SU413570A1 - - Google Patents

Description

one

The invention relates to a device for monitoring the isolines of high-voltage electrical installations and provides for limiting damage reproduction times by disconnecting installations.

Invention. Can iiaimi irimeyenne nance zantspe (: 1bmot () To stators gene) at) p () in, work iOLUHx i block with a transformer. In this case, the insulation state of the stator winding on the housing is monitored and detected as a decrease in its electrical resistance, 1a and a direct earth fault at any point of the winding, i.e., one hundred percent coverage of the protected object, as well as all attachments of the generator voltage .

A device of one hundred percent earth protection of a generator – transformer block is known, consisting of those connected in series with an arcing generator of a constant voltage generator, a measuring unit and a capacitor shunting them. A battery with a charging unit is used as a source in the device. The battery voltage is superimposed on the insulation of the generator and creates a current through it, the value of which is judged on the state of the insulation. The measuring device is a current relay with an electronic amplifier. Shunt capacitor provides nor9

maximum arc-coil operation, since it has a high resistance for direct current and low for the fundamental frequency of n other harmonics.

The disadvantage of a new device is the use of a bale gauge, KOTopHii does not allow sufficiently accurate control. isolation state. The oscillations and jumps of the source source cause the corresponding changes in the magnitude of the choke produced by the source through the generator isolation. These changes are captured by the current metering body, and it provides false information about the change in insulation resistance. To reduce the voltage fluctuations, a battery with a charging unit is used as a source. However, the battery pack and the charge unit are very hard and complex in the system and, moreover, they are expensive.

The invention makes it possible to eliminate the indicated residues due to the fact that a magnetic amplifier with two differentially connected control windings is used as a measuring organ, one of which is connected via a ballast resistor with a voltage source, and the other is connected via a control winding and a resistor)

Parallel to the shunt capacitor, with a capacitor connected in series with the winding.

The drawing shows the prnntsinialnaya scheme of the device.

The power supply of the unformator 1 is connected to the receiver and the vessel 2, dyui {, its constant voltage applied to the co-resistance, and the insulation of the generator. The pair of Mociy 2 to transformer 1 is connected to the bridge 3 and the working windings of the magnetic amplifier 4, in series with which the output relay 5. is connected. The rectifying bridge 2 through the ballast resistor 6, limiting the direct current at short. Zakokanin in the generator, is associated with differentially connected windings 7 and 8 of the magnetic amplifier. Winding 7 is connected in series with the nervous windings of measuring transformers 9 of nania s iia generator 10 terminals 10. 06 winding 8 through a resistor 11 setting triggered by single-element | 1ena national, regional 7 and Imitir to a capacitor 12. Pair-to-resistor yciaiiKH 11 and a dongle capacitor 13, with the help of which it was os111, yet with-: with tuning off jumps from power supply. To protect ycTpoiiCTBa from possible non-overvoltages from the side of a nongranular generator, and parallel to the shunt capacitor 12 is connected a ramp-up | 1ic 14.

The proposed device works next .1, in the image.

G1os1o 1NY11 Izh, created :. the height of the amicable bridge 2 is a ballast resistor 6 and an overhang) aw; 1 enn: 7 with resistance r and turns iVr, an arc-suppressing coil or windings of transformers 9, co-insulate the generator insulation to ground and iostuna; reversed to Mociy 2. At the same time, under the influence of an irregular (vi; 3, arising resistance of the winding t and resistance of pulsation, a constant current flows through the control winding 8th of the resistance rg and the number m of turns Ws and through the resistor Triggering setpoints with resistance. The currents flowing in the windings are created by an MSD, controlling the operation of the magnetic amplifier. Thanks to the inclusion of the windings of the control, the dms of the windings 7 magnetizes, and the msd to the windings 8 demagnetizes magnetic amplifier.

The amplifier works in relay and is configured so that it works. i.e., non-reliable: 1.it enters the saturation state, with equality of ms.s. control windings. Thus, the trigger condition of the magneto amplifier is characterized by the expression:

 - /; 4/7 Oh, and eCviH take into account that

t / ,, 3

And L: -,

. THAT expression

KI +

 i- r

four

W W

A-of + g,

(R. + / -s

In case of equal resistances and turns of the windings, the condition for the operation of the magnetic snubber is:. As can be seen, in the static mode, the response of the magnetic amplifier and, accordingly, the accuracy of the protection operation are not determined at all by the load and, therefore, do not depend on its oscillations.

In the normal state of the isolation of the heperator, its resistance is much greater than the sonro1T-1 of the setpoint. This corresponds to a significant current in the winding of the control 7 and the inequality of the mrs control windings / sW8 / 7V7. The magnetic amplifier is in a demagnetized state. When reducing the insulation resistance to a value equal to the resistance of the set point, C () 01tzetstuet the pr1 property of the msd. windings of equilibrium, magnesia; the amplifier, transition c) to the receiver, is triggered and delivers the voltage on the output relay 5, which in the output .Hcn: vK: ciTi from the libroopa setpoint resistance will give either the current; 1 unimpeded | sigial or de; | S1vuet on oi kl10che11ie defensive paiopa gene.

In dynamic mode when jumping iHyo Hiero nanr ages; in n, er.i and windings of control 7 and 1 nuntiru 10H, its capacitor 12 arises not in the current 1 TCJK, msh from which .moi 6ni 1 yzvat1).: ozhpu | ;; p;: lp) Tu: 1gni1-nogo amplification. | . Odlgko not (because .l; 1el (; re: n1st {) |) for i no. Pk, why the condensation 13, 11 skgg-yk pyiipo1p him paprpi vyp5aet peredpiky current ta. and konde 1sator 13.

When sootvetsnu10N1ei magnitude and last mrs from the current in the winding 8 completely compensates for the ms.s. from transition | ok; I, () (; weave 7 and excludes IeM by the very lo / i; puyu) ab {poo. Mag1ch-pog (: strengthen, 1 while jumping; ax pptayuisgo papr zhs: 11;.

PRED, METTES OF THE INVENTION

The device is equipped with a ground protection system for the generator-transformer unit, containing I1, its source of constant voltage, to which the mercury body is connected, and P1u1gpruin. Copdeisator, characterized in that, with the goal: to ensure increased accuracy and reliability of work, as a measuring body, magic; amplifier with .-. Differential diodes of the control coils, one of which is connected via a ballast resistor with a voltage test, and the other through the control control winding and the setpoint operation resistor.h is connected in parallel with the shunt capacitor, and a capacitor is connected in series with the winding.