柔性互联直流微网群一致性协调控制

通过隔离双向直流-直流(direct current-direct current, DC-DC)换流器互联多直流微电网,不仅能实现子微网间有效电气隔离及故障隔离,还可灵活控制互联功率。为提升基于隔离双向DC-DC换流器互联直流微电网集群系统稳定性和可靠性,提出一种一致性协调式控制策略,使得整个集群形成一有机整体。无论哪一直流微电网发生功率扰动,均可实现系统内所有平衡单元联动,为受扰微电网提供紧急功率支撑,改善受扰微网直流电压动态特性,减小受扰电网直流电压稳态偏差,且扰动功率由全系统平衡单元依据其等效功率分配系数比合理承担。此外,所提控制策略仅仅利用就地测量信息,无需子系统间相互通信,可靠性高。最后通过PSCAD/EMTDC仿真验证了所提控制策略的有效性。

Consensus-based Coordinated Control of DC Microgrid Clusters

Flexible interconnection among DC microgrid clusters through isolated bidirectional DC-DC converters, not only can achieve electrical and fault isolation among subsystems, but also can realize interconnected power transmission flexibly. In order to improve the stability and reliability of isolated bidirectional DC-DC converter based DC microgrid cluster, a consensus-based coordinated control is proposed in this paper, by which the whole cluster can be regarded as an organic unity. No matter which subsystem suffers power disturbance, all balance units can respond to it and provide emergency power for the disturbed subsystem, the dynamic and steady state performance of DC bus voltage of the disturbed subsystem can be improved simultaneously, and the disturbed power is allocated by all balance units according to their equivalent power allocation ratio reasonably. In addition, the proposed method only relies on local measurement, which enhances system reliability greatly. Eventually, the effectiveness of the proposed method is verified by simulation in PSCAD/ EMTDC.