RU2556704C2 - Single-phase voltage transformer - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: low-voltage windings for electricity consumption measurement (5) and voltage measurement (6) placed at an isolation cylinder (4) are made as a combined winding with at least one layer, wherein turns of at least one wire of the winding for electricity consumption measurement (5) are intermitted with turns of at least one wire of the winding for voltage measurement (6). Two windings in each layer have identical number of turns having the same depth. The layers of low-voltage windings for electricity consumption measurement (5) and voltage measurement are divided by insulation cylinders (9) and wire ends of the both windings may be united at the beginning and ending of each winding.

EFFECT: providing universal construction for the voltage transformer that allows due to placement of windings for electricity consumption measurement and voltage measurement at the same way in regard to the high-voltage winding ensuring constant values for reactive component of short-circuit impedance between the high-voltage winding and each of the low-voltage windings as well as eliminating potential occurrence of difference between these values.

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Description

The present invention relates to electrical engineering and can be used in voltage transformers for indoor and outdoor installations, used to account for the consumption of electricity, voltage measurement and to ensure the operation of relay protection devices, automation and alarm.

Currently, voltage transformers with two low-voltage windings are known, namely with a “C” winding for simultaneous metering of power consumption and voltage measurement and with a “T” winding for ensuring the operation of relay protection, automation and signaling devices (Handbook of high-voltage electrical apparatuses , edited by VV Afanasyev, - L .: Energoatomizdat, Leningrad Branch, 1987, pp. 381-413, 470) - [1]. The active part of the voltage transformer includes: a magnetic circuit, a primary winding of high voltage (HV) and two secondary windings of low voltage "C" and "T".

However, the known voltage transformers [1] with two secondary windings cannot be used in cases where the terminals of the winding to account for the energy consumption "C" must be closed and sealed to prevent unauthorized access to them. It turns out that access to the winding "C" for the purpose of measuring voltage is also absent.

The closest in technical essence to the proposed solution and selected as a prototype is a voltage transformer (CO 153-34.20.122-2006 "Norms for the technological design of AC substations with a higher voltage of 35-750 kV", clause 9.1.7., Approved by JSC " FGC UES ”dated 16.06.2006 by order No. 187) - [2], which, in addition to standard magnetic circuits, includes a primary HV high-voltage winding, a low-voltage secondary winding for measuring voltage, and a low-voltage secondary winding to provide relay protection ites, automation and signaling “T”, includes a secondary winding of low voltage to account for energy consumption. Moreover, the secondary low voltage winding for accounting for power consumption is usually denoted by "C ₁ ", and the secondary low voltage winding for measuring voltage is denoted by "C ₂ ".

However, in the known design of the active part of the voltage transformer [2], the winding for measuring voltage "C ₂ " cannot provide the same measurement accuracy as the accuracy of the metering winding of the energy consumption "Q" at the same maximum power of their loads, since the winding for measuring voltage " C ₂ "is situated between the winding metering of electricity consumption« C ₁ 'and the winding for relaying, automation and alarm «T» and removed from the high-voltage winding BH a greater distance than the accounting winding Flow rate electricity «C _1".

This leads to an increase in the reactive component of the short circuit resistance of the windings BH and "C ₂ " compared to the reactive component of the short circuit resistance of the windings BH and "C ₁ ", that is, to an increase in the absolute value of the error in the readings of the voltage of the winding "C ₁ ".

The objective of the proposed technical solution is to create a reliable and simple design of the voltage transformer windings, which will eliminate the possibility of a difference between the values of the reactive components of short-circuit resistances in the BH - "C ₂ " windings and in the BH - "C ₁ " windings, to obtain electric power metering windings “C ₁ ” and for measuring voltage “C ₂ ” of the same power with the same accuracy class of windings “C ₁ ” and “C ₂ ”.

The technical effect of using the proposed design of the voltage transformer windings is:

- creation of a universal design of a voltage transformer with the possibility of using one type of transformer in circuits where the energy consumption and voltage measurement are taken from various windings “C ₁ ” and “C ₂ ” of the voltage transformer, and where the energy consumption and voltage measurement are taken from one winding "C" without loss in accuracy.

The solution of this problem and the corresponding technical result are achieved by the fact that in the proposed single-phase voltage transformer containing a magnetic circuit, on the insulating cylinder of which there is a low voltage coil of relay protection, automation and alarm, on top of which coils of low voltage are used for metering energy consumption and measuring voltage, on top of which on the insulating cylinder there is a high voltage winding, and low voltage windings Energy metering and voltage measurements are made in the form of a joint winding with at least one layer, in which the turns of at least one wire of the metering energy winding are alternated with turns of at least one voltage measuring winding wire while both windings in each layer have the same number of turns that are made of the same height, in addition, the layers of the low voltage windings, energy consumption metering and voltage measurements are separated by insulating cylinders, while seedlings wires both windings are adapted to combine the wires at the beginning and end of each of the windings.

The implementation of a low-voltage windings in a single-phase transformer to account for the energy consumption and voltage measurement (C ₁ and C ₂ ) in the form of a layer joint winding with the same number of turns of one and the other winding, the same height of the turns wound with one or more parallel wires each, and placing them equally with respect to the high voltage winding (BH), the reactive component of the short circuit resistance between the BH winding and each of them (C ₁ and C ₂ ) is constant, and also between the windings oh BH and winding C in the case of simultaneous accounting of power consumption and voltage measurement when connecting the ends of the wires of the windings C ₁ and C ₂ in parallel in the terminal box of the voltage transformer.

Comparison of the proposed single-phase voltage transformer with the prior art and the lack of a description of a similar technical solution in known sources of information allows us to conclude that the proposed device meets the criterion of "novelty."

The claimed device is characterized by a combination of features exhibiting new qualities, which allows us to conclude that the proposed technical solution meets the criterion of "inventive step".

The drawing schematically shows the active part of the proposed single-phase voltage transformer with low voltage windings, metering energy consumption, voltage measurement and ensuring the operation of relay protection, automation and alarm systems.

The single-phase voltage transformer proposed in the drawing comprises: a magnetic circuit - 1; an insulating cylinder - 2, located on the magnetic circuit 1; winding low voltage relay protection, automation and alarm (T) - 3, placed on the insulating cylinder 2; insulating cylinder - 4, located on the low voltage winding of relay protection, automation and alarm (T) 3; winding metering energy consumption (C ₁ ) - 5; voltage measurement winding (C ₂ ) - 6; an insulating cylinder - 7, which is located on the outer layer of low voltage consisting of turns of windings for metering energy consumption (C ₁ ) 5 and measuring voltage (C ₂ ) 6; high voltage winding (BH) - 8, made on an insulating cylinder 7.

If the windings of accounting for energy consumption (C ₁ ) 5 and voltage measurement (C ₂ ) 6 have several joint layers, then these layers are separated from each other by insulating cylinders - 9.

The ends of the wires at the beginning and at the end of the metering winding (C ₁ ) 5 are designated a ₁ and x _1, respectively, and the ends of the wires at the beginning and at the end of the metering winding (C ₂ ) 6 are marked a ₂ and x _2, respectively. The ends of the wires at the beginning and at the end of the low voltage winding of the relay protection, automation and alarm (T) 3 are indicated a _d and x _d respectively.

The high voltage winding current lead (BH) 8 is designated as - A, and the low voltage winding lead of BH 8 is indicated as - X.

Offered in the drawing a single-phase voltage transformer operates as follows.

, где $${\overline{U}}_1$$

- первичное напряжение обмотки высокого напряжения 8; $${\overline{U}}_2$$

- вторичное напряжение обмоток низкого напряжения 3, 5 и 6; К_ном - номинальный коэффициент трансформации, равный $$\frac{W_{BH}}{W_{C_1}}$$

для обмотки (С₁) 5, или $$\frac{W_{BH}}{W_{C_2}}$$

для обмотки (C₂) 6, или $$\frac{W_{BH}}{W_{C_T}}$$

для обмотки (Т) 3 (W - число витков в обмотке).The primary high voltage applied to the VH 8 winding induces in the low voltage winding of relay protection, automation and alarm (T) 3, the low voltage metering winding (C ₁ ) 5 and the low voltage winding measuring voltage (C ₂ ) 6 the voltage proportional to the primary the voltage applied to the winding BH 9. However, due to errors caused by power losses in the magnetic circuit 1 and in the low voltage windings 3, 5 and 6, the secondary voltage vector in the windings 3, 5 and 6, rotated 180 ° electrical degrees and at ction to the primary voltage is not identical in magnitude and phase with the primary voltage vector, i.e. $${\overline{U}}_{\mathrm{one}}\ne {\overline{U}}_2\cdot {\mathrm{TO}}_{n\mathrm{about}m}$$

where $${\overline{U}}_{\mathrm{one}}$$

- the primary voltage of the high voltage winding 8; $${\overline{U}}_2$$

- secondary voltage of low voltage windings 3, 5 and 6; To _nom - nominal transformation ratio equal to $$\frac{W_{BH}}{W_{C_{\mathrm{one}}}}$$

for winding (C ₁ ) 5, or $$\frac{W_{BH}}{W_{C_2}}$$

for winding (C ₂ ) 6, or $$\frac{W_{BH}}{W_{C_T}}$$

for winding (T) 3 (W is the number of turns in the winding).

The minimum error in determining the magnitude of the high voltage is achieved, first of all, by reducing the distance between the windings, reducing their thickness (radial size) and increasing the height of the windings, that is, by reducing the magnitude of the reactive component of the short circuit resistance between the windings BH 8 and T 3 either between windings BH 8 and C ₁ 5, or between windings BH 8 and C ₂ 6.

In order for the low voltage windings to account for the energy consumption (C ₁ ) 5 and measure the voltage (C ₂ ) 6 at a given load power, each winding has the same high accuracy class, they are wound in parallel wires on the outer cylindrical surface of the insulating cylinder 4 separating the winding low voltage relay protection, automation and alarm (T) 3 from the low voltage windings of the metering of electricity consumption (C ₁ ) 5 and voltage measurement (C ₂ ) 6. Thus, the windings (C ₁ ) 5 and (C ₂ ) 6 have the same high the other, the same inner and outer diameters by winding them on the same insulating cylinder. With the multi-layer joint winding of the windings (C ₁ ) 5 and (C ₂ ) 6, they retain the above advantages, since the winding of the wires of the windings (C ₁ ) 5 and (C ₂ ) 6 in each subsequent layer is carried out on the surface of the separating the previous from the subsequent layer insulating cylinder 9.

Moreover, if the wires of the beginning of the windings (C ₁ ) 5 and (C ₂ ) 6 are interconnected and the wires of the ends of the windings (C ₁ ) 5 and (C ₂ ) 6 are interconnected, then instead of two windings, each of which had W _C1 = W _C2 turns, it turns out one having the same number of turns and wound with at least two parallel wires, the winding, which is the only winding (C), which serves to account for energy consumption and voltage measurement at the same time.

The proposed single-phase voltage transformer can be used in substations, where energy consumption and voltage are measured using separate high-precision windings (C ₁ ) 5 and (C ₂ ) 6 of the transformer. When windings (C ₁ ) 5, (C ₂ ) 6 are connected in parallel, and as a result of one winding C, from two parallel windings (C ₁ ) 5 and (C ₂ ) 6, the energy consumption and voltage measurement can be taken into account using one winding C, providing a given accuracy class at the required load power.

Claims (1)

A single-phase voltage transformer containing a magnetic circuit, on the insulating cylinder of which there is a low voltage winding of relay protection, automation and alarm, on top of which coaxially on the insulating cylinder there are low voltage windings for metering energy consumption and voltage measurements, on top of which a high voltage winding is placed on the insulating cylinder, characterized the fact that the windings of low voltage metering energy consumption and voltage measurements are made in the form of at least one layer, in which the turns of at least one wire of the metering winding are alternating with the turns of at least one wire of the voltage measuring winding, while both windings in each layer have the same number of turns that are made of the same height, in addition , the layers of the low voltage windings of metering energy consumption and voltage measurements are separated by insulating cylinders, while the ends of the wires of both windings are made with the possibility of combining the wires at the beginning and at the end of each of the windings.