Short-circuit Current Frequency Measurement and Zero Prediction Method Based on Least Square Correlation Coefficient

doi:10.16628/j.cnki.2095-8188.2021.10.003

Abstract

Abstract:

The actual frequency of the power grid is measured based on the principle of maximum linear correlation coefficient of the least square method,and the power grid actual frequency is used to construct the least square method coefficient matrix,and then the characteristic parameters of the short-circuit current are identified,based on which the zero-crossing point of the short-circuit current is predicted.The simulation results show that the method can effectively measure the actual frequency of the power grid,and can eliminate the short-circuit current characteristic parameters and zero prediction errors caused by asynchronous sampling frequency offset.

Key words: zero prediction, linear correlation coefficient, least square method, frequency offset

CLC Number:

TM561

ZOU Dewei, WANG Liantie, MENG Yu, MA Shaohua. Short-circuit Current Frequency Measurement and Zero Prediction Method Based on Least Square Correlation Coefficient[J]. LOW VOLTAGE APPARATUS, 2021, 0(10): 13-17.

Figures/Tables 7

References 18

[1]	王建华, 张国钢, 耿英三, 等. 智能电器最新技术研究及应用发展前景[J]. 电工技术学报, 2015, 30(9):1-11.
[2]	PARIKH U, BHALIA B. SVR-based current zero estimation technique for controlled fault interruption in the series-compensated transmission line[J]. IEEE Transactions on Power Delivery, 2013, 28(3):1364-1372. doi: 10.1109/TPWRD.2013.2247425
[3]	张培铭. 智能低压电器技术研究[J]. 电器与能效管理技术, 2019(15):10-20.
[4]	李刚, 高享想, 刘浩军, 等. 高压交流断路器大容量短路开断与关合试验技术[J]. 高压电器, 2018, 54(2):68-75,83.
[5]	曹良, 严会君, 李萧. 断路器智能控制技术实用性分析[J]. 电气应用, 2018, 37(22):64-66.
[6]	韦惠慧, 刘向军. 断路器状态评估方法综述[J]. 电器与能效管理技术, 2019(15):59-64.
[7]	吴巧玲, 缪希仁, 许火炬, 等. 相控开关的早期故障检测及过零预测方法研究[J]. 电气技术, 2016, 17(7):24-30.
[8]	HUANG Z, XIANG Z. Computer solution of nonlinear equations for real-time fault current parameter identification[J]. Journal of Information & Computational Science, 2014, 11(16):5835-5842.
[9]	李生茂. 基于RLS算法的短路故障相控开断研究[D]. 大连:大连理工大学, 2015.
[10]	李蕊. 故障电流相控分断电流零点预测算法的研究[D]. 大连:大连理工大学, 2009.
[11]	HUANG Z, DUAN X, ZOU J, et al. Research on fault inception detection for controlled fault interruption[J]. Journal of Computational Information Systems, 2012, 8(9):3851-3858.
[12]	THOMAS R, DAALDER J E. An adaptive,self-checking algorithm for controlled fault interruption[C]// The 15th Power Systems Computation Conference,Belgium, 2005:22-26.
[13]	方春恩, 林蔓, 李伟, 等. 基于WLMS算法的高压断路器可控开断故障电流研究[J]. 高压电器, 2009, 45(6):40-43.
[14]	黄智慧, 段雄英, 邹积岩, 等. 基于改进RLS算法的故障电流参数估计[J]. 中国电机工程学报, 2014, 34(15):2460-2469.
[15]	荣文帅, 蔡志远. 断路器同步分断短路电流零点预测方法研究[J]. 电工技术学报, 2019, 34(15):3167-3174.
[16]	李红蕾, 袁召, 冯英, 等. 三种短路故障电流相控分断零点预测算法的对比[J]. 电网技术, 2015, 39(4):1133-1138.
[17]	尹立君, 蔡志远. 基于递推最小二乘算法的合成试验控制方法研究[J]. 电器与能效管理技术, 2020(4):11-17.
[18]	马少华. 126 kV高压真空断路器永磁操动机构及其同步控制技术的研究[D]. 沈阳:沈阳工业大学, 2009.

序号	基波频率 /Hz	正弦分量幅值 /kA	余弦分量幅值 /kA	直流分量峰值 /kA	谐波阶数	时间常数 /ms
1	49.52	8	8	—	—	—
2	49.71	12	12	5	3,5	45
3	50.28	11	11	4	3,5,7	60
4	50.48	10	10	6	2,3,5,7	45

序号	实际频率/Hz	估算频率/Hz	最大相关系数	相对误差/%
1	49.52	49.531	0.999 1	0.02
2	49.71	49.715	0.998 2	0.01
3	50.28	50.276	0.998 0	0.01
4	50.48	50.469	0.997 5	0.02

序号	参数矩阵频率/Hz	正弦分量幅值/kA	相对误差/%	余弦分量幅值/kA	相对误差/%	直流分量幅值/kA	相对误差/%	时间常数/ms	相对误差/%
1	50.000	7.991	0.13	7.623	5.71	—	—	—	—
1	49.531	7.993	0.09	8.001	0.01	—	—	—	—
2	50.000	11.970	0.25	11.790	1.78	5.293	5.86	33.63	25.27
2	49.715	11.980	0.17	12.010	0.08	5.012	0.24	44.90	0.22
3	50.000	10.960	0.36	11.340	3.09	3.696	7.60	142.41	137.35
3	50.276	10.990	0.09	11.010	0.09	4.000	0	59.89	0.18
4	50.000	9.950	0.50	10.290	2.90	5.770	3.83	96.21	113.80
4	50.469	9.990	0.10	10.000	0	6.010	0.17	44.90	0.22

序号	系数矩阵50 Hz 预测误差/ms	系数矩阵频率修正后预测误差/ms	精度提升/%
1	0.602	0.036	94.0
2	0.353	0.023	94.1
3	0.974	0.021	97.8
4	1.536	0.035	97.7