A method and apparatus for detecting the interlayer insulation condition of a dry-type transformer.

Abstract

This invention belongs to the field of insulation condition detection technology, specifically relating to a method and apparatus for detecting the interlayer insulation condition of a dry-type transformer. The steps include: building a layered simulation analysis model of the dry-type transformer in finite element simulation software; determining the resistance values ​​of the critical state of interlayer insulation degradation and the critical state of insulation collapse of the dry-type transformer through interlayer insulation fault tests; simulating and obtaining the sensitive state quantity values ​​under the critical state of interlayer insulation degradation and the critical state of insulation collapse; collecting the voltage and current of the three-phase high-voltage and low-voltage windings of the dry-type transformer under actual operating conditions, calculating the actual sensitive state quantity values ​​of each phase during the operation of the dry-type transformer, comparing them with the simulation values, and determining the interlayer insulation condition of each phase of the dry-type transformer under test. This invention achieves accurate and real-time monitoring and early warning of the interlayer insulation condition of dry-type transformers, effectively reducing fault risks and ensuring the safe and stable operation of the power system.

Description

Technical Field

[0001] This invention belongs to the field of insulation condition detection technology, specifically relating to a method and apparatus for detecting the interlayer insulation condition of a dry-type transformer. Background Technology

[0002] Dry-type transformers, as high-performance power equipment, possess numerous advantages such as low maintenance pressure, high efficiency, energy saving and environmental protection, fire resistance, and explosion protection. They are widely used in power distribution systems, accounting for nearly 50% of the total transformer usage. However, during operation, dry-type transformers are susceptible to inter-layer insulation faults due to various factors including manufacturing processes, temperature, humidity, voltage stress, mechanical vibration, and load characteristics. According to relevant statistics, the proportion of inter-layer insulation faults in dry-type transformers is showing an increasing trend year by year, becoming one of the significant hidden dangers threatening the safe and stable operation of dry-type transformers.

[0003] Traditional insulation monitoring methods are mostly based on the assessment of overall insulation performance, making it difficult to accurately identify localized interlayer insulation degradation in its early stages. If interlayer insulation faults are not effectively detected and addressed in the early stages, the faults will rapidly expand, easily leading to serious accidents such as transformer winding short circuits and burnouts. This will not only cause huge economic losses but may also lead to power outages, posing a serious threat to the reliability and stability of the power system. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method and device for detecting the interlayer insulation status of dry-type transformers. By combining interlayer insulation fault test and finite element simulation model, accurate and real-time monitoring and early warning of the interlayer insulation status of dry-type transformers are realized, which effectively reduces the fault risk and ensures the safe and stable operation of the power system.

[0005] To achieve the above objectives, the present invention provides a method for detecting the interlayer insulation state of a dry-type transformer, comprising the following steps:

[0006] S1. For the dry-type transformer under test, a layered simulation analysis model of the dry-type transformer is built in the finite element simulation software.

[0007] S2. Based on the current and voltage transformers and three-phase voltage regulators installed on the dry-type transformer, the resistance values ​​of the critical state of interlayer insulation deterioration and the critical state of collapse of the dry-type transformer are determined by interlayer insulation fault test.

[0008] S3. Based on the simulation analysis model of dry-type transformers, the numerical values ​​of sensitive state quantities under the critical state of interlayer insulation degradation of dry-type transformers are obtained through simulation. And the numerical values ​​of sensitive state quantities under the critical state of interlayer insulation collapse in dry-type transformers. ;

[0009] S4. Collect the voltage and current of the three-phase high-voltage and low-voltage windings of the dry-type transformer under actual operating conditions, and calculate the actual sensitive state values ​​of each phase during the operation of the dry-type transformer. ,and and By comparing the results, the interlayer insulation status of each phase of the dry-type transformer under test can be determined.

[0010] As a preferred embodiment of the present invention, in S1, a three-dimensional model consistent with the actual transformer is constructed using the "electromagnetic field-external circuit" coupling in the ANSYS finite element simulation software, and each phase winding on the high-voltage side of the three-dimensional model is constructed layer by layer according to the actual situation to obtain a dry-type transformer simulation analysis model.

[0011] As a preferred embodiment of the present invention, the method for determining the resistance values ​​of the critical state of interlayer insulation deterioration and the critical state of collapse of the dry-type transformer through interlayer insulation fault test in S2 is as follows:

[0012] S2.1 The three-phase voltage regulator is connected to the high-voltage side three-phase winding of the dry-type transformer, and the low-voltage side winding is open. The taps connecting the adjacent two layers of the high-voltage winding of the dry-type transformer are connected through contact resistors to simulate the interlayer insulation resistance under different insulation degradation levels. The current flowing through the contact resistor and the voltage across its two ends are monitored by current and voltage transformers.

[0013] S2.2. Gradually increase the voltage of the high-voltage winding through a three-phase voltage regulator. Within the maximum current range that the high-voltage winding conductors can withstand, measure the current flowing through the short-circuit turns until the maximum current that the conductors can withstand is reached and the voltage increase is stopped.

[0014] S2.3. Based on the measured curve of the relationship between the winding interlayer insulation resistance and the fault layer current, take the two interlayer insulation resistance values ​​corresponding to the two points with the largest rate of change on the curve as the resistance values ​​of the critical state of interlayer insulation deterioration and the critical state of interlayer insulation collapse. The larger resistance value is the resistance value of the critical state of interlayer insulation deterioration, and the smaller resistance value is the resistance value of the critical state of interlayer insulation collapse.

[0015] As a preferred embodiment of the present invention, the relationship between the interlayer insulation resistance of the winding and the fault layer current is expressed as follows:

[0016] ;

[0017] In the formula, This refers to the winding fault layer current; This refers to the induced voltage in the winding fault layer. For winding fault layer resistance; It represents the interlayer insulation resistance.

[0018] As a preferred embodiment of the present invention, in S3, based on the resistance values ​​of the critical state of interlayer insulation degradation and the critical state of collapse of the dry-type transformer obtained in S2, the interlayer insulation resistance value of a certain phase winding is set in the external circuit of the dry-type transformer simulation analysis model to simulate the critical state of interlayer insulation degradation and the critical state of collapse of that phase. The sensitive state quantities of the critical state of interlayer insulation degradation and the critical state of collapse of the dry-type transformer are determined according to the voltage and current sudden changes. , and verify , The error between the values ​​of the corresponding sensitive state quantities measured in the interlayer insulation fault test and the values ​​of the corresponding sensitive state quantities is within the allowable range.

[0019] As a preferred embodiment of the present invention, in S4... The calculation method is as follows: the zero-sequence component is included to measure the unbalance, the difference between the improved voltage and current unbalance is used as the sensitive state quantity, and the sensitive state quantity is standardized to a per-unit value:

[0020] Improve voltage imbalance :

[0021] ;

[0022] Improve current imbalance :

[0023] ;

[0024] Actual sensitive state quantity values :

[0025] ;

[0026] Will Per-unit valueization:

[0027] ;

[0028] In the formula, , , These represent the positive-sequence, negative-sequence, and zero-sequence voltage components on the high-voltage side of a dry-type transformer, respectively. , , These represent the positive-sequence, negative-sequence, and zero-sequence current components on the high-voltage side of a dry-type transformer, respectively. , , These represent the positive-sequence, negative-sequence, and zero-sequence voltage components on the high-voltage side of a per-unit dry-type transformer; , , These represent the positive-sequence, negative-sequence, and zero-sequence current components on the high-voltage side of a per-unit dry-type transformer, respectively.

[0029] As a preferred embodiment of the present invention, in S4, the method for determining the interlayer insulation state of each phase of the dry-type transformer being tested is as follows: when When the interlayer insulation is normal; when When the interlayer insulation is in a damaged warning state; when At that time, the interlayer insulation is in a state of collapse.

[0030] As a preferred embodiment of the present invention, when the interlayer insulation is in a damaged warning state, a warning command is issued and a visual output is made; when the interlayer insulation is in a collapsed state, a trip command is issued and a visual output is made.

[0031] As a preferred embodiment of the present invention, in S5, the voltage and current of the three-phase high-voltage and low-voltage windings of the dry-type transformer under actual working conditions are collected by an information acquisition system. The information acquisition system includes a low-voltage winding voltage / current sensor, a high-voltage winding voltage / current sensor, a signal acquisition unit, a logic analysis unit, a communication unit, and a human-machine interface. The low-voltage winding voltage / current sensor and the high-voltage winding voltage / current sensor are respectively installed in the low-voltage winding and the high-voltage winding of the dry-type transformer. The output terminal of each voltage / current sensor is connected to the signal input terminal of the signal acquisition unit. The output terminal of the signal acquisition unit is connected to the input terminal of the logic analysis unit. The output terminal of the logic analysis module is connected to the human-machine interface through the communication unit.

[0032] A device for detecting the interlayer insulation state of a dry-type transformer includes a memory, a processor, and a computer program stored in the memory and capable of running on the processor. The method described above is implemented by the processor executing the computer program.

[0033] The beneficial effects of this invention are:

[0034] This invention combines interlayer insulation fault testing with finite element simulation models to accurately determine the critical and collapse state resistance values ​​of interlayer insulation in dry-type transformers, and uses the simulation model to model the response curves under different insulation states. Based on this, sensitive state quantities in actual operation are calculated and compared with thresholds, enabling accurate identification and early warning of good, damaged, and collapse states of interlayer insulation. This effectively solves the problem that traditional detection methods struggle to identify localized interlayer degradation in its early stages, reducing the probability of accidents.

[0035] This invention utilizes ANSYS simulation software to model response curves under different insulation conditions and compares them with actual voltage and current data, significantly improving the consistency and reliability between the model and actual operating conditions. Through a modular data acquisition and processing system, real-time monitoring and analysis of the operating status of dry-type transformers are achieved. The system has a clear structure, a high degree of automation, and is widely adaptable to different types of dry-type transformers, demonstrating good engineering adaptability and promising prospects for widespread application.

[0036] This invention can not only accurately monitor the interlayer insulation status of dry-type transformers, but also issue early warning commands when insulation is damaged and trip commands when insulation collapses, effectively preventing serious accidents such as transformer burnout, ensuring the reliability and safety of transformer operation, reducing economic losses, and improving the overall stability and power supply reliability of the power system. It is of great significance to the safe and stable operation of the power system. Attached Figure Description

[0037] Figure 1 This is a flowchart illustrating the principle of this invention;

[0038] Figure 2 This is a flowchart of the present invention for determining the fault phase;

[0039] Figure 3 This is a schematic diagram of the wiring principle for interlayer insulation fault testing of dry-type transformers in an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of a dry-type transformer simulation analysis model constructed in layers based on ANSYS finite element simulation software in an embodiment of the present invention.

[0041] Figure 5 This is a side view of the simulation analysis model of a dry-type transformer;

[0042] Figure 6 This is a top view of the simulation analysis model of a dry-type transformer;

[0043] Figure 7 This is a schematic diagram of the information acquisition system in an embodiment of the present invention. Detailed Implementation

[0044] The embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0045] like Figure 1 As shown, a method for detecting the interlayer insulation state of a dry-type transformer includes the following steps:

[0046] S1. For the dry-type transformer under test, a layered simulation analysis model of the dry-type transformer is built in the finite element simulation software.

[0047] S2. Based on the current and voltage transformers and three-phase voltage regulators installed on the dry-type transformer, the resistance values ​​of the critical state of interlayer insulation deterioration and the critical state of collapse of the dry-type transformer are determined by interlayer insulation fault test.

[0048] S3. Based on the simulation analysis model of dry-type transformers, the numerical values ​​of sensitive state quantities under the critical state of interlayer insulation degradation of dry-type transformers are obtained through simulation. And the numerical values ​​of sensitive state quantities under the critical state of interlayer insulation collapse in dry-type transformers. ;

[0049] S4. Collect the voltage and current of the three-phase high-voltage and low-voltage windings of the dry-type transformer under actual operating conditions, and calculate the actual sensitive state values ​​of each phase during the operation of the dry-type transformer. ,and and By comparing the results, the interlayer insulation status of each phase of the dry-type transformer under test can be determined.

[0050] In S1, a three-dimensional model consistent with the actual transformer is built using the "electromagnetic field-external circuit" coupling in the ANSYS finite element simulation software. Each phase winding on the high-voltage side of the three-dimensional model is constructed layer by layer according to the actual situation to obtain the simulation analysis model of the dry-type transformer.

[0051] In S2, the method for determining the resistance values ​​of the critical state of interlayer insulation degradation and the critical state of collapse of dry-type transformers through interlayer insulation fault tests is as follows:

[0052] S2.1 The three-phase voltage regulator is connected to the high-voltage side three-phase winding of the dry-type transformer, and the low-voltage side winding is open. The taps connecting the adjacent two layers of the high-voltage winding of the dry-type transformer are connected through contact resistors to simulate the interlayer insulation resistance under different insulation degradation levels. The current flowing through the contact resistor and the voltage across its two ends are monitored by current and voltage transformers.

[0053] S2.2. Gradually increase the voltage of the high-voltage winding through a three-phase voltage regulator. Within the maximum current range that the high-voltage winding conductors can withstand, measure the current flowing through the short-circuit turns until the maximum current that the conductors can withstand is reached and the voltage increase is stopped.

[0054] S2.3. Based on the measured curve of the relationship between the winding interlayer insulation resistance and the fault layer current, take the two interlayer insulation resistance values ​​corresponding to the two points with the largest rate of change on the curve as the resistance values ​​of the critical state of interlayer insulation deterioration and the critical state of interlayer insulation collapse. The larger resistance value is the resistance value of the critical state of interlayer insulation deterioration, and the smaller resistance value is the resistance value of the critical state of interlayer insulation collapse.

[0055] The relationship between the interlayer insulation resistance of the winding and the fault layer current is expressed as follows:

[0056] ;

[0057] In the formula, This refers to the winding fault layer current; This refers to the induced voltage in the winding fault layer. For winding fault layer resistance; It represents the interlayer insulation resistance.

[0058] In S3, based on the resistance values ​​of the critical state of interlayer insulation degradation and the critical state of collapse of the dry-type transformer obtained in S2, the interlayer insulation resistance value of a certain phase winding is set in the external circuit of the dry-type transformer simulation analysis model. The corresponding critical state of interlayer insulation degradation and the critical state of collapse of that phase are simulated. The sensitive state quantities of the critical state of interlayer insulation degradation and the critical state of collapse of the dry-type transformer are determined according to the voltage and current abrupt changes. , and verify , The error between the values ​​of the corresponding sensitive state quantities measured in the interlayer insulation fault test and the values ​​of the corresponding sensitive state quantities is within the allowable range.

[0059] In S4, The calculation method is as follows: the zero-sequence component is included to measure the unbalance, the difference between the improved voltage and current unbalance is used as the sensitive state quantity, and the sensitive state quantity is standardized to a per-unit value:

[0060] Improve voltage imbalance :

[0061] ;

[0062] Improve current imbalance :

[0063] ;

[0064] Actual sensitive state quantity values :

[0065] ;

[0066] Will Per-unit valueization:

[0067] ;

[0068] In the formula, , , These represent the positive-sequence, negative-sequence, and zero-sequence voltage components on the high-voltage side of a dry-type transformer, respectively. , , These represent the positive-sequence, negative-sequence, and zero-sequence current components on the high-voltage side of a dry-type transformer, respectively. , , These represent the positive-sequence, negative-sequence, and zero-sequence voltage components on the high-voltage side of a per-unit dry-type transformer; , , These represent the positive-sequence, negative-sequence, and zero-sequence current components on the high-voltage side of a per-unit dry-type transformer, respectively.

[0069] The method for determining the interlayer insulation state of each phase of the dry-type transformer under test is as follows: when When the interlayer insulation is normal; when When the interlayer insulation is in a damaged warning state; when At that time, the interlayer insulation is in a state of collapse.

[0070] When the interlayer insulation is in a damaged warning state, a warning command is issued and a visual output is provided; when the interlayer insulation is in a collapsed state, a trip command is issued and a visual output is provided.

[0071] The complete process for determining the faulty phase is as follows: Figure 2 As shown, after issuing a trip command, the system determines which phase has a fault based on the values ​​of the sensitive status variables of each phase. For example, if the sensitive status variable value of phase A is the largest, then phase A is determined to be faulty.

[0072] In S5, the voltage and current of the three-phase high-voltage and low-voltage windings of the dry-type transformer under actual operating conditions are collected through an information acquisition system. The information acquisition system includes a low-voltage winding voltage / current sensor, a high-voltage winding voltage / current sensor, a signal acquisition unit, a logic analysis unit, a communication unit, and a human-machine interface. The low-voltage winding voltage / current sensor and the high-voltage winding voltage / current sensor are respectively installed in the low-voltage winding and the high-voltage winding of the dry-type transformer. The output terminal of each voltage / current sensor is connected to the signal input terminal of the signal acquisition unit. The output terminal of the signal acquisition unit is connected to the input terminal of the logic analysis unit. The output terminal of the logic analysis module is connected to the human-machine interface through the communication unit.

[0073] Figure 3 This is an exemplary wiring diagram for testing interlayer insulation faults in a dry-type transformer. Figure 3 Chinese: C TA C TB C TC For high-voltage winding current transformers; C Td High-voltage current transformers for short-circuit layer; L A L B L C L a L b L c and L A1 L A2 Inductance for high and low voltage windings and the non-short-circuit layer of the short-circuit phase; RA R B R C R a R b R c and R a1 R a2 The resistance of the high-voltage and low-voltage windings and the non-short-circuit layer of the short-circuit phase; L AD R AD For the short-circuit layer inductance and resistance; R dld Interlayer insulation resistance; U A U B U C These are the phase voltages applied to the high-voltage side of the dry-type transformer via a three-phase voltage regulator; I A I B I C I a I b I c I d The test measures the current in the high-voltage and low-voltage windings and the short-circuit layer. During the test, the low-voltage winding of the transformer is open, and the voltage of the high-voltage winding is gradually increased using a three-phase voltage regulator to detect the changes in the current flowing through the high-voltage winding and the fault layer.

[0074] Figures 4-6 This is an exemplary schematic diagram of a dry-type transformer simulation analysis model constructed layer by layer based on ANSYS finite element simulation software.

[0075] A schematic diagram of the information collection system is shown below. Figure 7 As shown, the information acquisition system includes a current acquisition system and a voltage acquisition system. In the current acquisition system, low-voltage winding current sensors and high-voltage winding current sensors are installed in the low-voltage and high-voltage windings of the dry-type transformer, respectively. The output terminal of the current sensor is connected to the signal input terminal of the signal acquisition unit, and the output terminal of the signal acquisition unit is connected to the input terminal of the logic analysis unit. The output terminal of the logic analysis module is connected to the human-machine interface through a communication unit. In the voltage acquisition system, there are low-voltage winding voltage sensors, high-voltage winding voltage sensors, a signal acquisition unit, a logic analysis unit, a communication unit, and a human-machine interface. The low-voltage winding voltage sensors and high-voltage winding voltage sensors are installed in the low-voltage and high-voltage windings of the dry-type transformer, respectively. The output terminal of the voltage sensor is connected to the signal input terminal of the signal acquisition unit, and the output terminal of the signal acquisition unit is connected to the input terminal of the logic analysis unit. The output terminal of the logic analysis module is connected to the human-machine interface through a communication unit.

[0076] The current acquisition system and the voltage acquisition system can share the same signal acquisition unit, logic analysis unit, communication unit, and human-machine interface.

[0077] Example 2: A device for detecting the interlayer insulation state of a dry-type transformer, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein the method in Example 1 is implemented by the processor executing the computer program.

Claims

1. A method of detecting the state of interlayer insulation of a dry-type transformer, characterized by It comprises the following steps: S1, for the detected dry-type transformer, a layered dry-type transformer simulation analysis model is built in finite element simulation software; S2, based on the current, voltage transformer and three-phase voltage regulator installed on the dry-type transformer, the resistance values of the dry-type transformer interlayer insulation deterioration critical state and collapse critical state are determined through interlayer insulation fault test; S3, based on the resistance values of the dry-type transformer interlayer insulation critical state and collapse critical state obtained in S2, by setting the interlayer insulation resistance value of a certain phase winding outside the dry-type transformer simulation analysis model, corresponding to simulate the interlayer insulation critical state and collapse critical state of the phase, and determine the sensitive state quantity value of the dry-type transformer interlayer insulation critical state and collapse critical state according to the voltage and current mutation , ; S4, collecting the voltage and current of three-phase high-voltage and low-voltage windings of the dry-type transformer under actual working conditions, calculating the actual sensitive state quantity value of each phase of the dry-type transformer in operation , and , and performing comparison to determine the interlayer insulation state of each phase of the detected dry-type transformer; The calculation method is: the zero sequence component is taken into account to measure the unbalance degree, the improved voltage and current unbalance degree difference is calculated, and the difference is normalized as the actual sensitive state quantity value: Improving voltage unbalance : ； Improving current imbalance : ； Computing an improved voltage, current unbalance difference : ； will be described below. normalization, to obtain : ； wherein, , , represent the positive-, negative- and zero-sequence voltage components of the high-voltage side of the dry-type transformer, respectively; , , represent the positive-, negative- and zero-sequence current components of the high-voltage side of the dry-type transformer, respectively; , , represent the normalized positive-, negative- and zero-sequence voltage components of the high-voltage side of the dry-type transformer, respectively; , , represent the normalized positive-, negative- and zero-sequence current components of the high-voltage side of the dry-type transformer, respectively.

2. The method for detecting the insulation state between layers of a dry-type transformer according to claim 1, characterized in that: In the S1, the "electromagnetic field-external circuit" coupling in the ANSYS finite element simulation software is used to build a three-dimensional model consistent with the actual transformer, and each phase winding of the high voltage side in the three-dimensional model is layered according to the actual situation to obtain the dry-type transformer simulation analysis model.

3. The method for detecting the insulation state between layers of a dry-type transformer according to claim 1, characterized in that: In the S2, the method for determining the resistance values of the dry-type transformer interlayer insulation deterioration critical state and collapse critical state through interlayer insulation fault test is: S2.1, the three-phase winding of the high voltage side of the dry-type transformer is connected with the three-phase voltage regulator, the low voltage side winding is open, the taps connected by the adjacent two layers of the high voltage winding of the dry-type transformer are connected through the contact resistance to simulate the interlayer insulation resistance under different insulation deterioration degrees, and the current flowing through the contact resistance and the voltage across the contact resistance are monitored through the current and voltage transformer; S2.2, the voltage of the high voltage winding is gradually increased through the three-phase voltage regulator, and the current flowing through the short-circuit turns is measured within the maximum current range that the conductor of the high voltage winding can withstand until the maximum current that the conductor can withstand stops increasing; S2.3, according to the measured winding interlayer insulation resistance-fault layer current relationship curve, the two interlayer insulation resistance values corresponding to the two points with the maximum change rate on the curve are taken as the resistance values of the interlayer insulation deterioration critical state and the collapse critical state, wherein the larger resistance value is the resistance value of the interlayer insulation deterioration critical state, and the smaller resistance value is the resistance value of the interlayer insulation collapse critical state.

4. The method for detecting the insulation state between layers of a dry-type transformer according to claim 3, characterized in that: The relationship between the winding interlayer insulation resistance and the fault layer current is represented as: ； wherein is the winding fault layer current; is the winding fault layer induced voltage; is the winding fault layer resistance; is the interlayer insulation resistance.

5. The method for detecting the insulation state between layers of a dry-type transformer according to claim 2, characterized in that: In the S3, the verification , is within the allowed range of error from the corresponding sensitive state quantity value measured in the interlayer insulation fault test.

6. The method for detecting the insulation state between layers of a dry-type transformer according to claim 1, characterized in that: The method for determining the interlayer insulation state of each phase of the dry-type transformer under detection in the S4 is that when the interlayer insulation is normal; when the interlayer insulation is in a damage warning state; and when the interlayer insulation is in a collapse state.

7. The method for detecting the insulation state between layers of a dry-type transformer according to claim 6, characterized in that: When the interlayer insulation is in the damage warning state, a pre-warning instruction is issued and visual output is performed; when the interlayer insulation is in the collapse state, a trip instruction is issued and visual output is performed.

8. The method for detecting the insulation state between layers of a dry-type transformer according to claim 1, characterized in that: In the S4, the voltages and currents of the three-phase high voltage and low voltage windings of the dry-type transformer under actual working conditions are collected through the information collection system, which comprises a low voltage winding voltage / current sensor, a high voltage winding voltage / current sensor, a signal collection unit, a logic analysis unit, a communication unit and a man-machine interface, the low voltage winding voltage / current sensor and the high voltage winding voltage / current sensor are respectively installed in the low voltage winding and the high voltage winding of the dry-type transformer, the output ends of each voltage / current sensor are connected with the signal input end of the signal collection unit, the output end of the signal collection unit is connected with the input end of the logic analysis unit, and the output end of the logic analysis module is connected with the man-machine interface through the communication unit.

9. A device for detecting the interlayer insulation state of a dry-type transformer, characterized in that: It comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, and the computer program is executed by the processor to realize the detection method of the interlayer insulation state of the dry-type transformer according to any one of claims 1-8.

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