CN103928225B - A kind of method transforming 220kV off circuit tap changing transfor mer device body as ULTC device body - Google Patents

Abstract

The invention relates to a method for transforming the body of a 220kV non-excitation voltage regulating transformer into a body of an on-load voltage regulating transformer. The distance between the phase C core and the core column is increased; ② Rewind the low-voltage winding on the A-phase iron core column, the B-phase iron core column, and the C-phase iron core column, and wrap the high-voltage winding outside the low-voltage winding, and the high-voltage winding outside Wind the regulator winding. ③Replace the upper iron yoke that matches the A-phase iron core column, B-phase iron core column and C-phase iron core column; The voltage regulating winding taps of the number of turns are connected in series with the high voltage winding. The present invention improves on the basis of the existing transformer body, avoiding the replacement of new transformers. The transformation ratio can be adjusted anytime and anywhere, no power outage is needed, manpower and material resources are saved, and electricity sales efficiency is increased.

Description

A method for transforming the body of a 220kV non-excitation tap-regulating transformer into an on-load tap-changing transformer body

technical field

The invention relates to a method for transforming a transformer body, in particular to a method for transforming a 220kV non-excitation voltage regulating transformer body into an on-load voltage regulating transformer body.

Background technique

As power users have higher and higher requirements for power quality, the power transmission equipment of power companies has also been upgraded year by year to ensure that users are provided with safe, energy-saving and high-quality power energy. Among them, voltage quality is an important symbol of high-quality electric energy. The quality of the voltage transmitted by the line is mainly determined by the voltage of the substation bus, and the voltage of the bus is determined by the transformation ratio of the main transformer of the substation. Since the non-excitation voltage regulating transformer cannot adjust the transformation ratio with electricity, once the transformer is electrified, the level of the bus voltage cannot be adjusted. If the bus voltage exceeds the qualified range, the transformer needs to be powered off to adjust the transformation ratio, and then it can be put into operation again after passing the DC resistance test. It can be seen that the non-excitation voltage regulating transformer is only suitable for areas where the load is relatively stable. If the load changes greatly day and night and seasonally, the off-excitation tap changer will not be able to meet the needs of frequent adjustment of the transformation ratio, while the on-load tap changer has a special advantage. It can adjust the transformation ratio anytime and anywhere. Requirements for the voltage quality of the busbar on the load side. At present, the body structure of the known 220kV non-excitation voltage regulating transformer is composed of a three-phase five-column iron core, a low-voltage winding, and a high-voltage winding. The three-phase low-voltage windings are respectively wound on the three cores of the three-phase five-column iron core, the three-phase high-voltage windings are respectively wound on the outer layer of the low-voltage windings, and the lead wires of the non-excitation voltage regulating switch are respectively connected with the three-phase high-voltage coils. However, once this type of transformer is put into operation, the tap cannot be adjusted, the transformation ratio is fixed, and the output voltage is stable. If adjustment is required, the power must be cut off. Due to the increasing number of power grid users and the difficulty of load forecasting, it is impossible to predict the stability of the output voltage of the transformer in advance. Therefore, the transformer needs to adjust the transformation ratio anytime and anywhere to meet the requirements of the voltage quality on the load side.

Contents of the invention

In order to overcome the deficiency that the existing 220kV off-excitation tap-regulating transformer cannot be adjusted anytime and anywhere, the present invention provides a method for transforming the body of the 220kV off-excitation tap-changing transformer into an on-load tap-changing transformer body. Changing the shape of the transformer can adjust the transformation ratio anytime and anywhere.

The technical solution adopted by the present invention to solve its technical problems is:

A method for transforming the body of a 220kV off-excitation voltage regulating transformer into an on-load voltage regulating transformer body. The body of the 220kV off-excitation voltage regulating transformer has a three-phase five-column iron core, and the three-phase five-column iron core is It consists of two left and right core side yokes, an upper iron yoke, an A-phase core leg, a B-phase core leg and a C-phase core leg, and the method includes the following steps:

① Increase the distance between the left and right core side yokes, A-phase core columns, B-phase core columns and C-phase core columns;

② Rewind the low-voltage winding 5 on the A-phase iron core column, the B-phase iron core column, and the C-phase iron core column, wrap the high-voltage winding outside the low-voltage winding, and wind the voltage regulating winding outside the high-voltage winding;

③ Replace the upper iron yoke that matches the A-phase iron core column, B-phase iron core column and C-phase iron core column;

④ Make taps of the voltage regulating winding, and connect the taps of the voltage regulating winding in different directions and different numbers of turns in series with the high voltage winding through the on-load voltage regulating tap changer.

The advantages and beneficial effects of the present invention are: the transformer body of the present invention is improved on the basis of the existing transformer body, and the rated voltage ratio after the improvement is changed from 220±2×2.5%/66 to 230±8×1.25 %/69 adapts to the requirements of system voltage changes and avoids buying new transformers. The transformation ratio can be adjusted anytime and anywhere, no power outage is needed, manpower and material resources are saved, the benefit of electricity sales is increased, and the reliability of power supply is improved, which has good economic benefits.

Description of drawings

Figure 1 is a schematic diagram of the body structure of a 220kV non-excitation voltage regulating transformer;

Fig. 2 is a schematic diagram of the structure of the on-load tap changer transformed by the method.

In the figure 1. three-phase five-column iron core, 2. iron core side yoke, 3. upper iron yoke, 4. high-voltage winding, 5. low-voltage winding, 6. A-phase iron core leg, 7. B-phase iron core leg, 8. C-phase iron core pillar, 9. iron core window, 10. voltage regulating winding.

detailed description

Below in conjunction with accompanying drawing, the present invention is described in further detail:

As shown in Figure 1, the body structure of the 220kV non-excitation voltage regulating transformer is as follows: there are two left and right iron core side yokes 2, upper iron yoke 3, A-phase iron core column 6, B-phase iron core column 7 and C-phase iron core A three-phase five-column core 1 composed of columns 8, four cores are formed between the left and right core side yoke 2, the upper yoke 3, the core column 6 of the A phase core, the core column 7 of the B phase iron core, and the core column 8 of the C phase iron core Window 9 and low-voltage winding 5 are respectively wound on A-phase core leg 6, B-phase core leg 7, and C-phase core leg 8, and low-voltage winding 5 is wound on the outer layer of high-voltage winding 4.

A method of transforming a 220kV non-excitation voltage regulating transformer body into an on-load voltage regulating transformer body of the present invention comprises the following steps:

① Cut off a part of the left and right side yokes 2 of the three-phase five-leg core, the core leg 6 of the A-phase core, the core leg 7 of the B-phase core, and the core leg 8 of the C-phase core until the remaining part can meet the requirements of A The phase iron core column 6, the B phase iron core column 7 and the C phase iron core column 8 can be wound with voltage regulating windings on the outside of the high voltage coil, so that the left and right iron core side yokes 2, the A phase iron core column 6, and the B phase iron core The distance between the column 7 and the C-phase iron core column 8 is increased.

②Rewind the low-voltage winding 5 on the A-phase core leg 6, the B-phase core leg 7, and the C-phase core leg 8, wrap the high-voltage winding 4 on the outside of the low-voltage winding, and wind the voltage-regulating winding 10 on the outside of the high-voltage winding.

③Replace the upper iron yoke that matches the A-phase iron core column 6, B-phase iron core column 7 and C-phase iron core column 8.

④ Make taps of the voltage regulating winding 10, and the number of winding turns between different taps is different. Through the on-load voltage regulating tap changer, connect the taps of the voltage regulating winding 10 in different directions and different numbers of turns in series with the high voltage winding 4. Realize the adjustment of the transformation ratio of the transformer, and meet the requirement of adjusting the output voltage of the transformer anytime and anywhere.

As shown in Figure 2, the body structure of the transformed on-load tap changer transformer is as follows: two left and right iron core side yokes 2, upper iron yoke 3, A-phase iron core column 6, B-phase iron core column 7, and C-phase iron core Columns 8 together form a three-phase five-column core 1, between the two left and right core side yokes 2, upper yoke 3, A-phase core column 6, B-phase core column 7, and C-phase core column 8 to form four The iron core window 9 and the low voltage winding 5 are respectively wound on the A-phase iron core leg 6, the B-phase iron core leg 7 and the C-phase iron core leg 8, the high-voltage winding 4 is wound outside the low-voltage winding 5, and the voltage regulating winding 10 is wound on the high-voltage Outside the winding 4, the distribution of the low-voltage winding 5-high-voltage winding 4-voltage regulating winding 10 is formed on the core column from the inside to the outside.

Claims (1)

1. the method transforming 220kV off circuit tap changing transfor mer device body as ULTC device body, it is unshakable in one's determination that described 220kV off circuit tap changing transfor mer device body has three-phase and five-pole, described three-phase and five-pole iron core is made up of two, left and right return yoke unshakable in one's determination, upper yoke, A phase iron core column, B phase iron core column and C phase iron core column, it is characterised in that the method comprises the following steps:

1. two, left and right return yoke 2 unshakable in one's determination unshakable in one's determination for three-phase and five-pole, A phase iron core column 6, B phase iron core column 7 and C phase iron core column 8 are respectively reamed a part, cut and can meet A phase iron core column 6, B phase iron core column 7 and C phase iron core column 8 in high-tension coil outer felt around tap-changing windings to remaining part, make left and right spacing between two return yokes 2 unshakable in one's determination, A phase iron core column 6, B phase iron core column 7 and C phase iron core columns 8 strengthen；

2. on A phase iron core column, B phase iron core column, C phase iron core column, rewind low pressure winding 5, outside low pressure winding, be wrapped with high pressure winding, outside high pressure winding, be wound around tap-changing windings；

3. the upper yoke matched with A phase iron core column, B phase iron core column and C phase iron core column is changed；

4. tap-changing windings is made tap, by on-load tap changer, by different directions, the tap-changing windings tap of the different number of turn and high pressure windings in series.