SU113942A2 - High Speed Detection Directional Relay - Google Patents

Description

BASIC Auth. St. No. 99390 describes a high-speed detection directional relay of resistance, made on the basis of an electromagnetic relay with a closed magnetic system and a falling cortex pr: and the action of the relay. In such a relay, a germanium triode with a common emitter controlled from the base and a DC relay connected to the triode collector circuit can be used as an indicator zero.

The proposed relay is a further development of the relay, which is described in ed. St. No. 99390 and reduces the dependence of the operating parameters of the relay on temperature.

For this purpose, germanium diodes having the same temperature coefficient with the indicated triode and serving simultaneously to protect it from overloads are used as rectifiers.

The drawing shows a diagram of the proposed relay.

The relay is based on the principle of comparing rectified values proportional to the current / line and voltage V in the protected area minus the product of the current / resistance Z (set resistance).

The currents 1. or / B in the protected are supplied to the relay by means of a transformer 1. To change the radius of the characteristics of the relay in the complex plane in the primary windings of the transformer 1 and the secondary windings of the transformer 2, perform desoldering.

In order to reduce the pulsations, the current flowing from Trapsformer 1 is rectified by splitting it into three currents shifted 120 ° one relative to the other. For this purpose, a choke 3, a capacitor 4, an active resistance 5 and a group of hermetic 1 diodes 6 are present in the relay circuit. A current proportional to the voltage difference V at the plug and the voltage drop / Z at the set resistance is fed to the circuit from transformers 2 and 7 The splitting and rectification of a current proportional to the difference indicated is a.up1; it is detected by means of chokes 8, a capacitor 9, active resistances 10 and 11, and diodes 12.

For reliable operation of the relay at low voltages supplied from transformer 2 (for example, during a short circuit near substation buses), a 1 amp circuit consisting of droplets 13, a capacitor 14 and an active resistor 15 is introduced into the secondary circuit of this transformer. .

Resistance 16 is used in the circuit as a potentiometer d, l for fine adjustment of the relay response resistance. Resistance 17 serves to obtain the required shift of the emf induced in the secondary winding of the transformer 7 with respect to the current in its primary winding. Resistance 18 provides a latching operation of the relay 19 during a short circuit in its area of operation.

A null indicator, made in the form of germanium triode 20 with a common emitter controlled from the base, was applied as the main sensing element of the relay, in the collector circuit of which a direct current relay 19 is connected, and the circuit executive includes resistor 18 with its contacts 21.

The emitter-base circuit of triode 20 is included in the comparison circuit for the difference of compared currents.

The power supply to the collector-emitter is provided from a DC source located at the protected object, or from a special stabilizer fed from current transformers. This stabilizer supplies a rectified voltage to triode 20, the value of which is maintained within the required limits when changing currents in the i3: MCii: iTC-ibiibix trlmgformators / circuit over a wide range.

The circuit of the triode and the parameters of its elements are chosen so that in the norm, Kzhime, when

the currents are small and the voltage is high, the voltage at the output of the triode has a value not exceeding 20 volts. (This magnitude is determined by the voltage drop from the rectified current in the resistance 5 and the resistance of the diodes 6 in the right direction). This eliminates the need to protect the triode from breakdown by excessive recording voltage.

The triode is prevented from overload by the operating current at close short circuits by shunting the emitter-base circuit with a small resistance of the diodes 12 in direct voltage.

Since the resistance of the diodes 12 in the forward direction strongly depends on the temperature, and the resistance. 11 is relatively small, an increase in temperature causes an increase in the current supplied to the input of triode 20. This prevents the relay from acting nonselectively in normal mode in cases of a significant increase in ambient temperature.

The capacitor 22, a shunt input of the triode 20, serves to filter the residual variable components in the rectified currents in steady state and transient modes.

Subject invention

High Speed Detection Directional Relay by Aut. St. No. 99390 using a germanium triode with a common emitter controlled from the CTOpiOHbi base as a null indicator, in the collector circuit of which a direct current relay is connected, characterized in that, in order to reduce the temperature dependence, a rectifier used , have the same temperature coefficient with a triode and serve simultaneously to protect the rest from overload.

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