A Piecewise Bounded Constrained Optimization Method for Evaluation of Load Harmonic Contribution in Distribution Network

Abstract

The invention discloses a piecewise bounded constraint optimization method for evaluating the contribution of distribution network load harmonics. The Haar wavelet packet transform is used to determine the time window of the background harmonic impedance change, and then the measured harmonic is measured according to the background harmonic impedance. Accurately segment the wave data to adapt to the working conditions of background harmonic impedance changes; then, for each data segment, a segmented bounded constraint optimization model for harmonic contribution evaluation is established, and the sequential quadratic programming method is used to solve the segmented Boundary constrained optimization model accurately estimates all instantaneous harmonic contributions of harmonic source loads, and finally obtains the total harmonic contribution of harmonic source loads by weighted summation. The method of the invention can accurately and quantitatively evaluate the harmonic contribution of the harmonic source load in the distribution network under the background harmonic impedance change.

Description

Technical field [0001] The invention relates to the field of electric power systems, in particular to a segmented bounded constrained optimization method for evaluating the harmonic contribution of a distribution network load. Background technique [0002] With the development of the power system, distributed power microgrids and electric vehicles will be connected to the power grid on a large scale, more power electronic devices and non-linear devices will be used, and power harmonic injection will cause more and more serious impacts. For the problem of harmonic pollution, rewards and penalties should be based on the recommended limits of IEEE 519-1992 and IEC 61000-4-7 standards. The premise of its implementation is to quantitatively evaluate the harmonic contribution of the main harmonic source load. Most of the existing methods assume that the background harmonic impedance characteristics remain unchanged. However, the reconstruction of the network in the actual distribution ...

AI Technical Summary

Problems solved by technology

Most of the existing methods assume that the impedance characteristics of the background harmonics remain unchanged. However, the reconstruction of the network in the actual distribution network, the switching of equipment status and the input of reactive power compensation will all lead to changes in the impedance of the background harmonics, which in turn will cause harmonic source Changes in Harmonic Pollution Generated by Loads

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