Method for evaluating overload capacity of current transformer in strong electromagnetic field environment

Abstract

The invention discloses a method for evaluating the overload capacity of a current transformer in a strong electromagnetic field environment, and belongs to the field of current transformer performance test and evaluation. The method comprises the following steps: firstly, building a current transformer overload capacity test platform in a strong electromagnetic field environment, and according to resistive, capacitive and inductive loads, winding voltage and current of the current transformer and winding and iron core temperature rise changes when the current transformer is under different load conditions; and respectively calculating overload resistive, capacitive and inductive load adaptability factors of the current transformer in the strong electromagnetic field environment so as to calculate the overload adaptability factors of the current transformer in the strong electromagnetic field environment, thereby evaluating the overload capacity of the current transformer in the strong electromagnetic field environment. According to the method, the overload capacity of the current transformer in the strong electromagnetic field environment can be accurately evaluated, and the method has important practical significance on the operation safety and reliability of power equipment and the operation stability of a power system.

Description

Technical Field

[0001] The invention belongs to the field of current transformer performance testing and evaluation, and particularly relates to a method for evaluating the overload capacity of a current transformer in a strong electromagnetic field environment. Background Art

[0002] In modern power systems, current transformers (CTs) are critical devices for measuring and protecting circuits, and their performance directly impacts system protection and control. They accurately convert current signals, providing essential data support for monitoring systems. When abnormal current flow is detected, they trigger protection mechanisms to prevent equipment damage. Therefore, the accuracy and reliability of CTs are crucial for the safe and stable operation of power systems. However, in strong electromagnetic fields, CTs may be susceptible to electromagnetic interference, which can affect their performance and lead to measurement errors, compromising system safety. By evaluating the overload capacity of CTs in strong electromagnetic fields, we can prevent CT failures caused by overload, ensure CT safety, and improve the reliability and stability of the entire system. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for evaluating the overload capacity of a current transformer in a strong electromagnetic field environment, which can accurately evaluate the overload capacity of a current transformer in a strong electromagnetic field environment, ensure the safety of the current transformer, and ensure the safe, stable and reliable operation of the power system.

[0004] A method for evaluating the overload capacity of a current transformer in a strong electromagnetic field environment comprises the following steps:

[0005] The first step is to build a current transformer overload capacity test platform in a strong electromagnetic field environment

[0006] The strong electromagnetic field environment current transformer test platform is composed of a test box (1), a current transformer winding (2), a winding bracket (3), a power supply device (4), a current transformer core (5), an electromagnetic interference generator (6), an electromagnetic field tester (7), a current measuring device (8), a voltage measuring device (9), a load measuring device (10), a first temperature sensor (11), a second temperature sensor (12), a third temperature sensor (13), and a terminal host (14), wherein:

[0007] The power supply device (4) is connected to the current transformer winding (2) to provide electric energy for the current transformer; the electromagnetic interference generator (6) is connected to the electromagnetic field tester (7) to monitor and record electromagnetic field parameters in real time; the current transformer winding (2) is connected to the current measuring device (8), the voltage measuring device (9) and the load measuring device (10), and is supported by four winding brackets (3) and placed inside the test box (1); the first temperature sensor (11), the second temperature sensor (12) and the third temperature sensor (13) are respectively placed at the edge of the current transformer winding (2), the position of the winding (2) close to the iron core (5) and the current transformer iron core (5); the current measuring device (8), the voltage measuring device (9), the load measuring device (10), the first temperature sensor (11), the second temperature sensor (12) and the third temperature sensor (13) are all connected to the terminal host (14) to monitor the winding voltage, current changes and the winding and iron core temperature rise in real time;

[0008] The second step is to calculate the adaptability factor of the current transformer overload resistive load in a strong electromagnetic field environment.

[0009] 1) An electromagnetic field with a relatively high magnetic field strength is generated by an electromagnetic interference generator (6). At this time, the current transformer can still work normally in the electromagnetic field environment inside the test box (1). The magnetic field strength at this time is recorded as H0, with a unit of A / m; a power supply device (4) provides electric energy to the current transformer. The rated current flowing through the primary side of the current transformer is recorded as I0, with a unit of A; the rated voltage of the primary side of the current transformer is recorded as U0, with a unit of V; the rated load connected to the secondary side of the current transformer at this time is obtained by a load measuring device (10). The load is a resistive load, recorded as Z0, with a unit of Ω; the value measured by the first temperature sensor (11) is recorded as T Zf0 , the measurement value of the second temperature sensor (12) is recorded as T Zs0 The third temperature sensor (13) measures a value T Zt0 , the unit is ℃;

[0010] 2) To ensure that the current transformer can still work normally and not damage its internal structure, gradually increase the resistive load, each time by 0.05Z0, and increase it 4 times, namely 0.05Z0, 0.1Z0, 0.15Z0, and 0.2Z0. The measured value of the current measuring device (8) is recorded as I Zi , i=1, 2, 3, 4, all in A; the value measured by the voltage measuring device (9) is recorded as U Zi , i=1, 2, 3, 4, all in V; the value measured by the first temperature sensor (11) is recorded as T Zfi , i=1, 2, 3, 4; the value measured by the second temperature sensor (11) is recorded as T Zsi, i=1, 2, 3, 4; the value measured by the third temperature sensor (11) is recorded as T Zti , i = 1, 2, 3, 4; the above temperature units are all ° C; the values ​​measured above when i = 1, 2, 3, 4 correspond to the increase of resistive load by 0.05Z0, 0.1Z0, 0.15Z0, 0.2Z0 respectively;

[0011] 3) Calculate the current transformer overload resistive load adaptability factor ZLAF in a strong electromagnetic field environment:

[0012]

[0013] The third step is to calculate the current transformer overload capacitive load adaptability factor under strong electromagnetic field environment

[0014] 1) An electromagnetic field with a relatively high magnetic field strength is generated by an electromagnetic interference generator (6). At this time, the current transformer can still work normally in the electromagnetic field environment inside the test box (1). The magnetic field strength at this time is recorded as H0, with a unit of A / m; the power supply device (4) provides electric energy to the current transformer. The rated current flowing through the primary side of the current transformer is recorded as I0, with a unit of A; the rated voltage of the primary side of the current transformer is recorded as U0, with a unit of V; the rated load connected to the secondary side of the current transformer at this time is obtained by the load measuring device (10). The load is a capacitive load and is recorded as X c0 , the unit is Ω; the value measured by the first temperature sensor (11) is recorded as T Xf0 , the measurement value of the second temperature sensor (12) is recorded as T Xs0 The third temperature sensor (13) measures a value T Xt0 , the unit is ℃;

[0015] 2) To ensure that the current transformer can still work normally and not damage its internal structure, gradually increase the capacitive load by 0.05X each time. c0 , increased 4 times, respectively 0.05X c0 , 0.1X c0 , 0.15X c0 , 0.2X c0 , the current measuring device (8) measures the value and records it as I Xi , i=1, 2, 3, 4, all in A; the value measured by the voltage measuring device (9) is recorded as U Xi , i=1, 2, 3, 4, all in V; the value measured by the first temperature sensor (11) is recorded as T Xfi , i=1, 2, 3, 4; the value measured by the second temperature sensor (11) is recorded as T Xsi , i=1, 2, 3, 4; the value measured by the third temperature sensor (11) is recorded as T Xti, i=1, 2, 3, 4; the above temperature units are all ℃; the above measured values ​​when i=1, 2, 3, 4 correspond to the capacitive load increasing by 0.05X c0 , 0.1X c0 , 0.15X c0 , 0.2X c0 ;

[0016] 3) Calculate the current transformer overload capacitive load adaptability factor CLAF in a strong electromagnetic field environment:

[0017]

[0018] Step 4: Calculate the adaptability factor of the current transformer overload inductive load under strong electromagnetic field environment

[0019] 1) An electromagnetic field with a relatively high magnetic field strength is generated by an electromagnetic interference generator (6). At this time, the current transformer can still work normally in the electromagnetic field environment inside the test box (1). The magnetic field strength at this time is recorded as H0, with a unit of A / m; the power supply device (4) provides electric energy to the current transformer. The rated current flowing through the primary side of the current transformer is recorded as I0, with a unit of A; the rated voltage of the primary side of the current transformer is recorded as U0, with a unit of V; the rated load connected to the secondary side of the current transformer at this time is obtained by the load measuring device (10). The load is an inductive load and is recorded as X l0 , the unit is Ω; the value measured by the first temperature sensor (11) is recorded as T Lf0 , the measurement value of the second temperature sensor (12) is recorded as T Ls0 The third temperature sensor (13) measures a value T Lt0 , the unit is ℃;

[0020] 2) To ensure that the current transformer can still work normally and not damage its internal structure, gradually increase the inductive load by 0.05X each time. l0 , increased 4 times, respectively 0.05X l0 , 0.1X l0 , 0.15X l0 , 0.2X l0 , the current measuring device (8) measures the value and records it as I Li , i=1, 2, 3, 4, all in A; the value measured by the voltage measuring device (9) is recorded as U Li , i=1, 2, 3, 4, all in V; the value measured by the first temperature sensor (11) is recorded as T Lfi , i=1, 2, 3, 4; the value measured by the second temperature sensor (11) is recorded as T Lsi , i=1, 2, 3, 4; the value measured by the third temperature sensor (11) is recorded as T Lti, i=1, 2, 3, 4; the above temperature units are all ℃; the above measured values ​​when i=1, 2, 3, 4 correspond to the inductive load increasing by 0.05X l0 , 0.1X l0 , 0.15X l0 , 0.2X l0 ;

[0021] 3) Calculate the current transformer overload inductive load adaptability factor ILAF in a strong electromagnetic field environment:

[0022]

[0023] Step 5: Calculate the overload adaptability factor OAF of the current transformer under strong electromagnetic field environment:

[0024]

[0025] Where a, b, and c represent the weight coefficients of resistive, capacitive, and inductive loads, respectively, and can be determined based on the importance of different load types in actual application scenarios.

[0026] Step 6: Evaluate the overload capacity of the current transformer in a strong electromagnetic field environment

[0027] The overload adaptability factor (OAF) of the current transformer is used to evaluate the overload capacity of the current transformer. If the adaptability factor (OAF) is greater than or equal to 1, it indicates that the current transformer has good overload capacity and adaptability and can operate stably in a strong electromagnetic field environment. If the adaptability factor (OAF) is less than 1, it indicates that the overload capacity and adaptability of the current transformer are poor and measures need to be taken, such as replacing the equipment or limiting the load.

[0028] The beneficial effect of the present invention is that it can accurately evaluate the overload capacity of the current transformer in a strong electromagnetic field environment, which has important practical significance for the safety and reliability of power equipment operation and the stability of power system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the test platform structure used in the method of the present invention;

[0030] Figure 2 Flow chart of the method of the present invention. DETAILED DESCRIPTION

[0031] The implementation process of the present invention is further described in detail below with reference to the accompanying drawings. A method for evaluating the overload capacity of a current transformer in a strong electromagnetic field environment comprises the following steps:

[0032] The first step is to build a current transformer overload capacity test platform in a strong electromagnetic field environment

[0033] The strong electromagnetic field environment current transformer test platform is composed of a test box (1), a current transformer winding (2), a winding bracket (3), a power supply device (4), a current transformer core (5), an electromagnetic interference generator (6), an electromagnetic field tester (7), a current measuring device (8), a voltage measuring device (9), a load measuring device (10), a first temperature sensor (11), a second temperature sensor (12), a third temperature sensor (13), and a terminal host (14), wherein:

[0034] The power supply device (4) is connected to the current transformer winding (2) to provide electric energy for the current transformer; the electromagnetic interference generator (6) is connected to the electromagnetic field tester (7) to monitor and record electromagnetic field parameters in real time; the current transformer winding (2) is connected to the current measuring device (8), the voltage measuring device (9) and the load measuring device (10), and is supported by four winding brackets (3) and placed inside the test box (1); the first temperature sensor (11), the second temperature sensor (12) and the third temperature sensor (13) are respectively placed at the edge of the current transformer winding (2), the position of the winding (2) close to the iron core (5) and the current transformer iron core (5); the current measuring device (8), the voltage measuring device (9), the load measuring device (10), the first temperature sensor (11), the second temperature sensor (12) and the third temperature sensor (13) are all connected to the terminal host (14) to monitor the winding voltage, current changes and the winding and iron core temperature rise in real time;

[0035] The second step is to calculate the adaptability factor of the current transformer overload resistive load in a strong electromagnetic field environment.

[0036] 1) An electromagnetic field with a relatively high magnetic field strength is generated by an electromagnetic interference generator (6). At this time, the current transformer can still work normally in the electromagnetic field environment inside the test box (1). The magnetic field strength at this time is recorded as H0, with a unit of A / m; a power supply device (4) provides electric energy to the current transformer. The rated current flowing through the primary side of the current transformer is recorded as I0, with a unit of A; the rated voltage of the primary side of the current transformer is recorded as U0, with a unit of V; the rated load connected to the secondary side of the current transformer at this time is obtained by a load measuring device (10). The load is a resistive load, recorded as Z0, with a unit of Ω; the value measured by the first temperature sensor (11) is recorded as T Zf0 , the measurement value of the second temperature sensor (12) is recorded as T Zs0 The third temperature sensor (13) measures a value T Zt0 , the unit is ℃;

[0037] 2) To ensure that the current transformer can still work normally and not damage its internal structure, gradually increase the resistive load, each time by 0.05Z0, and increase it 4 times, namely 0.05Z0, 0.1Z0, 0.15Z0, and 0.2Z0. The measured value of the current measuring device (8) is recorded as I Zi , i=1, 2, 3, 4, all in A; the value measured by the voltage measuring device (9) is recorded as U Zi , i=1, 2, 3, 4, all in V; the value measured by the first temperature sensor (11) is recorded as T Zfi , I=1, 2, 3, 4; the value measured by the second temperature sensor (11) is recorded as T Zsi , i=1, 2, 3, 4; the value measured by the third temperature sensor (11) is recorded as T Zti , i = 1, 2, 3, 4; the above temperature units are all ° C; the values ​​measured above when i = 1, 2, 3, 4 correspond to the increase of resistive load by 0.05Z0, 0.1Z0, 0.15Z0, 0.2Z0 respectively;

[0038] 3) Calculate the current transformer overload resistive load adaptability factor ZLAF in a strong electromagnetic field environment:

[0039]

[0040] The third step is to calculate the current transformer overload capacitive load adaptability factor under strong electromagnetic field environment

[0041] 1) An electromagnetic field with a relatively high magnetic field strength is generated by an electromagnetic interference generator (6). At this time, the current transformer can still work normally in the electromagnetic field environment inside the test box (1). The magnetic field strength at this time is recorded as H0, with a unit of A / m; the power supply device (4) provides electric energy to the current transformer. The rated current flowing through the primary side of the current transformer is recorded as I0, with a unit of A; the rated voltage of the primary side of the current transformer is recorded as U0, with a unit of V; the rated load connected to the secondary side of the current transformer at this time is obtained by the load measuring device (10). The load is a capacitive load and is recorded as X c0 , the unit is Ω; the value measured by the first temperature sensor (11) is recorded as T Xf0 , the measurement value of the second temperature sensor (12) is recorded as T Xs0 The third temperature sensor (13) measures a value T Xt0 , the unit is ℃;

[0042] 2) To ensure that the current transformer can still work normally and not damage its internal structure, gradually increase the capacitive load by 0.05X each time. c0 , increased 4 times, respectively 0.05X c0 , 0.1X c0 , 0.15Xc0 , 0.2X c0 , the current measuring device (8) measures the value and records it as I Xi , i=1, 2, 3, 4, all in A; the value measured by the voltage measuring device (9) is recorded as U Xi , i=1, 2, 3, 4, all in V; the value measured by the first temperature sensor (11) is recorded as T Xfi , i=1, 2, 3, 4; the value measured by the second temperature sensor (11) is recorded as T Xsi , i=1, 2, 3, 4; the value measured by the third temperature sensor (11) is recorded as T Xti , i=1, 2, 3, 4; the above temperature units are all ℃; the above measured values ​​when i=1, 2, 3, 4 correspond to the capacitive load increasing by 0.05X c0 , 0.1X c0 , 0.15X c0 , 0.2X c0 ;

[0043] 3) Calculate the current transformer overload capacitive load adaptability factor CLAF in a strong electromagnetic field environment:

[0044]

[0045] Step 4: Calculate the adaptability factor of the current transformer overload inductive load under strong electromagnetic field environment

[0046] 1) An electromagnetic field with a relatively high magnetic field strength is generated by an electromagnetic interference generator (6). At this time, the current transformer can still work normally in the electromagnetic field environment inside the test box (1). The magnetic field strength at this time is recorded as H0, with a unit of A / m; the power supply device (4) provides electric energy to the current transformer. The rated current flowing through the primary side of the current transformer is recorded as I0, with a unit of A; the rated voltage of the primary side of the current transformer is recorded as U0, with a unit of V; the rated load connected to the secondary side of the current transformer at this time is obtained by the load measuring device (10). The load is an inductive load and is recorded as X l0 , the unit is Ω; the value measured by the first temperature sensor (11) is recorded as T Lf0 , the measurement value of the second temperature sensor (12) is recorded as T Ls0 The third temperature sensor (13) measures a value T Lt0 , the unit is ℃;

[0047] 2) To ensure that the current transformer can still work normally and not damage its internal structure, gradually increase the inductive load by 0.05X each time. l0 , increased 4 times, respectively 0.05X l0 , 0.1X l0 , 0.15X l0, 0.2X l0 , the current measuring device (8) measures the value and records it as I Li , i=1, 2, 3, 4, all in A; the value measured by the voltage measuring device (9) is recorded as U Li , i=1, 2, 3, 4, all in V; the value measured by the first temperature sensor (11) is recorded as T Lfi , i=1, 2, 3, 4; the value measured by the second temperature sensor (11) is recorded as T Lsi , i=1, 2, 3, 4; the value measured by the third temperature sensor (11) is recorded as T Lti , i=1, 2, 3, 4; the above temperature units are all ℃; the above measured values ​​when i=1, 2, 3, 4 correspond to the inductive load increasing by 0.05X l0 , 0.1X l0 , 0.15X l0 , 0.2X l0 ;

[0048] 3) Calculate the current transformer overload inductive load adaptability factor ILAF in a strong electromagnetic field environment:

[0049]

[0050] Step 5: Calculate the overload adaptability factor OAF of the current transformer under strong electromagnetic field environment:

[0051]

[0052] Where a, b, and c represent the weight coefficients of resistive, capacitive, and inductive loads, respectively, and can be determined based on the importance of different load types in actual application scenarios.

[0053] Step 6: Evaluate the overload capacity of the current transformer in a strong electromagnetic field environment

[0054] The overload adaptability factor (OAF) of the current transformer is used to evaluate the overload capacity of the current transformer. If the adaptability factor (OAF) is greater than or equal to 1, it indicates that the current transformer has good overload capacity and adaptability and can operate stably in a strong electromagnetic field environment. If the adaptability factor (OAF) is less than 1, it indicates that the overload capacity and adaptability of the current transformer are poor and measures need to be taken, such as replacing the equipment or limiting the load.

[0055] The beneficial effect of the present invention is that it can accurately evaluate the overload capacity of the current transformer in a strong electromagnetic field environment, which has important practical significance for the safety and reliability of power equipment operation and the stability of power system operation.

Claims

1. A method for evaluating the overload capacity of a current transformer in a strong electromagnetic field environment, characterized in that: The following steps are involved: The first step is to build a current transformer overload capacity test platform under strong electromagnetic field environment The strong electromagnetic field environment current transformer test platform is composed of a test box (1), a current transformer winding (2), a winding bracket (3), a power supply device (4), a current transformer core (5), an electromagnetic interference generator (6), an electromagnetic field tester (7), a current measuring device (8), a voltage measuring device (9), a load measuring device (10), a first temperature sensor (11), a second temperature sensor (12), a third temperature sensor (13), and a terminal host (14), wherein: The power supply device (4) is connected to the current transformer winding (2) to provide electric energy for the current transformer; the electromagnetic interference generator (6) is connected to the electromagnetic field tester (7) to monitor and record electromagnetic field parameters in real time; the current transformer winding (2) is connected to the current measuring device (8), the voltage measuring device (9) and the load measuring device (10), and is supported by four winding brackets (3) and placed inside the test box (1); the first temperature sensor (11), the second temperature sensor (12) and the third temperature sensor (13) are respectively placed at the edge of the current transformer winding (2), the position of the winding (2) close to the iron core (5) and the current transformer iron core (5); the current measuring device (8), the voltage measuring device (9), the load measuring device (10), the first temperature sensor (11), the second temperature sensor (12) and the third temperature sensor (13) are all connected to the terminal host (14) to monitor the winding voltage and current changes and the winding and iron core temperature rise in real time; The second step is to calculate the overload resistive load adaptability factor of the current transformer in a strong electromagnetic field environment. 1) An electromagnetic field with a high magnetic field strength is generated by an electromagnetic interference generator (6), and the current transformer can still work normally in the electromagnetic field environment inside the test box (1). The magnetic field strength at this time is recorded as H0, with a unit of A / m; the power supply device (4) provides electric energy to the current transformer, and the rated current flowing through the primary side of the current transformer is recorded as I0, with a unit of A; the rated voltage of the primary side of the current transformer is recorded as U0, with a unit of V; the rated load connected to the secondary side of the current transformer at this time is obtained by a load measurement device (10), and the load is a resistive load, recorded as Z0, with a unit of Ω; the value measured by the first temperature sensor (11) is recorded as T Zf0 The measured value of the second temperature sensor (12) is recorded as T Zs0 The value measured by the third temperature sensor (13) is denoted as T Zt0 , the unit is ℃; 2) To ensure that the current transformer can still work normally and not damage its internal structure, the resistive load is gradually increased by 0.05Z0 each time, and increased 4 times in total, namely 0.05Z0, 0.1Z0, 0.15Z0, and 0.2Z0. The value measured by the current measuring device (8) is recorded as I Zi , i = 1, 2, 3, 4, all in A; the value measured by the voltage measuring device (9) is recorded as U Zi , the unit is V; the value measured by the first temperature sensor (11) is recorded as T Zfi The measured value of the second temperature sensor (11) is denoted as T Zsi The third temperature sensor (11) measures a value denoted as T Zti ; The above temperature units are all ℃; The above measured values ​​when i=1, 2, 3, 4 correspond to the increase of resistive load by 0.05Z0, 0.1Z0, 0.15Z0, 0.2Z0 respectively; 3) Calculate the current transformer overload resistive load adaptability factor ZLAF in a strong electromagnetic field environment: The third step is to calculate the current transformer overload capacitive load adaptability factor under strong electromagnetic field environment 1) An electromagnetic field with a high magnetic field strength is generated by an electromagnetic interference generator (6). At this time, the current transformer can still work normally in the electromagnetic field environment inside the test box (1). The magnetic field strength at this time is recorded as H0, with a unit of A / m; the power supply device (4) provides electric energy to the current transformer. The rated current flowing through the primary side of the current transformer is recorded as I0, with a unit of A; the rated voltage of the primary side of the current transformer is recorded as U0, with a unit of V; the rated load connected to the secondary side of the current transformer at this time is obtained by the load measurement device (10). The load is a capacitive load and is recorded as X c0 , in Ω; the value measured by the first temperature sensor (11) is denoted as T Xf0 The measured value of the second temperature sensor (12) is recorded as T Xs0 The value measured by the third temperature sensor (13) is denoted as T Xt0 , the unit is ℃; 2) To ensure that the current transformer can still work normally and not damage its internal structure, gradually increase the capacitive load by 0.05X each time. c0 , increased 4 times, respectively 0.05X c0 , 0.1X c0 , 0.15X c0 , 0.2X c0 , the value measured by the current measuring device (8) is recorded as I Xi , i = 1, 2, 3, 4, all in A; the value measured by the voltage measuring device (9) is recorded as U Xi , the unit is V; the value measured by the first temperature sensor (11) is recorded as T Xfi The measured value of the second temperature sensor (11) is denoted as T Xsi The third temperature sensor (11) measures a value denoted as T Xti ; The above temperature units are all ℃; The above measured values ​​when i=1, 2, 3, 4 correspond to the capacitive load increasing by 0.05X c0 , 0.1X c0 , 0.15X c0 , 0.2X c0 ; 3) Calculate the current transformer overload capacitive load adaptability factor CLAF in a strong electromagnetic field environment: Step 4: Calculate the adaptability factor of the current transformer overload inductive load under strong electromagnetic field environment 1) An electromagnetic field with a high magnetic field strength is generated by an electromagnetic interference generator (6). At this time, the current transformer can still work normally in the electromagnetic field environment inside the test box (1). The magnetic field strength at this time is recorded as H0, with a unit of A / m; the power supply device (4) provides electric energy to the current transformer. The rated current flowing through the primary side of the current transformer is recorded as I0, with a unit of A; the rated voltage of the primary side of the current transformer is recorded as U0, with a unit of V; the rated load connected to the secondary side of the current transformer at this time is obtained by the load measurement device (10). The load is an inductive load and is recorded as X l0 , in Ω; the value measured by the first temperature sensor (11) is denoted as T Lf0 The measured value of the second temperature sensor (12) is recorded as T Ls0 The value measured by the third temperature sensor (13) is denoted as T Lt0 , the unit is ℃; 2) To ensure that the current transformer can still work normally and not damage its internal structure, gradually increase the inductive load by 0.05X each time. l0 , increased 4 times, respectively 0.05X l0 , 0.1X l0 , 0.15X l0 , 0.2X l0 , the value measured by the current measuring device (8) is recorded as I Li , i = 1, 2, 3, 4, all in A; the value measured by the voltage measuring device (9) is recorded as U Li , the unit is V; the value measured by the first temperature sensor (11) is recorded as T Lfi The measured value of the second temperature sensor (11) is denoted as T Lsi The third temperature sensor (11) measures a value denoted as T Lti ; The above temperature units are all ℃; The above measured values ​​when i=1, 2, 3, 4 correspond to the inductive load increasing by 0.05X l0 , 0.1X l0 , 0.15X l0 , 0.2X l0 ; 3) Calculate the current transformer overload inductive load adaptability factor ILAF in a strong electromagnetic field environment: Step 5: Calculate the overload adaptability factor OAF of the current transformer under strong electromagnetic field environment: Among them, a, b, and c represent the weight coefficients of resistive, capacitive, and inductive loads, respectively, which can be determined according to the importance of different load types in actual application scenarios; Step 6: Evaluate the overload capacity of the current transformer in a strong electromagnetic field environment The current transformer overload adaptability factor OAF is used to evaluate the overload capacity of the current transformer. If the adaptability factor OAF ≥ 1, it means that the current transformer has good overload capacity and adaptability and can work stably in a strong electromagnetic field environment; if the adaptability factor OAF < 1, it means that the current transformer overload capacity and adaptability are poor, and measures need to be taken, such as replacing equipment or limiting the load.

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