中文摘要：

为适应目前电网限制风电场上网发电量的要求，风电机组需要具备全程风速范围内的功率限发调节能力。对变速风力发电机的限负荷控制策略进行了研究，建立了风电机组功率对象的数学模型，分析了可实现机组功率调节的桨距角控制模式和转矩控制模式，并建立了仿真模型，针对多种典型工况进行详细的仿真对比。结果表明，转矩控制模式下风电机组调节过程具有更好的动态特性，更适合于实现电网限发条件下的变速风电机组功率控制。

英文摘要：

To adapt to present constraint of limiting the wind power capacity transmitted from wind farms to power grids, it is necessary for wind turbine generating units to possess the ability of regulating and limiting the generating capacity in whole wind speed range. The de-load control strategy for variable speed wind turbine generating unit is researched and a mathematical model of active output of variable speed constant frequency （VSCF） wind turbine generating unit is established, and the pitch angle control mode and the torque control mode, by which the active output of VSCF generating trait can be adjusted, are analyzed and corresponding simulation models are built to carry out detailed simulative comparison among various typical operating conditions. Simulation results .show that under the torque control mode the regulating process of wind turbine generating unit possesses better dynamic characteristics, thus such a control mode is more suitable to control active output of VSCF wind turbine generating units under the constraint of limiting generating capacity.