基于事件触发的DFIG次同步附加阻尼控制方法  

Event-Triggered Based Sub-Synchronous Supplementary Damping Control Method of DFIG

作　　者：曹澄沙 肖湘宁[1] 张剑[2] 

机构地区：[1]华北电力大学电气与电子工程学院,北京市102206 [2]电力规划设计总院,北京市100120

出　　处：《电力建设》2017年第9期103-110,共8页Electric Power Construction

基　　金：国家电网公司科技项目(SGXJ0000KXJS1500669)

摘　　要：为快速、准确判断和有效抑制双馈感应发电机(double fed induction generator,DFIG)并网经串补输电系统送出发生的次同步控制互作用(sub-synchronous control interaction,SSCI)问题,首先分析了DFIG经串补送出系统SSCI的作用路径,并经数学推导给出了SSCI发生判据。然后,基于该判据,进一步提出了一种基于SSCI事件触发的DFIG次同步附加阻尼控制方法,提出了适用于快速检测需求的次同步频率提取方法;引入了迟滞环节来解决电机参数不确定导致的误判问题,提高方法的鲁棒性;设计了相频特性平滑的带通滤波器,增强了控制方法对频率变化SSCI问题的适用性。最后,进行PSCAD/EMTDC仿真验证,结果表明所提控制方法能够在风速变化、串补度变化及风机参数不确定情况下较好地阻尼SSCI,且由于引入了SSCI事件判断机制,附加控制在未出现SSCI风险时退出运行,不影响风机变流器的主控制功能。与已有的附加阻尼控制方法相比,所提控制方法在较高串补度下仍然具有较好的抑制效果。To fast and accurately estimate, and effectively mitigate sub-synchronous control interaction （SSCI） problems which occurs when the doubly-fed induction generator （DFIG） is connected to series compensation transmission system, this paper firstly analyzes the function path of SSCI and presents its occurrence criterion through the mathematical deduction. Then, based on this criterion, this paper puts forward a SSCI event-triggered based sub-synchronous supplementary damping control strategy of DFIG, and proposes the sub-synchronous frequency extraction method for rapid detection demand; adds hysteresis link to solve the misjudgment problems caused by generator parameter uncertainty and improve the robustness of the method; designs a band- pass filter for smoothing phase-frequency characteristics and improves the applicability of the control method to frequency varying SSCI problems. Finally, the simulation results from PSCAD/EMTDC indicate that the proposed control method still has good damping ability for SSCI when the wind speed or the series compensation degree changes, and even when the generator parameters are inaccurate. At the same time, when there is no SSCI risk, the supplementary damping control will quit operation according to the introduced SSCI event judging mechanism, so it will not influence the main control function of the DFIG inverter. Compared with the existing supplementary damping control methods, the proposed method still has better mitigation effect with higher compensation level.

关 键 词：双馈感应发电机(DFIG) 串补输电系统 次同步控制互作用(SSCI) 事件触发 附加阻尼控制 

分 类 号：TM732[电气工程—电力系统及自动化]