SU400951A1 - DEVICE FOR CURRENT START OF REMOTE PROTECTION - Google Patents

Description

one

The invention relates to the field of electrical engineering and can be applied in the distant shielding of the electrical power supply line (for example, with low magnification, such is the neo-symmetric short for | Mg.

Nowadays, as a device for pu- titation of protection, overcurrent relays, impedance relays and ipra are used.

Above the starting of the maximum current relay is the insufficient sensitivity. To nwai1M1met1pichnom short circuit and m through transient resistances, especially on heavily loaded .1I1n.i x transmission. Relays of the FULLY S01p roti1l1i are complex in design and may malfunction when they are damaged in voltage circuits, but (Directional resistance relays, in addition, have a dead zone for voltage and may deselectively for short closures. not outside the protected area.

The aim of the invention is to increase the sensitivity of the device to .neo1Mmeter1H short-circuit.

This is achieved due to the fact that the device responds to the ratio of the absolute values of the highest current of the phases to the lowest and triggers if this ratio exceeds the established value.

The layout of the image on the draw.

The trans reactors / included in the secondary C & Ai current transformers have two sec. Primary windings. One secondary winding is connected to the working rectifier bridge 2, the output of which includes a smoothing condiver 3, and the other secondary winding is connected to the brake of rectifying bridge 4, the output of which includes a smoothing condator 5 and potentiometer 6. Negative conclusions of all workers and tarmoz . The bridge bridges are connected together. The positive output of each working bridge 2 through the N-1 indicator 7 and the diodes 8 9 connected to the output of the potentiometer 6 of the same phase. The points of accumulation of diodes 8 9 of all phases are connected by Bi.viecTe.

With a slight difference, the currents of the three phases in the normal operation of the mains electrical network or three-phase short circuits and the operating voltage at the outputs of the diodes 8, proportional to the absolute value of the greatest current of the phases, is less than any braking voltage at the outputs of the eccyometers (). In this case, all the diodes 8 and 9 are locked, but-nD HD katopjj are de-energized and starting the relay does not work.

Prl significant differences from each other

the absolute values of the phase currents at a short-circuited iesymmetric short-circuit operating voltage at the outputs of dyads 8, proportional to the currents of the damaged phases, is greater than the voltage at the output of potentiometer 6 in the circuit of the intact phase. Zero-one. Indicator 7 in the circuits of damaged phases is flowed around by the current and is operating. , produces a bunch of distance protection, and switching, in the current and voltage circuits of distant protection organs.

The ratio of the transfer factors of the working and brake circuits of the device should cooTiBeincTiBOiBaTb to the conditions of operation of the alarm and emergency differences of the absolute values of the phase currents and non-operation at their acceptable difference.

PRINCIPLES OF THE INVENTION A device for current release of a remote protection circuit for asymmetrical short circuits, comprising three trans-reactors, to which secondary indicators are connected null indicators, characterized in that, in order to increase the sensitivity, one secondary winding transreactors are connected via a working bridge with a center and an output and two diodes connected to the null indicator, which is connected via a braking rectifier bridge to the other secondary winding of the transceiver, and -negative conclusions rectifying diode bridge and the point of the compound sootvetst1venno interconnected.

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