JPS59190672A - Measurement of corona for electric equipment - Google Patents

Abstract

PURPOSE:To enable the detection of a discharge pulse simply based on a corona discharge by utilizing the capacity of an intermediate electrode between a high voltage section and a low voltage section. CONSTITUTION:When testing a corona, the cable 7 of a DC high voltage generator 11 is removed and a corona detector 4 is connected to a lead terminal 18 generating a DC high voltage. A pulse by the corona discharge propagates to the detector 4 through intermediate electrodes 15-15'' and a capacitor voltage divider circuit with an insulation layer 9 and can be detected by observing a waveform with a Braun tube or the like. With this method, the measurement of a corona discharge can be done simply in high voltage equipments of all descriptions including a bushing-leading type as well as the conventional type such as leading an output with a cable and accurately as compared to a method employing an oil-immersed microphone.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] In high-voltage electrical equipment, it is necessary to measure corona discharge generated in the equipment body inside the storage tank or the like.

FIG. 1 shows a conventional measurement circuit for high-voltage electrical equipment equipped with a bushing in a bronc diagram.

In the figure, 1 is a tank that houses electrical equipment, and 2 is a bushing that insulates and supports a conductor that draws output to the outside.

Further, 3 is a coupling capacitor prepared for detecting corona discharge, and 4 is a corona detector connected to this H1, such as a menloscope using a cathode ray tube.

When trying to measure corona discharge of electrical equipment-11,
Load line carried to bushing 2 (hasushi bushing 2
Connect with the coupling content 3 through all connection conductors,
For example, the current working voltage f: is applied to the input side of the electrical equipment body housed in the electrical equipment tank 1, and the corona detector 4
The amount of corona generated (il) is measured.

However, the above-mentioned measurement method is generally not applicable to equipment that draws output directly from the electrical equipment tank using a cable without using a bushing, as it is not possible to connect the terminal to which the measurement circuit is connected. I can't.

For this reason, we have taken measures such as placing several submerged microphones on the outside side panels of electrical equipment tanks.

However, it is not possible to accurately measure the amount of corona generated using only measurements using an oil-immersed microphone.

[Disclosure of the invention]

By the way, when considering high-voltage electrical equipment, it is often found that an intermediate electrode or a plate for various purposes is disposed between the high-voltage part and the low-voltage part that constitute the equipment. If there is an intermediate electrode or a shield plate between the high-voltage part and the low-voltage part, it becomes possible to detect the discharge pulse based on the above-mentioned corona discharge by electrically utilizing the capacitance between them.

The present invention has been made focusing on the above-mentioned points, and as a result, it is not only a type of high-voltage electrical equipment that is drawn out by a cable, but also a type of high-voltage electrical equipment that is drawn out by a busing. Electrical equipment also eliminates the need for coupling capacitors, which are only used to detect corona discharge.
This method makes it possible to measure the amount of corona discharge extremely easily.

Figure 3 shows an example of electrical equipment to which the present invention can be applied -0 The figure shows a DC high voltage generator.

Reference numeral 11 indicates the entire DC high voltage generator, Tr is a polyphase transformer, and the polyphase transformer Tr has an iron core C and a primary winding 12 (low voltage 9
(for example, 440 V) and a plurality of secondary windings 13 (high voltage). And the primary-secondary winding 12~
13, there is an insulating layer made of, for example, insulating paper 2, plastic film, etc.]/l and the intermediate electrodes 15.15', 15''
Insulation between the two is performed using a condenser partial voltage.

Reference numeral 16 denotes a 7-old ring, +7fd rectifier circuit, 7 a high-voltage side extraction cable, and 18 an external extraction terminal connected to the intermediate electrode I5, which in the illustrated example shows the lowest potential of the intermediate electrode.

19 indicates the outermost insulating layer, and 20Ii is an insulating medium such as insulating gas or insulating oil.

In the illustrated example, the primary winding I is connected to the AC power supply (not illustrated).
When a predetermined voltage is applied to each secondary winding 13 and rectifier I
A predetermined high DC voltage is generated at end E via cable 7 and is supplied to an accelerator, for example. During the corona test, if the cable 7 is removed and the corona detector 4 is connected to the lead terminal 18 while generating a DC high voltage in the same way as above, the pulses caused by the corona discharge will be applied to the intermediate electrode 15.
．． The signal propagates to the detector 4 via a condenser voltage divider circuit formed by the electrodes 15' and 15'' and the insulating layer 9, and can be detected by observing the waveform of the detector 4 using a cathode ray tube or the like.

In the illustrated embodiment, the intermediate electrode 15 at the lowest potential is connected to the extraction terminal 18, but this is for the purpose of making extraction from high-voltage electrical equipment relatively simple electrically; It can also be drawn out from the electrode.

FIG. 2 shows a block diagram of the measuring circuit of the present invention. As can be understood from the explanation of the actual example, if the intermediate electrode or electrostatic shielding plate 8 is present between the high voltage section 5 and the low voltage section 6, the The intermediate electrode or electrostatic baffle plate 8 is coupled by capacitance and causes a discharge pulse due to corona discharge to appear on the corona detector 4 as a pulse waveform.

[action, effect]

As explained above, according to the present invention, it is possible to easily measure corona discharge in all high-voltage equipment, including not only conventional types that draw out their output using cables, but also busing/output types. It has become possible to measure more accurately than conventional underwater microphones.

[Brief explanation of drawings]

FIG. 1 shows a complete block diagram of a conventional corona measuring circuit for electrical equipment. Figure 2 (a block diagram showing the corona measurement circuit invented by Amagi). Figure 3 shows an example of high-voltage electrical equipment to which the invention is applied. 1.11...Electrical equipment, 2 Buzosing, 3 Coupling capacitor, 4 Corona detector, 5-low pressure section, 6-high pressure section,
7 Pull-out cable, 8 Electrostatic shielding plate, 121st winding, 132nd winding, 14 Insulating layer, 15° 15', 15
"・Intermediate electrode, 16 Shield ring, I7... Rectifier, 18 Input, output terminal, 19-Outer insulating layer. Figure 3

Claims (1)

[Claims] (1) Connect the lead conductor to the outside to an intermediate electrode or electrostatic barrier plate provided between the low-voltage part and the high-voltage part of electrical equipment, and 1) measure corona discharge using the N self-conductor. A corona measurement method for electrical equipment that uses