An Improved LVRT Control Strategy For Squirrel-cage Induction Generator-based Wind Power System with Full Power Converter

Abstract

With wind power penetration increasing, the low voltage ride-through (LVRT) operation of wind power is important and compulsory for power system itself stability and safety. For squirrel-cage induction generator (SCIG) based wind power system with full power converter, the LVRT operation performance, to some extent, depends on the control strategy of the drivng full power converter. to the system stability. To increase the LVRT performance of SCIG-based wind power system, an improved control strategy is proposed. An improved control strategy is proposed. In the proposed control strategy, the DC-link voltage is controlled with generator side converter, and consequently the active and recative power, transferred into power grid, are directly controlled with the grid-side converter. Compared with the conventional control strategy, the proposed one make the power balance of the full power converter be automatically maintained during grid fault process, and then the LVRT operation can be achieved without discharge chopper circuit. With this control strategy, the vector control based dual loop control scheme for generator-side and grid-side converters are designed respectively in the paper. To validate the design and analysis, the simulation model was built in the Matlab/Simulink environment, and some important results were reported in the paper.