CN107946053A - A kind of dry type loaded capacity regulating voltage regulating sub-connecting switch of transformer - Google Patents

Abstract

A dry-type tap changer for on-load capacity-regulating voltage-regulating transformers, including an on-load capacity-regulating system; The transmission shaft and the high-pressure transmission shaft, the low-pressure transmission shaft and the high-pressure transmission shaft are connected through a transmission mechanism, and one of the transmission shafts is connected to the power mechanism; the low-pressure side cam is installed on the low-pressure transmission shaft, and each low-pressure side cam corresponds to a low-pressure side vacuum The low-pressure side cam is connected to the moving contact of the corresponding low-pressure side vacuum bubble; the high-pressure side cam is installed on the high-voltage transmission shaft, and each high-pressure side cam corresponds to a high-pressure side vacuum bubble, and the high-pressure side cam is connected to the corresponding high-pressure side vacuum bubble. Moving contact connection; can also include on-load voltage regulating system. The tap changer realizes the on-load switching of the switch without interruption of power supply, reduces the size of the switch, and drives the vacuum bubbles to run in sequence through the cams of different phases. It has a simple structure, compact size and reliable operation.

Description

A dry-type on-load capacity-regulating voltage-regulating transformer tap-changer

technical field

The invention relates to a tap changer used for on-load capacity regulation and voltage regulation of a dry-type transformer, and belongs to the technical field of distribution transformer on-load tap changers.

Background technique

Distribution transformer is one of the main equipment of distribution network, with a large quantity and a wide range. As a new type of equipment to reduce power distribution loss, the capacity-adjusting and voltage-regulating transformer can change the capacity in time according to the power load. It is a new type of energy-saving distribution transformer that can effectively reduce losses. The oil-immersed transformer technology and technology of on-load capacity regulation and voltage regulation are becoming more and more mature. At present, it has been popularized and applied nationwide, and has received good energy-saving effects. However, it is limited to the requirements of fire prevention and explosion protection. Indoor installation places such as residential quarters, shopping malls, and office buildings cannot be used, and it still cannot replace traditionally used dry-type transformers. The peak-to-valley rotation of these places is also very frequent. The time-period peaks generally appear during the working hours of the day, while the time-period peaks of residential quarters generally appear during breakfast, lunch and evening hours. The seasonal load peaks are mainly cooling load in summer and heating in winter. The load and the sudden increase in the holiday load represented by the Spring Festival.

At present, dry-type transformers account for about 15% to 20% of distribution transformers in large and medium-sized cities, and with the continuous advancement of urban construction in my country, this proportion will continue to rise. How to reduce the distribution of urban residential areas? The loss of electrical transformers will be the focus of extensive attention in the field of transformer manufacturing in the future. As a new type of energy-saving dry-type transformer, the on-load capacity-adjusting and voltage-regulating dry-type transformer can convert the rated capacity of the transformer according to the actual load size, solve the problem of "big horses and small cars" in the distribution network, and reduce the comprehensive loss of the transformer And the overall cost, effectively solve the problem of large no-load loss caused by long-term no-load operation of the transformer. At the same time, it can automatically adjust the voltage with load, solve the "low voltage" problem in time, increase the voltage qualification rate, improve the power quality of users, and ensure the safe and reliable use of electricity by residents.

Dry-type on-load capacity-regulating tap-changer, matching with three-phase AC 50Hz, rated voltage 10kV and below dry-type on-load capacity-regulating tap-changer, realizes the conversion of large and small capacity states of the transformer under the condition of uninterrupted power supply And voltage rise and fall, reduce transformer loss, improve power quality. Different from the oil-immersed on-load capacity-regulating voltage-regulating transformer, the dry-type on-load capacity-regulating voltage-regulating transformer is installed indoors, and the insulating medium is air, so the matched on-load capacity regulating tap-changer needs to have no Oily, flame retardant, explosion-proof performance. The safety distance requirement for electrical insulation in the air is larger than that in oil, but it is limited to the requirements of the on-site installation environment, and the volume of the dry-type OLTC tap-changer cannot be infinitely increased.

At present, the main technical difficulties of dry-type OLTC include:

(1) When the high-voltage contact "Y-D" of the capacity regulating switch is switched, the stage voltage is large, and it is difficult to extinguish the arc between the contacts. The method of simply using vacuum bubbles instead of the selector switch will cause a large volume due to too many vacuum bubbles, and the circuit structure will be complicated, and the cost will also be greatly increased.

(2) The structure of the traditional mechanical driving method is complicated, and it is not easy to realize the requirement of simultaneous switching of three phases.

(3) The switching current of the low-voltage side contact is large during the switching process. The current known switch structure has the problems of high temperature rise of the contact and easy aging of the insulation, and the insulation structure inside the switch cannot meet the insulation distance requirements under oil-free conditions. .

Contents of the invention

Aiming at the shortcomings of the existing dry-type on-load capacity-regulating voltage-regulating switch technology, the invention provides a dry-type on-load capacity-regulating voltage-regulating transformer tap changer with reliable insulation, small size, simple structure and convenient switching.

The dry-type on-load capacity-regulating voltage-regulating transformer tap-changer of the present invention adopts the following technical solutions:

The dry-type on-load capacity-regulating voltage-regulating transformer tap changer includes an on-load capacity-regulating system; the on-load capacity-regulating system includes a capacity-regulating quick switching mechanism and a capacity-regulating switching energy storage device, and the capacity-regulating quick switching mechanism includes a low-voltage transmission shaft and high-voltage transmission shaft, low-voltage transmission shaft and high-voltage transmission shaft are connected through a transmission mechanism (gear transmission), and one of the transmission shafts is connected with a power mechanism (motor or reducer); the low-pressure side cam is installed on the low-voltage transmission shaft, A low-pressure side cam corresponds to a low-pressure side vacuum bubble, and the low-pressure side cam is connected to the moving contact of the corresponding low-pressure side vacuum bubble; a high-pressure side cam is installed on the high-voltage transmission shaft, and each high-pressure side cam corresponds to a high-pressure side vacuum bubble, and the high-pressure side cam is connected to a high-pressure side vacuum bubble. The cam is connected with the moving contact of the corresponding high-voltage side vacuum bubble.

The transmission shaft connected with the power mechanism (motor or reducer) is also connected with the capacity regulating and switching energy storage device.

The above-mentioned dry-type on-load capacity-regulating voltage-regulating transformer switch also includes an on-load voltage-regulating system; The shaft is connected with the power mechanism, cams are arranged on the pressure regulating camshaft, and each cam corresponds to a pressure regulating vacuum switch tube.

The pressure regulating camshaft is connected with the pressure regulating switching energy storage device.

The capacity-adjusting switching energy storage device and the pressure-regulating switching energy storage device use springs, which store energy in the springs through mechanical mechanisms, and then release the energy stored in the springs to drive the drive shaft to move.

The invention realizes the switching of the switch with load and uninterrupted power supply, and at the same time avoids the problem of insulation between the contacts of the selective switch, reduces the size of the switch, and drives the vacuum bubbles to run in sequence through the cams of different phases. The structure is simple, the volume is compact, and the operation Reliable, easy for users to overhaul, the voltage fluctuation is small when the capacity adjustment and voltage adjustment are switched, and the normal use of electrical equipment will not be affected. By using the vacuum bubble as the arc extinguishing device and optimizing the circuit design, the internal insulation distance of the switch is reduced, and it has the characteristics of reliable insulation, small size, simple structure, and uninterrupted power supply during the switching process.

Description of drawings

Fig. 1 is a schematic diagram of a low-voltage side circuit in a dry-type on-load capacity-adjusting voltage-regulating transformer switch of the present invention.

Fig. 2 is a schematic diagram of the high-voltage side circuit in the switch of the dry-type on-load capacity-adjusting voltage-regulating transformer of the present invention.

Fig. 3 is a schematic diagram of the low-voltage side control mechanism in the switch of the dry-type on-load capacity-regulating voltage-regulating transformer of the present invention.

Fig. 4 is a schematic diagram of the high-voltage side control mechanism in the switch of the dry-type on-load capacity-adjusting voltage-regulating transformer of the present invention.

Fig. 5 is a schematic diagram of the capacity adjustment process of the switch of the dry-type on-load capacity and voltage regulating transformer of the present invention.

Among the figure: 101. low pressure transmission shaft, 102. high pressure transmission shaft, 201. low pressure side cam, 202. high pressure side cam.

Detailed ways

The dry-type on-load capacity-adjusting voltage-regulating transformer tap changer of the present invention, its circuit includes the low-voltage side circuit shown in Figure 1 and the high-voltage side circuit shown in Figure 2, the voltage regulation function is realized by the high-voltage side circuit, and the capacity adjustment function is realized by The high-voltage side circuit and the low-voltage side circuit are realized together. Both capacity adjustment and voltage adjustment adopt a single resistance transition circuit, the single resistance transition circuit has only one resistor (r1 in Figure 1, R1 or R2 in Figure 2), and the arc contact only has one main arc contact and one transition contact . The structure of this transition circuit is particularly simple, the task of contact switching is light, the electrical life is long, the number of arc contacts and transition resistors is small, the structure is simple, and the cost performance is high. It satisfies the demand for miniaturization of the dry-type on-load capacity and voltage regulation tap-changer.

In the low-voltage side circuit shown in Figure 1, each phase winding in the three-phase low-voltage winding includes three parts: winding I, winding II and winding III. In the state of large capacity, winding I and winding II are connected in parallel; in the state of small capacity, winding I and winding II are connected in series. The first end a1 of the winding I and the first end a2 of the winding II are connected through the low-voltage vacuum bulb LVK1 and the low-voltage transition resistor r1 connected in series on the one hand, and directly connected through the low-voltage vacuum bulb LVK2 on the other hand. The tail end x1 of the winding I is connected with the head end a2 of the winding II through a low-voltage vacuum bulb LVK3. The tail end x1 of the winding I is connected with the tail end x2 of the winding II through a low-voltage vacuum bulb LVK4. The tail end x2 of winding II is directly connected to the head end a3 of winding III.

In the high-voltage side circuit shown in Figure 2, each phase winding in the three-phase high-voltage winding includes a common section and a voltage regulating section. Two vacuum switching tubes, HVK4 and HVK5, are used in the voltage regulating section, and the transition resistor R2 is placed under the HVK5 vacuum tube. In the state of large capacity, the three-phase windings are connected in delta; in the state of small capacity, the three-phase windings are connected in star shape. Taking the A-phase winding as an example, the tail end of the A-phase winding, that is, the voltage regulation section, is connected to the on-load voltage regulation system, the outgoing line of the on-load voltage regulation system is connected to the on-load capacity regulation system, and the two outgoing lines of the on-load capacity regulation system are respectively connected to The head ends of other phases are connected to the star line.

The high-voltage side circuit and the low-voltage side circuit are located on both sides of the insulating partition at the same height. The high-voltage side circuit and the transformer connection terminal are drawn from the back of the cabinet, and the low-voltage side circuit and the transformer connection terminal are drawn from the top of the cabinet.

The on-load voltage regulation system in the present invention includes a voltage regulation fast switching mechanism and a voltage regulation switching energy storage device. There are six cams on the top, and each two cams correspond to a phase winding. These two cams drive two vacuum switch tubes HVK4 and HVK5 (see Figure 2), and operate according to a certain program. The vacuum switch tube (choose 1kV) is used as the switch The main component is the main contact for switching, which reduces or eliminates the working arc, realizes gear shifting, and the quick contact works as a negative contact alternately. The pressure regulating camshaft can also be connected with the pressure regulating switching energy storage device. The pressure regulating switching energy storage device adopts a spring, which stores energy in the spring through a mechanical mechanism, and then releases the energy stored in the spring to drive the pressure regulating camshaft to move. When the selection is completed, the spring energy storage mechanism releases energy to drive the pressure regulating camshaft to quickly rotate an angle. The cam installed on the pressure-regulating camshaft regularly lifts and loosens the vacuum tube to make the vacuum tube switch on, off, and on, and cooperate with the quick contact to change the conductive working circuit and realize the alternating of the conductive rod input circuit. Work. The conduction and disconnection of the vacuum tube are stipulated to be completed within a certain period of time to prevent power failure, arcing and other phenomena.

The voltage regulation realization process is similar to the on-load tap changer on the traditional dry-type transformer.

The on-load capacity adjustment system in the present invention includes a capacity adjustment quick switching mechanism and a capacity adjustment switching energy storage device. The capacity adjustment quick switching mechanism includes the low-voltage transmission shaft 101 shown in FIG. 3 and the high-voltage transmission shaft 102 shown in FIG. 4 . The low-voltage transmission shaft 101 and the high-voltage transmission shaft 102 are used for capacity adjustment switching, and all moving contacts of the capacity adjustment switching are fixed on the low-voltage transmission shaft 101 and the high-voltage transmission shaft 102, and the transmission shafts are made of insulating materials.

The low-voltage transmission shaft 101 and the high-voltage transmission shaft 102 are connected through a transmission mechanism (gear transmission), and one of the transmission shafts is connected with the power mechanism (motor or reducer). connect. The switching energy storage device adopts a spring and is located on the other side of the transmission shaft. It stores energy in the spring through a mechanical mechanism, and then releases the energy stored in the spring to drive the transmission shaft of the quick switching mechanism to move. The two transmission shafts use the same motor and switching energy storage device. Driven by the energy storage device, the low-voltage side circuit and the high-voltage side circuit are fully synchronized.

Referring to Fig. 3, four low-pressure side cams 201 are installed on the low-pressure transmission shaft 101, and the four low-pressure side cams are in different phases, respectively driving four vacuum bubbles of LVK1, LVK2, LVK3 and LVK4 (see Fig. 1 ), and the low-pressure side cams It is connected with the moving contact of the vacuum bubble, and the static contact of the vacuum bubble is fixed on the insulating plate. As the low-voltage transmission shaft 101 rotates, it moves according to the on-off sequence shown in FIG. 5 , and the process is reversible, so as to realize the conversion between series and parallel connection of the first section of the low-voltage coil winding and the second section of the winding of each phase of the transformer. The vacuum bubbles in the three-phase low-voltage windings are installed on the same transmission shaft, which ensures that the three-phase low-voltage windings are fully synchronized.

Referring to Fig. 4, three high-pressure side cams 202 are installed on the high-voltage transmission shaft 102, and the three high-pressure side cams 202 are in different phases, respectively driving three vacuum bubbles HVK1, HVK2, and HVK3. The high-pressure side cams 202 and the corresponding vacuum bubbles The moving contact of the vacuum bubble is fixed on the insulating plate. With the rotation of the high-voltage transmission shaft 102, the three vacuum bubbles move according to the on-off sequence shown in Figure 5, and the process is reversible, so as to realize the conversion between the D-shaped connection and the Y-shaped connection of the high-voltage coil of each phase of the transformer. The vacuum bubbles in the three-phase high-voltage windings are installed on the same high-voltage transmission shaft 102 to ensure that the actions of the three-phase high-voltage windings are fully synchronized.

The vacuum bulb LVK1 is connected to the resistor r1, and the vacuum bulb HVK1 is connected to the resistor R1. During the capacity adjustment conversion process, the vacuum bulb LVK1 and the vacuum bulb HVK1 are first closed and finally disconnected to ensure the connection of the transition resistor and realize continuous power supply. During the conduction period of vacuum bubble LVK1 and vacuum bubble HVK1, vacuum bubble LVK2, vacuum bubble LVK3, vacuum bubble LVK4, vacuum bubble HVK2, and vacuum bubble HVK3 are switched off in the order shown in Figure 5 to realize capacity conversion.

An insulating cylinder with an opening in the middle is fixed on the low-voltage transmission shaft 101 and the high-voltage transmission shaft 102. A voltage-regulating movable contact is fixed on the insulating cylinder. The insulating cylinder and the transmission shaft are fixedly connected by bearings, within the specified rotation range. , to achieve mutual non-influence and non-interference during rotation.

The on-load voltage regulation system and the on-load capacity regulation system are two sets of independent mechanisms, which are independent of each other in structure and do not interfere with each other. They are controlled by the controller to avoid simultaneous actions.

Claims (6)

1. A dry-type on-load capacity-regulating voltage-regulating transformer tap-changer, comprising an on-load capacity-regulating system; it is characterized in that: the on-load capacity-regulating system comprises a capacity-regulating fast switching mechanism and a capacity-regulating switching energy storage device, and The capacity quick switching mechanism includes a low-pressure transmission shaft and a high-pressure transmission shaft. The low-pressure transmission shaft and the high-pressure transmission shaft are connected through a transmission mechanism, and one of the transmission shafts is connected to the power mechanism; a low-pressure side cam is installed on the low-pressure transmission shaft, and each low-pressure side The cam corresponds to a low-pressure side vacuum bubble, and the low-pressure side cam is connected to the moving contact of the corresponding low-pressure side vacuum bubble; the high-pressure side cam is installed on the high-voltage transmission shaft, and each high-pressure side cam corresponds to a high-pressure side vacuum bubble, and the high-pressure side cam is connected to the corresponding The moving contact connection of the vacuum bubble on the high-voltage side. 2. The dry-type on-load capacity-regulating voltage-regulating transformer tap-changer according to claim 1, characterized in that: the transmission shaft connected to the power mechanism is also connected to the capacity-regulating switching energy storage device. 3. The dry-type on-load capacity-adjusting voltage-regulating transformer tap changer according to claim 2, characterized in that: the capacity-regulating switching energy storage device adopts a spring. 4. The dry-type on-load capacity-regulating voltage-regulating transformer tap-changer according to claim 1, characterized in that: it also includes an on-load voltage regulation system; the on-load voltage regulation system includes a voltage regulation fast switching mechanism, and the voltage regulation is fast The switching mechanism includes a power mechanism and a pressure regulating camshaft, the pressure regulating camshaft is connected with the power mechanism, cams are arranged on the pressure regulating camshaft, and each cam corresponds to a pressure regulating vacuum switch tube. 5. The dry-type on-load capacity regulating voltage regulating transformer tap changer according to claim 3, characterized in that: the voltage regulating camshaft is connected to the voltage regulating switching energy storage device. 6. The dry-type on-load capacity-regulating voltage-regulating transformer tap-changer according to claim 5, characterized in that: the capacity-regulating switchable energy storage device and the voltage-regulating switchable energy storage device use springs.