Comprehensive evaluation method for line loss level of low-voltage transformer area

Abstract

A comprehensive evaluation method for the line loss level of a low-voltage transformer area comprises the steps as follows: equivalent resistance of distribution lines in the low-voltage transformer area is calculated respectively; the line loss rate and head end average load current of a low-voltage circuit are measured; a load curve characteristic coefficient and a three-phase unbalanced line loss correction coefficient are calculated respectively; the theoretic line loss rate in the low-voltage transformer area is calculated, and the measured line loss rate and the theoretic line loss rate are compared, so that the management line loss level in the low-voltage transformer area is judged; and the like, wherein the head end average load current, the load curve characteristic coefficient, the three-phase unbalanced line loss correction coefficient and the like are calculated along with a calculation method of the theoretic line loss of the to-be-calculated low-voltage transformer area after a simultaneous equation set is established. According to the method, the parameters and a management line loss evaluation threshold can be accurately calculated, and comprehensive evaluation of the line loss level of the low-voltage transformer area can be accurately completed further; and particularly, when electricity stealing and leakage conditions occur, the method can accurately judge the line loss level, and misjudgments are avoided.

Description

technical field [0001] The invention relates to a method for evaluating the line loss level of a low-voltage station area in a power system. Background technique [0002] A distribution transformer and its users and corresponding distribution lines are collectively referred to as a low-voltage station area. The line loss in the low-voltage station area is divided into the operating line loss caused by the actual operation of the power network and the management and system of the electric industry management department have not yet reached the ideal level (for example, electricity is stolen, the aging of the line is not replaced in time and the leakage is caused) Manage line loss. Among them, since the management line loss is equal to the measurement line loss (the difference between the total meter electricity on the secondary side of a low-voltage station transformer and the sum of the electricity seen by each user) minus the theoretical line loss, the management line loss...

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Problems solved by technology

However, since the existing equivalent resistance method can only obtain a relatively accurate theoretical line loss rate under the premise that there is no leakage of electricity, when electricity theft and / or leakage occurs in a low-voltage station area, it is calculated according to Both the characteristic coefficient of the load curve and the three-phase unbalanced line loss correction coefficient will have large errors. In this case, the theoretical line loss rate cannot be calculated accurately, which makes the comparison with the measured line loss rate The obtained management line loss evaluation threshold is also inaccurate, resulting in misjudgment

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