Method and system for estimating load model parameters of electric system on line

Abstract

The invention relates to a method and a system for estimating the load model parameters of an electric system on line. When an on-load tap changer of a transformer in a substation is acted or a compensating capacitor in the substation is switched, a monitoring device at the feeder line outlet end of the substation or the junction of a power supply company and users records and analyzes system side disturbance caused by the process so as to estimate the load model parameters, wherein the estimation method comprises the following steps of: (1) detecting voltage disturbance generated by the system per se in real time by using the monitoring device; (2) after detecting the voltage disturbance, judging whether the disturbance is caused by acting the on-load tap changer or switching the compensating capacitor in the substation, if so, executing the step (3), and otherwise, returning to the step (1); (3) calculating relevant voltage and power changes and estimating load parameters according to the voltage and power changes; (4) saving the load parameters calculated on the basis of each-time disturbance in a database; and (5) carrying out regression analysis to mass of data saved in the database and then calculating the load parameters on different times in one day and one season.

Description

Technical field [0001] The invention relates to an online estimation method and system for parameters of a power system load model. Background technique [0002] The load of the power system refers to the total active power and reactive power demand of each power user under the feeder or substation. The characteristic of load power changing with voltage, or voltage-based load model, refers to the active and reactive power requirements of the load under different input voltages. As we all know, the size of the load power changes with the fluctuation of the supply voltage. This voltage-affected load model has a crucial influence on the calculation of power transmission capacity, the evaluation of voltage stability, and many other related researches on power systems. [0003] In the past 30 years, two types of load model parameter estimation methods have been proposed. The first category is based on load type methods. This method relies on the response characteristics of the vario...

AI Technical Summary

Problems solved by technology

However, since the voltage fluctuations mentioned in these articles are not representative in the power system, and the frequency of occurrence is difficult to estimate, this load model estimation method is not universally applicable, especially it is difficult to ensure that the load model is different at different times and Seasonal Accuracy

This shortcoming of poor accuracy and representation severely restricts the practical feasibility of the methods mentioned in these articles

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