Abstract: Due to the higher and higher requirement of operation characteristics of wind turbine,a kind of novel low voltage ride-through scheme for constant-speed and constant-frequency（CSCF） wind turbine is proposed.The back-to-back converter with anti-parallel thyristors are put into use during fault occur,through which wind turbine connects with power grid.At the same time,the generator terminal voltage amplitude and frequency can maintain rated value through proper reactive power compensation and active power absorption,which make wind turbine work stably under transient low voltage.In this paper,the mathematical models of each part of wind turbine system are built firstly,and the control strategies of converter are described and analyzed.In the end,the precise simulation model of wind turbine and low voltage ride through equipment are built on PSCAD/EMTDC platform.Three kinds of different faults that include 25%,50% and 80% voltage sags are simulated,and the results verify the feasibility and reliability of proposed improved low voltage ride through scheme.