CN105301550A - Split series combined voltage transformer - Google Patents

Abstract

The invention discloses a split series combined voltage transformer. Using the principle of series voltage addition, the primary winding of a non-standard voltage level 420kV upper-level standard voltage transformer is connected in series with the primary winding of a 330kV lower-level standard voltage transformer to form a combined type. The primary winding of the voltage transformer, the primary winding of the high-voltage isolation transformer is connected in series with the secondary winding of the 420kV upper-level standard voltage transformer, and the secondary winding is connected in series with the secondary winding of the 330kV lower-level standard voltage transformer to form a combined voltage transformer The secondary winding, the upper and lower standard voltage transformers are separated and independent, and the 420kV upper standard voltage transformer can be lifted to a safe height through the electrohydraulic system, and combined with the 330kV lower standard voltage transformer to form a 750kV standard voltage transformer , and the 330kV lower-level standard voltage transformer works independently and reliably.

Description

Split series combined voltage transformer

technical field

The invention relates to a split-series combined voltage transformer, in particular to a combined standard voltage transformer which can be applied to field error measurement of 330kV and 750kV transformers.

Background technique

At present, it is the most common and traditional method to use electromagnetic standard transformers for on-site calibration of 750kV voltage transformers, that is, to use the high-precision 750kV standard voltage transformers as a reference, connect the transformer under test with it in parallel, and use the transformer error The calibrator obtains the difference between the two on the secondary side. However, as the voltage level of the standard voltage transformer is increased to 750kV, it is very difficult to deal with the insulation structure of the single transformer, the manufacturing process is very difficult, and the price is very expensive. A single 750kV electromagnetic standard voltage transformer weighs about 1 ton and has a height of 4 to 5 meters. At the test site, a crane is required to closely cooperate with its hoisting, moving and wiring, which brings many safety hazards, and the work efficiency is not high. In the process, the huge and heavy standard transformer is very easy to be damaged.

Furthermore, the existing single 750kV standard voltage transformer can only be used in field error experiments of 750kV voltage transformers. From the perspective of the national power grid structure, the number of 750kV substations is far less than the number of 330kV substations. How to make the 750kV standard Potential transformers can also be applied to the error test of 330kV transformers, so as to improve equipment utilization, reduce work complexity, and improve economic benefits are issues worthy of further study.

Contents of the invention

In view of the above problems, the present invention provides a split-series combined voltage transformer with reasonable structure, small size, low cost and can be applied to 330kV and 750kV on-site voltage transformer error tests.

In order to achieve the above object, the split series combined voltage transformer of the present invention includes: an upper-level insulator, an upper-level standard voltage transformer, a lower-level insulator, a connecting part, a high-voltage isolation transformer, a lower-level standard voltage transformer and a lifting device. The lifting device is provided with a lifting platform, and the upper level insulator and the upper level standard voltage transformer are arranged on the lifting platform;

The lifting device raises the lifting platform to a safe height,

The primary winding of the upper-level standard voltage transformer is connected in series with the primary winding of the lower-level standard voltage transformer to form the primary winding of the split series combined voltage transformer; the secondary winding of the upper-level standard voltage transformer is connected in series with the primary winding of the high-voltage isolation transformer , the lower-level standard voltage transformer is connected in series with the secondary winding of the high-voltage isolation transformer to form the secondary winding of the split-series combined voltage transformer.

Further, the voltage level of the upper-level standard voltage transformer is 420kV, and the voltage level of the lower-level standard voltage transformer is 330kV.

Further, the lifting device is a hydraulic jacking device.

Beneficial effect

The split series combined voltage transformer and method of the present invention have the following beneficial effects compared with the prior art:

In the split-series combined voltage transformer of the present invention, the primary winding of the upper-level standard voltage transformer is connected in series with the primary winding of the lower-level standard voltage transformer to form the primary winding of the split-series combined voltage transformer; the second winding of the upper-level standard voltage transformer The secondary winding is connected in series with the primary winding of the high-voltage isolation transformer, and the lower-level standard voltage transformer is connected in series with the secondary winding of the high-voltage isolation transformer to form the secondary winding of the split-series combined voltage transformer. On the one hand, the series mode ensures that the 330kV lower-level standard voltage transformer and the combined 750kV standard voltage transformer can work independently and reliably, which improves the utilization rate of equipment. On the other hand, it reduces the insulation requirements of a single standard transformer, effectively reducing The volume and weight of the present invention are convenient for transportation and ensure safe and reliable testing.

Description of drawings

Fig. 1 is the structural diagram of split series combined voltage transformer of the present invention;

Fig. 2 is a schematic circuit diagram of the split series combined voltage transformer of the present invention.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings.

Example

As shown in Figure 1, the split-series combined voltage transformer in this embodiment includes: upper-level insulators, upper-level standard voltage transformers, lower-level insulators, connecting parts, high-voltage isolation transformers, lower-level standard voltage transformers and lifting devices, The lifting device is provided with a lifting platform, and the upper-level insulator and the upper-level standard voltage transformer are arranged on the lifting platform.

The relationship between the upper and lower insulators and the upper and lower standard voltage transformers: in the high-voltage standard voltage transformer, the standard voltage transformer part belongs to the standard measurement equipment. This equipment cannot bear the actual design high voltage and is connected by its high-voltage side The insulator is designed for high voltage, so as to prevent the standard voltage transformer part from being burned due to overvoltage.

The lifting device raises the lifting platform to a safe height, wherein the lifting device is a hydraulic jacking device. The lifting device raises the lifting platform from the initial position to a safe height of 4m or more.

The primary winding of the upper-level standard voltage transformer is connected in series with the primary winding of the lower-level standard voltage transformer to form the primary winding of the split series combined voltage transformer; the secondary winding of the upper-level standard voltage transformer is connected in series with the primary winding of the high-voltage isolation transformer , the lower-level standard voltage transformer is connected in series with the secondary winding of the high-voltage isolation transformer to form the secondary winding of the split-series combined voltage transformer.

Non-standard voltage level 420kV upper-level standard voltage transformer 3 and 330kV lower-level standard voltage transformer 7 are stacked in a series structure. The high-voltage isolation transformer 6 is used as the addition winding for the secondary winding series connection of the present invention, and its function is to add the secondary voltages of the upper and lower standard voltage transformers, and output from the lower standard voltage transformer 7. The upper and lower voltage equalizing rings 1 are located at both ends of the upper insulator 2, which can improve the distribution of the electric field and improve the insulation level of the equipment. The upper-level insulator 2 ensures reliable insulation of the upper-level standard voltage transformer 3, the lower-level insulator 4 ensures reliable insulation between the upper-level standard voltage transformer 3, the lower-level insulator 4 and the high-voltage isolation transformer 6, and the connecting part 5 connects the upper and lower standard voltage transformers 3 , the lower standard voltage transformer 7 and the high-voltage isolation transformer 6, and ensure the reliable insulation of the three parts.

As shown in Figure 2, the circuit schematic diagram of the split series combined voltage transformer of the present invention, the 420kV upper standard voltage transformer 3 is jacked up to a safe height through the electrohydraulic system, and its primary winding A ₁ N ₁ (primary side voltage U ₁₁ =420kV) and the primary winding A ₂ N ₂ (primary side voltage U ₁₂ =330kV) of the lower standard voltage transformer 7 are connected in series to form the primary winding AN of the present invention, and the primary voltage U 1 of the cascaded transformer is U ₁ =U ₁₁ +U ₁₂ =750kV, the secondary winding a ₁ n ₁ of the upper standard voltage transformer 3 is connected in series with the secondary winding a ₂ n ₂ of the lower standard voltage transformer 7 through the isolation transformer 6, forming the secondary winding an of the present invention , the secondary voltage is U ₂ .

It should be understood for the present invention that the above-mentioned embodiments have further described the purpose, technical solutions and beneficial effects of the present invention in further detail. The above are only embodiments of the present invention and are not intended to limit the present invention. Within the spirit and principles of the present invention, any modifications, equivalent replacements, improvements, etc., should be included in the protection scope of the present invention, and the protection scope of the present invention should be based on the protection scope defined in the claims.

Claims (3)

1. A split-series combined voltage transformer, characterized in that it comprises: an upper-level insulator, an upper-level standard voltage transformer, a lower-level insulator, a connection part, a high-voltage isolation transformer, a lower-level standard voltage transformer and a lifting device, the The lifting device is provided with a lifting platform, and the upper level insulator and the upper level standard voltage transformer are arranged on the lifting platform; The lifting device raises the lifting platform from the initial position to a safe height of 4m or more. The primary winding of the upper-level standard voltage transformer is connected in series with the primary winding of the lower-level standard voltage transformer to form the primary winding of the split series combined voltage transformer; the secondary winding of the upper-level standard voltage transformer is connected in series with the primary winding of the high-voltage isolation transformer , the lower-level standard voltage transformer is connected in series with the secondary winding of the high-voltage isolation transformer to form the secondary winding of the split-series combined voltage transformer. 2 . The split-series combined voltage transformer according to claim 1 , wherein the voltage level of the upper-level standard voltage transformer is 420 kV, and the voltage level of the lower-level standard voltage transformer is 330 kV. 3. The split series combined voltage transformer according to claim 1, characterized in that the lifting device is a hydraulic jacking device.