双馈水轮发电机快速功率响应的控制策略研究

与常规水轮发电机组相比，双馈水轮发电机组响应速度更快、工作水头更宽，但由于双馈发电机及变频器的使用，其控制更加复杂。首先，本文基于负荷优化理论，提出了一种在等单位功率曲线上寻找最小单位流量的方法，用于改进最优转速寻优策略；其次，依据电机定子磁链定向矢量控制理论，结合双通道励磁和多变量误差叠加的控制方法，将滞环电流控制引入到双馈水轮发电机励磁控制策略中，得到快速产生电压源变换器触发信号的方法；最后，建立了双馈水轮机单机无穷大发电系统仿真模型。在实现变速恒频功能的基础上，对改变给定功率工况进行仿真研究，并与常规水电站同工况仿真对比。结果表明，本文提出的控制方法可明显缩短功率响应的调节时间，具有一定的参考应用价值。

Control strategies for rapid power responses of doubly-fed hydro generators

Doubly-fed hydro turbine units have a higher response speed and a wider working head than those of conventional hydro turbine units. But application of doubly-fed generators and frequency converters requires more complicated control methods. First, this paper develops a new method based on the load optimization theory for finding the minimum unit flows on equal unit power curves to improve the optimization method of optimal speeds. Then, according to the theory of stator flux orientation vector control and through double-channel excitation and multivariable error superposition, we integrate the current hysteresis vector control into a doubly-fed turbine generator excitation control strategy and obtain a method for rapid generation of the trigger signals of voltage source converters. Finally, we construct a simulation model of the single-machine infinite-bus system with doubly-fed turbines and achieve a variable speed and constant frequency (VSCF) function. And the operation cases of changing the given power are examined and compared with the conventional cases. The results show that our new control method significantly shortens the adjusting time of power response of a hydropower station.