基于DBS的直流微电网能量协调控制策略研究

Energy Coordinated Control of DC Microgrid Based on DBS

随着直流微电网系统的广泛应用,其控制技术得到不断关注。直流微电网系统由光伏阵列、电动汽车充换站、大电网及其接口变换器构成。针对其结构特点,采用一种能量协调控制策略以维持直流母线的电压稳定。该控制策略根据直流微电网中母线电压信息(DBS)进行运行模式划分,不同运行模式下,直流微电网各单元的控制策略可进行无缝切换,实现系统协调自治。采用下垂控制实现对多个光伏阵列或者电动汽车蓄电池模块的功率均分。仿真结果表明,直流母线电压保持稳定的同时,直流微电网系统能够在并离网不同模式间进行平滑切换,验证了控制策略的可行性与有效性。

DC microgrid system consists of PV array, electric vehicle charging station, AC grid and its interface converters. In this paper, an energy coordinated control strategy is proposed according to the features of DC microgrid to maintain the stability of DC bus voltage. This strategy divides the operating modes according to DC bus signaling （DBS） in the microgrid, and the different control schemes for subsystems under different operating modes can be switched seamlessly to achieve coordinated autonomy of the whole system. The droop control is adopted to share power among photovoltaic arrays or electric vehicle battery modules. Simulation shows that DC microgrid system can smoothly switch between grid-connected and islanding modes in the condition of keeping DC bus voltage stable, which verifies the feasibility and effectiveness of the proposed control strategy.