A method for evaluating the heavy overload resistance of laminated core of distribution transformer

Abstract

The present invention discloses a method for evaluating the heavy overload resistance of a distribution transformer's laminated core, comprising the following steps: obtaining the distribution transformer's nameplate parameters and sound level measurement type test results, measuring the distribution transformer's noise pressure after 30 minutes of stable operation at different load rates, and measuring the surface temperature rise of the distribution transformer's laminated core after different periods of stable operation at a load rate of 1.4 times, thereby calculating the noise factor and temperature rise factor. Finally, determining the laminated core overload factor to evaluate the distribution transformer's heavy overload resistance. The present invention has the beneficial effect of proposing a method for evaluating the heavy overload resistance of a distribution transformer's laminated core, which can provide a method for optimizing the production design and service performance evaluation of distribution transformer laminated cores.

Description

Technical Field

[0001] The present invention belongs to the field of electrical equipment status assessment, and in particular relates to a method for assessing the heavy overload resistance of a distribution transformer laminated core. Background Art

[0002] Distribution transformers are the core equipment of distribution networks. They convert AC power of one voltage into AC power of another voltage to meet the electricity needs of users. Their safe and stable operation is crucial to the power industry.

[0003] Due to the volatility of power loads, distribution transformers may face severe overload conditions. Due to the unique structure of the distribution transformer's laminated core, severe overload conditions can lead to increased heat generation and magnetostriction, which in turn increases noise. Insufficient overload tolerance can significantly shorten the transformer's lifespan and impact the lives of nearby residents. However, there is currently no accurate and rapid method for determining the overload tolerance of distribution transformer laminated cores. Therefore, to ensure the long-term safe and stable operation of distribution transformers, an assessment method for the overload tolerance of distribution transformer laminated cores is urgently needed. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for evaluating the heavy overload resistance of the laminated core of a distribution transformer. The distribution transformer is a three-phase structure, and the core is made of laminated silicon steel sheets. The method comprises the following steps:

[0005] 1) Obtain the nameplate parameters and sound level test results of the distribution transformer, including rated capacity Q and rated sound pressure H;

[0006] 2) According to the rated capacity Q of the distribution transformer, the noise pressure of the distribution transformer is measured at 0.6 times, 0.8 times, 1.0 times, 1.2 times, and 1.4 times the load rate after stable operation for 30 minutes. i , H i The noise pressure of the distribution transformer after stable operation for 30 minutes at i times Q, i can be 0.6, 0.8, 1.0, 1.2, or 1.4;

[0007] 3) According to the rated capacity Q of the distribution transformer, the surface temperature rise of the distribution transformer core after stable operation for 15 minutes, 30 minutes, 45 minutes and 60 minutes at a load rate of 1.4 times is measured. p , T p The surface temperature rise of the distribution transformer core after stable operation p min under 1.4 times Q, p can be 15, 30, 45, 60;

[0008] 4) Based on the test results of 2) and 3), the noise factor α and temperature rise factor β are obtained:

[0009]

[0010]

[0011] Where, f is the influencing factor related to the material of silicon steel sheet;

[0012] 5) Evaluate the heavy overload resistance of the distribution transformer laminated core according to the laminated core overload factor:

[0013] η=jα+kβ(3)

[0014] Where η is the laminated core overload factor, j and k are empirical coefficients related to the installation environment of the distribution transformer. If η≤1, it is considered that the distribution transformer laminated core's heavy overload resistance capacity is qualified, otherwise it is considered that there is a problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The figure shows a flow chart for evaluating the heavy overload capacity of the laminated core of a distribution transformer. DETAILED DESCRIPTION

[0016] The following further describes the implementation process of the present invention in conjunction with the accompanying drawings. Figure 1 The process includes the following steps:

[0017] 1) Obtain the nameplate parameters and sound level test results of the distribution transformer, including rated capacity Q and rated sound pressure H;

[0018] 2) According to the rated capacity Q of the distribution transformer, the noise pressure of the distribution transformer is measured at 0.6 times, 0.8 times, 1.0 times, 1.2 times, and 1.4 times the load rate after stable operation for 30 minutes. i , H i The noise pressure of the distribution transformer after stable operation for 30 minutes at i times Q, i can be 0.6, 0.8, 1.0, 1.2, or 1.4;

[0019] 3) According to the rated capacity Q of the distribution transformer, the surface temperature rise of the distribution transformer core after stable operation for 15 minutes, 30 minutes, 45 minutes and 60 minutes at a load rate of 1.4 times is measured. p , T p The surface temperature rise of the distribution transformer core after stable operation p min under 1.4 times Q, p can be 15, 30, 45, 60;

[0020] 4) Based on the test results of 2) and 3), the noise factor α and temperature rise factor β are obtained:

[0021]

[0022] Where, f is the influencing factor related to the material of silicon steel sheet;

[0023] 5) Evaluate the heavy overload resistance of the distribution transformer laminated core according to the laminated core overload factor:

[0024] η=jα+kβ(3)

[0025] Where η is the laminated core overload factor, j and k are empirical coefficients related to the installation environment of the distribution transformer. If η≤1, it is considered that the distribution transformer laminated core's heavy overload resistance capacity is qualified, otherwise it is considered that there is a problem.

[0026] The beneficial effect of the present invention is that a method for evaluating the heavy overload resistance of the distribution transformer laminated core is proposed, which can provide a method for the production optimization design and service performance evaluation of the distribution transformer laminated core.

Claims

1. A method for evaluating the heavy overload resistance of a distribution transformer laminated core, characterized in that: The distribution transformer is a three-phase structure with a core made of stacked silicon steel sheets. It includes the following steps: 1) Obtain the nameplate parameters and sound level test results of the distribution transformer, including rated capacity Q and rated sound pressure H; 2) According to the rated capacity Q of the distribution transformer, the noise pressure of the distribution transformer is measured at 0.6 times, 0.8 times, 1.0 times, 1.2 times, and 1.4 times the load rate after stable operation for 30 minutes. i , H i The noise pressure of the distribution transformer after stable operation for 30 minutes at i times Q, i can be 0.6, 0.8, 1.0, 1.2, or 1.4; 3) According to the rated capacity Q of the distribution transformer, the surface temperature rise of the distribution transformer core after stable operation for 15 minutes, 30 minutes, 45 minutes and 60 minutes at a load rate of 1.4 times is measured. p , T p The surface temperature rise of the distribution transformer core after stable operation p min under 1.4 times Q, p can be 15, 30, 45, 60; 4) Based on the test results of 2) and 3), the noise factor α and temperature rise factor β are obtained: Where, f is the influencing factor related to the material of silicon steel sheet; 5) Evaluate the heavy overload resistance of the distribution transformer laminated core according to the laminated core overload factor: η=jα+kβ(3) Where η is the laminated core overload factor, j and k are empirical coefficients related to the installation environment of the distribution transformer. If η≤1, it is considered that the distribution transformer laminated core's heavy overload resistance capacity is qualified, otherwise it is considered that there is a problem.

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