtraditional control strategy was validated. The simulation displayed that the improvedstrategy can inhibit the responds such as rotor current and voltage of the WTG on a certainextent but the effect is not enough and protection act exist delay.The active crowbar protection strategy was validated aiming at the defects of strategyabove based on the test bench. The simulation result showed that this strategy have betterLVRT ability compared with the improved strategy above.