基于干扰观测器的低压交直流混合微电网互联变流器反步控制策略  

Backstepping Control Strategy for Interlinking Converters in Low-voltage Hybrid AC/DC Microgrid Based on Disturbance Observer

作　　者：谌毅 杨黎晖[1] 王平凡 CHEN Yi;YANG Lihui;WANG Pingfan(School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学电气工程学院,西安710049

出　　处：《高电压技术》2022年第10期4082-4092,共11页High Voltage Engineering

基　　金：陕西省重点研发计划(2021GY–132)。

摘　　要：针对低压交直流混合微电网的互联变流器,提出一种含有动作阈值的功率外环控制策略,以实现全局负载功率按子网的额定容量进行合理分配,并有效防止互联变流器因微小扰动而频繁切换工作模式。另一方面,考虑到负荷变化或分布式发电出力变化引起的功率波动,以及互联变流器系统建模存在的误差,基于静止坐标系推导了含有等效扰动项的互联变流器时域数学模型,提出基于干扰观测器的内环反步控制策略,以有效抑制扰动项对系统的影响、改善互联变流器应对外界扰动时的动态响应性能,并增强微电网系统的鲁棒和稳定性。基于典型交直流混合微电网的仿真模型,验证所提出控制策略的有效性。结果表明,所提控制策略能使混合微电网系统实现全局负载功率按比例分配且具有良好的动态响应性能。In a low-voltage hybrid AC/DC microgrid,a novel power outer loop control strategy with action threshold is proposed for interlinking converter,which can realize the appropriate distribution of the global load power according to the rated capacity of the subgrids and prevent the interlinking converter from frequently switching operation mode due to small disturbance effectively.On the other hand,the power fluctuations caused by load changes or the output power changes of distributed generation units,as well as the modeling errors of interconnected converter systems,are taken into consideration,and the time-domain mathematical model of interconnected converters with equivalent perturbation term is derived based on stationary frame.The backstepping control based on disturbance observer is proposed to suppress the influence of disturbance term and enhance the robust stability of the microgrid system,which can improve the dynamic response of the interlinking converter under external disturbance.Eventually,the effectiveness of the proposed control strategy is verified in the simulation model of a typical hybrid AC/DC microgrid.The results show that hybrid microgrid can share global load power proportionally with satisfactory dynamic response performance via the proposed control strategy.

关 键 词：互联变流器 动态响应 静止坐标系 干扰观测器 反步控制 

分 类 号：TM46[电气工程—电器] TM721.3