SU1663690A1 - Shunt capacitor bank - Google Patents

Abstract

The invention relates to electric power industry, specifically to adjustable reactive power compensation devices, and can be used for stepwise power control of high voltage shunt capacitor banks assembled from low voltage capacitors. The goal is to reduce the cost of the battery and increase the reliability of its operation. The three-stage power regulation of the capacitor bank is carried out by two switching devices (switches) 5 and 6 and the capacitance of groups 1 and 2 of capacitors. In order to ensure the normal operation of the component capacitors 4 (without voltage overload), the number of rows 3 of capacitors in group 1 must correspond to the linear voltage of the network, and the number of rows in group 2 to the phase voltage of the supply network. With the poles open, the contacts of the switches 5 and 6 of the shunt capacitor battery are in a de-energized state. With the open poles of the switch 6 and the open poles of the switch 5, groups 1 and 2 of the capacitors are interconnected in series and operate under reduced voltage. 1 hp f-ly, 2 ill.

Description

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mi (switches) 5 and 6 and the capacity of groups 1 and 2 capacitors. In order to ensure the normal operation of the component capacitors 4 (without voltage overload), the number of rows 3 of capacitors in group 1 must correspond to the linear voltage of the network, and the number of rows in group 2 to the phase voltage of the supply network. With

The invention relates to electric power industry, specifically to adjustable reactive power compensation devices, and can be used for stepwise power control of high voltage shunt capacitor banks assembled from low voltage capacitors.

The purpose of the invention is to reduce the cost of the battery and increase the reliability of its operation.

Fig. 1 is a schematic diagram of a shunt capacitor battery; Fig. 2 shows structural diagrams of replacing a device in various stages of power control.

The shunt capacitor battery consists of two three-phase groups 1 and 2 of capacitors connected in series in series. Each of the groups is made by serially connecting rows of 3 parallel-connected capacitors 4.

Output terminals 2-1, 2-2, 2-3 of the second group of capacitors are interconnected. The first input switch 5 is connected to the input terminals 1-1, 1-2, 1-3 of the first group of capacitors. The a, b points and the three-phase groups 1 and 2 are connected via a second input switch 6 to the opposite phases of the network. In addition, the battery contains three single-phase voltage measuring transducers 7, 8, and 9 and a protection relay 10. The primary windings 7-1, 8-1, 9-1 of converters 7, 8 and 9 in each phase of the battery are connected between the midpoint a, b and from the series connection of the rows of the first group of capacitors and the input terminals 2-1.2-2, 2-3 second group of capacitors. The secondary windings 7-2, 8-2, 9-2 converters 7, 8 and 9 are assembled into an open triangle, at the input of which protection relay 10 is turned on.

The magnitude of the reactive power generated by the battery in the mains supply, the reversed poles (contacts) of the switches 5 and 6 of the shunt capacitor battery is in a de-energized state. With the open poles of the switch 6 and the open poles of the switch 5, groups 1 and 2 of the capacitors are connected in series with each other and operate under reduced voltage, 1 hp ff, 2 Il.

it is made by the state of its switches 5 and 6 and the capacitance of groups 1 and 2 of capacitors.

In order to ensure the normal operation of the component capacitors 4 (without voltage overload), the number of rows 3 of capacitors in group 1 must correspond to the linear voltage of the network, and the number of rows in group 2 to the phase voltage of the supply network.

When the poles (contacts) of the switches 5 and 6 are open, the shunt capacitor battery is in a de-energized state.

When the poles of the switch 6 are open and the poles of the switch 5 are open, groups 1 and 2 of the capacitors are connected in series (Fig. 2a) and operate under reduced voltage. In this case, there is the lowest level of generated reactive power.

When the poles of the switch 5 are open and the switches of the switch 6 are closed, only the second group of capacitors is connected to the network (Fig. 26), moreover, under the nominal voltage.

In this case, the reactive power generated by the battery is equal to the installed capacity of the capacitors of this group.

With the poles of the switches 5 and 6 closed, the capacitor group 1 is triangular and connected to the line voltage, and the group 2 is connected to the phase voltage of the network (Fig. 2b). In this case, the battery generated power is equal to the sum of the installed capacities of the capacitors of both groups.

Thus, with the assembly of both groups of identical capacitors, the range of control of the reactive power of the device is

7.45: 2.73: 1.

In this case, at all stages of reactive power generation, the monitoring of the operating state of the capacitor groups is carried out by measuring the asymmetry of their phase capacitances. Indicated

the measurements are carried out by means of converters 7, 8 and 9.

If a capacitor is damaged in any of the groups, the conductivity of the phase containing this capacitor changes, which 5 causes a change in the voltage applied to the primary winding of the corresponding voltage converter. The indicated voltage variation depends on the degree of asymmetry of the phase conductors - 10 bridges, i.e. on the size of the damage. As a result, an unbalance voltage appears at the output of an open triangle, the magnitude of which is controlled by the protection relay 10. When the last setting reaches 15, the operation of the relay 10 disconnects the battery.

Such a battery circuit allows two

switching devices to carry out a three-stage regulation of its 20 power while maintaining control of the operating state of the component capacitors in all battery operating modes. In addition, the possibility of short circuits with uncoordinated 25 actions of switching devices is excluded, which contributes to its reliability in operation.

Claims (2)

Claim 1. Shunt capacitor battery, 30 consisting of two three-phase capacitor groups, connected in series with each other and made of series of parallel-connected capacitors, two switches, through the first of which the free terminals of the first group of capacitors are connected to the terminals for connection with the mains, the free terminals of the second group of capacitors are interconnected, as well as voltage meters, the primary windings of which are connected to groups of capacitors, and W orienting — to a battery life state sensor, characterized in that, in order to reduce the cost of the battery and increase the reliability of its operation, the connection points of the capacitor groups are connected to non-named phases of the second switch connected to the terminals for connection to the network, 2. Condenser battery according to claim 1. This is due to the fact that the primary windings of the voltage meters are connected in each phase of the battery between the midpoint of series-connected series of parallel-connected capacitors of the first group and the combined terminals of the second group of capacitors, and the secondary windings are connected in delta closed to the operating state sensor batteries.