低压微网中永磁风力发电系统逆变器控制策略研究

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,逆变器的电流内环采用瞬时反馈电容电流控制,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,本文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,外环瞬时有功无功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,有效验证了本文控制策略的可行性。

Study on Control Strategy of Permanent Magnet Wind Power System for Inverter in low voltage micro-grid

In low voltage micro net, with permanent magnet wind power grid system inverter as the research object, mainly studies the wind power generation system in the grid and off-grid system under two kinds of model of the inverter control strategy. For system in the grid and off-grid, current inner loop using instantaneous feedback capacitance current of inverter control, effectively solved the system instability caused by LCL filter control problem. For two different mode, in this paper, the grid inverter control mode system adopts instantaneous power outer ring, transient capacitance current PIR inner loop control; under the off-grid mode ,load voltage used for the outer ring, transient capacitance current PIR for inner ring double closed loop control. Through the simulation analysis, instantaneous active reactive power control loop to achieve the system inverter grid-connected wind farms is given power control, under the condition of the system output power change, the current is fast accurate dynamic tracking performance, implement the power decoupling control system, ensure that the system output high quality electricity, verify the feasibility of this control strategy effectively.