JPH0543514U - Load tap switching device - Google Patents

Abstract

(57) [Summary] [Purpose] Even if there is oil leakage in the piping line of the hot-line oil purifier of the tap switching device under load, stop the switching switch or tap selection switch until the oil level drops to the level. The purpose is to [Structure] The oil discharge pipe system communicating with the hot-line oil purifier of the load tap changer was set up below the bottom of the switch container up to the height of the container head. Use an inverted U-shaped passage that communicates with the live oil purifier, and make the top of this drain pipe and the container side of the oil flow protection relay of the conservator pipe, or the wall of the container head sufficiently larger than the inner diameter of the drain pipe. A structure in which small tubes with a small inner diameter are used for communication. [Effect] Even if there is an oil leak in the piping system of the hot-line oil purifier, the oil level does not drop to the switching switch or the tap selection switch, and the freshly purified oil returns to the hot-line oil purifier again. It does not affect the operating characteristics of the oil flow protection relay.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a tap switching device under load, and relates to piping between a container accommodating a switching switch or a tap selection switch and a hot-line oil purifier.

[0002]

[Prior Art]

 The switches that control the opening and closing of current, such as the switching switch of the tap changer during load and the tap selection switch, are installed in a container filled with insulating oil in order to easily extinguish the arc that occurs when switching the current. It is housed. Normally, in electrical equipment in which the container is filled with insulating oil, a conservator is installed above the container in order to suppress changes in pressure inside the container due to volume changes due to changes in the temperature of the filled insulating oil. Since the container and the conservator are connected by piping, the same configuration is applied to the present invention, and even if the container is filled with insulating oil and the volume of the insulating oil changes due to temperature change, tap switching The switch or tap select switch is always immersed in insulating oil. An oil flow protection relay is installed in the middle of the conservator piping that connects the container containing the tap changeover switch or tap selection switch to the conservator. This is because an abnormal arc is generated when the current cutoff of the tap changeover switch or the tap selective switch fails or dielectric breakdown between taps occurs, but the insulating oil decomposes due to the energy of the abnormal arc. However, if gasification causes the pressure inside the container to rise, an abnormal oil flow will occur from the container to the conservator. This oil flow is provided to activate the oil flow protection relay and detect the abnormality. The load tap switching device is attached to the transformer body, and the transformer is connected to the power system and switches the winding taps of the transformer according to the voltage of the power system. An arc is generated in the switching device every time the tap is switched, the insulating oil decomposes and pollutes, and the dielectric strength decreases.Therefore, in the tap switching device under load used for a high-voltage transformer, a filter is usually used. A live-line oil purifier consisting of a pump and a pump is attached, and this hot-line oil purifier filters the insulating oil in the container about once a day to purify it and operates so as to prevent deterioration of electrical insulation performance. Has been done. The insulating oil filtration system by the hot-line oil purifier of the tap changer during load is connected to the oil supply port of the hot-line oil purifier located below the container containing the switching switch or the tap selection switch. The bottom of the container is connected by an oil drain pipe, and the outlet of the hot-line purifier and the head of the container are connected by an oil supply pipe. Operation is continued by preventing the deterioration of the electrical insulation characteristics of the insulating oil by filtering with the filter of the oil purifier and purifying in the system that returns to the head of the container by the oil supply pipe. In the load tap changer having such a configuration, if oil leaks to the filter or pump of the hot-line oil purifier, or the drain pipe or oil supply pipe located below the container head, If the insulating oil filled in the container leaks out and the switching switch or tap selection switch is exposed, the arc will not be extinguished, which may lead to an accident such as a short circuit due to a decrease in the dielectric strength between taps.

In order to ensure dielectric strength even if oil leaks from the hot-line oil purifier and piping, it is necessary to install a switch switch or tap selection switch around the switch switch and tap selection switch that require insulation and insulation performance. It is necessary to take care so that even the insulating oil does not come out, but as a method to do so, as shown in Japanese Utility Model Publication No. 60-42718, insert the tip of the oil drain pipe into the bottom of the container, and then from the top of the container. Take out the drain pipe by connecting it to the hot-line oil purifier, and connect the drain pipe between the part taken out from the top of the container of the drain pipe and the conservator or the conservator pipe connecting the container and the container. A structure in which a thin tube with an inner diameter that is sufficiently smaller than the inner diameter is used for communication, or as shown in Official Utility Model Publication No. 3-11868, the oil drain pipe is raised from the bottom of the container to the position of the container head, and the Leading to a live-line oil purifier as a letter The oil supply pipe is connected to the container head from the hot line oil purifier, and the inverted U-shaped top of the oil drain pipe and the oil supply pipe are thin tubes with an inner diameter sufficiently smaller than the inner diameter of the oil drain pipe. A communication configuration is shown. With this structure, when oil leakage occurs in the hot-line oil purifier, the oil drain pipe, or the oil supply pipe, and the oil level drops to the inverted U-shaped top of the oil drain pipe, Gas invades the oil drain pipe to eliminate the siphon effect and prevent further oil leakage, and the insulation strength of the switching switch or tap selection switch is secured.

[0004]

[Problems to be solved by the device]

 The previously proposed load tap switching device has the following problems. In the configuration disclosed in Japanese Utility Model Laid-Open No. 60-42718, since the oil discharge pipe and the conservator are connected by a thin pipe, a bypass pipe is provided between the container and the conservator. Although the configuration is not disclosed, there is a drawback in that the oil flow relay normally provided in the middle of the conservator piping is bypassed, which adversely affects the operation characteristics of the oil flow protection relay. Further, in the configuration disclosed in the Official Utility Model Publication No. 3-11868, the insulating oil filtered by the hot-line oil purifier will be sucked into the oil discharge pipe through the thin pipe from the oil supply pipe, and will be purified. Insulating oil that has just been freshly returned to the hot-line oil purifier has the drawback of lowering the oil purification efficiency.

The present invention has been made in order to solve the above problems, and normally does not affect the operating characteristics of the oil flow protection relay provided in the conservator piping, and it is purified. Even if the insulating oil immediately after the operation is not returned to the hot-line oil purifier, and there is oil leakage in the hot-line oil purifier and the piping that forms the oil purification route, the oil level of the insulating oil in the container The purpose is to provide a tap changer under load that stops the outflow of insulating oil before the temperature falls below a safe level.

[0006]

[Means for Solving the Problems]

 The tap changer under load according to the present invention includes a top portion of the drain pipe located at the height of the head of the container, and a portion of the conservator piping that is closer to the container than the portion provided with the oil flow protection relay or the container. The head wall is connected by a thin tube with an inner diameter sufficiently smaller than the inner diameter of the oil drain pipe.

[0007]

[Action]

 In the tap changer for load according to the present invention, the part of the drain pipe located at the height of the container head and the part of the conservator pipe where the oil flow protection relay is provided communicates with the container or the container By communicating with the head wall, an abnormal arc is generated during the operation of the tap changer during load, the pressure inside the container rises, and the insulating oil flows into the conservator. Although the relay operates and detects an abnormality, it does not affect the operating characteristics because there is no thin tube that bypasses the oil flow relay as in the past. In addition, some of the purified insulating oil will never be returned without being used.

[0008]

【Example】

 Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the structure of a load tap changer according to an embodiment of the present invention. In the figure, 1 is a switching switch, 2 is a switching contact part of the switching switch 1, 3 is a switching switch 1 and a container in which the switching contact part of the switching switch 1 is accommodated and in which insulating oil 4 is accommodated. 5 is a live line oil purifier, 6 is an oil drain pipe that communicates the bottom of the container 3 with the inlet of the live line oil purifier, and the top 61 located at the height of the head of the container from the bottom of the container 3 The pipe is routed through the system to the inlet of the hot oil purifier 5. Reference numeral 7 denotes an oil supply pipe that connects the discharge port of the hot-line oil purifier 5 and the head of the container 3 to return the purified insulating oil 4 to the container 3. Reference numeral 8 is a conservator provided above the container 3, and 9 is a conservator pipe that connects the head of the container 3 and the conservator 8 with each other. An oil flow protection relay 10 is provided to detect an abnormality when an oil flow is generated on the conservator 8 side by decomposing and gasifying and increasing the pressure. Reference numeral 11 connects the inverted U-shaped top portion 61 of the oil drain pipe 6 located at the height of the head of the container 3 with the portion of the conservator pipe 9 that connects the oil flow protection relay 10 to the container 3 side. It is a thin tube. Reference numeral 12 is a transformer tank to which the container 3 is attached, 13 is a breather that removes moisture when breathing in the gas space portion of the conservator 8, and 14 is a breather pipe that connects the conservator 8 and the breather 13 to each other.

The hot-line oil purifier 5 is normally operated once a day, and is managed so as to purify the insulating oil 4 in the container 3. The hot-line oil purifier 5 is composed of a pump and a filter (not shown). When the operation command is received, the pump rotates, and the insulating oil 4 in the container 3 is sucked from the bottom of the container 3 by the oil drain pipe 6. It is sent to a filter, purified, and purified in a circulation path that returns from the head of the container 3 to the inside of the container 3 through the oil supply pipe 7. After a certain period of operation, the pump stops and one purification is completed. If oil leaks in the piping system including the hot-line oil purifier 5 that purifies the insulating oil in the container 3, the oil level will flow out until the thin tube 11 is exposed. When it is lowered to the exposed level, the air sucked from the breather 14 enters the top 61 of the oil discharge pipe 6 through the thin pipe 11, the siphon effect of the oil discharge pipe is lost, and the oil leakage stops. In this way, even if an oil leak occurs in the piping system including the hot-line oil purifier 5, the switching switch or tap selection switch is not exposed to the air, preventing disconnection failures and accidents such as tap short circuits. can do.

Example 2. In the first embodiment, the thin pipe 11 is connected between the drain pipe 6 and the conservator pipe 9, but the drain pipe 9 and the head wall of the container 3 are formed by the thin pipe 11 which is sufficiently smaller than the inner diameter of the drain pipe 6. It goes without saying that the same effect can be obtained even if they are communicated.

[0011]

[Effect of the device]

 With the tap switching device under load according to the present invention, even if an oil leak occurs, the oil level does not drop until the switching switch or the tap selection switch is exposed, and accidents such as loss of cutoff or short circuit between taps occur. In addition, like the conventional method in which the drain pipe and the oil supply pipe are connected by a thin tube, the insulating oil that has just been purified flows into the hot-line purifier again without being used. There is nothing to do. Furthermore, since the oil flow protection relay is not bypassed by a thin tube, it does not affect the operating characteristics of the oil flow relay.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the configuration of a load tap switching device according to an embodiment of the present invention.

[Explanation of symbols]

 1 Switching switch 2 Contact part of switching switch 3 Container 4 Insulating oil 5 Live line oil purifier 6 Oil drain pipe 7 Oil supply pipe 8 Conservator 9 Conservator pipe 10 Oil flow protection relay 11 Thin pipe

Claims (1)

[Scope of utility model registration request] 1. A container containing a switching switch or a tap selector and filled with insulating oil, a conservator arranged above the container, and an oil flow on the way between the container and the conservator. A conservator pipe communicated via a protection relay, a hot-line oil purifier arranged below the container, and an oil supply pipe communicating the discharge port of the hot-line oil purifier with the head of the container. , A height of the head of the container of the oil drainage pipe, which is provided with an oil drainage pipe communicating from a filler port of the hot line oil purifier to a bottom of the container via a height of the head of the container, Characterized in that the top portion located at, and the portion of the conservator pipe on the container side of the portion where the oil flow protection relay is provided or the head of the container are connected by a thin tube having an inner diameter sufficiently smaller than the inner diameter of the oil drain pipe. Load tap switching device.