低压微网中永磁风力发电系统逆变器控制策略研究

Study on control strategy of permanent magnet wind power system for inverter in low voltage micro-grid

在低压微网中,以永磁风力发电并网系统的逆变器为研究对象,主要研究了风力发电系统在并网和离网两种模式下系统逆变器的控制策略。对于系统处于并网和离网情况下,逆变器电流内环采用瞬时电容反馈电流控制,有效解决了因LCL滤波器引起的系统不稳定控制问题。针对两种不同模式下,对并网模式下系统的逆变器控制采用瞬时功率外环、瞬时电容电流PIR内环控制;离网模式下采用负载电压为外环、瞬时电容电流PIR控制为内环的双闭环控制。经过仿真分析,外环瞬时功率控制实现了风力发电并网系统逆变器给定功率控制,在系统输出功率发生变化的情况下,电流具有快速精确的动态跟踪性能,实现了系统功率解耦控制,保证了系统输出高质量电能,有效验证了文中控制策略的可行性。

In low voltage micro-grid, with permanent magnet wind power grid system inverter as the research object, this paper mainly studies the inverter control strategy of wind power generation system in the grid and off-grid system under two kinds of models. For system in the grid and off-grid, the current inner loop uses instantaneous feedback ca- pacitance current of inyerter control, which effectively solves the system instability caused by LCL fher control prob- lem. For two different modes, in this paper, the grid inverter control mode system adopts instantaneous power outer loop, transient capacitance current PIR inner loop control; under th~ off-grid mode, load voltage used for the outer loop, transient capacitance current PIR for inner loop double closed loop control. Through the simulation analysis, in- stantaneous active and ：reactive power control of outer loop achieves the given power control for the inverter grid-con- nected wind farms, under the condition of the system output power changes, the current has fast and accurate dynamic tracking performance implements the power decoupling control, which ensures that the system outputs high quality electricity, ：verifies the feasibility of this control strategy effectively.