基于轨迹灵敏度的戴维南等效参数迭代优化辨识

Identification of Thevenin Equivalent Parameters Using Iterative Optimization Approach Based on the Trajectory Sensitivity

提出一种基于轨迹灵敏度的戴维南等效参数迭代优化辨识方法。该方法将戴维南等效参数辨识归结为数值优化问题,以节点电压计算值平方和电压实测值平方的差最小为目标,优化模型简单、求解方法可靠。结合戴维南等效参数对节点电压的轨迹灵敏度,对辨识参数的初值自适应变步长修正,进而提高参数辨识的精度。由于该方法仅采用当前时刻的实测节点电压、功率数据,有效避免了现有戴维南等效参数辨识方法针对不同假设条件的局限,具有使用范围广、辨识结果有效性强、计算速度快的特点。简单2节点系统和新英格兰10机39节点系统的仿真验证了所提方法的实用性和有效性,有在线应用前景。

An iterative optimized identification method of Thevenin equivalent parameters based on trajectory sensitivity is proposed.This method formulates the identification of Thevenin equivalent parameters as an optimization problem.Its objective is to minimize the difference between the square of calculated voltage and the one of the measured voltage,which is simple and reliable to compute.The initial value of the identification parameter is adaptively step-changing adjusted based on the trajectory sensitivity of the equivalent parameters to the node voltage,which improves the identification precision.In the proposed method,only the current time measured data of node voltage and power are used,so it can effectively avoid the defects in the existing equivalent parameters identification methods,which have the limitation of different assumptions.The proposed method also has a wide using range,good validity of identification results and fast calculation speed.The simulation of simple 2-node system and New England 10-machine 39-node system demonstrates the effectiveness and practicality of the proposed method which has the prospect of application in real-time power system.