孤岛微电网电压不平衡自补偿控制研究

Research on Voltage Unbalance Self-compensation Control of the Isolated Island Microgrid

随着分布式发电系统和微电网的发展,发电单元不仅需要向电网注入功率,还需要在孤岛模式下保证提供较高的电能质量。提出了一种孤岛微电网的电压不平衡自补偿控制策略。该控制方案是在发电单元逆变器的控制器上实施的,首先设计了传统的包含虚拟阻抗调节的下垂控制,然后设计了电压电流双闭环比例谐振控制器,最后在传统控制器的基础上引入了自平衡控制,并基于系统参数分析了系统的稳定性。为了验证控制策略的有效性,基于实时仿真平台搭建了微网孤岛运行试验平台,开展了相关试验研究,试验结果表明所提出的方法能较好实现电压不平衡自补偿。

With the development of distributed generation system and microgrid,power generation unit not only needs to inject power into the grid,but also needs to provide a high quality of power supply in the island mode.A voltage unbalance self-compensation control strategy in an islanded microgrid was proposed.The method was implemented on the local controller of the power generation unit inverter.At first,the traditional droop controller which contains the virtual impedance regulation was designed.Then the voltage and current double closed-loop proportional resonant controller was also designed.At last,the self-compensation control based on traditional controller was introduced,and aiming the research object,the stability of the system was analyzed with the system parameters.In order to verify the effectiveness of the control strategy,based on the real time simulation platform,some experiments of the microgrid isolated island operation was carried out.The results demonstrate the effectiveness of the proposed method in the compensation of voltage unbalance.