SU324009A1 - Device for protecting from current leakages - Google Patents

Abstract

A DEVICE FOR PROTECTION AGAINST LEAKAGE CURRENT in the mine contact networks of the electric locomotive haulage, based on the principle of imposing an operating current of the reduced frequency on the current of the contact network, characterized in that, in order to increase reliability and ensure automatic detuning compensation when moving electric locomotives, it is equipped with two high-frequency generators operating current, whose frequencies are located symmetrically with respect to the resonant frequency of the fence, included in the power supply circuits of electric locomotives and in the contact network, and generator moves through the phase shifters are connected demodulators whose outputs are connected in series.

Description

(L 132 Known devices for protection against current leaks in mine contact networks of electric locomotive haulage, based on the principle of imposing an operational current of increased frequency on the current of a contact network. A disadvantage of the known devices is protection detuning when electric locomotives move, in order to increase reliability and ensure automatic compensation detuning when moving electric locomotives the proposed device is equipped with two high-frequency generators operatively: o current, the frequencies of which are located symmetrically refers The resonant frequency of the barriers included in the power supply circuits of electric locomotives and into the contact network, and demodulators connected to the output of the generators are connected in series. Figure 1-4 shows a schematic diagram of the proposed device; consists of two generators 1 and 2 of the operational high-frequency current, phase shifters 3 and 4, demodulators 5 and 6, DC amplifier 7 and relay unit 8. To block the path to the high frequency current through the source the power supply of the contact network and the engines 9 and 10 of electric locomotives on the ground in the contact wire and on electric locomotives are installed by the barrier 11 and electric locomotive 12,13, which are parallel resonant circuits with a resonant frequency where. (l) and 03, j are the frequencies operational current generators. The sensing elements that react when a person touches the contact wire are ring demodulators 5 and 6. The demodulator is a six-terminal with two pairs of input bb and one pair of terminals in which the average voltage or current is the output is proportional to the projection of the vector of one of the output currents - installation of a protection device at the end of the alternating current on the direction of the line vector of currents I, and 1 (FIG. 4), of the vector of the other (commuting or flowing through the gates and the control inputs direct voltage peremennogodemodul tori displaced on odinakotoka). opposite in magnitude

When electric locomotives move from a place, the voltage supplied from generators 1 and 2 through phase shifters 3 and 4 at output aa of demodulators 5 and 6 is switching. The voltage at the inputs of bb demodulators is proportional to the measured current flowing through the barrier filters and leakage into the contact network. The sum of the DC voltages from the output of the demodulators is fed to the DC amplifier 7, at the output of which the relay threshold device 8 is turned on. The relay device, acting on the disconnecting device 14, shuts off the supply voltage of the contact network when a person touches or Leakage The voltage at the output of each demodulator is proportional to the magnitude of the operating current at the input bb and cosine of the angle оС between this current and the switching voltage. Therefore, when the current at the output of the demodulator is zero. All barriers have the same frequency-phase characteristics and thus provide the same current phase shifts / tp / (figure 2). Phase shifters 3,4 rotate the phase of the voltage supplied from 90 ° at. Generator 90 ° at This setting of the barrier filters, the projection of the vector of the total current at each of the two parts, G), and H) to the corresponding switching voltage vectors. Consequently, the voltage at the outputs in the demodulator also; are zero. When leakage current I „, (fig.Z) appears, the projection of the sum of the currents I ,, -, at each of the frequencies CO, and CO, the corresponding switching voltage vectors are not zero, and the output of the amplifier 7 is supplied with a voltage equal to the sum of the voltages at the outputs of demodulators 5 and 6. The voltages at the outputs of the demodulators are proportional to the currents Igbix, --bix, - With this, the relay device 8, acting on the disconnecting device 11, shuts off the supply voltage of the contact network.

3, 324009 .4

Signals are angles of edges due to their own projections, are equal in magnitude and anti-inductance of the contact network. When the signs are positive, the result is the vectors of currents 1, and the in- put voltage of the imbalance to the projection current vectors of the input of the DC amplifier 7 I and 1 to the vectors of the switching voltages 5 is zero.

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fig.Z

Claims (1)

DEVICE FOR PROTECTION AGAINST CURRENT LEAKAGE in mine contact networks of electric locomotive haulage, based on the principle of superimposed high frequency operating current on the contact network current, characterized in that, in order to increase reliability and provide automatic compensation for detuning when moving electric locomotives, it is equipped with two high-frequency generators operating current, whose frequencies are located symmetrically with respect to the resonant frequency of the traps included in the power supply circuit of electric locomotives and in the contact network, and in The outputs of the generators through phase shifters are connected demodulators, the outputs of which are connected in series.