JPH0630775U - Separate collector plate charging indicator - Google Patents

Abstract

(57) [Abstract] [Purpose] The charging indicator is a special high voltage LS mount, OC
If it is used by attaching it to the grounding side such as B or the bottom of the bushing of the transformer, it is not necessary to stop the work for attachment and removal. The display content of the indicator is easy to see. There are merits such as. Taking advantage of such merits, the present invention provides a charging indicator that is attached to the ground side and displays in correspondence with the live line and dead line of the high-voltage charging section. [Constitution] In a conventional charge indicator circuit composed of a current collector 2, an AC / DC converter circuit 3, a liquid crystal drive circuit 4, and a liquid crystal element 5, a liquid crystal is provided only when the circuit voltage exceeds a set threshold value. Operates to display. The charge indicator 11 is configured by adding the threshold voltage setting voltage determination circuit 6 and the switch circuit 7.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention mainly relates to a charging indicator which is used by being attached to the ground side of a high-voltage device such as a transformer or LS having a special high voltage or higher and detecting and displaying whether or not the target high-voltage device is in a charged state. is there.

[0002]

[Prior art]

 The charging indicator is a safety device that displays on the liquid crystal device that voltage is being applied to the charging part of the power receiving and transforming equipment, and prevents accidents due to illusions and misidentifications. The most common conventional charging indicator has a circuit configuration as shown in FIG. 3 and is integrally configured with a case, and is directly mounted near the high-voltage charging section for use. In FIG. 3, 1 is a high-voltage charging unit such as a conductor or a power receiving and transforming facility, and 9 is a ground. The circuit configuration of the charging indicator 10 is a current collector plate 2 made of two conductive materials P1 and P2, an AC / DC conversion circuit 3, a liquid crystal drive circuit 4, and a liquid crystal element 5.

The two current collector plates 2 detect an AC electric field around the high-voltage charging unit 1 and supply the energy of the electric field to the AC / DC converter circuit 3 as an AC current IA (hereinafter referred to as a current collector current). . The AC / DC conversion circuit 3 converts the current collector plate current IA into DC and supplies it to the liquid crystal drive circuit 4. This DC voltage VD is called a circuit voltage, and its magnitude depends on the current collector current IA. The liquid crystal drive circuit 4 outputs a liquid crystal drive waveform of the voltage VD. If the magnitude of the circuit voltage VD exceeds the display threshold of the liquid crystal element 5, the liquid crystal element 5 is clearly displayed. In the conventional charging indicator 10, when the voltage of the high-voltage charging unit 1 reaches a predetermined rated voltage V0 to ground, the circuit voltage VD is adjusted so as to exceed the indicated threshold value with a margin.

The charging indicator 10 of the type that is used by being directly attached to the high-voltage charging unit 1 needs to be attached and detached while the power receiving and transforming equipment is in a work stopped state. When used for extra-high voltage power receiving and transforming equipment, these equipments are generally installed over a few meters above ground, and the position of the charging section and overhead line is high, so the content displayed on the charging indicator 10 installed is It becomes difficult to see. There was a drawback. If there is a charging indicator that can be attached to the ground potential part and used, such a drawback can be solved. However, it has not been known at all in the past how to accurately distinguish and display the induced electric field from the other side, such as the LS and CB, and the electric field directly generated by the charging unit to be detected.

As a result of experiments and measurement surveys, the practical use of the conventional charging indicator 10 in which the charging indicator is attached to the ground side is to show the display characteristics of the liquid crystal element and the current collector plate of the charging indicator 10. It was found impossible from the relationship between the characteristics of the current IA and the circuit voltage VD. This is because, when the conventional charging indicator 10 is attached to the ground side and used, it is inevitable that the indication as to whether or not the charging section to be detected is in a live state is ambiguous. In order to eliminate the above-mentioned defects, the inventor operates the conventional charge indicator 10 so that the liquid crystal display is performed only when the circuit voltage exceeds a certain threshold voltage. It has been discovered that the charge indicator 11 may be configured by adding a voltage discriminating circuit and a switch circuit.

FIG. 4 is a diagram showing an example of the circuit configuration of the charging indicator 11 attached to the ground side, and the same reference numerals are used for the same parts as in FIG. Reference numeral 6 is a voltage discrimination circuit, and 7 is a switch circuit. Of the operation of each part of the circuit, the points that are particularly different from those described in FIG. 4 will be described. Of the two current collector plates 2, P1 forms a stray capacitance C1 with the high-voltage charging unit 1, and the magnitude of the current collector current IA is the magnitude of C1, in other words, the magnitude of P1. It depends on Since P2 is directly connected to the ground 9, it can be omitted.

The voltage discrimination circuit 6 has a threshold voltage set therein. For example, if the threshold value is set to 2.8V, when the circuit voltage VD is 2.8V or less, the output of the voltage discriminating circuit 6 is at the L level, the switch circuit 7 remains open, and the liquid crystal element 5 is driven. No voltage is applied. When the circuit voltage VD exceeds the set threshold value of 2.8V, the output of the voltage discrimination circuit 6 becomes H level, the switch circuit 7 is closed, and a clear liquid crystal display is performed. Therefore, this threshold value is reached by the minimum value of the circuit voltage VD reached by the electric field directly generated by the high-voltage charging unit 1 to be detected and the induced conductive field from the other side such as another line or LS or CB. It may be set at an intermediate value between the maximum value of the circuit voltage VD.

[0008]

[Problems to be solved by the device]

 However, when the charging indicator 11 having the above-mentioned configuration is integrally formed, a use failure may occur. For example, in the case of a transformer, the most important place to check whether it is live or not is a place with a ladder that rises above the transformer. However, the place where this ladder is located is generally away from the high voltage bushing of the transformer and is not suitable as a site for detecting the electric field. Even in the case of LS, when the grounding mechanism is attached, it may be difficult to confirm the display of the charging indicator because the grounding mechanism interferes. As described above, there is a problem in use when there is no suitable mounting place for the high-voltage equipment or when the electric field detector and the place where it is desired to confirm the display contents of the charging indicator are separated.

[0009]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems in use, the present invention separates the current collector plate from the constituent parts of the charging indicator 11, and insulates the current collector plate to form a current collector plate portion, and another alternating The display unit is composed of the conversion circuit, the liquid crystal drive circuit, the voltage discrimination circuit, the switch circuit, and the liquid crystal element, and the current collector plate and the display unit, and the coaxial cable connecting the two units. The charging indicator is composed of three parts.

[0010]

[Action]

 The current collector separated charging indicator of the present invention configured as described above has the current collector part placed on the ground side of the high-voltage equipment where it is most suitable for electric field detection, and is the most effective for safety in high-voltage work and the like. It can be used by attaching the display unit to a comfortable place or a place where it is easy to see.

[0011]

【Example】

 FIG. 1 is a diagram showing a configuration example of the present invention. The current collector separated type charging indicator 12 of the present invention is composed of three parts of a current collector 20, a display 30, and a coaxial cable 40. The current collector plate portion 20 is processed so that the periphery of the current collector plate 2 (P1 in FIG. 4) is wrapped with an insulating material 21. The display unit 30 includes an AC / DC conversion circuit 3, a liquid crystal drive circuit 4, a liquid crystal element 5, a voltage determination circuit 6, and a switch circuit 7. In the coaxial cable 40, one end of the core wire 41 is connected to the current collector plate 2, and the other end is connected to one end on the input side of the AC / DC conversion circuit 3. Further, the braided jacket 42 of the coaxial cable 40 is grounded together with the other end on the input side of the AC / DC converting circuit 3. Therefore, the current collector P2 is omitted from the components of the charge indicator 11 shown in FIG.

In FIG. 1, the collector plate 2 detects an electric field generated by the high-voltage charging unit 1 such as a high-voltage bushing through the stray capacitance C1 and displays the energy of the electric field as a collector plate current IA. Supply to the unit 30. Its size is about several μA. Therefore, if the collector plate 2 is not completely insulated, the collector plate current IA easily leaks to the ground in the case of rain, etc., and the display operation becomes uncertain. In this sense, the insulation treatment with the insulating material 21 is important. Suitable methods of insulation include sealing in a plastic case and molding. The coaxial cable 40 is a conductor that transmits the current collector current IA to the display unit 30. When a simple covered electric wire is used in this portion, this conductor wire serves as a current collector plate, and the magnitude of the current collector plate current IA is deviated depending on the surrounding electric field condition. In order to reduce the transmission loss of the coaxial cable 40, one having a small electrostatic capacitance CS between the core wire 41 and the braided jacket 42 is suitable. The operation of the display unit 30 is the same as that described with reference to FIG. 4, and the description thereof is omitted here.

FIG. 2 is a diagram showing an embodiment in which the current collector separation type charging indicator 12 of the present invention is applied to the transformer 50. The collector plate portion 20 is attached to the flange of the high pressure bushing 51. The display unit 30 is installed next to the ladder 52 on the opposite side of the high pressure bushing 51. The coaxial cable 40 connecting both parts is fitted on the upper surface of the transformer tank 53. The worker 60 can easily check the display content of the display section 30 of the charge collecting plate separation type charge indicator 12 before climbing the ladder 52, and can avoid an illusion or a misunderstanding.

[0014]

[Effect of device]

 The current collector separation type charging indicator 12 of the present invention solves the inconvenient problem of using the charging indicator 11 which can be attached to the ground side and greatly contributes to the safety of high-voltage work. It is a thing.

If the current collector plate 20 and the coaxial cable 40 have dielectric strength, the current collector plate-separated type charging indicator 12 of the present invention directly attaches the current collector plate portion 20 to the high voltage charging portion 1 and displays the display portion 30. It can also be used by placing it on the ground side where it is easy to see. The current collector separated type charging indicator of the present invention can distinguish and display the strength of the electric field with a certain threshold value.Therefore, when the charging indicator is attached to each of the three-phase charging parts, the conventional charging indicator cannot. There is an effect that it becomes possible to accurately display the open phase that was not present.

[Brief description of drawings]

FIG. 1 is a view for explaining the configuration and operation of a current collector separation type charging indicator of the present invention.

FIG. 2 is a diagram showing an example in which the present invention is applied to a transformer.

FIG. 3 is a diagram for explaining a circuit configuration and an operation of a conventional charging indicator.

FIG. 4 is a diagram showing a circuit configuration of a charging indicator that can be attached to the ground side.

[Explanation of symbols]

 2 current collecting plate 3 AC / DC converting circuit 4 liquid crystal driving circuit 5 liquid crystal element 6 voltage discriminating circuit 7 switch circuit 12 current collecting plate separation type charging indicator of the present invention 20 current collecting plate section 30 display section 40 coaxial cable 41 coaxial cable core wire 42 Coaxial cable braided jacket

Claims (1)

[Scope of utility model registration request] 1. A current collecting plate portion having a current collecting plate subjected to an insulation treatment,
A display unit in which a portion including an AC / DC conversion circuit, a liquid crystal drive circuit, a voltage determination circuit, a switch circuit, and a liquid crystal element is integrally configured, and a coaxial cable. The coaxial cable has three parts. The other end of the core wire is connected to one end on the input side of the AC / DC converting circuit, and the braided jacket of the coaxial cable and the other end on the input side of the AC / DC converting circuit are both grounded. Separated electric charging indicator.