CN202159568U - Three-level on-load adjusting capacity distribution transformer - Google Patents

Abstract

The utility model provides a three-level on-load adjusting capacity distribution transformer, belonging the field of a device which is provided with a switching tap without the need for interrupting load current. The transformer can automatically detect the capacity of the carried load to determine the reasonable running capacity mode of the transformer based on the decision and judgment, thus, the transformer realizes the automatic adjustment of the capacity under the condition of uninterrupted power of the transformer. The transformer provided includes a transformer body, an on-load adjusting capacity switch, an on-load adjusting capacity control device, a high voltage electric control switch, a low voltage electric control switch, and a current transformer, and the capacity transformation is realized by the on-load adjusting capacity control device, the on-load adjusting capacity switch, the high voltage electric control switch, and the low voltage electric control switch. The transformer provided completes the adjustment of the capacity of the transformer to enable the on-load adjusting capacity distribution transformer to run in an economical way under the condition of meeting the needs of load all the time without the need for power interruption.

Description

A three-stage on-load capacity regulating distribution transformer

technical field

The utility model belongs to the field of devices with switching taps without interrupting the load current, in particular to a three-stage on-load capacity regulating power distribution transformer.

Background technique

At present, the production technology of domestic 10kV small-capacity no-load capacity-adjusting transformers is relatively mature. Generally, when the power is cut off during the season, the transformer capacity is changed without excitation. Due to the limitation of the contact structure of the capacity regulating switch, the no-load capacity regulating distribution transformer has only mature products with a voltage level of 10kV and a capacity below 315kVA, which greatly restricts the promotion and use of capacity regulating transformers. A total of nearly 10,000 capacity regulating transformers are used nationwide, of which 8,562 are used in rural power grids. Because the off-load capacity regulating transformer cannot adjust the capacity with electricity, which affects the user's power supply reliability; in addition, the off-load capacity regulating transformer is not suitable for frequent adjustments, and generally only performs seasonal adjustments. During seasonal load conversion, the monthly electricity sales of distribution transformers for most power supplies are used as the basis for capacity adjustment, which lacks timeliness and scientificity. Because the monthly electricity sales are the copied electricity of the previous month, using it as the basis for capacity adjustment in the next month will cause the capacity adjustment to be delayed, cause damage to the capacity regulating transformer, and fail to fully exert the role of the capacity regulating transformer.

The on-load capacity regulating transformer can effectively solve the existing problems and limitations of the existing off-load capacity regulating transformer, automatically monitor and control in real time, and adjust the capacity reasonably according to the actual load. Judging from the search results of domestic and foreign literature, there is no relevant information on the technology of on-load capacity-regulating transformers abroad, and there are few reports on the control system of capacity-regulating transformers with on-load capacity-adjusting functions in China. The early products are only suitable for on-load The automatic control of capacity-regulating transformers, the application of two-pole on-load capacity-regulating distribution transformers with a ratio of large and small rated capacities close to 3:1 or 2:1 in the power system is still in the pilot operation and gradual improvement stage.

my country's rural electricity consumption is mainly concentrated in summer and autumn, and the remaining seasons are mainly used for lighting. In the busy farming season, the transformer overload operation phenomenon is serious, and in the off-season of electricity consumption, the load rate is low, and "big horse-drawn carts" appear again. The phenomenon. At present, the loss of distribution transformers in rural power grids in my country is still quite serious, the seasonality and period characteristics of electricity load are obvious, and the electricity load presents an obvious ladder-like distribution. The original two-pole capacity adjustment cannot meet the economical operation requirements of distribution transformers in areas where partial load fluctuations present a stepped distribution. The no-load loss of distribution transformers is large, and the phenomenon of energy waste is serious.

Utility model content

In order to overcome the defects of the prior art, the purpose of this utility model is to propose a three-stage on-load capacity regulating distribution transformer. The transformer has three rated capacities, which can automatically detect the size of the load and determine the reasonableness of the transformer through decision-making. The operating capacity mode realizes three kinds of rated capacity automatic adjustment when the transformer is not powered off, so that the no-load loss of the distribution transformer is greatly reduced, and the effect of energy saving and loss reduction is obvious.

For realizing the utility model purpose, this adopts following technical scheme to realize:

A three-stage on-load capacity-regulating distribution transformer, the transformer includes a transformer body with a high-voltage winding and a low-voltage winding, an on-load capacity-regulating switch, and the improvement is that the transformer includes an on-load capacity-regulating control device, and The high-voltage electric control switch, the low-voltage electric control switch and the load current transformer are electrically connected to the on-load capacity regulation control device.

Another preferred technical solution of the present invention is: the transformer body is provided with a high-voltage bushing and a low-voltage bushing, the high-voltage winding is provided with a high-voltage winding tap, and the low-voltage winding is provided with a low-voltage winding tap.

Another preferred technical solution of the present invention is: the load current transformer, the secondary outlet terminal of the load current transformer, the electronically controlled outlet terminal of the high-voltage electronically controlled switch, and the electronically controlled outlet terminal of the low-voltage electronically controlled switch and the control end of the on-load capacity-regulating switch are respectively electrically connected to the on-load capacity-regulating control device.

Another preferred technical solution of the present invention is: the high-voltage side of the three-stage on-load capacity regulating distribution transformer is connected to the same high-voltage power supply after being connected in parallel with the high-voltage electric control switch, and the low-voltage side is connected with the load current mutual induction after being connected in parallel with the low-voltage electric control switch device connected.

Another preferred technical solution of the present invention is: the high-voltage electric control switch is connected to the high-voltage bushing, and the low-voltage electric control switch is connected to the low-voltage bushing.

Another preferred technical solution of the present invention is: the transformer body is connected to the on-load capacity regulating switch through a high-voltage winding tap and a low-voltage winding tap.

Another preferred technical solution of the present invention is: the high-voltage windings can be connected in star or delta, and the low-voltage windings can be connected in parallel or in series.

Owing to adopting above-mentioned technical scheme, the beneficial effect of the utility model is:

1. The transformer has three rated capacities

The two two-stage on-load capacity regulating transformer bodies are respectively composed of high-voltage windings that can realize star-shaped and delta connection and low-voltage windings that can realize series-parallel connection. The connection mode of the high-voltage winding and the low-voltage winding of the two transformer bodies is changed, and the high-voltage electric control switch and the low-voltage electric control switch are controlled to realize the high-voltage and low-voltage parallel connection or independent operation of the two two-stage on-load capacity regulating transformer bodies, so that the transformer has three rated capacities ;

That is, large, medium and small rated capacities;

2. The transformer can automatically adjust the rated capacity under the condition of uninterrupted power supply

The on-load capacity regulating switch, the transformer high-voltage electric control switch and the low-voltage electric control switch are controlled by the on-load capacity regulating control device, and the connection mode of the high-voltage winding and the low-voltage winding of the two-stage on-load capacity regulating transformer body is changed. It can automatically realize the three-level on-load capacity adjustment distribution transformer's combined operation mode conversion of large, medium and small capacities, and has a three-level on-load capacity adjustment function;

3. Reduce transformer no-load loss

The on-load capacity regulation control device can detect the voltage, current, switch state parameters and load size of the low-voltage side of the three-stage on-load capacity regulation distribution transformer, and form a three-stage on-load capacity regulation control strategy based on the load size and capacity adjustment setting value to judge The output control command controls the action of the on-load capacity regulating switch, the high-voltage electric control switch and the low-voltage electric control switch, and completes the star-angle conversion and series-parallel conversion of the high-voltage and low-voltage winding coils inside the transformer, effectively avoiding the "big horse-drawn trolley" state, that is, to reduce the no-load loss of the transformer;

4. Save energy

The transformer completes the transformer capacity adjustment process without power outage, so that the on-load capacity regulating distribution transformer can operate in an economical way while always meeting the load demand, saving energy consumption.

Description of drawings

Below in conjunction with accompanying drawing, the utility model is further described:

Figure 1 is the overall design of the three-stage on-load capacity regulating distribution transformer;

Figure 2 is the working principle of the three-stage on-load capacity regulating distribution transformer;

Fig. 3 is a wiring diagram of a high-voltage angle-connected low-voltage parallel-connected on-load capacity-regulating switch of an on-load capacity-regulating distribution transformer in a large-capacity state;

Fig. 4 is a wiring diagram of a high-voltage angle-connected low-voltage parallel on-load capacity-regulating switch in the middle capacity state of an on-load capacity-regulating distribution transformer;

Fig. 5 is a wiring diagram of a high-voltage star-connected low-voltage series on-load capacity-regulating switch in a small-capacity state of an on-load capacity-regulating distribution transformer;

Reference signs:

101, 102 - transformer body, 201, 202, 203, 204, 205, 206 - high voltage electric control switch, 301, 302, 303, 304, 305, 306 - low voltage electric control switch, 4 - on-load capacity regulation control device, 501, 502- on-load capacity regulating switch, 601, 602- high voltage winding, 701, 702- high voltage winding tap, 801, 802- low voltage winding, 901, 902- low voltage winding tap, 1001, 1002- high voltage bushing, 1101, 1102-low voltage bushing, 12-load current transformer.

Detailed ways

The following are the embodiments of the present invention, and the technical solutions realized by the present invention will be further described below in conjunction with the accompanying drawings.

The utility model relates to a distribution transformer capable of realizing three-stage on-load automatic capacity adjustment, which is a distribution transformer capable of automatically adjusting the rated capacity operation mode. The three-stage on-load capacity regulating distribution transformer is suitable for places with obvious stepped distribution of electricity load, concentrated electricity consumption, and low annual average load rate, and is suitable for construction and transformation of rural power grids.

Example 1:

Figure 1 is the overall design of the three-stage on-load capacity regulating transformer. As shown in the figure, the three-stage on-load capacity regulating distribution transformer includes high-voltage electric control switches 201, 202, 203, 204, 205, 206, low-voltage electric control switches 301, 302, 303, 304, 305, 306, and a transformer body 101 , 102, load current transformer 12 and on-load capacity regulation control device 4, the transformer body 101, 102 is a two-stage on-load capacity regulation transformer body. The two on-load capacity regulating switches 501 and 502 have the same technical performance, and each two-stage on-load capacity regulating distribution transformer body 101 and 102 is equipped with an on-load capacity regulating switch 501 and 502, that is, the transformer body 101 is equipped with on-load capacity regulating The switch 501 and the transformer body 102 are equipped with an on-load capacity adjustment switch 502, and the conversion of the on-load capacity adjustment switches 501 and 502 can realize the change of the connection mode of the high-voltage windings 601 and 602 and the low-voltage windings 801 and 802 of the two transformer bodies 101 and 102, so that each The body of the on-load capacity regulating transformer has a two-stage rated capacity operation mode. Its structural principle is to control the high-voltage electric control switches 201, 202, 203, 204, 205 by two two-stage on-load capacity regulating transformer bodies 101, 102 (installed in a shared box) through the on-load capacity regulating control device 4 , 206, low-voltage electric control switches 301, 302, 303, 304, 305, 306 and on-load capacity-regulating switches 501, 502 to realize capacity conversion, making it a combined on-load capacity-regulating transformer with three-stage on-load capacity-regulating function.

The parts of the transformer body 101, 102 are electrically controlled and switched by the on-load capacity regulating switches 501, 502, so that the high-voltage windings 601, 602 of each phase and the low-voltage windings 801, 802 of each phase are changed in connection mode (parallel or series), so that Two on-load capacity-regulating transformer bodies 101 and 102 that meet the parallel operation conditions are combined to form an overall-running on-load capacity-regulating transformer, so as to realize the parallel operation of the two on-load capacity-regulating transformer bodies 101 and 102 in a large-capacity mode, and one Independent operation is an intermediate capacity mode, and the intermediate capacity can be switched on-load capacity adjustment again to realize small-capacity operation. The high-voltage side of the three-stage on-load capacity-adjusting distribution transformer is connected in parallel with the same high-voltage power supply through their respective high-voltage electric control switches 201, 202, 203, 204, 205, and 206, and its low-voltage side is connected to the same high-voltage power supply through their respective low-voltage electric control switches 301, 302, 303, 304, 305, 306 parallel load circuit is equipped with a load current transformer 12, the secondary outlet terminal of the load current transformer 12, the electric circuit of the high voltage electric control switch 201, 202, 203, 204, 205, 206 The control outlets and the electric control outlets of the low-voltage electric control switches 301, 302, 303, 304, 305, 306, the control terminals of the on-load capacity adjustment switches 501, 502 are electrically connected with the on-load capacity adjustment control device 4 respectively, forming three Level on-load capacity-adjusting capacity-adjusting distribution transformer as a whole. The high-voltage winding taps 701, 702 and the low-voltage winding taps 901, 902 are electrically connected to the on-load capacity regulating switches 501, 502, respectively.

The on-load capacity adjustment switches 501 and 502 are composed of switching oil chambers, fast mechanisms, motors, manual shaft heads, pressure release devices, and oil suction joints. The switching oil chambers at the bottom of the on-load capacity regulating switches 501 and 502 are installed in the transformer oil tank through the transformer oil tank cover and sealed and isolated from the transformer oil in the oil tank. The fast mechanism is located above the switching oil chamber and communicates with it and is higher than the transformer oil tank cover. It is equipped with a mechanism for the on-load capacity adjustment switches 501 and 502 to realize rapid capacity adjustment, a gear indicating electrical device, and a motor stepping control device. The switch oil chamber is sealed and isolated from the outside through the upper flange cover.

Example 2:

Figure 2 is the working principle of the three-stage on-load capacity regulating transformer. Taking a three-stage on-load capacity-regulating transformer with a rated capacity of 1000kVA as an example to illustrate its capacity-regulating principle: the on-load capacity-regulating transformer is composed of two 500kVA two-stage on-load capacity-regulating distribution transformers. When running in parallel, it reaches its high-capacity state, and the rated capacity is 1000kVA at this time; when there is only one two-stage on-load capacity regulating transformer running, it is an intermediate capacity, and the rated capacity is 500kVA; The capacity regulating transformer is running, and after 1:2 on-load capacity regulation, the rated capacity becomes 250kVA at this time, so the transformer will have three rated capacity levels of 250kVA, 500kVA, and 1000kVA.

Example 3:

Fig. 3 is a wiring diagram of an on-load capacity-regulating transformer in a large-capacity state with a high-voltage corner connected to a low-voltage parallel on-load capacity-regulating switch. In the figure, A, B, C, X, Y and Z represent the terminals of high-voltage windings 601 and 602 respectively, a ₁ , a ₂ , b _{1 , b 2} , c ₁ , c ₂ , x ₁ , x _{2 ,} y ₁ , y ₂ , z ₁ and z ₂ represent the terminals of the low-voltage windings 701 and 702, respectively. The high voltage windings 601 and 602 of the two on-load capacity regulating transformer bodies 101 and 102 are connected in delta, the low voltage windings 801 and 802 are connected in parallel, and the corresponding phases of the high voltage windings 601 and 602 and the low voltage windings 801 and 802 operate in parallel respectively. , at this time the on-load capacity regulating transformer is in the high-capacity operation mode.

Example 4:

Figure 4 is the wiring diagram of the on-load capacity-regulating switch in the middle capacity state of the on-load capacity-regulating transformer with high-voltage corner connection and low-voltage parallel connection. In the figure, A, B, C, X, Y and Z represent the terminals of high-voltage windings 601 and 602 respectively, a ₁ , a ₂ , b _{1 , b 2} , c ₁ , c ₂ , x ₁ , x _{2 ,} y ₁ , y ₂ , z ₁ and z ₂ represent the terminals of the low-voltage windings 701 and 702, respectively. One of the two on-load capacity regulating transformer bodies 101, 102 is in the running state, and the high-voltage windings 601, 602 are delta-connected, the low-voltage windings 801, 802 are connected in parallel, and the other transformer body 101 or 102 is out of operation. Sometimes the on-load capacity regulating transformer is in the middle capacity operation mode as a whole.

Example 5:

Fig. 5 is a wiring diagram of the high-voltage star-connected low-voltage series on-load capacity-regulating switch in the small-capacity state of the on-load capacity-regulating transformer. In the figure, A, B, C, X, Y and Z represent the terminals of high-voltage windings 601 and 602 respectively, a ₁ , a ₂ , b ₁ , b 2 , c ₁ , c ₂ , x ₁ , x _{2 ,} y ₁ , y ₂ , z ₁ and z ₂ represent the terminals of the low-voltage windings 701 and 702, respectively. One of the two on-load capacity regulating transformer bodies 101, 102 is in the running state, and the high-voltage windings 601, 602 are star-connected, the low-voltage windings 801, 802 are connected in series, and the other transformer body 101 or 102 is out of operation. Sometimes the on-load capacity regulating transformer is in the small-capacity operation mode as a whole.

The invention has been described herein in terms of specific exemplary embodiments. Appropriate substitutions or modifications will be apparent to those skilled in the art without departing from the scope of the present invention. The exemplary embodiments are illustrative only, and not limiting of the scope of the invention, which is defined by the appended claims.

Claims (7)

1. a three-stage on-load capacity-regulating distribution transformer, said transformer includes a transformer body (101,102) with a high-voltage winding (601,602) and a low-voltage winding (801,802), an on-load capacity-regulating switch ( 501, 502), characterized in that the transformer includes an on-load capacity regulation control device (4), and a high-voltage electric control switch (201, 202, 203, 204, 205, 206), low-voltage electric control switches (301, 302, 303, 304, 305, 306) and load current transformers (12). 2. A three-stage on-load capacity regulating distribution transformer according to claim 1, characterized in that the transformer body (101, 102) is provided with high-voltage bushings (1001, 1002) and low-voltage bushings (1101, 1102), the high-voltage windings (601, 602) are provided with high-voltage winding taps (701, 702), and the low-voltage windings (801, 802) are provided with low-voltage winding taps (901, 902). 3. A three-stage on-load capacity regulating distribution transformer as claimed in claim 1, characterized in that the load current transformer (12), the secondary outlet end of the load current transformer (12), the high voltage The electric control outlet terminals of the electric control switches (201, 202, 203, 204, 205, 206), the electric control outlet terminals of the low-voltage electric control switches (301, 302, 303, 304, 305, 306) and the The control ends of the on-load capacity regulation switches (501, 502) are respectively electrically connected to the on-load capacity regulation control device (4). 4. A three-stage on-load capacity-regulating distribution transformer as claimed in claim 1, characterized in that the high-voltage side of the three-stage on-load capacity-regulating distribution transformer passes through high-voltage electric control switches (201, 202, 203, 204 , 205, 206) are connected in parallel with the same high-voltage power supply, and the low-voltage side is connected with the load current transformer (12) after being connected in parallel with low-voltage electric control switches (301, 302, 303, 304, 305, 306). 5. A three-stage on-load capacity regulating distribution transformer according to claim 1 or 2, characterized in that the high-voltage electric control switches (201, 202, 203, 204, 205, 206) and the high-voltage bushing The tubes (1001, 1002) are connected, and the low-voltage electric control switches (301, 302, 303, 304, 305, 306) are connected to the low-voltage bushings (1101, 1102). 6. A three-stage on-load capacity regulating distribution transformer according to claim 1 or 2, characterized in that the transformer body (101, 102) is connected by high-voltage winding taps (701, 702) and low-voltage winding taps (901) , 902) are connected to the on-load capacity regulation switches (501, 502). 7. A three-stage on-load capacity regulating distribution transformer according to claim 1, characterized in that the high-voltage windings (601, 602) can be connected in star or delta, and the low-voltage windings (801, 802 ) can be connected in parallel or in series. the

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