﻿ 基于电流幅值量测的微电网状态估计 State Estimation of Micro-Grid Based on Current Amplitude Measurement

Smart Grid
Vol.05 No.03(2015), Article ID:15473,5 pages
10.12677/SG.2015.53015

State Estimation of Micro-Grid Based on Current Amplitude Measurement

Hao Cong1,2, Xiangyang Zhao1, Wen Luo2

1School of Automation Science and Electrical Engineering, Beihang University, Beijing

2Jiangxi ENACS Renewable Energy Resources and Micro Grid Innovations Co., Ltd., Ji’an Jiangxi

Email: conghao726@163.com

Received: Jun. 1st, 2015; accepted: Jun. 21st, 2015; published: Jun. 24th, 2015

ABSTRACT

The reliability and accuracy of real-time data in the database is the foundation of control, operation and accurate analysis in the micro-grid energy management. The data collection of the real- time data acquisition system is not complete and there are inaccurate measurements; it’s difficult for the power flow calculation and other advanced analysis functions to resolve those problems. So the micro-grid state estimation for the real-time data is imperative. In this paper, seven bran- ches in the micro-grid are analyzed in state estimation after the analysis of the basic principles of state estimation using the real and imaginary parts of the current in branches as the state variables. The deviation of theoretical estimate of the branch current amplitude and the actual value is within the acceptable range.

Keywords:Micro-Grid, Energy Management, State Estimation, Current Amplitude

1北京航空航天大学自动化科学与电气工程学院，北京

2江西仪能新能源微电网协同创新有限公司，江西 吉安

Email: conghao726@163.com

1. 引言

2. 最小二乘估计法基本原理

(1)

(2)

(3)

3. 以支路电流的实部和虚部为状态变量的状态估计方法

(1) 状态变量确定

(4)

：支路l上p相电流的实部；

：支路l上p相电流的虚部。

(5)

：由所有支路上各相电流的实部所组成的向量；

：由所有支路上各相电流的虚部所组成的向量。

(2) 量测变换

(6)

(7)

(3) 目标函数

(8)

(4) 算法流程

Figure 1. Process of state estimation

a) 读取配电网测量终端电流数据构造测量向量Z；

b) 初始化各支路电流实部和虚部构造状态变量x；

c) 根据状态变量和测量向量计算G(x)、U(k)、并计算状态量更新值

d) 判断模值是否满足收敛判据，若满足，输出此时状态量，若不满足，继续执行c)。

4. 算例分析

(1) 通过各节点的有功、无功注入量和各支路的电流幅值量测，经过状态估计后，可由上述表1结果得知电流在冗余量测信息的基础上得到一定程度的修正，提高数据的可靠程度，估计出微电网系统当前的运行状态。

(2) 偏差较大的节点在实际中需注意是否是因为量测干扰出现的数据错误，可以通过增加量测、改进测量与数据传输系统或者寻求更合适的状态估计潮流优化方法来提高数据的可靠性与完整性。

Figure 2. Circuit diagram

Table 1. Comparison of branch current amplitude before and after state estimation

5. 结论

State Estimation of Micro-Grid Based on Current Amplitude Measurement. 智能电网,03,123-128. doi: 10.12677/SG.2015.53015

1. 1. 郑漳华, 艾芊 (2008) 微电网的研究现状及在我国的应用前景. 电网技术, 16, 27-31.

2. 2. Lu, C.N., Teng, J.H. and Liu, W.H.E. (1995) Distribution system state estimation. IEEE Transactions on Power Systems, 10, 229-240.

3. 3. Baran, M.E. and Kelle, A.W. (1994) State estimation for real-time monitoring of distribution systems. IEEE Transactions on Power Systems, 9, 1601-1609.

4. 4. 于尔铿, 刘广一, 周京阳 (1998) 能量管理系统(EMS). 科学出版社, 北京.

5. 5. 于尔铿 (1985) 电力系统状态估计. 水利电力出版社, 北京.

6. 6. 张建华, 黄伟 (2010) 微电网运行控制与保护技术. 中国电力出版社, 北京.

7. 7. 刘振亚 (2010) 智能电网技术. 中国电力出版社, 北京.

8. 8. 张永健 (2009) 电网监控与调度自动化. 中国电力出版社, 北京.

9. 9. Lin, W.M. and Teng, J.H. (1996) Distribution fast decoupled state estimation by measurement pairing. IEE Proceedings—Generation, Transmission and Distribution, 143, 43-48.

10. 10. Wang, H.B. and Schulz, N.N. (2004) A revised branch current-based distribution system state estimation algorithm and meter placement impact. IEEE Transaction on Power Systems, 19, 207-213.

11. 11. 张伯明, 陈寿孙, 严正 (2007) 高等电力网络分析. 清华大学出版社, 北京.

12. 12. 张德喜, 赵磊生 (2010) MATLAB语言程序设计教程. 中国铁道出版社, 北京.

13. 13. 原思聪 (2011) MATLAB语言与应用技术. 国防工业出版社, 北京.