A method for estimating impedance of low-voltage user circuit based on unary model

Abstract

A unigram model-based low-voltage user loop impedance estimation method, which relates to the technical field of power management. On the basis of time sequence data of a voltage and current collected by a user smart meter, a user loop impedance ZL is defined, and a KVL loop voltage equation is used to derive and construct a unigram linear model of the low-voltage user loop impedance. In the loop impedance estimation method, first of all, on the basis of the statistical division of regional peak, valley and normal periods, a data collection period is selected, the current step time of a user is observed at an interval of 5 min within a time period, and voltage and current data at the time before and after the step are frozen. Then, data of one day is taken as a sample for linear regression analysis to estimate the user loop impedance ZL, and the loop impedance value ZL may be used to estimate a healthy aging degree for low-voltage distribution network lines and the abnormal power consumption behavior of the user.

Description

technical field [0001] The invention belongs to the technical field of electric power management, and in particular relates to a method for estimating the impedance of a low-voltage user circuit based on a unitary model. Background technique [0002] With the increase of the service life of the line and the erosion of the external harsh natural environment, the line will gradually age. On the one hand, there is a possibility of disconnection in the aging line, and more often, after the aging of the wire, the insulation performance decreases, and leakage or short circuit is prone to occur. However, the lines of the low-voltage distribution network are complicated, and the impact of faults is small. Considering the input-output ratio and other reasons, in the operation and management of the low-voltage distribution network, the power flow of the distribution network is rarely calculated. An important indicator of the operation of the low-voltage distribution network is "line lo...

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Problems solved by technology

[0002] With the increase of the service life of the line and the erosion of the external harsh natural environment, the line will gradually age. On the one hand, there is a possibility of disconnection in the aging line, and more often, after the aging of the wire, the insulation performance will decline, and leakage or short circuit will easily occur.

However, the lines of the low-voltage distribution network are complicated, and the impact of faults is small. Considering the input-output ratio and other reasons, in the operation and management of the low-voltage distribution network, the power flow of the distribution network is rarely calculated. An important indicator of the operation of the low-voltage distribution network is "line loss". "It is also mainly calculated by the method of power difference, so the calculation involving the line impedance of the distribution network has always been a blind area of ​​research

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