| 引用本文: | 李世明,卢建刚,王茜,等.外网扩展电压源支路Ward等值模型及其在状态估计中的应用[J].电力系统保护与控制,2018,46(15):76-84.[点击复制] |
| LI Shiming,LU Jiangang,WANG Qian,et al.Extended voltage-source-branch ward-equivalent-circuit model of external network and its application in state estimation[J].Power System Protection and Control,2018,46(15):76-84[点击复制] |
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| 摘要: |
| 随着互联电网建设的加强，各区域网络之间的联系日益紧密，在内网状态估计时考虑外部电网的影响已成为一种趋势。现有的基于外网扩展Ward等值的状态估计方法，不仅需要外网提供等值阻抗参数，还需要等值状态信息，同时要求等值状态和内网状态在采样时间上保持一致。在实际系统中，互联电网一体化的计算周期和内网独立状态估计的计算周期难以保持一致，从而易因采样时间的不同步而使外网等值状态和内网不匹配，给内网状态估计带来较大误差。鉴于此，在已有的外网扩展电压源支路Ward等值模型的基础上，提出了等值阻抗参数和状态参数的计算方法。该模型与扩展Ward等值相比，相同之处是等值阻抗支路的结构及其参数，不同之处是等值注入功率。后者在边界节点，前者在等值电源节点。相应所提模型的等值状态信息只有等值电源节点的电压和功率，该状态量可以基于节点功率平衡方程仅通过边界节点的内网电压和支路功率来确定。因此，所提模型的状态量与内网的状态量完全匹配，不存在扩展Ward等值的状态不匹配问题，从而可以大幅度提高含外网等值独立内网状态估计的精度。同时，所提模型继承了扩展Ward等值的阻抗支路结构与参数，因而在全网信息已知时具有与扩展Ward等值相当的等值精度。IEEE39节点系统的仿真结果验证了所提方法的有效性。 |
| 关键词: 外网静态等值 状态估计 扩展Ward等值 节点功率平衡 静态安全分析 |
| DOI：10.7667/PSPC171117 |
| 投稿时间：2017-07-25修订日期：2017-09-20 |
| 基金项目:国家自然科学基金项目(51477017) |
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| Extended voltage-source-branch ward-equivalent-circuit model of external network and its application in state estimation |
| LI Shiming,LU Jiangang,WANG Qian,WANG Bin,ZHANG Chao,YAN Wei |
| (Electric Power Dispatching Control Center, Guangdong Power Grid Corporation, Guangzhou 510600, China;State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University, Chongqing 400044, China) |
| Abstract: |
| With the strengthening of interconnection power grid construction, the connection between the regional networks is becoming increasingly close, and it’s becoming a trend to consider the influence of external power grid in the internal network state estimation. The existing state estimation method based on the extended Ward equivalence of external grid, needs both the impedance parameters and state parameters of the external network equivalent model, and requires that the equivalence state and the internal network state remain consistent in the sampling time. In the actual power system, the calculation cycles of interconnected power grid and internal network independent state estimation are difficult to maintain consistency, and it’s easy to lead to large errors due to the mismatch of the state information of the internal network and external network. Based on the existing extended voltage-source-branch Ward-equivalent-circuit model, this paper presents the calculation method of equivalent impedance parameters and state parameters. Compared with the extended Ward equivalent model, the same is the structure and parameters of the equivalent impedance branch, the difference is the equivalent injection power. The latter is at the boundary node and the former is equivalent to the power node. And the equivalent state information of the proposed model only has the voltage and power of the equivalent power node, which can be calculated from the voltage and power information of the boundary nodes based on the node 基金项目:国家自然科学基金项目(51477017) power balance. Accordingly, the state information of the proposed model is completely matched with the state information of the internal network, and there is no state mismatching problem of the extended Ward equivalence, which can greatly improve the accuracy of the independent internal network state estimation with the external network equivalent. At the same time, the proposed model inherits the impedance branch structure and parameters of extended Ward equivalence, so that when the whole network information is known, it has the similar equivalent accuracy with the extended Ward equivalent model. The simulation result on IEEE 39 bus system verifies the correctness of the proposed method. This work is supported by National Natural Science Foundation of China (No. 51477017). |
| Key words: external network static equivalence state estimation extended Ward equivalence node power balance static security analysis |
