SU33596A1 - Device for differential protection of transmission lines and electrical anergy - Google Patents

Description

A device for differential protection of transmission lines of electrical energy is proposed, consisting of special equipment installed at each end of the protected LINE. The latter contains: 1) a generator of high-frequency oscillations modulated by the load current and sent to the other end of the LINE, 2) a receiver of similar oscillations coming from the other end of the line; 3) an individual electromagnetic device used to modulate high-frequency oscillations depending on the load current; 4) a differential relay used to compare currents excited by the load current at the end of the line and the load at the other end of the line.

The indicated relay is connected to an electrical circuit, excited by frequency modulated oscillations at both ends of the LINE. Arising in the circuit, in case of inequality of the load current at the ends of the line, the beats must drive the relay.

In FIG. 1 depicts the electrical circuit of the device; FIG. 2, 3, and 4 are various forms of execution serving to modulate high-frequency oscillations of an electromagnetic device.

As already stated above, to the protected LINE, high-frequency oscillators 16 and / a are attached at both ends of the line (Fig. 1). Such generators are already used for the purposes of telephone communication, therefore the creation of special generators is not required. In addition, they install receivers of modulated oscillations Zb to Za and electromagnetic devices 2b and 2a, which are powered by load current and serve to change the self-induction or capacitance in the circuit of the modulating oscillator. These devices are special 1 oscillators, whose frequency depends on the power of the current supplied to them from the current transformers connected at the ends of the line.

As can be seen from the diagram, these oscillations are supplied to high frequency generators and sent from both ends of the line to opposite directions.

The frequency range of the devices 2a and 2b is chosen in such a way as not to interfere with the transmission, by means of the same telephone call generators OR signaling. At both ends of the section, there are installed receivers Za and Zb of modulated oscillations coming from the other end of the LINE, and electrical circuits b and 6a of the beats.

These circuits are driven by coils: links 4b, 4a, 5b, and 5a are excited on one side directly from devices 2 and 2a, which are at the same end, and

“On the other hand, through the medium of the high-voltage communication, from the devices located at the opposite ends of the site.

Since in the latter the relationship between the oscillation frequency and the current is unambiguous, it is obvious that if the currents at opposite ends of the section are equal, the frequencies of the devices 2a and 2b are also equal; the equality of the currents at the ends of the line is broken and that the beats are generated in the circuits of the ba and 6b and a current arises that drives the relay 7a VI b into action. The last, I will act simultaneously on the 8a l 8b clock, turn off the damaged line on both sides.

The electromagnetic device used for modulating -frequency oscillations, depending on the MOCTH of the load current, is powered by the load current and is used to change the self-induction of FIG. 2 and 3) or capacitance (FIG. 4) in the circuit of the modulating oscillator — can be performed, for example, in such a way that the current corresponding to the current at one end of the section excites the magnet coil 7 of the electromagnet, the measles of which serves to move the heart chi self-induction included in the generator circuit (Fig. 2). It is clear. that the frequency of the generator will depend on the current supplied to the coil /.

For the case depicted in FIG. 3, the current corresponding to the current at the ends of the section, the passage through the additional coil / reactive coil 2, underneath, “agnichit” it and changes the permeability MocTb of the iron core of the coil, which

causes a change in self-induction in the modulating oscillator circuit.

In the form of an electromagnetic device according to FIG. 4 Measuring electromagnet, depending on the strength of the current, moves the plates of the capacitor 2 of the generator circuit.

The subject matter of the invention.

Claims (2)

1. Device for differential protection of transmission lines of electrical energy, consisting of: installed at each end of the protected line: a) a generator of high-frequency oscillations modulated by a load current and sent to the other end of the line, b) a receiver of similar modulated oscillations coming from the other end a line and c) a differential relay used to compare the currents excited by the load current at that end of the line and the load current at the other end of the line, characterized by that; that the relay is included in an electrical circuit, excited by frequency-modulated oscillations at both ends of the line, it is an objective that the beats that occur in the circuit in the case of unequal load currents at both ends of the line can energize the relay. 2. The form of the device according to claim 1, characterized in that an electromagnetic device is used to modulate high-frequency oscillations depending on the load current and is used to change the self-induction or capacitance in the circuit of the modulating generator (Fig. 2 3, 4) . . in the author's testimony of I. V. A. Mikhailov No. V. Olehovich and 33596 F “rE ig f «r4 Fig 5