SU185411A1 - METHOD FOR TESTING HIGH-VOLTAGE SWITCHES FOR DISABLING RATIO ABILITY - Google Patents

Description

The present invention relates to methods for testing high-voltage switches for switching capacity, containing, as a power source, synchronous generators with a step-up transformer or oscillatory circuits A. A. Goreva.

Usually, when testing parts of powerful high-voltage break switches from power sources, the power of which can ensure testing only one break (or several, but not all), all other breaks are not connected to the executive installation and no current flows through them during the test. . In this case, if the action of the individual faults is interconnected (common gas pipeline, blow valve, etc.), insufficiently equivalent test conditions are created.

In the proposed method, parallel to all the breaks, except for the test subject, a low-impedance shunt resistance is selected, chosen from the conditions for providing the required shape of the curve of the restoring voltage.

To prevent premature extinguishing of the arc in series with a low-impedance shunt resistor, a switch is switched on, the contacts of which close at the moment when the arc extinguishes,

If this turns out to be insufficient, then in parallel with all the breaks, except for the subject, a high-resistance shunt resistance is connected, which can be broken up into equal or unequal parts.

FIG. 1 is a schematic diagram of the testing of switches by the proposed method; in fig. 2, 3, 4, 5 and 6 - breaks of the tested switch using respectively a circuit breaker, high resistance (one or broken into the same or unequal parts) and a high-speed circuit breaker.

The test facility contains a power source PI (synchronous generator or an oscillating circuit A. A. Goreva), an operational protective switch GV, including an apparatus VA, adjustable reactors, a damping resistance R and a capacitor C. The test multi-breaker is connected to the unit either directly or via boost transformer.

Parallel to the breaks of the switch, excluding the test break (or discontinuities) of the RI, a low resistance is connected. The magnitude of this resistance is chosen so as not to distort the shape and magnitude of the voltage recovered at the test break. This resistance greatly facilitates the extinction of the arc in the breaks shunted by it. When the arc duration is equal to or slightly longer than one half-period, the arc is shunted in shunt discontinuities, all the power supply voltage is applied to the test discontinuity, and the voltage recovery form according to the norms is provided by selecting the resistance JRi and the capacitor capacity that can be connected either directly to to the subject rupture, or to the entire switch as a whole (dotted line).

Due to the presence of resistance RI in the event of "failure, the test gap will not have full test current, but a current limited by this resistance, which greatly facilitates testing and research without frequent replacement of test contacts and arc suppressors.

If the design of the switch is such that the duration of the arc is noticeably longer than one half-period or is several half-periods, the presence of resistance RI MO. When testing, it leads to premature extinction of the arc in shunt discontinuities, and consequently, in the subject. To reduce the likelihood of premature extinguishing of the arc in series with the indicated resistance, an auxiliary contactor VZ is turned on, the contacts of which close in the half current flow period in which the extinction of the arc is expected. If this is not enough, then in a number of cases it is possible to connect to all discontinuities, except for the subject, a high-resistance shunt resistance RS, the value of which should not affect the extinction of the arc in the discontinuities shunted by it.

In case of premature extinction of the arc, due to the presence of resistance R, all the source voltage falls on the subject rupture, which in this case must break through; thereafter, all the voltage acts on the shunt breaks, which in a number of cases must also break through.

In order to increase the efficiency of arc extension, high-impedance resistance shunting is carried out according to the so-called cascade scheme. In this case, several high-resistance shunting resistors of the same size are used, connected to the circuit so that the first resistance shunts all the breaks, except for the subject, and each subsequent break is one break less than the previous one. High impedance shunt resistances can be connected as shown in FIG. 5, but in this case to ensure the cascade overlapping of the shunting resistance discontinuities

jRs should be significantly different from each other.

The equivalence of the tests of the multi-disconnect switch is ensured even if a series of breaks is shunted only by the fast-action switch 3 (Ri Q). This method requires a more advanced closure, since to ensure the necessary equivalence, the closure of its contacts must take place several hundred microseconds before the current passes through a zero value at which the arc extinguishes is expected. However, using only a high-speed closure allows testing of multi-break switches with integrated low-resistance shunts.

If the arc is longer than one half period, to prevent premature extinction of the arc parallel to the bridged discontinuities, resistances RS or Rt are connected, or 7 5.

Claims (5)

1. A method of testing high-voltage breakers for breaking capacity by discontinuities, whose actions are interconnected, using a partial power source and a device for regulating restoring voltage, characterized in that, in order to bring the test conditions closer to the real and limit the current in case of failure to extinguish the arc with the test break, parallel to all the breaks, except The test person is connected to a low-impedance shunt resistance chosen from the condition of providing the required shape of the voltage recovery curve. 2. The method according to claim 1, characterized in that, in order to prevent the premature arc extinction, in series with a low-impedance shunt resistance, includes a contactor, whose contacts are closed in a preselected current half-period when the arc extinguishes. 3. Method according to np. 1 and 2, characterized in that, in order to prevent premature extinction of the arc, a high-resistance shunt resistance is connected in parallel to all the breaks, except for the subject. 4. Method according to paragraphs. 1-3, characterized in that, in order to create conditions for the cascade overlapping of shunted discontinuities, the indicated high-resistance shunt resistance they are broken up into equal-sized parts that cascadely shunt all breaks, except for the subject. 5. Method according to paragraphs. 1-3, characterized in that the high-resistance shunt resistance broken into unequal parts of the size, which shunt individual breaks.