CN113257549A - High-capacity double-device height impedance phase-shifting transformer with additional reactor - Google Patents

Abstract

The invention relates to a high-capacity double-device height impedance phase-shifting transformer with an additional reactor, and belongs to the field of power transformers. The technical scheme is as follows: the series transformer oil tank is communicated with the excitation transformer oil tank through a pipeline; each phase of the series transformer is composed of a high-voltage coil Lcg and a low-voltage coil Lcd, the low-voltage coil Lcd of the series transformer is in a delta connection method, a tap terminal of each phase shift coil LLt of the excitation transformer is connected with a fixed contact of a resistance type on-load tap switch of the phase, two ends of each phase shift coil LLt are connected with a positive end and a negative end of the phase polarity selector KZF1, and a movable contact of the polarity selector KZF1 is connected with one end of the low-voltage coil Lcd of the corresponding phase of the series transformer. The invention can control the current of each parallel branch of the parallel power system through the phase angle regulation of the phase-shifting transformer, thereby solving the over-current problem caused by the parallel transmission line and ensuring the stable and high-efficiency operation of the power system.

Description

High-capacity double-device height impedance phase-shifting transformer with additional reactor

Technical Field

The invention relates to a high-capacity double-body height impedance phase-shifting transformer with an additional reactor, which is suitable for power regulation of a parallel transmission line of a power system and can limit the short-circuit current of the system, and belongs to the field of power transformers.

Background

Large-scale power systems are required to have high reliability and high efficiency, and are generally formed by connecting a plurality of power systems in parallel, the reliability and load distribution of each power system are determined by different characteristic parameters of the system, and main influence factors are line impedance and power factor. The application of the phase-shifting transformer in the parallel transmission line greatly improves the reliability of the power system and greatly limits the short-circuit current of the system. The main application of the high-impedance phase-shifting transformer in the power system can be summarized as follows: a. protecting a transmission line of a power system from overload; b. improving the stability of the power system; c. controlling power flow of different power networks for long-distance parallel overhead lines and cable lines; d. the capacity of an original power transmission system can be increased; e. the high-impedance phase-shifting transformer is additionally provided with the additional reactor, so that the short-circuit current of the system can be greatly limited. However, the prior art is difficult to meet the technical requirements, and the short-circuit current of the system cannot be greatly limited, so that the operation stability of the power system is influenced.

Disclosure of Invention

The invention aims to provide a high-capacity double-reactor height impedance phase-shifting transformer with an additional reactor, which can control the current of each parallel branch of a parallel power system through phase angle regulation of the phase-shifting transformer, thereby solving the over-current problem caused by a parallel transmission line, limiting the short-circuit current of the system, ensuring the stable and high-efficiency operation of the power system and solving the technical problems in the prior art.

The technical scheme of the invention is as follows:

a high-capacity double-device height impedance phase-shifting transformer with an additional reactor comprises a series transformer oil tank, an excitation transformer oil tank, a series transformer, an excitation transformer and a resistance type on-load tap switch K with a polarity selector KZF1, and is provided with an additional reactor LRC, wherein the additional reactor LRC comprises LRC1, LRC2 and LRC 3; the series transformer oil tank is communicated with the excitation transformer oil tank through a pipeline; each phase of the series transformer consists of a high-voltage coil Lcg and a low-voltage coil Lcd, the low-voltage coil Lcd of the series transformer is in a triangular connection method, each phase of the high-voltage coil Lcg of the series transformer is respectively connected with one end S1, one end S2 and one end S3 of a power supply, and each phase of the high-voltage coil Lcg of the series transformer is respectively connected with one end L1, one end L2 and one end L3 of a corresponding load after being connected with an additional reactor LRC; each phase of the excitation transformer consists of a high-voltage coil LLg and a phase shifting coil LLt, the high-voltage coil LLg of the excitation transformer is in star connection, and one end, opposite to the star connection, of the high-voltage coil LLg of each phase of the excitation transformer is respectively connected with a center tap of the high-voltage coil Lcg of the corresponding phase of the series transformer; the tapping terminal of each phase shift phase coil LLt of the excitation transformer is connected with the fixed contact of the resistance type on-load tap-changer of the phase, the two ends of the phase shift phase coil LLt are connected with the positive end and the negative end of the phase polarity selector KZF1, and the moving contact of the polarity selector KZF1 is connected with one end of the low-voltage coil Lcd of the corresponding phase of the series transformer; additional reactors LRC1, LRC2 and LRC3 are connected in series in front of the outgoing lines of the sleeves of L1, L2 and L3 at one end of the load, and the bodies of the additional reactors LRC1, LRC2 and LRC3 are placed in a series transformer oil tank.

The invention has the following positive effects: the phase angle regulation of the phase-shifting transformer can control the current of each parallel branch of a parallel power system, thereby solving the problem of over-current caused by parallel transmission lines, limiting the short-circuit current of the system and ensuring the stable and high-efficiency operation of the power system.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a single phase wiring diagram of an embodiment of the present invention;

FIG. 3 is a vector diagram according to an embodiment of the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings and examples.

A high-capacity double-device height impedance phase-shifting transformer with an additional reactor comprises a series transformer oil tank, an excitation transformer oil tank, a series transformer, an excitation transformer and a resistance type on-load tap switch K with a polarity selector KZF1, and is provided with an additional reactor LRC, wherein the additional reactor LRC comprises LRC1, LRC2 and LRC 3; the series transformer oil tank is communicated with the excitation transformer oil tank through a pipeline; each phase of the series transformer consists of a high-voltage coil Lcg and a low-voltage coil Lcd, the low-voltage coil Lcd of the series transformer is in a triangular connection method, each phase of the high-voltage coil Lcg of the series transformer is respectively connected with one end S1, one end S2 and one end S3 of a power supply, and each phase of the high-voltage coil Lcg of the series transformer is respectively connected with one end L1, one end L2 and one end L3 of a corresponding load after being connected with an additional reactor LRC; each phase of the excitation transformer consists of a high-voltage coil LLg and a phase shifting coil LLt, the high-voltage coil LLg of the excitation transformer is in star connection, and one end, opposite to the star connection, of the high-voltage coil LLg of each phase of the excitation transformer is respectively connected with a center tap of the high-voltage coil Lcg of the corresponding phase of the series transformer; the tapping terminal of each phase shift phase coil LLt of the excitation transformer is connected with the fixed contact of the resistance type on-load tap-changer of the phase, the two ends of the phase shift phase coil LLt are connected with the positive end and the negative end of the phase polarity selector KZF1, and the moving contact of the polarity selector KZF1 is connected with one end of the low-voltage coil Lcd of the corresponding phase of the series transformer; additional reactors LRC1, LRC2 and LRC3 are connected in series in front of the outgoing lines of the sleeves of L1, L2 and L3 at one end of the load, and the bodies of the additional reactors LRC1, LRC2 and LRC3 are placed in a series transformer oil tank.

In an embodiment, the resistive on-load tap-changer K is used to adjust the output voltage of the excitation transformer (plus or minus, automatically adjusted by an operating mechanism associated with the resistive on-load tap-changer K). This voltage energizes the core of the series transformer, which has a high voltage winding Lcg for each phase connected at its leading end to the input line and at its trailing end to the output line, and a load current flowing through the winding, the series transformer and exciter transformer being wired as shown in fig. 1. In the case of such a connection, the voltage change at the low-voltage coil Lcd, which is connected in a delta configuration, on the series transformer leads or lags the voltage at the corresponding high-voltage coil LLg of the excitation transformer by 90 °. This voltage is transmitted to the corresponding high voltage winding Lcg on the series transformer and produces a voltage

And

(see FIG. 3), which make the power supply side voltage of the present phase-shifting transformer

And load side voltage

A phase angle change is generated between the two, and the output voltage is the same as the input voltage, which is the basic function (phase angle change) of the phase-shifting transformer. The voltage of the power supply side and the load side of the high-capacity double-body phase-shifting transformer are equalHowever, the phase angle difference between the two sides is continuously adjustable within a certain range, and the current of each parallel branch of the parallel power system can be controlled through the phase angle adjustment of the phase-shifting transformer, so that the overcurrent problem caused by the parallel transmission circuit is solved, and the power system is stable and efficient to operate.

As can be seen from the embodiment shown in fig. 1-3, it includes a series transformer tank, an excitation transformer tank, a series transformer, an excitation transformer, a resistive on-load tap changer K with a polarity selector KZF 1; the series transformer oil tank is communicated with the excitation transformer oil tank through a pipeline; each phase of the series transformer consists of a high-voltage coil Lcg and a low-voltage coil Lcd, the low-voltage coil Lcd of the series transformer is in a triangular connection method, each phase of the high-voltage coil Lcg of the series transformer is respectively connected with one end S1, S2 and S3 of a power supply, and each phase of the high-voltage coil Lcg of the series transformer is respectively connected with one end L1, L2 and L3 of a corresponding load after being connected with an additional reactor LRC; each phase of the excitation transformer consists of a high-voltage coil LLg and a phase shifting coil LLt, the high-voltage coil LLg of the excitation transformer is in star connection, and one end, opposite to the star connection, of the high-voltage coil LLg of each phase of the excitation transformer is respectively connected with a center tap of the high-voltage coil Lcg of the corresponding phase of the series transformer; the tapping terminal of each phase shift phase coil LLt of the excitation transformer is connected with the fixed contact of the resistance type on-load tap-changer of the phase, the two ends of the phase shift phase coil LLt are connected with the positive end and the negative end of the phase polarity selector KZF1, and the moving contact of the polarity selector KZF1 is connected with one end of the low-voltage coil Lcd of the corresponding phase of the series transformer. In fig. 1, SOLO and N are different ground terminals, respectively.

Claims (1)

1. The utility model provides a large capacity has additional reactor dual devices height impedance phase-shifting transformer which characterized in that: the system comprises a series transformer oil tank, an excitation transformer oil tank, a series transformer, an excitation transformer and a resistance type on-load tap-changer K with a polarity selector KZF1, and is provided with an additional reactor LRC which comprises LRC1, LRC2 and LRC 3; the series transformer oil tank is communicated with the excitation transformer oil tank through a pipeline; each phase of the series transformer consists of a high-voltage coil Lcg and a low-voltage coil Lcd, the low-voltage coil Lcd of the series transformer is in a triangular connection method, each phase of the high-voltage coil Lcg of the series transformer is respectively connected with one end S1, one end S2 and one end S3 of a power supply, and each phase of the high-voltage coil Lcg of the series transformer is respectively connected with one end L1, one end L2 and one end L3 of a corresponding load after being connected with an additional reactor LRC; each phase of the excitation transformer consists of a high-voltage coil LLg and a phase shifting coil LLt, the high-voltage coil LLg of the excitation transformer is in star connection, and one end, opposite to the star connection, of the high-voltage coil LLg of each phase of the excitation transformer is respectively connected with a center tap of the high-voltage coil Lcg of the corresponding phase of the series transformer; the tapping terminal of each phase shift phase coil LLt of the excitation transformer is connected with the fixed contact of the resistance type on-load tap-changer of the phase, the two ends of the phase shift phase coil LLt are connected with the positive end and the negative end of the phase polarity selector KZF1, and the moving contact of the polarity selector KZF1 is connected with one end of the low-voltage coil Lcd of the corresponding phase of the series transformer; additional reactors LRC1, LRC2 and LRC3 are connected in series in front of the outgoing lines of the sleeves of L1, L2 and L3 at one end of the load, and the bodies of the additional reactors LRC1, LRC2 and LRC3 are placed in a series transformer oil tank.

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