面向LCC中压直流接入的双馈风力发电系统宽频率范围控制

Wide Frequency Range Control of Doubly-Fed Wind Power Generation System for LCC Medium Voltage DC Access

针对单机独立运行的双馈风力发电系统,提出一种面向中压直流接入的宽频率范围控制策略。与传统的电网换相换流器(LCC)直流接入不同的是,通过对双馈风力发电机转子侧换流器与LCC的协调控制,使得定子频率随着风速变化在一个较宽范围内变化,与此同时保持定子磁链不变,从而实现双馈风力发电机的高效运行。对单台1.5 MW双馈风力发电机组宽频率范围控制策略进行了仿真,结果表明从切入风速到额定风速的最大风能追踪区域,均可实现宽频率范围控制,且全风速范围内效率均有所提高。

A wide frequency range control strategy for medium voltage DC access is proposed for doubly-fed wind power generation system with stand-alone operation. Compared with the traditional line-commutated converter(LCC) DC connection, through the coordinated control of the rotor side converter and the grid converter of the doubly-fed wind generator, the stator frequency changes in a wide range with the wind speed, while keeping the stator flux unchanged, so as to realize the efficient operation of the doubly-fed wind generator. Simulation is carried out with the wide frequency range control strategy of a single 1.5 MW doubly-fed wind generation. The simulation results show that in the maximum wind energy tracking region from the cut-in wind speed to the rated wind speed, wide frequency range control can be achieved, and the efficiency is improved in the whole wind speed range.