功率自适应分配的孤岛直流微网控制策略研究

Research on control strategy with power adaptive allocation for isolated DC micro-grid

针对直流微网中线路阻抗分布差异对负荷功率准确分配和公共母线电压稳定造成的不利影响,提出一种基于虚拟阻抗的功率自适应分配控制策略。通过注入微小脉冲扰动和检测实现对线路阻抗的主动辨识,并将获取的阻抗信息引入基于虚拟阻抗功率自适应分配控制中,实现了负荷功率的准确分配,从而提高了DG的能源利用效率,减少了环流的产生;同时由于其弥补了线路阻抗造成的压降,较好地提升了公共母线的电压整体水平。所提控制策略在实现负荷功率准确分配的基础之上,同时母线电压一直能够维持在较高的电压水平,且无通信网络要求,经济可靠且具有热插拔功能。最后仿真和实验结果较好地验证了所提控制策略的可行性。

A power adaptive distribution control strategy based on virtual impedance is proposed to deal with the adverse effects of line impedance distribution differences on accurate load power distribution and common bus voltage stability in DC micro-grid.The active identification of line impedance is realized by injecting micro-pulse disturbance and detection,and the obtained impedance information is introduced into the adaptive distribution control based on virtual impedance power to achieve accurate distribution of load power,thus improving the energy utilization efficiency of DG and reducing the generation of circulation.Meanwhile,because it makes up for the voltage drop caused by the line impedance,the overall voltage level of the public bus is improved.The proposed control strategy can achieve accurate distribution of load power,and the bus voltage can be maintained at a high voltage level all the time,and there is no communication network requirement,and it is economical and reliable with hot plug function.Finally,simulation and experimental results verify the feasibility of the proposed control strategy.