| 引用本文: | 刘益青,高伟聪,魏欣,王秀广.考虑群延迟和暂态时延的短窗低通滤波器设计[J].电力自动化设备,2018,(11): |
| LIU Yiqing,GAO Weicong,WEI Xin,WANG Xiuguang.Design of short-window low-pass filter considering group delay and transient delay[J].Electric Power Automation Equipment,2018,(11): |
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| 摘要: |
| 为采用基于采样值和正弦信号模型的快速保护算法，并防止重采样环节的频率混叠，智能变电站的数字化保护需要数字低通滤波器配合。提出一种基于Tukey窗函数，并且同时考虑滤波器幅频特性和群延迟、暂态时延的低通滤波器设计方法。该方法首先确定窗函数时域宽度Tc和截止频率fc，再根据采样频率fs和固定不变的fc，确定滤波器的长度N≤2fs/fc，最后根据N和fc得到完整的滤波器系数。通过理论分析、数字仿真和静态实验，研究了所设计滤波器的幅频特性、群延迟和暂态时延。对采用所设计滤波器的母线保护进行RTDS实验，通过对比表明，按所提方法设计的滤波器在群延迟和暂态时延性能上明显优于传统窗函数法设计的滤波器，降低了滤波器环节对保护速动性的影响。 |
| 关键词: 智能变电站 Tukey窗函数 低通数字滤波器 群延迟 暂态时延 |
| DOI：10.16081/j.issn.1006-6047.2018.11.004 |
| 分类号:TM77 |
| 基金项目:山东省自然科学基金资助项目(ZR2018MEE039) |
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| Design of short-window low-pass filter considering group delay and transient delay |
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LIU Yiqing1, GAO Weicong2, WEI Xin3, WANG Xiuguang3
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1.School of Electrical Engineering, University of Jinan, Jinan 250022, China;2.Shandong Vocational College of Foreign Affairs Translation, School of Information Engineering, Weihai 264504, China;3.Integrated Electronic Systems Lab Co.,Ltd.,Jinan 250100, China
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| Abstract: |
| The digital relays in smart substations need the assistance of low pass digital filters in order to adopt fast algorithms based on sampling values and sine signal models and avoid the frequency aliasing during resampling. A design method of low pass filter based on Tukey window function is proposed, which simultaneously considers the amplitude frequency characteristic, group delay and transient delay. Firstly, the time domain width Tc and cutoff frequency fc of window function are determined, then the filter length N is determined to be less than or equal to 2 fs / fcaccording to the sampling frequency fs and the fixed fc, finally the complete filter coefficients can be obtained by N and fc. The amplitude frequency characteristics, group delay and transient delay of the designed filter are studied through theoretical analysis, digital simulation and static experiment. The RTDS experiment of a busbar protection adopting the designed filter shows that the designed filter is obviously superior to the filter designed by the traditional window function method in the aspects of group delay and transient delay, and the designed filters can effectively reduce the influence of filters on the speed of protection. |
| Key words: smart substation Tukey-window function low-pass digital filter group delay transient delay |
