Research on Synchronous Phasor Measurement Algorithm of Power System Based on Improved DFT
Jin Tao1, Chen Yiyang1, Duan Xiaohua1, Tang Xiaoyan2
1. College of Electrical Engineering and Automation Fuzhou University Fuzhou 350116 China 2. State Grid Nanping Power Supply Bureau of Fujian Electric Power CO. Ltd Nanping 353000 China
Abstract:Discrete Fourier transform has many advantages, such as easy for embedding, high efficiency, and etc, so it is widely used in synchronized phasor measurement in power system. However, due to the existence of non-synchronous sampling and frequency domain discretization, the spectrum leakage and fence which cause the errors of calculation result will occur when the DFT is used in phase measurement. To solve this problem, in this paper the equations of phase angle error are deduced in the non-synchronous sampling, then the difference of phase angles is utilized to track the frequency of power measurement signal. Accordingly a method of synchronized phasor measurement based on improved DFT algorithm is proposed. The calculation results of improved DFT algorithm are divided into an integer part and a fractional part, and the fractional part is modified by the equivalent replacement. The simulation results show that the method has higher accuracy and anti-jamming capability, and the performance has greatly improvement compared with the traditional algorithm. On this basis, a phasor measurements unit hardware system is designed by using TMS320F2812. Utilizing it, accurate measurement results of frequency, amplitude and phase angle are obtained.
金涛,陈毅阳,段小华,唐晓艳. 基于改进DFT的电力系统同步相量测量算法研究[J]. 电工技术学报, 2017, 32(17): 1-10.
Jin Tao, Chen Yiyang, Duan Xiaohua, Tang Xiaoyan. Research on Synchronous Phasor Measurement Algorithm of Power System Based on Improved DFT. Transactions of China Electrotechnical Society, 2017, 32(17): 1-10.
[1] 王成山, 武震, 李鹏. 微电网关键技术研究[J]. 电工技术学报, 2014, 29(2): 59-68. Wang Chengshan, Wu Zhen, Li Peng. Research on key technologies of micro grid[J]. Transactions of China Electrotechnical Society, 2014, 29(2): 59-68. [2] Bhui P, Senroy N. Online identification of tripped line for transient stability assessment[J]. IEEE Transactions on Power Systems, 2016, 31(3): 2214-2224. [3] 蔡超, 陆于平. 一种提高智能变电站PMU相量测量精度的改进采样值调整算法[J]. 电力自动化设备, 2014, 34(3): 149-154. Cai Chao, Lu Yuping. Improved sampled value adjustment algorithm increasing measurement precision of smart substation PMU[J]. Electric Power Automation Equipment, 2014, 34(3): 149-154. [4] 毕天姝, 陈亮, 薛安成, 等. 基于鲁棒容积卡尔曼滤波器的发电机动态状态估计[J]. 电工技术学报, 2016, 31(4): 163-169. Bi Tianshu, Chen Liang, Xue Ancheng, et al. Dynamic state estimator forsynchronous machines based on robust cubature Kalman filter[J]. Transactions of China Electrotechnical Society, 2016, 31(4): 163-169. [5] 罗蛟, 江亚群, 黄纯, 等. 基于DRSC窗递推DFT算法的电力谐波检测[J]. 电工技术学报, 2013, 28(9): 47-53. Luo Jiao, Jiang Yaqun, Huang Chun, et al. Power system harmonic parameters estimation based on recursive DFT algorithm with DRSC window[J]. Transactions of China Electrotechnical Society, 2013, 28(9): 47-53. [6] Cupertino F, Lavopa E , Zanchetta P, et al. Running DFT-based PLL algorithm for frequency, phase, and amplitude tracking in aircraft electrical systems[J]. IEEE Transactions on Industrial Systems, 2011, 58(3): 1027-1035. [7] Yang Rengang, Xue Hui. A novel algorithm for accurate frequency measurement using transformed consecutive points of DFT[J]. IEEE Transactions on Power Systems, 2008, 23(3): 1057-1062. [8] 刘华吾, 胡海兵, 邢岩. 有限字长对滑动窗DFT稳定性的影响研究[J]. 电工技术学报, 2016, 31(11): 22-31. Liu Huawu, Hu Haibing, Xing Yan. Research of finite-word-length effects on the stability of the sliding DFT[J]. Transactions of China Electrotechnical Society, 2016, 31(11): 22-31. [9] 姚文轩, 滕召胜, 唐求, 等. 非同步采样下电力系统相量测量修正算法[J]. 仪器仪表学报, 2013, 34(7): 1518-1523. Yao Wenxuan, Teng Zhaosheng, Tang Qiu, et al. Power system phasor measurement and correction algorithm under asynchronous sampling[J]. Chinese Journal of Scientific Instrument, 2013, 34(7): 1518-1523. [10]Xia Tao, Liu Yilu. Single-phase phase angle measurements in electric power systems[J]. IEEE Transactions on Power Systems, 2010, 25(2): 844-852. [11]许珉, 王玺, 程凤鸣. 基于Hanning窗递推DFT算法的测频方法[J]. 电力自动化设备, 2010, 30(11): 73-74. Xu Min, Wang Xi, Cheng Fengming. Frequency measuring based on Hanning windowed recursive DFT algorithm[J]. Electric Power Automation Equipment, 2010, 30(11): 73-74. [12]刘亚梅, 惠锦, 杨洪耕. 电力系统谐波分析的多层DFT插值校正法[J]. 中国电机工程学报, 2012, 32(25): 182-188. Liu Yamei, Hui Jin, Yang Honggeng. Multilayer DFT interpolation correction approach for power system harmonic analysis[J]. Proceedings of the CSEE, 2012, 32(25): 182-188. [13]王科, 陈丽华, 麦瑞坤, 等. 基于扩展卡尔曼频率跟踪的DFT同步相量测量算法[J]. 电网技术, 2014, 38(9): 2519-2524. Wang Ke, Chen Lihua, Mai Ruikun, et al. An improved discrete Fourier transformation based synchronous phasor measurement algorithm using frequency tracking founded on extended Kalman filter[J]. Power System Technology, 2014, 38(9): 2519-2524. [14]谢运华, 赵庆生, 郭贺宏, 等. 基于高精度测频的修正DFT相量及功率测量算法[J]. 电力系统保护与控制, 2016, 44(12): 23-28. Xie Yunhua, Zhao Qingsheng, Guo Hehong, et al. A modified DFT of phasor and power measurement algorithm based on high precision frequency measurement[J]. Power System Protection and Control, 2016, 44(12): 23-28. [15]王茂海, 孙元章. 基于DFT的电力系统相量及功率测量新算法[J]. 电力系统自动化, 2005, 29(2): 20-24. Wang Maohai, Sun Yuanzhang. A DFT-based method for phasor and power measurement in power systems[J]. Automation of Electric Power Systems, 2005, 29(2): 20-24. [16]符玲, 韩文朕, 麦瑞坤, 等. 基于时频信息的动态同步相量测量算法[J]. 中国电机工程学报, 2015, 35(23): 6075-6082. Fu Ling, Han Wenzhen, Mai Ruikun, et al. Time-frequency information-based dynamic phasor estimator[J]. Proceedings of the CSEE, 2015, 35(23): 6075-6082. [17]符玲, 韩文朕, 麦瑞坤, 等. 基于频域动态模型的同步相量测量算法[J]. 中国电机工程学报, 2015, 35(6): 1371-1378. Fu Ling, Han Wenzhen, Mai Ruikun, et al. Dynamic phasor estimator based on frequency-domain model[J]. Proceedings of the CSEE, 2015, 35(6): 1371-1378. [18]禹永植, 张忠民, 席志红. 基于傅里叶变换的高精度频率及相量算法[J]. 电网技术, 2007, 31(23): 83-86. Yu Yongzhi, Zhang Zhongmin, Xi Zhihong. A high-precision algorithm for frequency and phasor based on Fourier transform[J]. Power System Technology, 2007, 31(23): 83-86. [19]Q/GDW 1131-2014电力系统实时动态检测技术规范[S]. 北京: 国家电网公司, 2014. [20]肖雄波, 夏立, 王黎明. 一种改进状态模型的动态相量测量算法[J]. 电机与控制学报, 2015, 19(12): 47-52. Xiao Xiongbo, Xia Li, Wang Liming. A dynamic phasor measurement algorithm based on improved state model[J]. Electric Machines and Control, 2015, 19(12): 47-52. [21]王平, 高阳, 王林泓, 等. 基于DSP与FPGA的实时电能质量监测终端系统[J]. 电力系统保护与控制, 2012, 40(12): 125-129. Wang Ping, Gao Yang, Wang Linhong, et al. Research of real time power quality monitoring system based on DSP and FPGA[J]. Power System Protection and Control, 2012, 40(12): 125-129. [22]李庆莲, 雷民, 徐伟专. 霍尔传感器的角差对功率测量的影响[J]. 电测与仪表, 2014, 51(20): 95-98. Li Qinglian, Lei Min, Xu Weizhuan. Influence of Holzer sensors angle difference on power measurement[J]. Electrical Measurement & Instrumentation, 2014, 51(20): 95-98.