Stationary induction apparatus

Abstract

A stationary induction apparatus (100) is provided with a winding (120) that is covered by first insulating paper (1), a thermometer (192), a heating unit (193), second insulating paper (2), and a control unit (190). The thermometer (192) measures a temperature of or around 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 a current flowing to the heating unit (193) such that a temperature of or around the second insulating paper (2) is equal to a measurement of the thermometer (192).

Description

stationary induction equipment

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

[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 an insulated sampling lead wire. The tank houses a coil and an iron core and is filled with a cooling medium. The sampling tank is connected to the tank to introduce the cooling medium and has an opening for removing samples. The insulated sampling lead wire is installed inside 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 formed under the same conditions as the most severely deteriorated part of the tank.

[0003] Japanese Utility Model Application Laid-Open Publication No. 4-30712

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

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

[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 both the thermometer and the heating unit. The control unit adjusts the value of the current flowing through the heating unit so that the temperature of the second insulating paper or the periphery of the second insulating paper is equivalent to the temperature measured by the thermometer.

[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.

[0008] 1 is a cross-sectional view showing a configuration of a stationary induction device according to an embodiment.

[0009] A static induction device according to one 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 will be designated by the same reference numerals, and their description will not be repeated. In the following embodiment, a shell-type transformer will be used 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 one 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 the configuration of a stationary induction device according to an embodiment. As shown in Fig. 1, stationary induction device 100 according to an embodiment of the present disclosure includes a winding 120 covered with first insulating paper 1, a thermometer 192, a heating unit 193, second insulating paper 2, and a control unit 190. 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. Stationary induction device 100 further includes an iron core 130, a conservator 140, a heat sink 150, a bushing 160, and lead wires 161.

[0011] The winding 120 is wound around the iron core 130. The winding 120 has a conductor covered with first insulating paper 1. The winding 120 and the iron core 130 are housed in the tank 110 while immersed in the insulating oil 10. In other words, the tank 110 houses the winding 120 while immersed in the insulating oil 10.

[0012] A radiator 150 is connected to the tank 110. The radiator 150 cools the insulating oil 10 by dissipating heat circulating within the tank 110 by convection. A conservator 140 is connected to the tank 110. The conservator 140 is configured to be able to absorb changes in volume of the insulating oil 10 within 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 is provided in the tank 110 to drain the insulating oil 10 within 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 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 from the housing 170.

[0014] A heating unit 193 is disposed inside the housing 170. The second insulating paper 2 is heated by the heating unit 193. The heating unit 193 is, for example, an electric heater. The heating unit 193 is covered by the second insulating paper 2. Specifically, the base portion of the second insulating paper 2 in the extension direction is wrapped around the heating unit 193, and the tip portion of the second insulating paper 2 in the extension direction is configured to protrude from the tip of the heating unit 193 and be removable. The second insulating paper 2 is provided in an amount corresponding to the number of times a life assessment, which will be described later, is performed. Note that the second insulating paper 2 is not limited to a configuration in which it covers the heating unit 193, as long as it is configured to be heated by the heating unit 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, kraft 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 also be the temperature around winding 120. Thermometer 192 is attached to the top of winding 120. This allows thermometer 192 to measure the temperature of high temperature region HP, which is the highest temperature around winding 120.

[0017] Control unit 190 is electrically connected to 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 that of winding 120.

[0018] The control unit 190 adjusts the current value flowing through the heating unit 193 so that the temperature of the second insulating paper 2 or the area surrounding the second insulating paper 2 is equivalent to the temperature measured by the thermometer 192. Here, the temperature of the second insulating paper 2 or the area surrounding the second insulating paper 2 is not limited to the temperature of the second insulating paper 2 itself, but may also refer to the temperature surrounding the second insulating paper 2. In other words, the control unit 190 can heat the second insulating paper 2 to a temperature equivalent to the high-temperature region HP. Therefore, the second insulating paper 2 is heated in a manner similar to the portion of the first insulating paper 1 that is heated to the highest temperature by heat generated by current flowing through the winding 120 when the stationary induction device 100 is operating. Therefore, by sampling 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, enabling highly accurate lifespan assessment of the stationary induction device 100.

[0019] The following describes the operation during the lifespan diagnosis of the stationary induction device 100. First, while the operation of the stationary induction device 100 continues and 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 sample is cut from the tip of the second insulating paper 2, 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 part 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 the stationary induction device 100 according to this embodiment, the heating unit 193 is connected to a power supply system different from that of the winding 120, and 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 area around the second insulating paper 2 becomes equal to the value measured by the thermometer 192. This makes it possible to stop the power supply to the heating unit 193 while maintaining the power supply to the winding 120, and therefore it is possible to collect second insulating paper 2 for measuring the degree of polymerization to estimate the degree of deterioration of the first insulating paper 1 covering the winding 120 while continuing to operate the stationary induction device 100.

[0022] In the stationary induction device 100 according to this embodiment, the housing 170 is connected to the tank 110 via the gate valve 180. This allows the insulating oil 10 in the tank 110 to be easily filled 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 second insulating paper 2 for measuring the degree of polymerization to be collected.

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

[0025] In stationary induction device 100 according to this 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 stationary induction device 100 according to this embodiment, winding 120 is connected to main circuit 162, and thermometer 192, heating unit 193, and control unit 190 are connected to auxiliary power supply circuit 191. This allows the operation of thermometer 192 and heating unit 193 to be controlled by control unit 190 separately from the operation control of 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 limiting. Therefore, the technical scope of the present disclosure should not be interpreted solely by the above-described embodiments, but should be defined based on the claims. Furthermore, all modifications within the scope and meaning equivalent to the claims are included.

[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 supply circuit, 192 Thermometer, 193 Heating unit, 194, 195 Wiring, HP High temperature area.

Claims

1. A stationary induction device comprising: a winding covered with a first insulating paper; a thermometer that measures the temperature of the winding or the vicinity of the winding; a heating unit connected to a power supply system different from that of the winding; a second insulating paper heated by the heating unit; and a control unit electrically connected to both the thermometer and the heating unit, wherein the control unit adjusts the value of the current flowing through the heating unit so that the temperature of the second insulating paper or the vicinity of the second insulating paper becomes equivalent to the temperature measured by the thermometer.

2. The stationary induction device according to claim 1, further comprising: a tank that contains the windings immersed in insulating oil; and a housing that is connected to the tank via a gate valve and contains the second insulating paper immersed in insulating oil.

3. A stationary induction equipment as described in claim 2, wherein the tank is provided with a first oil drain valve for draining insulating oil in the tank, and the housing is provided with a second oil drain valve for draining insulating oil in the housing.

4. The stationary induction device according to any one of claims 1 to 3, which is an oil-filled transformer or oil-filled reactor having a rated capacity of 1000 kVA or more.

5. A stationary induction machine according to any one of claims 1 to 4, wherein the thermometer is attached to an upper portion of the winding.

6. A stationary induction device according to any one of claims 1 to 5, wherein the winding is connected to a main circuit, and the thermometer, the heating section and the control section are connected to an auxiliary power supply circuit.

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