WO1997029494A1

WO1997029494A1 - A parallel winding voltage-regulating apparatus

Info

Publication number: WO1997029494A1
Application number: PCT/CN1996/000010
Authority: WO
Inventors: Yueliang Yu
Original assignee: Yueliang Yu
Priority date: 1996-02-06
Filing date: 1996-02-06
Publication date: 1997-08-14
Also published as: AU4662196A

Abstract

A parallel winding voltage-regulating apparatus includes a transformer whose voltage-regulating side consists of two parallel main windings, which are electric coupling through balancing reactor. The two main windings are tapped in the order of voltage value and connected sequentially to a stationary contact of a tap changing switch. A movable contact touches the two adjacent stationary contacts during a static output to achieve parallel supply of power without voltage interruption and circulation current. The present invention can be used for voltage-regulating on-load in substation or distribution, single-phase or multiphase compensation voltage-regulating and stabilizing, voltage stabilizing in house, voltage-regulating of electric furnace to control temperature, voltage-regulating of motor to control speed. Moreover, it can be used as DC voltage-regulating apparatus with large power and high efficiency if it is provided with rectifying device and filter.

Description

Shunt winding regulator

The present invention relates to an improvement of a transformer voltage regulating device, and in particular, it is a voltage regulating device without voltage abrupt change and circulating current during voltage switching.

Adopting the tap transformer, tap changer on-load voltage regulation technology, whether it is the distribution transformer voltage regulation, or the user voltage regulation, there are basically two ways at present, the first is the use of switches, relay contacts between the transformer taps Perform switching voltage regulation. If there is no auxiliary switching contact during voltage regulation, there will always be a moment when the moving contact is not in contact with the static contact. At this time, because the power supply and the load are open, a spark will be generated between the contacts. There will also be a sudden change in the instantaneous voltage. The second is a contact voltage regulator or an on-load tap-changer. The basic requirement is that during the voltage adjustment process, the moving contact can pass through the auxiliary contact to the two points of the voltage regulating winding (tap ) Contact, this will not cause a sudden change in voltage, but because there is always a voltage difference between the two points of the winding, a loop current must be generated. Both will cause damage to the switch, and it is almost impossible to overcome the sudden voltage changes and circulating currents generated during the voltage regulation process. Soviet patent SU1076963 "Stepless autotransformer voltage regulator without power interruption" proposes a technical solution to the voltage regulation of small power autotransformers without voltage interruption at switching instants and reducing circulating current, that is, an additional main winding with voltage regulation is added. The secondary windings connected in parallel are tapped in the order of the high and low voltages and are staggered with each other. They are connected in sequence with the static contacts of the tap changer. The moving contacts of the tap changer are only connected with one main winding tap when the power is stably supplied. Contact, and in the switching process, the two adjacent taps of the main winding and the secondary winding tap between them are shorted at different times by the moving contacts of the tap changer, which shows that the secondary winding only plays a transitional role, No voltage interruption in the process of voltage regulation and switching, and with the parallel connection of the main and auxiliary windings, the closed loop resistance is increased to reduce the circulating current from 350 amps to 25 amps, which is about 14 times. The problem of switching circulating current cannot be completely solved. It can be seen that the introduction of the secondary winding can only solve the uninterrupted voltage at the moment of switching. In addition to the presence of circulation, and, only in the secondary winding instantly switch function, its utilization rate. Poor economy.

The object of the present invention is to provide a transformer voltage regulating device with no voltage discontinuity and circulating current during voltage switching, high efficiency, energy saving and good economy.

The technical solution of the present invention is as follows:

1. Set two parallel wound main windings with taps on the voltage regulating side of the transformer. They are tightly coupled on the same magnetic circuit. Their taps are alternately arranged in order of high and low voltage and are connected to the static contacts of the tap changer in order. No voltage discontinuity is reached in the process of voltage regulation switching; 2. The two main windings are electrically coupled through a balance reactor to balance the voltage difference between adjacent static contacts shorted by the moving contact, so that the circulating current is zero; 3. It is required that the moving contacts of the tap changer can contact two adjacent static contacts at the same time when the power supply is stable. Only two static contacts are changed when the voltage is switched. One of the heads, in this way, can ensure that the two main windings are stably connected in parallel to supply power, which improves the utilization ratio of the windings, and there is no voltage discontinuity during voltage regulation switching, and does not cause winding circulating currents.

In summary, the present invention includes a transformer, a balance reactor, and a tap changer. Each phase of the transformer's voltage regulating side is composed of two parallel and wound main windings of equal conductive cross section in the same magnetic circuit and tightly coupled. According to the order of the voltage, the static contacts of the tap changer are alternately distributed on the two main windings and are connected to the tap changer in turn. The moving contact of the tap changer contacts two adjacent static contacts and forms a bow of the pressure regulating edge. At the I terminal, the two ends of the balanced reactor are respectively connected to «of the two main windings, and the center taps constitute the other bow I terminal of the pressure regulating side.

The advantages of the invention are as follows:

1. Since the moving contact of the tap changer changes only one of the two static contacts connected to it during voltage regulation switching, it does not cause voltage discontinuity at the moment of switching, and therefore, it will not occur at the terminal. Sudden changes in voltage, very low requirements for fast switching and arc extinguishing performance, can also simplify the structure and reduce costs;

2. Because the balanced reactor of the present invention is designed as a low-voltage saturated reactor, when there is a small difference current, the voltage generated at both ends of the balanced reactor and the main winding is sufficient to balance the two static contacts that are simultaneously contacted by the moving contact. The differential voltage between the heads will not cause circulating current. As a result, the tap-changer and transformer are not affected by the impact of the circulating current, which significantly extends the use.

^3. Since the two main windings always work in parallel, it is different from the secondary windings used in the prior art as the voltage-transition switching instantaneous transition function, which has a high utilization rate and (4 strong;

As the device of the present invention will no longer have a sudden change in voltage and current when the voltage is switched, there will be no energy loss, and the device will be more efficient and energy-saving.

The drawings of the present invention are briefly described as follows:

FIG. 1 is an electrical schematic diagram of the present invention.

FIG. ² is a schematic structural diagram of a tap changer according to the present invention.

Fig. 3 is a schematic diagram of the implementation of the invention for an autotransformer.

FIG. ₄ is a block diagram of the auto-transformer with compensation voltage regulation structure of the present invention.

FIG. 5 is a schematic structural view of an input as a trimming edge of the present invention.

FIG. 6 is a schematic diagram of a compensating voltage regulating structure with a commutating contact bridge according to the present invention.

In the following, we will give five embodiments of the present invention according to Figs. 1 to 6, and combine the description of these embodiments to further provide the technical details of the present invention.

Embodiment 1: With reference to Figs. 1 and 2, a voltage regulating device of the present invention, wherein the output side of the transformer is a voltage regulating side and a single-acting contact tap changer is given.

Referring to FIG. 1, the present invention includes a transformer 1, a balance reactor 2 and a tap changer 3. The transformer 1 includes two

- 1 - Parallel voltage-regulating main windings 11, 12 are windings with the same conductive cross-section and taps. Their taps are arranged in order according to the voltage level and alternately with the static contacts 31 of the tap changer 3. The windings 11 and 12 are connected to the two ends 21 and 22 of the balanced reactor 2 respectively, so that the main windings 11 and 12 are electrically coupled. The moving contact 30 of the tap changer 3 and the center tap 20 of the balanced reactor 2 are used for voltage regulation. Output.

Referring to FIG. 2, as shown in the figure, the moving contact 30 of the tap changer 3 is in contact with two adjacent static contacts 31 during stable power supply. At this time, the two main windings 11 and 12 are operated in parallel. When switching, the moving contact 30 only changes one static contact 31 that is in contact with it, while the other that is originally in contact with it still maintains miscellaneous contact. Therefore, although there is an instantaneous moving contact 30 only during switching, It is in contact with one static contact 31, but there is still a main winding connected. Therefore, there is no voltage discontinuity, but when the moving contact 30 returns from only one static contact 31 to two static contacts 31 at the same time Phase contact, at this instant of transition, there must be a voltage difference between the two static contacts 31, but due to the electrical coupling of the balance reactor 2 and the main windings 11, 12, a reverse voltage difference is generated to cancel it out, so Naturally, no circulation is generated.

If the tap-changer is linear or motor commutator, assuming that the static contact contact width is a and the static contact insulation distance is b, then the moving contact contact width c should be:

c <a + 2 b (Equation 1)

If the tap-changer is rotary, refer to (Equation 1) and so on.

If the parallel winding structure allows, the moving contact 30 of the tap changer 3 can slide directly on the winding without the tap. Example _2: Figure 3 shows a regulator according to the present invention and a tap autotransformer configuration. As shown in FIG. 3, two ends of the same potential of two parallel main windings 11 and 12 in the transformer 1 are each connected to two ends 21 ′, 22 ′ and 21, 22 of the balanced reactor 2. The center taps 20 'and 20 of the balanced reactors 2' and 2 are the input ends of the autotransformer 1, and any one tap 20 is used as the common end of the input and output of the transformer 1. The moving contact 30 of the tap changer 3 is At the other output, two balanced reactors 2 'and 2 can be combined in the same magnetic circuit to form a device.

Embodiment 3 FIG. 4 is a structural block diagram of a voltage regulating device with an autotransformer and a compensation transformer according to the present invention. As shown in FIG. 4, the input voltage is connected to the two central ends 20 ′ and 20 of the combined balanced reactor 2, and the four output ends 21 ′, 22 ′ and 21, 22 of the balanced reactor 2 are respectively connected to the transformer 1 main The windings 11 and 12 each have two equipotential terminals. Each tap of the transformer 1 is connected to each static contact 31 of the tap changer 3 in turn. The tap changer 3 has two moving contacts 30 and 30 ′. The primary side of the compensation transformer 5 is connected. In the winding 51, one end of its secondary winding 52 is connected to the input voltage Ui, the other end is the upper end of the output voltage Uo, and the lower end of the output voltage is connected to the lower end of the input voltage. Embodiment 4 _: FIG. 5 shows a voltage regulating device according to the present invention for performing voltage regulation by an electric actuator and automatically supplying power to two main windings in parallel. As shown in FIG. 5, the center tap 20 of the balanced reactor 2 and the moving contact 30 of the tap changer 3 are input voltage terminals. The two ends 21 and 22 of the balanced reactor 2 are respectively passed through the galvanometers 13 and 14 and the transformer 1. The two main windings 11 and 12 are connected to each other. The two galvanometers 13 and 14 feed the current sensing signals to the differential amplifier 15 to drive the electric actuator 16, and the electric actuator 16 drives the moving contact of the tap changer 3. The head 30 achieves parallel power supply of the two main windings 11, 12; the other input signal drives the electric actuator 16 from the control terminal 151 through the differential amplifier 15 to drive the contact 30 to achieve the purpose of automatic voltage regulation.

Embodiment 5: FIG. 6 shows a compensation voltage regulating device with an additional contact reversing bridge according to the present invention.

As shown in FIG. 6, in addition to driving the differential amplifier 15 by means of the current detection signals of the current detectors 13 and 14 of Embodiment 4, another input signal is input from the control terminal 151 to drive the electric actuator 16 to adjust the voltage. In addition to the moving contact 30 of the switch 3, a commutating contact bridge 4 and a compensation transformer 5 are connected. A pair of sides 40 of the commutating contact bridge 4 and the center tap 20 and The moving contact 30 of the switch 3 is connected; the other pair of edges 42 and 43 are connected to the primary winding 51 of the compensation transformer 5, the secondary winding 52 of the transformer 5 is connected to the input terminal of the transformer 1, and the other end is for voltage regulation The output end, the other end of transformer 1 is the common end of input and output. When the output voltage U ₀ = input voltage Ui, both fibers 44 and 45 are closed. When U _{0 is} greater than (less than) UiB inches, the contact

45 is closed (opened) and contact 46 is opened (closed).

It should also be noted that the device of the present invention may be single-phase or multi-phase. The tap changer 3 of the present invention may have a double-acting contact structure to form a dual-channel voltage regulating output device. The present invention may also be connected after the output. Rectifying and filtering unit to form a DC voltage regulating device.

In summary, the present invention can be used for power supply and distribution voltage regulation of power grids, voltage regulation of medium and small power users, and voltage regulation and stabilization of household appliances. The present invention is more suitable for large electric furnace voltage regulation and temperature control, and large electrolytic industry voltage regulation and current control. , Voltage regulation and speed control of large-scale motors, etc. In addition, the present invention can also be used for step-down starting devices of large-scale or extra-large-scale motors.

Claims

Rights request

1. A voltage regulating device for a parallel winding, comprising a transformer (1) and a tap changer (3), which is also characterized by a balance reactor (2), and each phase of the voltage regulating side of the transformer (1) consists of two parallel The main windings (11) and (12) of the parallel-wound equal-conductivity cross-section are tightly coupled on the same magnetic circuit, and their taps are alternately distributed in order of high voltage and are sequentially connected to the static contacts of the tap changer (3) ( 31); the moving contact (30) of the tap changer (3) is in contact with two adjacent static contacts (31), and constitutes a lead-out end of the pressure regulating edge; the balance reactor (2) The two ends (2) (22) are respectively connected to the ends of the two main windings (11), (12), and the center tap (20) constitutes the other leading end of the pressure regulating side.

2. The parallel winding voltage regulating device according to claim 1 or 2, characterized in that two equipotential ends of the two main windings (11) and (12) of the transformer (1) are respectively connected to a balanced reactor (2) '), (2) at both ends (21'), (22 ') and (21), (22), the two balanced reactors (2'), (2) center taps (20 '), (20 ) Forms a constant pressure end, and a center tap (20) and a moving contact (30) of the tap changer (3) form two pressure adjustment ends.

3. The parallel winding voltage regulating device according to claim 1, characterized in that two parallel main windings (11), (12) of the voltage regulating side of the transformer (1) pass through galvanometers (13), (14), respectively It is connected to both ends (21) and (22) of the balance reactor (2), and the two current detectors (13), (14) and differential amplifier (15), and the electric actuator (16) are connected in phase by circuit. Connected, the electric actuator (16) drives the moving contact (30) of the tap changer (3), the differential amplifier (15) also has a control terminal (15 1).

4. The parallel winding voltage regulating device according to claim 1 or 3, characterized in that there are two moving contacts ⁽ 30) and (30 ') on the tap changer (3), which respectively constitute two adjustable voltage outputs end.

5. The shunt winding voltage regulating device according to claim 1, further comprising a compensation transformer (5), the primary side (51) and two moving contacts (30) of the tap changer (3), (30 ') connection, one end of its secondary side (52> is connected to the input voltage, the other end is the output end, and the other input end of the transformer (υ is other than its other output end).

6. The shunt winding voltage regulating device according to claim 1 or 4, further comprising a commutating contact bridge (4) and a compensation transformer (5), one of the commutating contact bridge (4) Opposite sides (40) and (41) are connected to the output end of the original voltage regulator, the other opposite sides (42) and (43) are connected to the primary side (51) of the compensation transformer (5), and its secondary side (52) — Terminate the input voltage, the other end is the output, and the other input is bet on the other output.