Method for improving influence of self-heating of electric energy meter on performance of mutual inductor and electric energy meter

A technology of electric energy meters and transformers, which is applied in the field of three-phase intelligent electric energy meters of the national grid, can solve the problems affecting the measurement accuracy and increase of intelligent electric energy meters, and achieve the effect of eliminating additional errors, ensuring measurement accuracy and reducing investment

CN110780099AActive Publication Date: 2020-02-11HEXING ELECTRICAL +2
5 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2020-02-11

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention relates to a method for improving influence of self-heating of an electric energy meter on performance of a mutual inductor and an electric energy meter. The method for improving influence of self-heating of the electric energy meter on performance of the mutual inductor comprises the following steps of: S1, enabling the electric energy meter to regularly judge a current load of theelectric energy meter per second, and if a ratio of an absolute value of a difference between a current current and a maximum rated current Imax of the electric energy meter to the maximum rated current Imax of the electric energy meter is smaller than or equal to 2%, executing the step S2; S2, if the current current continuously meets the condition in the step S1 for compensation interval time delta t, calculating a gain compensation value n by utilizing a formula that n=(Tc-Ts) / delta t; and S3, reading an original power gain from a storage chip of the electric energy meter, carrying out an operation of adding or subtracting the gain compensation value n according to an error variation direction so as to obtain a power gain after compensation, and writing the power gain after compensationinto a metering chip. According to the invention, an additional error generated by the electronic mutual inductor under the running working condition due to temperature rising is reduced.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to a three-phase intelligent electric energy meter of the State Grid, especially a method for improving the influence of the self-heating of the electric energy meter on the performance of the transformer and the electric energy meter, which can reduce the additional energy generated by the temperature rise of the electronic transformer under operating conditions. Errors are mainly used in power systems. Background technique

[0002] When the electrical load is large and the electric energy meter terminal flows through a large current, it will generate heat (self-heating). The voltage and current signal measurement of the electric energy meter usually requires voltage and current transformers to further transform and reduce the power grid signal before it can be input to the conditioning circuit. The test shows that the output voltage of the electronic current transformer increases with the increase of temperature, which is speci...

Examples

Embodiment Construction

[0023] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0024] The invention compensates based on the characteristic of the output voltage of the electronic current transformer changing with temperature, that is, the characteristic of the error of the electric energy meter changing with the load time. Take 6 three-phase smart meters and run them for 1.5 hours respectively under the conditions of rated maximum current Imax, power factor 1.0L, and rated maximum current Imax, 0.5L. The curve characteristics of the error with time are as follows: figure 1 , figure 2 shown.

[0025] From the data of 6 watches, it can be concluded that under the conditions of power factor 1.0L and 0.5L, the characteristics of the error changing with the load time are the same, and the curves are all linear, and they tend to be stable after 1 hour. Therefore, the first hour can be compensated by adjusting the value of the power gain register ...