Static induction machine

Abstract

The stationary induction device (100) includes a winding (120) covered with a first insulating paper (1), a thermometer (192), a heating unit (193), a second insulating paper (2), and a control unit (190). The thermometer (192) measures the temperature of the winding (120) or the periphery of the winding (120). The heating unit (193) is connected to a power supply system different from that of the winding (120). The second insulating paper is heated by the heating unit (193). The control unit (190) is electrically connected to each of the thermometer (192) and the heating unit (193). The control unit (190) adjusts the value of the current passed through the heating unit (193) so that the temperature of the second insulating paper (2) or the periphery of the second insulating paper (2) becomes equal to the value measured by the thermometer (192).

Description

[Technical field]

[0001] The present disclosure relates to stationary induction machines. [Background technology]

[0002] A prior art document disclosing the configuration of a transformer is Japanese Utility Model Application Laid-Open Publication No. 4-30712 (Patent Document 1). The transformer described in Patent Document 1 includes a tank, a sampling tank, and a sampling insulated lead wire. The tank houses a coil and an iron core, and is filled with a cooling medium. The sampling tank communicates with the tank to introduce the cooling medium, and has an opening for removing samples. The sampling insulated lead wire is provided in the sampling tank so that the load current flowing through the coil can flow therethrough, and is covered with an insulator for measuring the degree of polymerization that is formed under the same conditions as the most severely deteriorated part of the tank. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 4-30712 Summary of the Invention [Problem to be solved by the invention]

[0004] In the transformer described in Patent Document 1, a load current flows through the coil in the sampling insulated lead wire, so that the operation of the transformer must be stopped when removing the insulator for measuring the degree of polymerization.

[0005] The present disclosure has been made in consideration of the above problems, and aims to provide a stationary induction device that can collect insulating paper for polymerization degree measurement while continuing to operate the stationary induction device. [Means for solving the problem]

[0006] A stationary induction device according to the present disclosure includes a winding covered with a first insulating paper, a thermometer, a heating unit, a second insulating paper, and a control unit. The thermometer measures the temperature of the winding or the periphery of the winding. The heating unit is connected to a power supply system different from that of the winding. The second insulating paper is heated by the heating unit. The control unit is electrically connected to each of the thermometer and the heating unit. The control unit adjusts the value of a current passed through the heating unit so that the temperature of the second insulating paper or the periphery of the second insulating paper becomes equivalent to the measurement value of the thermometer. Effect of the Invention

[0007] According to the present disclosure, insulating paper for measuring the degree of polymerization can be collected while the stationary induction device continues to operate. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a configuration of a stationary induction device according to an embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A static induction device according to an embodiment will be described below with reference to the drawings. In the following description of the embodiment, the same or corresponding parts in the drawings are given the same reference numerals, and the description thereof will not be repeated. In the following embodiment, a shell-type transformer will be described as an example of the static induction device, but the static induction device is not limited to a shell-type transformer and may be, for example, a core-type transformer or a reactor. The static induction device according to the embodiment is an oil-filled transformer or an oil-filled reactor with a rated capacity of 1000 kVA or more.

[0010] Fig. 1 is a cross-sectional view showing a configuration of a stationary induction device according to an embodiment. As shown in Fig. 1, a stationary induction device 100 according to an embodiment of the present disclosure includes a winding 120 covered with a first insulating paper 1, a thermometer 192, a heating unit 193, a second insulating paper 2, and a control unit 190. The stationary induction device 100 further includes a tank 110, a housing 170, a gate valve 180, a first oil drain valve 181, and a second oil drain valve 182. The stationary induction device 100 further includes an iron core 130, a conservator 140, a heat sink 150, a bushing 160, and a lead wire 161.

[0011] The winding 120 is wound around an iron core 130. The winding 120 has a conducting wire covered with a first insulating paper 1. The winding 120 and the iron core 130 are contained in the tank 110 in a state in which they are immersed in the insulating oil 10. In other words, the tank 110 contains the winding 120 in a state in which it is immersed in the insulating oil 10.

[0012] A radiator 150 is connected to the tank 110. The radiator 150 cools the insulating oil 10 circulating in the tank 110 by convection by dissipating heat. A conservator 140 is connected to the tank 110. The conservator 140 is configured to be able to absorb a change in volume of the insulating oil 10 in the tank 110 due to temperature. A bushing 160 is attached to the tank 110. The winding 120 and the bushing 160 are connected by a lead wire 161. The bushing 160, the lead wire 161, and the winding 120 are connected to a main circuit 162, which is a first power supply system. A first oil drain valve 181 for draining the insulating oil 10 in the tank 110 is provided in the tank 110.

[0013] The housing 170 is connected to the tank 110 via a gate valve 180, and contains the second insulating paper 2 in a state where it is immersed in the insulating oil 10. In other words, by opening the gate valve 180, the insulating oil 10 in the tank 110 can be filled into the housing 170. The housing 170 is provided with a second oil drain valve 182 for draining the insulating oil 10 in the housing 170.

[0014] A heating section 193 is disposed inside the housing 170. The second insulating paper 2 is heated by the heating section 193. The heating section 193 is, for example, an electric heater. The heating section 193 is covered by the second insulating paper 2. Specifically, a root portion of the second insulating paper 2 in the extension direction is wrapped around the heating section 193, and a tip portion of the second insulating paper 2 in the extension direction is configured to protrude from the tip of the heating section 193 and be removable. The second insulating paper 2 is provided in an amount corresponding to the number of times a life diagnosis, which will be described later, is performed. Note that the second insulating paper 2 is not limited to a form in which it covers the heating section 193, and may be configured to be heated by the heating section 193.

[0015] The second insulating paper 2 is preferably made of the same material and has the same thickness as the first insulating paper 1. Each of the first insulating paper 1 and the second insulating paper 2 is made of, for example, craft paper or pressboard made of cellulose.

[0016] Thermometer 192 measures the temperature of winding 120 or the periphery of winding 120. Here, the temperature of winding 120 or the periphery of winding 120 is not limited to the temperature of winding 120 itself, but may be the temperature around winding 120. Thermometer 192 is attached to the upper part of winding 120. In this way, thermometer 192 can measure the temperature of high temperature region HP, which is the highest temperature around winding 120.

[0017] Control unit 190 is electrically connected to each of thermometer 192 and heating unit 193. Specifically, control unit 190 and thermometer 192 are connected to each other by wiring 194. Control unit 190 and heating unit 193 are connected to each other by wiring 195. Thermometer 192, heating unit 193, and control unit 190 are connected to auxiliary power supply circuit 191, which is a second power supply system different from the first power supply system. In other words, heating unit 193 is connected to a power supply system different from winding 120.

[0018] The control unit 190 adjusts the value of the current flowing through the heating unit 193 so that the temperature of the second insulating paper 2 or the periphery of the second insulating paper 2 becomes equal to the measurement value of the thermometer 192. Here, the temperature of the second insulating paper 2 or the periphery of the second insulating paper 2 is not limited to the temperature of the second insulating paper 2 itself, but may be the temperature of the periphery of the second insulating paper 2. That is, the control unit 190 can heat the second insulating paper 2 to a temperature equal to the high temperature region HP. Therefore, the second insulating paper 2 is heated in a manner similar to the part of the first insulating paper 1 that is heated to the highest temperature by heat generated by the current flowing through the winding 120 when the stationary induction device 100 is in operation. As a result, by collecting the second insulating paper 2 and measuring the degree of polymerization, the degree of deterioration of the first insulating paper 1 can be accurately estimated, and the life diagnosis of the stationary induction device 100 can be performed with high accuracy.

[0019] Hereinafter, the operation of the stationary induction device 100 during the life diagnosis will be described. First, while the stationary induction device 100 continues to operate and the power supply from the first power supply system is maintained, the control unit 190 stops the power supply to the heating unit 193. With the gate valve 180 closed, the second oil drain valve 182 is opened to drain the insulating oil 10 inside the housing 170.

[0020] Next, a tip portion of the second insulating paper 2 is cut as a sample, and the average degree of polymerization of the sample is measured. From the average degree of polymerization of the sample of the second insulating paper 2, it is possible to estimate the degree of decrease in the degree of polymerization of the portion of the first insulating paper 1 that is heated to the highest temperature. In this way, by estimating the degree of decrease in the degree of polymerization of the first insulating paper 1, it is possible to assess the lifespan of the stationary induction device 100.

[0021] In stationary induction device 100 according to this embodiment, heating unit 193 is connected to a power supply system different from that of winding 120, and control unit 190 adjusts the value of current flowing through heating unit 193 so that the temperature of second insulating paper 2 or the area around second insulating paper 2 becomes equivalent to the measurement value of thermometer 192. This makes it possible to stop the power supply to heating unit 193 while maintaining the power supply to winding 120, so that second insulating paper 2 can be collected for measuring the degree of polymerization to estimate the degree of deterioration of first insulating paper 1 covering winding 120 while continuing to operate stationary induction device 100.

[0022] In the stationary induction device 100 according to the present embodiment, the housing 170 is connected to the tank 110 via the gate valve 180. This makes it possible to easily fill the insulating oil 10 in the tank 110 into the housing 170.

[0023] In the stationary induction device 100 according to this embodiment, the tank 110 is provided with a first oil drain valve 181 for draining the insulating oil 10 in the tank 110, and the housing 170 is provided with a second oil drain valve 182 for draining the insulating oil 10 in the housing 170. This allows only the insulating oil 10 inside the housing 170 to be drained, and the second insulating paper 2 for measuring the degree of polymerization can be collected.

[0024] The stationary induction device 100 according to the present embodiment is an oil-filled transformer or oil-filled reactor with a rated capacity of 1000 kVA or more. An oil-filled transformer or oil-filled reactor with a rated capacity of 1000 kVA or more has a larger amount of insulating oil 10 in the tank 110 than an oil-filled transformer or oil-filled reactor with a rated capacity of less than 1000 kVA. Therefore, the second insulating paper 2 for measuring the degree of polymerization can be collected without draining the insulating oil 10 in the tank 110, and therefore the consumption of the insulating oil 10 can be effectively reduced.

[0025] In stationary induction device 100 according to the present embodiment, thermometer 192 is attached to the upper part of winding 120. This allows thermometer 192 to measure the temperature of high temperature region HP, which is the highest temperature around winding 120.

[0026] In the stationary induction device 100 according to this embodiment, the winding 120 is connected to the main circuit 162, and the thermometer 192, the heating unit 193, and the control unit 190 are connected to an auxiliary power supply circuit 191. This allows the operation of the thermometer 192 and the heating unit 193 to be controlled by the control unit 190 separately from the operation control of the stationary induction device 100.

[0027] It should be noted that the above-described embodiments disclosed herein are illustrative in all respects and are not intended to be a basis for a restrictive interpretation. Therefore, the technical scope of the present disclosure is not interpreted solely by the above-described embodiments, but is defined based on the claims. Also, all modifications within the scope and meaning equivalent to the claims are included. [Explanation of symbols]

[0028] 1 first insulating paper, 2 second insulating paper, 10 insulating oil, 100 stationary induction device, 110 tank, 120 winding, 130 iron core, 140 conservator, 150 heat sink, 160 bushing, 161 lead wire, 162 main circuit, 170 housing, 180 gate valve, 181 first oil drain valve, 182 second oil drain valve, 190 control unit, 191 auxiliary power circuit, 192 thermometer, 193 heating unit, 194, 195 wiring, HP high temperature area.

Claims

1. A winding covered by a first insulating paper, a thermometer for measuring the temperature of the winding or in the vicinity of the winding, a heating part connected to a power supply system different from that of the winding, a second insulating paper heated by the heating part, and a control part electrically connected to each of the thermometer and the heating part, wherein the control part adjusts the current value flowing through the heating part so that the temperature of the second insulating paper or in the vicinity of the second insulating paper becomes equal to the measured value of the thermometer, a static induction device.

2. A tank for accommodating the winding in a state of being immersed in insulating oil, and further comprising a housing connected to the tank via a shut-off valve and accommodating the second insulating paper in a state of being immersed in insulating oil, the static induction device according to Claim 1.

3. The tank is provided with a first oil drain valve for draining the insulating oil in the tank, and the housing is provided with a second oil drain valve for draining the insulating oil in the housing, the static induction device according to Claim 2.

4. The static induction device is an oil-immersed transformer or an oil-immersed reactor with a rated capacity of 1000 kVA or more, the static induction device according to Claim 1.

5. The thermometer is attached to the upper part of the winding, the static induction device according to any one of Claims 1 to 4.

6. The winding is connected to the main circuit, and the thermometer, the heating part and the control part are connected to the auxiliary power supply circuit, the static induction device according to any one of Claims 1 to 4.

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