基于低带宽通信直流微网变换器自适应下垂均流技术研究

Research of adaptive droop current-sharing technique for DC micro-grid converters based on low-bandwidth communication

针对直流微电网的负载均流控制问题,对微电网的稳态均流、动态均流和母线电压稳定等方面进行了研究,对微电网常用均流控制策略进行了归纳,提出了基于低带宽通信的自适应下垂法。为了克服传统下垂控制的缺陷并获得良好的动态均流性能,增加了两个调整环,利用电流调整环调节下垂系数实现了稳态和动态均流,电压调整环抬升了母线电压。因控制均在本地实现,无需中心控制器,可靠性高。对不同的均流控制方案进行了对比实验。研究结果表明,静态均流误差<3%,动态均流误差<4%,该控制策略能实现直流微电网的动稳态均流和母线电压跌落补偿。

Aiming at realizing load current-sharing of dc micro-grid, static current-sharing, dynamic current-sharing, dc-bus voltage regulation and common current - sharing methods were researched, and the adaptive droop based on low bandwidth communication was proposed. In order to overcome the limitations of traditional droop control and to achieve excellent dynamic current-sharing performance, two regulators were added, with a current regulator to fine ne-tune droop coefficient and a voltage regulator to adjust voltage set point. Control was done lo- cally without center controller, which was of high reliability. Comparative experiments of different control methods were presented. The results indicate that static current error is smaller than 3% and dynamic current error is smaller than 4%. The proposed control method can effectively realize load current-sharing and restore the dc-bus voltage.