Transformer explosion-proof and fault monitoring device and method

Abstract

The invention discloses a transformer explosion-proof and fault monitoring device and method, and belongs to the technical field of power equipment. The specific device comprises a transformer oil tank pressure reduction module, an on-load tap-changer pressure reduction module, an oil and gas separation tank, a gas discharge pipeline, a nitrogen injection module, a transformer protection control cubicle, an oil-immersed cable oil tank pressure reduction module and a transformer module. The specific method comprises the following steps: acquiring transformer data; calculating a power factor / loss factor according to the acquired transformer bushing current; setting early warning threshold values of transformer capacitance, a power factor / loss factor and a partial discharge signal, and judging whether the data reach the corresponding early warning threshold values or not; and after any data in the judgment result reaches an early warning threshold value, judging that the transformer has a fault, triggering early warning and performing transformer pressure relief, thereby realizing explosion prevention and fault monitoring of the transformer. According to the invention, pressure relief protection of the transformer cable box, the on-load tap-changer module and the main oil tank is realized, and online monitoring and fault diagnosis of key monitoring signals are provided.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric power equipment, and in particular relates to explosion-proof technology for transformers, and more particularly to an explosion-proof and fault monitoring device and method for transformers. Background Art

[0002] Currently, transformers are widely used in power transmission and distribution systems. However, there is a risk of oil tank explosion and combustion during operation, especially under internal defect conditions such as short circuit and arc fault.

[0003] In the prior art, transformer explosions are usually caused by low impedance faults, which cause the oil to lose its insulating properties. The oil is vaporized, and the resulting gas increases in pressure due to liquid inertia, forming a pressure wave that causes the transformer to explode. These explosions usually result in expensive losses of power facilities. The prior art fails to effectively prevent explosions and fires caused by internal faults in transformers, fails to achieve real-time monitoring of internal faults in transformers, and fails to relieve pressure in a timely manner after a fault.

[0004] The existing technology does not clearly provide pressure relief protection measures for the key areas of the transformer equipment, such as the transformer oil tank, on-load tap changer and oil-immersed cable tank pressure reducing module. It is impossible to realize online operation health status monitoring and diagnosis of transformer equipment data, and it is impossible to timely know and obtain the direction of fault location after a transformer failure. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a transformer explosion-proof method, which can monitor multiple signals and prevent transformer explosion and fire through direct mechanical response once a transformer fails.

[0006] The present invention adopts the following technical solution.

[0007] A first aspect of the present invention provides a transformer explosion-proof and fault monitoring device, including a transformer oil tank pressure relief module, an on-load tap changer pressure relief module, an oil and gas separation tank, a gas discharge pipeline, a nitrogen injection module, a transformer protection control cabinet, an oil-immersed cable tank pressure relief module and a transformer module.

[0008] The transformer protection control cabinet is connected to the transformer module to monitor transformer module failures and issue early warnings, store nitrogen, and trigger transformer pressure relief;

[0009] The nitrogen injection module is connected to the transformer module and is used to inject nitrogen into the transformer box of the transformer module to cool the transformer and realize explosion-proof of the transformer;

[0010] The transformer module is connected with the transformer oil tank pressure relief module, the on-load tap changer pressure relief module and the oil-immersed cable oil tank pressure relief module to discharge oil and gas from the transformer oil tank, the on-load tap changer oil tank and the cable box oil circuit of the transformer module;

[0011] The transformer oil tank pressure reducing module is connected to the oil and gas separation tank and is used to transport the oil and gas in the transformer oil tank to the oil and gas separation tank;

[0012] The on-load tap changer pressure reducing module is connected to the oil and gas separation tank and is used to transport the oil and gas in the on-load tap changer oil tank to the oil and gas separation tank;

[0013] The oil-immersed cable oil tank pressure reducing module is connected to the oil and gas separation tank and is used to transport the oil and gas in the cable box oil circuit to the oil and gas separation tank;

[0014] The oil and gas separation tank is connected to the gas discharge pipeline and is used to separate the gas from the oil.

[0015] Preferably, the transformer protection control cabinet includes a data acquisition unit, a data processing unit, a pressure relief control unit and a nitrogen storage unit. The data acquisition unit is connected to the transformer module and is used for real-time monitoring of the transformer capacitance, transformer bushing current and partial discharge signal. The data acquisition unit is connected to the data processing unit and is used to transmit the collected data to the data processing unit.

[0016] Preferably, the data processing unit is connected to the pressure relief control unit and is used for receiving collected data, calculating power factor / dissipation factor, fault judgment, early warning and sending early warning signals.

[0017] Preferably, the pressure relief control unit of the transformer protection control cabinet is connected to the transformer module for receiving the early warning signal of the data processing unit, and triggering the discharge of oil and gas from the transformer oil tank of the transformer module by releasing the mechanical energy of the pressurized oil and gas.

[0018] Preferably, the nitrogen storage unit of the transformer protection control cabinet is connected to the pressure relief control unit, the nitrogen storage unit is used to store nitrogen, and receives the pressure relief signal of the pressure relief control unit to discharge nitrogen;

[0019] The nitrogen storage unit of the transformer protection control cabinet is connected to the nitrogen injection module to discharge nitrogen into the nitrogen injection module.

[0020] Preferably, the nitrogen storage unit of the transformer protection control cabinet is located in the safe area of ​​the transformer module, and is connected to the sensor equipment on the transformer box of the transformer module and the oil and gas separation tank circuit through cables to realize fault detection and oil and gas separation control, while storing explosion-proof nitrogen.

[0021] Preferably, the end of the gas discharge pipeline is located in a safe area of ​​the transformer module, and is used to discharge the gas separated from the oil and gas in the oil and gas separation tank to a remote area.

[0022] The second aspect of the present invention provides a transformer explosion-proof and fault monitoring method, which is operated on a transformer explosion-proof and fault monitoring device as described in the first aspect of the present invention, comprising:

[0023] Collect transformer data, including transformer capacitance, transformer bushing current and partial discharge signal;

[0024] Calculate the power factor / dissipation factor based on the collected transformer bushing current;

[0025] Set the warning thresholds for transformer capacitance, power factor / dissipation factor, and partial discharge signal, and determine whether the transformer capacitance, power factor / dissipation factor, and partial discharge signal have reached the corresponding warning thresholds;

[0026] When any data in the judgment result reaches the warning threshold, the transformer is judged to be faulty, the warning is triggered and the transformer is depressurized to achieve transformer explosion protection and fault monitoring.

[0027] Preferably, the loss factor is obtained by the ratio of the transformer bushing current to the standard current without fault;

[0028] The power factor is obtained by the ratio of the transformer bushing current to the vector sum of the transformer bushing current and the normal current without fault.

[0029] Preferably, when the partial discharge signal is greater than a set threshold, the defect position in the transformer tank is located according to the propagation time and propagation speed of the acoustic wave signal from the partial discharge source to the tank wall, and a fault warning is triggered.

[0030] Compared with the prior art, the beneficial effects of the present invention include at least:

[0031] The present invention provides pressure relief protection measures for the cable box, on-load tap changer module, and main oil tank in the key equipment area of ​​the transformer. The present invention proposes online monitoring status evaluation and intelligent fault diagnosis of equipment in the key area of ​​the transformer equipment based on key monitoring signals of capacitance, power factor, and frequency response partial discharge. After a fault occurs, R&D personnel can further determine the cause of the fault based on the early warning information, which provides a direction for subsequent processing for R&D personnel.

[0032] The present invention can quickly respond to the increase in internal pressure of the transformer after an accident occurs, greatly improve the accuracy and processing efficiency of equipment fault diagnosis, and effectively prevent transformer explosion and fire;

[0033] It reduces the expensive losses caused by transformer explosion and has significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic diagram of a transformer explosion-proof and fault monitoring device provided according to an embodiment of the present invention;

[0035] Figure 2 is a schematic diagram of a method for calculating a power factor of a transformer device provided in accordance with an embodiment of the present invention;

[0036] Figure 3 The present invention is a schematic diagram of transformer partial discharge signal collection according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0038] like Figure 1 As shown, embodiment 1 of the present invention provides a transformer explosion-proof and fault monitoring device, including: a transformer oil tank decompression module 1, an on-load tap changer decompression module 2, an oil and gas separation tank 3, a gas discharge pipeline 4, a nitrogen injection module 5, a transformer protection control cabinet 6, an oil-immersed cable tank decompression module 7 and a transformer module 8.

[0039] The transformer protection control cabinet 6 is connected to the transformer module 8 and is used to monitor the failure of the transformer module 8 and issue an early warning, store nitrogen, and trigger the transformer to release pressure;

[0040] The transformer protection control cabinet 6 includes a data acquisition unit, a data processing unit, a pressure relief control unit and a nitrogen storage unit. The data acquisition unit is connected to the transformer module 8 and is used for real-time monitoring of the transformer capacitance, transformer bushing current and partial discharge signal. The data acquisition unit is connected to the data processing unit and is used to transmit the collected data to the data processing unit.

[0041] The data processing unit is connected to the pressure relief control unit and is used for receiving collected data, calculating power factor / loss factor, fault judgment, early warning and sending early warning signals.

[0042] The pressure relief control unit of the transformer protection control cabinet 6 is connected to the transformer module 8 and is used to receive the early warning signal of the data processing unit. By releasing the mechanical energy of the pressurized oil and gas, the oil and gas are triggered to be discharged from the transformer oil tank of the transformer module 8.

[0043] The nitrogen storage unit of the transformer protection control cabinet 6 is connected to the pressure relief control unit. The nitrogen storage unit is used to store nitrogen and receive the pressure relief signal of the pressure relief control unit to discharge nitrogen;

[0044] The nitrogen storage unit of the transformer protection control cabinet 6 is connected to the nitrogen injection module 5 and is used to discharge nitrogen into the nitrogen injection module 5 .

[0045] The nitrogen storage unit of the transformer protection control cabinet 6 is located in the safe area of ​​the transformer module 8. It is connected to the sensor equipment on the transformer box of the transformer module 8 and the oil and gas separation tank 3 through cables to realize fault detection and oil and gas separation control, and store explosion-proof nitrogen at the same time.

[0046] The transformer module 8 is connected to the transformer oil tank pressure relief module 1, the on-load tap changer pressure relief module 2 and the oil-immersed cable oil tank pressure relief module 7, and is used to discharge oil and gas from the transformer oil tank, the on-load tap changer oil tank and the cable box oil circuit of the transformer module 8 respectively;

[0047] The transformer oil tank pressure reducing module 1 is connected to the oil and gas separation tank 3 and is used to transport the main pressure oil and gas in the transformer oil tank to the oil and gas separation tank 3;

[0048] The on-load tap changer pressure reducing module 2 is connected to the oil and gas separation tank, and is used to transport the high-pressure oil and gas in the on-load tap changer oil tank to the oil and gas separation tank 3;

[0049] The oil-immersed cable oil box pressure reducing module 7 is connected to the oil and gas separation tank 3 and is used to transport the high-pressure oil and gas in the oil circuit of the transformer cable box to the oil and gas separation tank 3 through the device.

[0050] Each branch pipeline of the oil and gas separation tank 3 is connected to the transformer oil tank pressure reducing module 1, the on-load tap changer pressure reducing module 2, and the oil-immersed cable oil tank pressure reducing module 7, and is used for the absorption and storage of high-pressure oil and gas and the oil and gas separation and discharge functions.

[0051] The oil and gas separation tank 3 is connected to the gas discharge pipeline 4, the end of which is located in the safe area of ​​the principle transformer and is connected to 3 for high-pressure gas discharge after oil and gas separation;

[0052] The end of the gas discharge pipeline 4 is located in a safe area of ​​the transformer module 8 and is used to discharge the gas separated from the oil and gas separation tank 3 to a remote area.

[0053] The nitrogen injection module 5 is connected to the transformer module 8 and is used to inject nitrogen into the transformer box of the transformer module 8 to cool the transformer and realize explosion-proof of the transformer;

[0054] The nitrogen injection module 5 is connected to the transformer protection control cabinet 6. Once the module is activated due to an electrical fault, nitrogen is injected from the transformer protection control cabinet 6 into the transformer box through the nitrogen injection module 5 to play a cooling and explosion-proof role.

[0055] Compared with the prior art, the beneficial effects of the present invention include at least:

[0056] The present invention provides pressure relief protection measures for the cable box, on-load tap changer module, and main oil tank in the key equipment area of ​​the transformer. The present invention proposes online monitoring status evaluation and intelligent fault diagnosis of equipment in the key area of ​​the transformer equipment based on key monitoring signals of capacitance, power factor, and frequency response partial discharge. After a fault occurs, R&D personnel can further determine the cause of the fault based on the early warning information, which provides a direction for subsequent processing for R&D personnel.

[0057] The present invention can quickly respond to the increase in internal pressure of the transformer after an accident occurs, greatly improve the accuracy and processing efficiency of equipment fault diagnosis, and effectively prevent transformer explosion and fire;

[0058] It reduces the expensive losses caused by transformer explosion and has significant economic and social benefits.

[0059] Embodiment 2 of the present invention provides a transformer explosion-proof and fault monitoring method, which is operated on a transformer explosion-proof and fault monitoring device described in Embodiment 1, and includes:

[0060] Step 1: Collect transformer data, including transformer capacitance, transformer bushing current and partial discharge signal;

[0061] Collect data on partial discharge phenomena and discharge location measurement and analysis, such as Figure 3 As shown, the collection point 10 of the control cabinet collects the partial discharge signal of the partial discharge collection point 9.

[0062] Step 2: Calculate the power factor / dissipation factor based on the transformer bushing current collected in step 1;

[0063] Solve for the transformer capacitance and power factor / dissipation factor (PF / DF), such as Figure 2 As shown: The loss factor, also called tan(δ), is calculated by taking the tangent of the angle δ between the measured current and the ideal current that would occur if there were no losses; the power factor is the cosine of the angle φ between the output voltage and the measured current, and is therefore also called cos(φ).

[0064] The current through the transformer bushing I R Compared with the normal current I C The ratio of tan(δ) to obtain the loss factor;

[0065] The current through the transformer bushing I Rand transformer bushing current I R and the standard current I C The ratio between the vector of and I, cos(φ), gives the power factor.

[0066] Step 3: Set the warning thresholds of transformer capacitance, power factor / dissipation factor and partial discharge signal, and determine whether the transformer capacitance, power factor / dissipation factor and partial discharge signal reach the corresponding warning thresholds;

[0067] Setting thresholds for capacitance and power factor / dissipation factor: Capacitance and power factor / dissipation factor measurements are used to check the insulation condition of power transformers and bushings. High oil conductivity, aging, and increased moisture content are symptoms of insulation aging, which also lead to increased losses, which can be quantified by measuring power factor or dissipation factor; capacitance exceeding the threshold indicates partial breakdown between the capacitive layers of the bushing. By measuring capacitance and losses, insulation problems can be detected before failure occurs.

[0068] After the partial discharge signal is collected, it is analyzed and diagnosed at the control cabinet and compared with the set thresholds of partial discharge phenomenon and discharge position. Once the partial discharge is abnormal, the control cabinet will give corresponding treatment measures to avoid transformer explosion accidents caused by partial discharge.

[0069] Step 4: When any data in the judgment result reaches the warning threshold, the transformer is judged to be faulty, the warning is triggered and the transformer is depressurized to achieve transformer explosion protection and fault monitoring.

[0070] Determine whether the fault is an insulation aging fault based on the judgment results of capacitance, power factor / dissipation factor and set threshold;

[0071] Based on the partial discharge phenomenon, the discharge location and the determination results of the set threshold, it is determined whether the fault is caused by aging, contamination or defects of the insulation material between different voltage potentials of the transformer.

[0072] Multiple acoustic sensors are magnetically mounted on the surface of the power transformer tank. Each sensor measures the propagation time of the acoustic signal from the partial discharge source to the tank wall. Through the acoustic partial discharge measurement, the weak points or defects of the insulation can be accurately located. The data collected by these sensors are compared simultaneously to accurately identify the defect location. When the partial discharge signal is greater than the set threshold, the defect location in the transformer tank is located based on the propagation time and propagation speed of the acoustic signal from the partial discharge source to the tank wall, and a fault warning is triggered.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A transformer explosion-proof and fault monitoring device, comprising a transformer oil tank decompression module (1), an on-load tap changer decompression module (2), an oil and gas separation tank (3), a gas discharge pipeline (4), a nitrogen injection module (5), a transformer protection control cabinet (6), an oil-immersed cable tank decompression module (7) and a transformer module (8), characterized in that: The transformer protection control cabinet (6) is connected to the transformer module (8) and is used to monitor the failure of the transformer module (8) and issue an early warning, store nitrogen, and trigger transformer pressure relief; The nitrogen injection module (5) is connected to the transformer module (8) and is used to inject nitrogen into the transformer box of the transformer module (8) to cool the transformer and realize explosion-proof of the transformer; The transformer module (8) is connected to the transformer oil tank pressure relief module (1), the on-load tap changer pressure relief module (2) and the oil-immersed cable oil tank pressure relief module (7) to discharge oil and gas from the transformer oil tank, the on-load tap changer oil tank and the cable box oil circuit of the transformer module (8); The transformer oil tank decompression module (1) is connected to the oil and gas separation tank (3) and is used to transport the oil and gas in the transformer oil tank to the oil and gas separation tank (3); The on-load tap changer pressure reducing module (2) is connected to the oil and gas separation tank (3) and is used to transport the oil and gas in the on-load tap changer oil tank to the oil and gas separation tank (3); The oil-immersed cable oil box decompression module (7) is connected to the oil and gas separation tank (3) and is used to transport the oil and gas in the cable box oil circuit to the oil and gas separation tank (3); The oil and gas separation tank (3) is connected to the gas discharge pipeline (4) and is used to separate the gas from the oil.

2. A transformer explosion-proof and fault monitoring device according to claim 1, characterized in that: The transformer protection control cabinet (6) comprises a data acquisition unit, a data processing unit, a pressure relief control unit and a nitrogen storage unit. The data acquisition unit is connected to the transformer module (8) and is used for real-time monitoring of transformer capacitance, transformer bushing current and partial discharge signals. The data acquisition unit is connected to the data processing unit and is used for transmitting the collected data to the data processing unit.

3. A transformer explosion-proof and fault monitoring device according to claim 2, characterized in that: The data processing unit is connected to the pressure relief control unit and is used for receiving collected data, calculating power factor / loss factor, fault judgment, early warning and sending early warning signals.

4. A transformer explosion-proof and fault monitoring device according to claim 2, characterized in that: The pressure relief control unit of the transformer protection control cabinet (6) is connected to the transformer module (8) and is used for receiving the early warning signal of the data processing unit. By releasing the mechanical energy of the pressurized oil and gas, the oil and gas are triggered to be discharged from the transformer oil tank of the transformer module (8).

5. The transformer explosion-proof and fault monitoring device according to claim 2, characterized in that: The nitrogen storage unit of the transformer protection control cabinet (6) is connected to the pressure relief control unit, and the nitrogen storage unit is used to store nitrogen and receive a pressure relief signal from the pressure relief control unit to discharge nitrogen; The nitrogen storage unit of the transformer protection control cabinet (6) is connected to the nitrogen injection module (5) and is used to discharge nitrogen into the nitrogen injection module (5).

6. The transformer explosion-proof and fault monitoring device according to claim 5, characterized in that: The nitrogen storage unit of the transformer protection control cabinet (6) is located in the safe area of ​​the transformer module (8), and is connected to the sensing equipment on the transformer box of the transformer module (8) and the oil and gas separation tank (3) through cables to realize fault detection and oil and gas separation control, while storing explosion-proof nitrogen.

7. The transformer explosion-proof and fault monitoring device according to claim 1, characterized in that: The end of the gas discharge pipeline (4) is located in a safe area of ​​the transformer module (8) and is used to discharge the gas separated from the oil and gas in the oil and gas separation tank (3) to a remote area.

8. A transformer explosion-proof and fault monitoring method, running on a transformer explosion-proof and fault monitoring device according to any one of claims 1 to 7, characterized in that: Collect transformer data, including transformer capacitance, transformer bushing current and partial discharge signal; Calculate the power factor / dissipation factor based on the collected transformer bushing current; Set the warning thresholds for transformer capacitance, power factor / dissipation factor, and partial discharge signal, and determine whether the transformer capacitance, power factor / dissipation factor, and partial discharge signal have reached the corresponding warning thresholds; When any data in the judgment result reaches the warning threshold, the transformer is judged to be faulty, the warning is triggered and the transformer is depressurized to achieve transformer explosion protection and fault monitoring.

9. A transformer explosion-proof and fault monitoring method according to claim 8, characterized in that: The loss factor is obtained by the ratio of the transformer bushing current to the standard current without fault. The power factor is obtained by the ratio of the transformer bushing current to the vector sum of the transformer bushing current and the normal current without fault.

10. A transformer explosion-proof and fault monitoring method according to claim 8, characterized in that: When the partial discharge signal is greater than the set threshold, the defect position in the transformer tank is located based on the propagation time and propagation speed of the acoustic wave signal from the partial discharge source to the tank wall, and a fault warning is triggered.

Images