SU391674A1 - DEVICE FOR CONNECTING RELAY PROTECTION CIRCUITS - Google Patents

Description

one

The invention relates to the field of relay protection and can be used for the lithium differential phase protection of the elements of electrical systems.

For supplying current circuits of relay protections, including differential-phase ones, two-winding current transformers with ferromagnetic closed cores having a nonmagnetic gap or localized magnetic circuit are used, as a rule.

With the help of the known differential, the Yfazpich potentsialy start-ups that disturb the moments of the passage of currents through bullet values. During transients due to the saturation of the core of the aperiodic component of the primary current, the angular error ino passes through the zero value to the transition at the nominal active, on: load 150 el. hail, which can cause peprasilpoy action protection.

The purpose of the invention is to simplify the construction of the 1I and reduce the angular incidence of the current transformer in transitional modes without significantly increasing its power or reducing the load, which will simplify the design of the differential-phase protection and increase their reliability.

In the proposed device, consisting of two cores (internal and external) with different non-magnetic gaps and secondary windings enveloping the software for one core, connected in series and turned off, the additional winding is applied to the side of the inner core, which creates a magnetic field, leperpdikul rp field of other windings.

FIG. 1 shows a device for connecting relay protection circuits; in fig. 2-

Electrical diagram of the device.

The device (Fig. 1) contains a core / having a small pemagpit gap (gaps) necessary to reduce the maximum residual induction. The part of the secondary winding 2, covering this core, turns on at the second with the second part of the winding 3, located on the core 4, the flow coupling of which is more linearly dependent on

the magnetizing current, remaining translucent than the flux linkage of the winding 2 up to the maximum multiplicity of the primary current. The counter-switching of windings 2 and 3 results in the fact that their total flux linkage

in the saturation region, core 1 decreases with increasing magnetizing current. The core of the core / ood of one of the parts of the secondary winding 2 is applied to the winding of the throttle 5, for example on the outer side of the core 1, which creates a magnetic

the field is orpendicular to the multi-part secondary winding, i.e. the winding of the throttle 5 has no inductive coupling with it. This winding increases the efficiency of the secondary circuit of the transformer, which reduces the angular (error. In operating modes, this device operates as a normal current transformer. Transient modes with a periodic period in the primary current (short circuits, inrush current) the secondary current waveform is distorted, but so that the angle of the cross "zero. on the transition through the zero value remains insignificant during the whole time of the transition process. Thus, the proposed device r as a current sensor “does not distort

required information about the earth current in transient conditions.

Subject matter

A device for connection of relay protection prices, comprising a current transformer with a secondary winding, consisting of two parts, each of which is located on its ring core with non-magnetic gaps and in series with which the winding of the chokes is different, simplify the design and reduce the angle of the Fascia (Posti, the throttle winding is installed between one of the secondary windings and the ring core, and its turns are located along the core.

fig 1

ig. t