摘要
研究逆变器无互联线冗余并联系统,针对传统无互联线下垂控制的不足,借鉴电力系统中应用于功率调度的分层控制方法,提出多层控制方法。第1层为改进的PQ下垂算法,对系统的频率及初始相位同时进行调节,以兼顾提高系统的动态和稳态性能;第2层控制检测系统交流母线电压的频率及幅值,以补偿下垂控制损害的负载调整率;第3层控制检测交流母线电压相位,实施直接同步调节,减小投入并联瞬间的冲击并避免动态相位失步。详细分析控制原理及各层控制之间的关系协调,并给出采用常规数字信号处理器的实现方法。由2台三相逆变器组成的并联系统的实验结果表明,多层控制无线并联方法实现了逆变器并联系统运行的稳定性和可靠性,具有好的动态和稳态性能。
In order to cope with the drawbacks of conventional droop method, a hierarchical control for inverters in parallel operation without interconnection is proposed refering to the hierarchical control applied to power dispatching in AC power systems. The hierarchical control consist of three levels. The primary control is based on an improved droop method, the sharing of the active and reactive power in each module is controlled and balanced by adjusting the phase and amplitude of the output voltage respectively. The secondary control is to compensate the droop of the output voltage from its reference, induced by the droop control, to improve the load regulation performance of the inverter. The last but not the least control limits the phase deviation between the inverter and the shared AC bus in order to ensure all the parallel inverters keeping in phase with each other. The operational principle and implementation was analyzed in detail. A prototype, configured by two paralleled inverters, was set up, on which many dynamic and steady experiments were carried out. Experiment results verify the validility of the proposed control.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2011年第36期33-39,共7页
Proceedings of the CSEE
基金
高等学校博士学科点专项科研基金资助项目(200802871040)
电力系统及发电设备控制和仿真国家重点实验室基金(SKLD09KM09)~~
关键词
逆变器
并联运行
下垂控制
多层控制
均流
inverters
parallel operation
droop method
hierarchical control
current sharing
