SU363155A1 - DEVICE FOR PROTECTION FROM REACTOR OVERVOLTAGE IN CIRCUIT BATTERY CHAIN - Google Patents

Description

one

The invention relates to high voltage electrical networks.

In the circuit of shunt capacitor batteries, in order to limit the inrush current during switching, reactors (high-voltage inductors) are installed to tune into resonance with high harmonics (battery-filters) or, conversely, to detonate it. As the frequency of free oscillations is several times higher than industrial, this causes large overvoltages on reactors when switching batteries.

For example, in a LOOV battery in converting substations of high-power direct current voltage, filter reactors are installed with a nominal voltage at the fundamental frequency of up to 20 kV, however, their insulation corresponds to the class of 220-330 kV, since almost all nanometers are applied to them when turned on. live battery powered network.

BACKGROUND OF THE INVENTION Receiver overvoltage protection devices in a capacitor battery circuit are known to contain a discharge circuit, the output of which is connected to the earth terminal of the reactor.

The limitation of these overvoltages by low voltage classes is unreliable and practically impossible, since it requires an excessive increase in their throughput. In addition, the presence of reactors

high harmonic voltages impede the operation of the charge.

FIG. Figure 1 shows the electrical circuit of the device for protection against overvoltage of the reactor as a capacitor bank; in fig. 2 - the same, but with a switch in the arrester circuit.

FIG. 1, fig. 2 the following notation is accepted: 1 — bus, 2 — high-voltage switch, 3 — battery, 4 — reactor, 5 — main part of the battery, 6 — part of the battery accommodating the reactor, 7 — discharger, and 8 — switch. In normal mode, compensating

Part of the battery 6 has a capacitance approximately equal to the inductive resistance of the reactor 4. As a result, the discharge 7 in the normal mode has almost no industrial voltage

frequency, which greatly facilitates the arc quenching conditions in it.

When you turn on the bus / switch 2 battery 3 transient occurs. At the same time, at the frequency of free oscillations, the resistance of the compensating part 6 of the battery becomes at least an order of magnitude less than the resistance of the reactor, the voltage on the discharger 7 is almost equal to the voltage on the reactor. The surge is punched

limits reloading in the reactor to the desired value. At the end of the transient process, in the main part 5 of the battery (which is accelerated by exclusion from the reactor circuit), one or two half-periods of the main frequency of the discharge battery 7 extinguishes the arc and the compensating capacitor is charged, and the charge current is limited by the reactor 4.

Taking into account that the accuracy of tuning the compensating capacitance reaches half the resistance of a number of capacitors (not more), and also taking into account the presence of higher harmonics, the discharge of the discharge can not always be provided to facilitate the suppression of the gaps in this case in series with it the switch to be turned off at the end of the alarm.

Subject invention

1. A device for protecting the reactor overvoltages in a capacitor bank circuit,

containing a gapper, the output of which is connected to the earthing terminal of the reactor, characterized in that, in order to increase reliability, the gating input is connected to a point inside a capacitor battery having

n The industrial frequency is the lowest potential relative to the reactor output.

2. Software device according to claim 1, characterized in that, in order to increase the arcing capacity of the arrester in series with it

The switch is turned off, which is turned off during the breakdown of the discharge head.