SU26002A1 - The method of increasing the discharge voltage of the surface discharge - Google Patents

Description

The present invention relates to devices designed to hinder the occurrence of a spark discharge between high-voltage wires or electrodes, in particular, devices for increasing the discharge voltage occurring on the surface of a dielectric separating the electrodes from each other.

As is well known, with an increase in the potential difference between the electrodes above a certain value, a corona occurs at the electrodes, and with a further increase in voltage, a spark occurs.

Consequently, the corona is a necessary step prior to the onset of surface discharge. The spark voltage is defined by the following expression:

y -ffRf + i,

where Vg is the potential difference causing a spark (discharge voltage),

If is the current flowing through the spark, Rf is the resistance of the spark, V is the potential difference, going to create ionization at the end of the spark. In this expression, the main element that determines the height of the discharge voltage is the resistance of the spark. The greater this resistance, the higher the discharge voltage.

Spark resistance can

be expressed as follows:

R

f Q

where C-some is constant, and Q is the total amount of electricity that has flowed since the start of the silent discharge. .

Therefore, zatsacha is reduced to reducing this amount

electricity. Since Q j idf NPi Q, t, where / is the instantaneous value of the discharge current, 4p is the average magnitude of the current per time, and t: by decreasing 4, according to the present invention, this goal is achieved by a method already known, namely by increasing the current resistance, not in that part of its path where it passes through an ionized dielectric (air), but in that part where it flows through conductor; The invention consists in using an auxiliary electrode to increase this resistance, connected to one main electrode through a high ohmic resistance and located between it and the other main electrode on the outer surface of the dielectric.

In FIG. 1 depicts a typical case of a combination of two high-voltage electrodes 1 and 2, of which one can be and is usually grounded, separated by a dielectric 3 in such a way that not all the space between the electrodes is filled with this gap, but that there is also a discharge on the surface of the dielectric, those. through the air. In the practical example of such a case of ownership | ots, all high-voltage bushings into the housings of transformers, oil coolers, etc., leads of high-voltage lines into enclosed spaces through bushing insulators, finally, fixing wires on suspension insulators, etc.

FIG. 2 depicts an exemplary embodiment of the device for carrying out the present invention. This figure shows the auxiliary electrode 4 placed between the grounded electrode 2 and the electrode 1 and connected to the electrode 2 through a significant ohmic resistance 5. This resistance is in the discharge current circuit and contributes to reducing the average current / cf, and, thereby,

and the amount of electricity flowing Q.

The effect of this resistance can be discerned by the following consideration. As the ytee has been said, the crown prevails in the spark gap. In the absence of a corona, electrodes 2 and 4 are identical; potential and are like one electrode. Therefore, a corona can occur and will actually occur only between the edge of electrode 4 and electrode 1. But as soon as a corona occurs, current will flow from electrode 2 to electrode 4. This current forms a voltage drop across the ohmic resistance 5 and the potential difference between 1 and 4 decreases by a voltage equal to this voltage drop. Consequently, the voltage between the electrodes 1 and 4 decreases and the discharge voltage, i.e. the voltage between electrodes 1 and 2 can reach and even exceed the amount at which the discharge would occur if

not; additional voltage electrgrd 4. Thus, in fact, the discharge voltage rises by an amount approximately equal to the voltage drop across the resistance 5.

In FIG. 3, the auxiliary electrode b is connected not to an external (grounded), but to an internal high-voltage electrode, and here the connection occurs through resistance 7. The action of this device is similar to that of the device shown in FIG. 2. A combination of both of these devices is also possible (Fig. 4). Finally, it is possible to use not one, but several / auxiliary electrodes located in one plane parallel to the plane of location of the main electrode, where they can be positioned not only axially along the side surface of the input (Fig. 5), but also radially along its face surface (Fig. 6), which may be in some cases more convenient or more advantageous from the point of view of the distribution of the floor.

The subject matter of the invention.

Claims (2)

1. (A method for increasing the discharge voltage of a surface discharge, characterized in that an electrode of an electrical device is either at a high potential or is grounded, or both is connected to an auxiliary electrode connected to the main electrode electrode through a high ohmic resistance and located between it and another main electrode on the outer surface of the dielectric. 2. Modification of the method according to claim 1 for the case of coaxial arrangement of electrodes, grounded and high potential, characterized in that not only one but several auxiliary electrodes are attached to the main electrode, located in the same plane, parallel to the plane of the main electrode, and representing segments of a ring. / Figl Fig X Physical §