SU1451797A1 - Device for compensating for reactive power - Google Patents

Abstract

The invention relates to electrical engineering, in particular, to reactive power compensation devices using switchable filter compensating (FC) circuits and smoothly controlled linear reactors. The goal is to increase reliability. In the case of a winding connection. 3 in a star with an ejected neutral at operational switch 41 of one of the FC circuits, for example, for switching the reactive power compensation level in steps, an additional switching element (CZ) 11 of the FC disconnectable circuit is preliminarily turned on. Then this circuit is disconnected from the CE 6 network and after that the included additional CE 11 is disconnected. As a result of connecting the neutral 9 of the FC circuit to be disconnected to the neutral 5 of the secondary winding of the transformer 4, the neutral potential 9 is prevented from shifting in the incomplete mode resulting from non-simultaneous an arc break in the phases of EC 6. At the same time, the amplitude of the voltage restored on the first disconnected phase of EC 6 is reduced by one and a half. In cases where the winding 3 of the transformer 4 is connected to a triangle or a star with an insulated neutral, the process proceeds as indicated. 1 hp f-ly, 1 ill. with "(L cd; about vi

Description

The invention relates to electrical engineering, namely to devices for compensating reactive power using step-compensated filter compensators and smoothly controlled linear reactors.

The purpose of the invention is to increase reliability.

The drawing shows a schematic diagram of the device.

The device contains a thyristor-reactor group consisting of compensating reactors 1 connected by anti-parallel connected thyristors 2 to a network fed from the secondary winding 3 of a step-down transformer 4 connected, for example, to a star with neutral neutral 5, device B, and filter compensation circuit 5 the phases of which consist of series-connected switching elements 6, capacitors 7 to reactors 8. The branches of opposite phases of filter compensation are connected in a star with an insulated neutral 9. Device The event contains a common 10, between which I and the neutral r 1 9 Ксшдой three-phase. The filter compensating circuit includes additional coupling elements 11, for example, disconnectors. In the presence of a neutral 5 of the secondary winding of the transformer D, a common bus 10 is connected to the neutral 5. The neutral 5 may be grounded,

The device works as follows,.

In case a star winding 3 is connected to a star with a neutral when one of the filter compensating circuits is quickly disconnected, for example, for switching the level of reactive power compensation stepwise, additional switching 1 element 11 of the filter compensating circuit is switched off, then the circuit is disconnected element 6, after that the switched-on additional switching element 11 is disconnected. As a result of connecting the neutral 9 of the switched-off compensating circuit 5 to the neutral of the secondary winding of the transformer 4 is prevented from moving neyuraln capacity at 9 napolnof aznom mode arising due to non-simultaneous arc obrsha phases kc g / tasch- $ onnym element 6:

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At the same time, the voltage amplitude, restoring the first disconnecting phase of the switching element 6, decreases by 1.5 times, which will increase its reliability.

When a transformer 4 winding 3 is connected in a triangle or a star with an insulated neutral, its neutral 9 is switched off by the switching element 11 to the bus 10, the necessary number of switching elements 11 of the remaining filter compensating switches are switched on at the same time, then the switchable switching element 6 is turned off circuit, after which all included additional switching elements 11 are disconnected. As a result, the connection to the neutral of the switchable filter the neutralizing circuit of neutrals of other filter compensating circuits, which due to their phase symmetry have a cool potential relative to the earth, a neutral switchable filter circuit of a circuit, despite the non-phase mode of the latter due to the non-simultaneous arc breakage by switching elements 6, the more neutral the potential will be, the more neutral the film - the trocom compensating circuits are connected to the bus 10; Studies show that the connection to the four and five filter compensating circuits to be disconnected is imerno same power gives substantially the .zhe effect as poddoednnenie to "eytrali transformer T, e. reduces the amplitude of the restoring voltage on the first disconnected phase by almost the same. Connecting the neutral of only one filter-compensating circuit ensures a reduction of the restoring voltage by more than 1.3 times, which in some cases may be sufficient for reliable operation of the switching elements,

Claims (2)

Thus, the introduction of additional switching elements, connected between the neutral of each three-phase filter-compensating circuit and the common fabric, increases the reliability of the reactive power compensation device. Formula invented and 1, A device for reactive power compensation, each phase a switching element is introduced by the number of filters on commutaries from other circuits and a common bus, with additional switching elements included between. common bus and neutral I of each three-phase filter-compensating circuit. contains a compensating reactor, connected by an all-parallel-connected thyristors to a network fed from the secondary winding of a step-down transformer, and at least two filter-compensating circuits, consisting of series-connected reactors and capacitors, under- 2. The device according to claim 1, tl and h kluenzhenrs to the network through switching stations so that, in order to increase the elements, the filter compensating efficiency when using chains of opposite phases are connected to the transformer nickname Here, with an isolated neutral, a striking winding into a star with a surface, characterized by the fact that, with a neutral, the common bus is connected for the purpose of increasing reliability, in addition to the 15 indicated neutral. The switching elements according to the number of filters about companies from other circuits and the common bus were introduced, with additional switching elements included between. common bus and neutral I of each three-phase filter-compensating circuit.  2. The device according to claim 1, that is, so that, in order to increase efficiency when using a transformer with a secondary winding connection to a star with a derived neutral, the common bus is connected with specified neutral.