【摘要】 采用传统下垂控制的多个分布式发电单元在孤岛运行时,由于线路阻抗不一致或本地负荷不平衡,会使各分布发电单元输出有功功率不均分,进而产生系统环流。针对此问题,提出一种改进的自适应调节下垂系数控制策略。其策略是以任一台逆变器为基准,对其采用传统下垂控制,将其输出有功功率信息传送到其它逆变器,从而以两台逆变器输出有功功率的差值来自适应地调节自身的P-U下垂系数,最终达到输出有功功率一致,减小系统环流。对该策略分别在线路阻抗不一致情况下带本地负荷和不带本地负荷的逆变器并联系统中进行仿真和实验验证,仿真和实验结果验证了该策略的正确性和可行性。更多还原

【Abstract】 When distributed generation(DG) units which adopt droop control operate in island mode,the output active powers of the DG units will not be shared accurately and system circulation will occur under the condition of line impedances or local loads are imbalanced.In order to achieve the power sharing and reduce the system circulation,a control strategy of adjusting droop coefficient adaptively is proposed in this paper.In this strategy,one inverter operates in traditional P-U droop control as a reference and informs its output active power to other inverters,then by using the active power difference to adjust the P-U droop coefficient of the slave inverter adaptively.The strategy carries on the simulation and experimental validations in paralleling inverters system under the condition of line impedances are not consistent with local loads and without load locals respectively to validate the correctness and feasibility of the proposed strategy.更多还原