Novel current transformer

Abstract

The utility model relates to a novel current transformer which comprises an insulating porcelain bushing, an oil tank located at the bottom of the insulating porcelain bushing and a metal expander assembly located at the top of the insulating porcelain bushing, the metal expander assembly comprises an expander shell and a metal expander located in the expander shell, and the metal expander is communicated with the oil tank through an inner cavity of the insulating porcelain bushing. A laser displacement sensor is arranged in the expander shell and comprises a transmitting end and a receiving end, and the transmitting end and the receiving end are located on the outer side of the metal expander and the inner side of the expander shell respectively. A temperature sensor, a pressure sensor and a hydrogen sensor are arranged in the metal expander and used for detecting the temperature, the pressure and the hydrogen concentration in the mutual inductor. The current transformer can monitor the displacement change of the metal expander and parameters such as the temperature, the pressure and the hydrogen concentration in the transformer in real time under the conventional function of detecting the current magnitude, monitoring is comprehensive, and whether the current transformer breaks down or not and the severity degree are known in time.

Description

Technical Field

[0001] The utility model relates to the technical field of mutual inductors, in particular to a novel current mutual inductor. Background Art

[0002] Current transformer is an important power equipment used to isolate high voltage and high current power system from low voltage and safe secondary equipment such as measuring instruments and control equipment. However, traditional current transformers are mainly designed based on the principle of electromagnetic induction. They are usually composed of a primary coil, a secondary coil and an iron core. The primary coil passes the current to be measured, while the secondary coil is used to induce a small current. The main advantages of traditional current transformers are simplicity, reliability and economy, but there are also some shortcomings, such as susceptibility to interference, low accuracy and difficulty in digitalization. Moreover, traditional current transformers often only focus on the measurement of current, and lack monitoring and compensation for other physical parameters in the environment, making the measured current value easily affected by environmental factors.

[0003] The design of new current transformers is also constantly improving. Compared with traditional current transformers, the traditional current transformers are integrated with measurement sensors. It not only retains the perception and amplification function of the traditional current transformer on the current, but also introduces the high-precision measurement capability of the sensor. This makes the new current transformer significantly improved in key performances such as measurement accuracy, response speed and stability. The utility model patent with authorization announcement number CN208171323U discloses a high-voltage oil-immersed current transformer detection system, including a temperature and pressure detection unit. The temperature and pressure detection unit includes a temperature sensor and a pressure sensor for measuring the temperature and pressure in the current transformer and transmitting the measured data remotely. The temperature and pressure detection unit also includes a hydrogen concentration measurement module for measuring the hydrogen concentration in the current transformer. The increase in gas temperature, pressure and H2 concentration can be used to judge whether the equipment may discharge and overheat, resulting in a large amount of gas generated inside.

[0004] Therefore, it is of great practical value to develop a new current transformer that can monitor hydrogen, displacement, temperature, pressure and compensate for environmental physical parameters in real time. Utility Model Content

[0005] The purpose of the utility model is to provide a new type of current transformer, which can monitor the hydrogen concentration, displacement, temperature and pressure parameters in the transformer in real time on the premise of having the traditional current magnitude monitoring function.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A new type of current transformer includes an insulating porcelain sleeve, an oil tank located at the bottom of the insulating porcelain sleeve, and a metal expander assembly located at the top of the insulating porcelain sleeve. The metal expander assembly includes an expander shell and a metal expander located in the expander shell. The metal expander is connected to the oil tank through the inner cavity of the insulating porcelain sleeve. A laser displacement sensor is arranged in the expander shell. The laser displacement sensor includes a transmitting end and a receiving end. The transmitting end and the receiving end are respectively located on the outside of the metal expander and the inside of the expander shell. A temperature sensor, a pressure sensor, and a hydrogen sensor are also arranged in the metal expander, which are respectively used to detect the temperature, pressure, and hydrogen concentration in the current transformer.

[0008] Furthermore, the temperature sensor, pressure sensor and hydrogen sensor are integrated three-in-one sensors, which are arranged in the metal expander, and the three-in-one sensor is connected to the signal processing module through a data line.

[0009] Furthermore, the oil tank top cover is provided with a pressure release device, and the pressure release device adopts an explosion-proof pipe or a pressure releaser.

[0010] Furthermore, an oil drain port is provided at the bottom of the oil tank.

[0011] Furthermore, an oil filling port is provided on the expander housing and is connected to the metal expander through an oil pipe.

[0012] Beneficial effects of the utility model:

[0013] The utility model current transformer can monitor the displacement change of the metal expander in real time by adding a laser displacement sensor to the current transformer, based on the traditional primary winding and secondary winding which can only detect the current size. When the displacement change exceeds the set threshold, an alarm can be issued. The current transformer is also equipped with temperature, pressure, and hydrogen sensors to comprehensively monitor the operating status of the transformer, and judge whether the current transformer has a fault and the severity of the fault through parameters such as temperature, pressure, and hydrogen concentration. Furthermore, the detected temperature can also be used to perform temperature compensation for the detected current parameters to improve the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the current transformer of the utility model.

[0015] The names corresponding to the marks in the figure are:

[0016] 1. Base; 2. Secondary winding; 3. Expander housing; 4. Laser displacement sensor; 5. Oil filling port; 6. Metal expander; 7. Three-in-one sensor; 8. Primary wiring terminal; 9. Insulating porcelain sleeve; 10. Insulating oil; 11. Primary winding; 12. Oil tank; 13. Signal processing module; 14. Pressure release device; 15. Secondary end signal receiving module; 16. Oil drain port. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the utility model.

[0018] Embodiments of the present utility model:

[0019] like Figure 1 As shown, the novel current transformer comprises a base 1, an insulating porcelain sleeve 9, an oil tank 12 at the bottom of the insulating porcelain sleeve 9, a metal expander 6 component at the top of the insulating porcelain sleeve 9, a primary winding 11, and a secondary winding 2. The insulating porcelain sleeve 9 is used to protect the insulation layer of the transformer, and is made of ceramic material. As the shell of the current transformer, it can withstand high voltage and ensure the safe operation of the current transformer.

[0020] The oil tank 12 is used to store insulating oil 10, and is also equipped with an oil level indicator (belonging to the prior art) inside, which is convenient for observing the oil level changes in the transformer. The top cover of the oil tank 12 is provided with a pressure release device 14, and the pressure release device 14 adopts an explosion-proof pipe or a pressure releaser. The explosion-proof pipe is installed on the top cover of the transformer, the pipe is connected to the atmosphere, and the pipe mouth is sealed with a film. When there is a fault inside the transformer, the oil temperature rises, the oil decomposes violently to produce a large amount of gas, which causes the pressure in the oil tank 12 to increase sharply, the explosion-proof pipe film is broken, and the oil and gas are sprayed out from the pipe mouth to prevent the transformer oil tank 12 from exploding or deforming. The pressure releaser is similar to the safety valve of a boiler. When the pressure in the oil tank 12 exceeds the specified value, the sealing door (valve) of the pressure releaser is pushed open and the gas is discharged.

[0021] An oil drain port 16, i.e., an oil drain valve, is provided at the bottom of the oil tank 12, which can be opened to drain the oil when necessary for maintenance or other operations.

[0022] The metal expander 6 assembly includes an expander housing 3 and a metal expander 6 located in the expander housing 3. The metal expander 6 is connected to the oil tank 12 through the inner cavity of the insulating porcelain sleeve 9. The main body of the metal expander 6 is an elastic element. When the volume of the insulating oil 10 in the mutual inductor changes due to temperature changes, the volume of the expander main body changes accordingly, which plays a role in volume compensation.

[0023] A laser displacement sensor 4 is provided in the expander housing 3. The laser displacement sensor 4 includes a transmitting end and a receiving end. The transmitting end and the receiving end are respectively located on the outside of the metal expander 6 and the inside of the expander housing 3, and are arranged relatively spaced up and down. The laser displacement sensor 4 monitors the displacement between the metal expander 6 and the expander housing 3, and sends an alarm signal when the displacement of the expander exceeds a certain threshold.

[0024] The expander housing 3 is provided with an oil filling port 5 which is connected to the metal expander 6 via an oil pipe. Oil filling is carried out through the oil filling port 5 .

[0025] A temperature sensor, a pressure sensor, and a hydrogen sensor are also provided in the metal expander 6, which are used to detect the temperature, pressure, and hydrogen concentration in the current transformer, respectively. The temperature sensor, the pressure sensor, and the hydrogen sensor are integrated three-in-one sensors 7, which are provided in the metal expander 6, and the three-in-one sensor 7 is connected to the signal processing module 13 via a data line. The signal processing module 13 is located at the lower part of the transformer, at the secondary side device, and can process the collected signals and transmit them to the monitoring terminal through the wireless communication module for the staff to view, and remind when the corresponding data exceeds the set threshold.

[0026] By using the monitored temperature parameters, the current measured by the current transformer can also be compensated to improve the measurement accuracy of the current transformer.

[0027] The primary winding 11 and the secondary winding 2 are used to realize the conversion and transmission of current. The primary winding 11 is the main winding in the mutual inductor, made of a wire or foil, and is used to pass current. The magnetic field generated by the current in the primary winding 11 will be transferred to the secondary winding 2 through the magnetic core. The secondary winding 2 is the secondary winding in the mutual inductor, made of a thin wire, and is used to sense the magnetic field generated by the primary winding 11. The output voltage of the secondary winding 2 is proportional to the current of the primary winding 11, and the current of the primary winding 11 can be indirectly measured by measuring the voltage of the secondary winding 2. The secondary end signal receiving module 15 is used to receive the output signal from the secondary winding 2, process the signal, and output the corresponding measurement result.

Claims

1. A new type of current transformer, comprising an insulating porcelain sleeve, an oil tank located at the bottom of the insulating porcelain sleeve, and a metal expander assembly located at the top of the insulating porcelain sleeve, characterized in that: The metal expander assembly includes an expander shell and a metal expander located in the expander shell. The metal expander is connected to the oil tank through the inner cavity of the insulating porcelain sleeve. A laser displacement sensor is provided in the expander shell. The laser displacement sensor includes a transmitting end and a receiving end. The transmitting end and the receiving end are respectively located on the outside of the metal expander and the inside of the expander shell. A temperature sensor, a pressure sensor and a hydrogen sensor are also provided in the metal expander, which are respectively used to detect the temperature, pressure and hydrogen concentration in the current transformer.

2. The new current transformer according to claim 1 is characterized in that: The temperature sensor, pressure sensor and hydrogen sensor are integrated three-in-one sensors, which are arranged in the metal expander. The three-in-one sensor is connected to the signal processing module through a data line.

3. The new current transformer according to claim 1 is characterized in that: The oil tank top cover is provided with a pressure release device, and the pressure release device adopts an explosion-proof pipe or a pressure releaser.

4. The new current transformer according to claim 1 is characterized in that: An oil drain port is arranged at the bottom of the oil tank.

5. The new current transformer according to any one of claims 1 to 4, characterized in that: The expander shell is provided with an oil filling port, which is connected with the metal expander through an oil pipe.

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