基于最小二乘法的油田配电网谐波状态估计方法

Harmonic State Estimation of Oilfield Distribution Based on Least Squares

摘要: 随着油田电网中变频器等非线性电力电子设备的日益增加，油田电网谐波源数量和类型不断增加。因此，研究油田电网中谐波传变机理十分有意义。谐波状态估计可为分析和掌握油田电网谐波传递规律提供有效手段。本文基于油田配电网结构特点与典型生产设备工作特性，将节点电压作为状态量，支路电流、母线电压、节点注入电流作为量测量，建立节点电压量测方程、支路电流量测方程、节点注入量测方程，建立了适用于油田配电网的谐波状态估计数学模型，并利用最小二乘法求解；通过考虑支路基波电流比值与谐波电流比值相关关系，校正欠定方程造成的误差。仿真结果证明了该方法的有效性。

Abstract: With the increasing number of nonlinear power electronic devices such as inverters in oilfield power grids, the number and types of harmonic sources in oilfield power grids continue to increase. Therefore, it is very meaningful to study the mechanism of harmonic transfer in oilfield power grids. Harmonic state estimation can provide an effective means for analyzing and mastering the harmonic transfer law of oilfield power grid. Based on the structural characteristics of oilfield distribution network and the working characteristics of typical production equipment, this paper takes node voltage as the state variable and branch current, bus voltage and node injection current as the measurement variable. The node voltage measurement equation, branch current measurement equation and node injection measurement equation are established. A mathematic model of harmonic state estimation for distribution network of oilfield is established and solved by least square method; the error caused by underdetermined equation is corrected by taking into account the correlation between the current ratio of branch wave and the harmonic current ratio. Simulation results demonstrate the effectiveness of the proposed method.