基于动态下垂系数的低压微电网无功控制策略

在低压微电网中,由于受到线路阻抗参数呈阻性以及阻抗值不匹配的影响,常规下垂控制方法往往存在功率耦合和稳态无功功率分配不均的问题。针对上述问题提出一种自适应系数的改进下垂控制方法。该策略通过引入基准虚拟电抗将等效输出阻抗调节为感性,削弱线路阻性成分带来的耦合问题,从而能够应用感性下垂控制;其次,引入低带宽通信,根据功率均分需求自适应调节下垂系数,消除线路阻抗不匹配问题,从而实现无功功率精确均分。相比于传统下垂控制方法,该方法适用任意线路阻抗条件下的微电网控制,具有良好的动、稳态性能。最后,通过Matlab/Simulink仿真证明了该方法的正确性与有效性。

Reactive Power Control Strategy of Low-Voltage Microgrid Applying Dynamic Droop Coefficient

In the low-voltage microgrid, due to the influence of the impedance of the line and the impedance mismatch, the conventional droop control often has the problems of power coupling and uneven distribution of steady-state reactive power. Aiming at the above problems, an improved droop control method with adaptive coefficients is proposed. This strategy adjusts the equivalent line impedance to inductive by introducing the reference virtual reactance, weakening the coupling problem caused by the line resistive component, so that inductive droop control can be applied; secondly, low-bandwidth communication is introduced, and the droop is adaptively adjusted according to the power sharing requirements. Coefficient is adjusted to eliminate the problem of line impedance mismatch, so as to achieve accurate and even distribution of reactive power. Compared with traditional droop control, this method is suitable for microgrid control under any line impedance condition, and has good dynamic and steady-state performance. The simulation results in Matlab/Simulink prove the correctness and effectiveness of the method.