Device of shunt compensation for power transmission line

FIELD: electrics.

SUBSTANCE: invention concerns current power transmission equipment, particularly high-voltage power transmission. Device includes reactive shunts connected by reactive switches to line, with additional special reactive shunts connected to the line in star network pattern with unearthed neutral conductor.

EFFECT: enhanced shunt compensation of power transmission line in low load mode, stability and reliability in elimination of single-phase short circuits at single-phase reclosing.

1 dwg

 

The invention relates to techniques for the transmission of electricity alternating current, namely the high-voltage transmission lines.

A device shunt compensation for power lines (Millionsten, Aly. Using static compensators for damping arc recharge during a pause in the main electric networks of ultra-high voltage lines.//Electricity, 1989, № 2, - p.7-13, Fig.1.), contains static thyristor joints with independent phase control, allowing you to pause mode single-phase automatic reclosing (main electric networks) to compensate for the corresponding interfacial capacitance line and the capacity of the emergency phase to earth and thereby reduce to acceptable levels the current arc is sustained.

The disadvantage of this device is its high cost.

It is also known device shunt compensation for power lines (NAS, Useraccess, Snejanka. The use of compensatory reactors to facilitate main electric networks of high-voltage lines.//Electric station, 1975, No. 12, - s-72, 1. - prototype). The scheme of this device is shown in the Appendix. The device cross-compensation for the transmission line 1 contains the shunt reactor 2 which are connected to the line through the reactor switches 3. In neutral shunt reactor 2 is provided on the merit compensation reactors 4 (by disconnecting switches 5, which continuum compensation reactor 4 in normal mode) in the event of single-phase short circuit 6 linear circuit 7. As a result, in the pause mode, the main electric networks is compensation uid tank line and accordingly to reduce the arc current is sustained.

The first disadvantage of this device is that the compensating reactor shunted by normal modes, can not be used to increase the degree of shunt compensation for power lines in the modes of its small download. As such, the need exists for a widely used lines 500 and 750 kV, in which the degree of shunt compensation is insufficient. Therefore, to improve the working conditions of such transmission requires additional installation of shunt reactors to bring the degree of compensation is close to 100%.

The second drawback is to reduce the level of resistance in the modes considerable downloads line because of the need for the introduction of the work at full capacity shunt reactors 2 to ensure the conditions of arc extinction recharge, because under normal conditions when the transmission of large capacity shunt reactors 2, normally disconnected from the line reactor circuit 3 according to the terms of mode voltage. The connection of shunt reactors 2 at ASU is the main electric networks implementation leads to a decrease in voltage on the tire, and accordingly reduces the level of resistance. Calculations show that the maximum power of the main electric networks holding in this case is reduced by 20-30%. And this, in turn, may require additional safety measures, such as disabling generation capacity and load, to preserve the stability.

The third disadvantage is connected with the necessity of switching all eight of the reactor switches in the implementation of main electric networks. Thus failure of any of the switches leads to the impossibility of main electric networks, contributing to an emergency situation and thereby reduces reliability.

The task of the invention is to increase the degree of shunt compensation of a transmission line in the regimes of small downloads line, as well as improving the stability and reliability by eliminating single-phase short circuits in the loop main electric networks.

This object is achieved in that in the known device, containing series-connected shunt reactors and switches, connected to the line special shunt reactors connected in the circuit of the stars with Rossellini neutral.

The drawing shows a structural diagram of the device for shunt compensation of a transmission line. The device shunt compensation of a transmission line 1 contains shunt reactors 2, dial-up reactor you what lucatelli 3, special shunt reactor 4 which are connected to the transmission line 1 via disconnectors 5.

The device operates as follows. Under normal conditions when the transmission of the low power special shunt reactors 4 provide an increase in the degree of shunt compensation of a transmission line. In normal modes with significant downloads of lines in the case of single-phase short circuit 6 emergency phase line 1 off line switches 7 and is connected reactor switches 3 single phase shunt reactor 2, same with the phase of a transmission line on which the short circuit occurs.

Thus, the increase in the degree of shunt compensation line in the modes of its small loads and increases the level of stability and reliability when conducting main electric networks in modes considerable downloads line.

The device shunt compensation for power lines containing shunt reactors connected to the line reactor circuit, wherein the line is additionally attached special shunt reactors connected in the circuit of the stars with Rossellini neutral.



 

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