SU481861A1 - Device for repeated testing of high-voltage circuit breakers for breaking capacity - Google Patents

Description

(54)

DEVICE FOR MULTIPLE TESTS OF HIGH-VOLTAGE SWITCHES ON THE DISABLE TENSION ABILITY

3 but with disconnecting element enabled. Optional reactor. The reactor can be shunted by a capacitor and a resistor, and they are connected via a switching apparatus between the first and second zero-crossing in the Breaker. FIG. 1 shows a diagram of the proposed device; in fig. 2 - curves of the currents flowing in the elements of the device during the experiments. The source of the disconnecting current circuit is (see Fig. 1) shock synchronous generator 1 (with voltage U), reactor 2, including apparatus 3, additional reactor 4, disconnecting element 5 and test switch 6. The high voltage circuit contains capacitor battery 7, reactor 8 and spherical discharge 9. Supplementary reactor 4 is shunted with capacitor 11 and resistor 12 through switching apparatus 10. The inductance of reactor 4 is several times smaller than the inductance of reactor 2, and the latter is comparable to the inductance of reactor 8. For shape control to willow voltage, a reducing on the test switch are used kotsdensa tori 13,14 jr resistors 15,16. The operation of the installation is carried out as follows. The experience starts by turning off; on the circuit 3: generator 1-reactor 2- switching on apparatus 3 - additional reactor 4- switching off element 5 - test switch 6 in which current L flows (see Fig. 2), while its amplitude is several times less current amplitude, the disconnection conditions of which are reproduced in this installation. At time t, the contacts of the disconnecting elec amp 5 and the test switch 6 are open, and at time t, the surge arresters 9 and the high voltage circuit closes. Up to the moment through the switching element 5 and the active BL switch 6 the current flows through this, both circuits of the circuit are inductably connected through the branch with reactors 4, and the currents in the coir of the disconnecting element 5 depend on both emf. (U, U) and all parameters of the scheme. For a qualitative review of the process in a short period of time from the triggering of the bit 9 to the arc strength in element 5, i.e. in the time interval I 2 3, the current is

4 i varies little, i. E. and i selects. The voltage is such that the currents in the branch from the tripping element 5, starting from the moment t, have the opposite direction. Considering that reactor inductance 4 is several times less than reactor inductance 2, part of the current j ,, is due to the discharge of the capacitor battery 7 (if we consider using the method of separately constituting current, due to charging voltage U, of the battery), will significantly exceed the part of the current branching into the circuit with generator 1. The current of the disconnecting element 5 will be equal to the difference of state э 4i, and by the end of short currents ti 23 will approach zero value, which will (-. vet arc extinction in element Note 5 and the formation of one sequential circuit: generator 1 - reactor 2 - including 3 - capacitor battery 7 - torus 8 - discharge 9 - test switch 6, in which current I I will flow through test switch 6 curve in Fig. 2), due to the total voltage of the voltages. + + O „and the total inductance L p of reactors 2.8, where LP and the inductance of reactors 2.8 are responsible. If these parameters are the same as in full power circuit, then r, .... -:, ... - -5 and the derivative of current d / will have the corresponding value, 11 when the current approaches zero. As willow is usually a synthetic circuit, the parameters of the circuits, oiroe, dividing the curve of the restored voltage of capacitor 13, resistor 1p of capacitor 14, resistor 16, choose 1 | s so as to obtain the same values of transient resistance (2 p) in the circuit (see Fig. 1) and in c & pi of full power. , The role of reactor 4 is visible from the consideration of the approach to zero value (-0 in the declining element. It is known that in the two-part i-2 synthetic diagram, the current is: nugao is equal to j 1. з - ili t-2 Uf dt dt (it biL, h as the parameters of the scheme are chosen so that 1 - --L-. dls. In Fig. 1, the value - .. i in the absence of in the scheme reactor 4 would be equal to AU - while the arbitrariness of dt-on current in the tested switch 6 at its approach to zero would be iil dt De L h of the same n the order as b. 1 in the same order as consequently, the derivative of the current in the disconnecting element 5 would significantly exceed the derivative of the current in the tested switch 6, since U-. up. 5 and switch 6 typically use separate gaps of the same switch, then the arc cannot be extinguished in element 5. Under the conditions indicated, switching off the reactor 4 in the disconnecting device reduces the current derivative when approaching zero and creates easier conditions for arc suppression, thanks to what provide The possibility of the operation of the proposed device. The value of the id. Aktivnost reactor 4 Ie1 is chosen so that the derivative of the current D - s with its cit approach to zero in the opening. The boiling element 5 has a value close to the value of the derivative of the current when it passes through zero in the switch being tested. Since when reactor 4 is turned on in branch with element 5, only a part of the current caused by the discharge of the capacitor battery 7 branches off, this condition can always be fulfilled with a corresponding ratio between the reactors 2,8,4. Since during voltage restorations on voltage 5, the voltage recovery rate is determined, in particular, by the voltage variation on reactor 4, the latter is bridged by a capacitor 11 and a resistor 12, which are chosen with such a calculation that & 1 significantly reduce the oscillation frequency the component of the voltage drop at the reactor 4. After arc arcing in Element 5, the reactor 4 and the bypass of its element are excluded from the test circuit, and therefore do not exert; affected by; the further flow of the process, i.e. nG is the form of current 1 (see fig. 2.), and on npticesses of voltage recovery on the tested switch. When considering the installations in ustanof; e (see Fig. 2), their procedures are considered when extinguishing the arc in element 5 at the moment. time t i. at the first transition f. current in element 5 through zero. In a series of cj teas, it is advisable to use a different installation setting, for example, to ensure arc quenching in the tripping element 5 not at the first step t o and at the second (moment t) current in the element 5 goes through zero. This is achieved by switching on the chain: capacitor 11 -. the resistor 12 at time t by closing the switching-on apparatus 10. At the same time, due to the high speed, the voltage on the element 5 is not extinguished, the arc will not be extinguished. In the case of arc extinction in cell 5, at the time t, the voltage attenuation on the capacitor battery 7 decreases, and the rate at which the current approaches zero in the test switch 6 (the dotted curve in Fig. 2) and the magnitude of the voltage returned is higher than in the previous voltage. a case that simultaneously increases: the voltage recovery rate at the switch under test. This may be necessary when testing with limited power supply sources (for example, capacitor bank 7). The subject of the invention. A device for repeated testing of high-voltage circuit breakers on a two-frequency synthetic circuit, containing a circuit of full frequency current and a high voltage circuit of a higher frequency, a circuit breaker and a circuit breaker, which in order to reliably quench the arc the disconnecting element at the coism & e values of the current of the industrialized chaotot and the current of increased frequency, successively with the otk; An additional reactor.,, 2. The device according to claim 1, that is, in order to reduce the voltage recovery rate from. The key element of the dual-frequency circuit, an additional reactor is shunted by a capacitor 1 | a resistor. 3. Device pp p.1 and 2, about tl and -

so that, with the provision of | in series with the sensor and arc quenching in the switching-off element, the switching-on apparatus is turned on, and when the second passage of current through it is switched, the switches of which are closed in between the first

the zero value and the rise in this and the second zero current transitions in

values of increasing stress, 5. disconnecting item.

481861

. S

7 A

FIG. one