阅读说明：本技术 适用于b型漏保的互感器磁芯热处理方法 (Heat treatment method of magnetic core of mutual inductor suitable for B-type leakage protection ) 是由 易明 王泽洋 于 2020-03-20 设计创作，主要内容包括：本发明涉及一种适用于B型漏保的互感器磁芯热处理方法,该热处理方法包括：步骤一、将待处理的互感器磁芯放置于纵磁炉内,并抽真空；步骤二、温度由室温升温至400℃,并保温10min；步骤三、温度由400℃升温至480℃-490℃,并保温60min-80min；步骤四、温度由480℃-490℃升温至558℃-562℃,之后保温90min并施加直流纵向磁场；步骤五、将炉体温度冷却至350℃及以下温度之后取出互感器磁芯成品。本发明的热处理方法能够处理得到高导磁、低矫顽力的互感器磁芯成品,该互感器磁芯成品具有较好的软磁性能,能够迅速响应外磁场的变化以使装设有该互感器磁芯成品的B型漏保及时进行正确动作,防止引发安全事故。(The invention relates to a heat treatment method of a magnetic core of a mutual inductor suitable for B-type leakage protection, which comprises the following steps: step one, placing a magnetic core of a mutual inductor to be processed in a longitudinal magnetic furnace, and vacuumizing; step two, heating the temperature from room temperature to 400 ℃, and preserving the heat for 10 min; step three, raising the temperature from 400 ℃ to 480-490 ℃, and preserving the heat for 60-80 min; step four, heating the temperature from 480-490 ℃ to 558-562 ℃, then preserving the temperature for 90min and applying a direct-current longitudinal magnetic field; and step five, cooling the furnace body to 350 ℃ and below, and taking out the finished product of the magnetic core of the mutual inductor. The heat treatment method can process to obtain the finished product of the transformer magnetic core with high magnetic permeability and low coercive force, the finished product of the transformer magnetic core has better soft magnetic performance, and can quickly respond to the change of an external magnetic field so as to ensure that the B-type leakage protection provided with the finished product of the transformer magnetic core can timely and correctly act to prevent safety accidents.)

1. A heat treatment method for a transformer magnetic core suitable for B-type leakage protection is characterized by comprising the following steps:

step one, placing a magnetic core of a mutual inductor to be processed in a longitudinal magnetic furnace, and vacuumizing;

step two, heating the temperature from room temperature to 400 ℃, and preserving the heat for 10 min;

step three, raising the temperature from 400 ℃ to 480-490 ℃, and preserving the heat for 60-80 min;

step four, heating the temperature from 480-490 ℃ to 558-562 ℃, then preserving the temperature for 90min and applying a direct-current longitudinal magnetic field;

and step five, cooling the furnace body to 350 ℃ and below, and taking out the finished product of the magnetic core of the mutual inductor.

2. The heat treatment method for the transformer core according to claim 1, wherein a lead wire is pierced in an axially inner portion of the transformer core; the fourth step is that: the temperature is increased from 480-490 ℃ to 558-562 ℃, then the temperature is kept for 90min, and 40A-50A direct current is input into the lead to form the direct current longitudinal magnetic field.

3. The method for heat-treating a transformer core according to claim 2, wherein the direct current inputted into the wire is 40A.

4. The method for heat-treating a transformer core according to claim 1, wherein the third step is: the temperature is increased from 400 ℃ to 480 ℃ and is kept for 60 min.

5. The method for heat-treating a transformer core according to claim 1, wherein said step four is: the temperature is increased from 480 ℃ to 560 ℃, and then the temperature is kept for 90min and a direct-current longitudinal magnetic field is applied.

6. The method for heat-treating a transformer core according to claim 1, wherein the coercivity of the finished transformer core is less than 0.6A/m.

7. The method for heat treating a transformer core according to claim 1, wherein the finished transformer core has a moment-to-magnetism ratio of greater than 0.92.

Technical Field

The invention relates to the technical field of leakage protectors, in particular to a heat treatment method of a magnetic core of a mutual inductor suitable for B-type leakage protection.

Background

The current earth leakage protectors used in the market are roughly divided into: the AC type leakage protector is developed and designed aiming at power frequency sinusoidal leakage current and can reliably protect the sinusoidal leakage current which is suddenly applied and slowly rises; compared with an AC leakage protector, the A-type leakage protector only improves the magnetic characteristic of a mutual inductor, can reliably protect sinusoidal leakage signals, and can also reliably protect leakage signals containing pulsating direct current components; the B-type leakage protector, also called a full current sensitivity leakage protector, can not only meet the design requirements of the A-type leakage protector, but also reliably protect sinusoidal alternating current signals, pulsating direct current signals and smooth signals which are up to 1 KHz.

At present, the magnetic core of the current transformer in the B-type leakage protection has poor soft magnetic performance, so that the magnetic core cannot respond to the change of an external magnetic field in time, further the B-type leakage protection cannot be tripped reliably in time, and safety accidents such as personal electric shock or electric fire can be caused seriously.

Disclosure of Invention

The invention aims to provide a heat treatment method of a transformer core suitable for B-type leakage protection, which can effectively improve the soft magnetic performance of the transformer core and can effectively reduce the hysteresis loss of the transformer core.

In order to achieve the purpose, the invention adopts the following technical scheme:

a heat treatment method for a transformer magnetic core suitable for B-type leakage protection comprises the following steps:

step one, placing a magnetic core of a mutual inductor to be processed in a longitudinal magnetic furnace, and vacuumizing;

step two, heating the temperature from room temperature to 400 ℃, and preserving the heat for 10 min;

step three, raising the temperature from 400 ℃ to 480-490 ℃, and preserving the heat for 60-80 min;

step four, heating the temperature from 480-490 ℃ to 558-562 ℃, then preserving the temperature for 90min and applying a direct-current longitudinal magnetic field;

and step five, cooling the furnace body to 350 ℃ and below, and taking out the finished product of the magnetic core of the mutual inductor.

Preferably, a wire is arranged in the axial inner part of the mutual inductor magnetic core in a penetrating way; the fourth step is that: the temperature is increased from 480-490 ℃ to 558-562 ℃, then the temperature is kept for 90min, and 40A-50A direct current is input into the lead to form the direct current longitudinal magnetic field.

Preferably, the direct current input in the wire is 40A.

Preferably, the third step is: the temperature is increased from 400 ℃ to 480 ℃ and is kept for 60 min.

Preferably, the fourth step is: the temperature is increased from 480 ℃ to 560 ℃, and then the temperature is kept for 90min and a direct-current longitudinal magnetic field is applied.

Preferably, the coercivity of the finished transformer magnetic core is less than 0.6A/m.

Preferably, the moment-to-magnetism ratio of the finished transformer core is greater than 0.92.

Compared with the prior art, the invention has the beneficial effects that:

the heat treatment method for the transformer magnetic core suitable for the B-type leakage protection, which is provided by the technical scheme, is characterized in that the transformer magnetic core to be treated is placed in a longitudinal magnetic furnace, heat preservation is respectively carried out for 10min, 60min-80min and 90min at the temperatures of 400 ℃, 480-490 ℃ and 558-562 ℃ in sequence, and magnetic treatment is carried out at the temperature of 558-562 ℃, so that the soft magnetic performance of the transformer magnetic core can be effectively improved on the basis of effectively reducing the coercive force of the transformer magnetic core, the magnetic hysteresis loss of the transformer magnetic core can be effectively reduced while the transformer magnetic core can rapidly respond to the change of an external magnetic field, and safety accidents caused by electric leakage can be effectively avoided.

Detailed Description

In order to better understand the present invention, the following description will be further described with reference to some examples. The various embodiments may be combined with each other to form other embodiments not shown in the following description.