WO2023092629A1

WO2023092629A1 - Variable-flux voltage-variation rectifier transformer for electric trolley

Info

Publication number: WO2023092629A1
Application number: PCT/CN2021/135183
Authority: WO
Inventors: 吴其亚; 张新根; 刘鹏飞; 宋志朋
Original assignee: 吴江变压器有限公司
Priority date: 2021-11-29
Filing date: 2021-12-02
Publication date: 2023-06-01
Also published as: CN114141510A

Abstract

The present invention belongs to the technical field of transformers, and particularly relates to a variable-flux voltage-variation rectifier transformer for an electric trolley. The variable-flux voltage-variation rectifier transformer comprises: a three-phase coil of a double-split four-coil structure, wherein the three-phase coil is divided into a valve-side coil and a grid-side coil corresponding to the valve-side coil, the valve-side coil is split into three first valve-side coils which are in a star connection and three second valve-side coils which are in a delta connection, the grid-side coil is split into three first grid-side coils which are in a delta connection and three second grid-side coils which are in a delta connection, and the first grid-side coil and the second grid-side coil in each phase of coils are connected in parallel; and the first grid-side coil or the second grid-side coil has a number of turns corresponding to a first gear of a first voltage of a grid valve and a second gear of a second voltage of the grid valve. In the present invention, the gear adjustment is convenient and flexible; not only can output voltages be conveniently exchanged on a valve side, but the gear adjustment requirements within a primary-side grid voltage tapping range can also be met; maintenance and management are facilitated; no structural change is generated; and the position of an external connecting line of a grid-side coil is not changed, such that field operation maintenance and management are facilitated.

Description

Flux-changing voltage-regulating rectifier transformer for tram

technical field

The invention belongs to the technical field of transformers, and in particular relates to a flux-changing voltage-regulating rectifier transformer for electric vehicles.

Background technique

The environment and climate have become important issues in the world today, and the use of trolleybuses can generally be regarded as green transportation with zero emissions of pollutants. At present, there are two kinds of DC traction power systems in the traction rectification station of tram (trackless) tram, namely DC 600V system and DC 750V system. Types also have limited values. It is the most ideal solution to realize the common traction system of DC 600V and DC 750V to realize mutual switching between the two systems.

Because the rectifier used in the tram (trackless) is an uncontrollable power diode, in the prior art, the voltage level of the DC output system is changed by adjusting the output voltage at the valve side of the rectifier transformer. This technical scheme mainly has the following problems:

First, the traction rectification station of tram (trackless) generally has an axial double-split four-coil structure, and a 12-pulse rectification composed of multiple sets of three-phase bridge rectifier circuits connected in parallel with two valve-side coils. The grid side is a 10kV system , The 600V DC system corresponds to the valve side AC output voltage of 485V, and the 750V DC system corresponds to the valve side AC output voltage of 590V. One of the two windings on the valve side is connected into a △ connection, and the other is connected into a Y connection, and the number of turns is different

times. In order to ensure the balance of voltage output, the no-load line voltage difference between the two windings on the valve side should be less than 0.3%, so the selectable ratio of turns on the valve side of the rectifier transformer is very limited. If the voltage output of 485V and 590V is realized by changing the number of turns on the valve side, it is difficult to ensure that the voltages of the two gears meet the requirement that the difference of the valve side no-load line voltage is less than 0.3%. In addition, the transformation ratio deviation between the grid side and the valve side of the transformer is required to be less than ±0.5%, which further narrows the selection range of the Y-connection and △-connection turns on the valve side. In summary, it is difficult to change the number of turns on the valve side. It is difficult to meet the national standard if the exact matching result is obtained.

Second, traction substations for trams (or trolleys) are generally built in prosperous urban areas with dense population and limited construction space. Therefore, the space in the traction power distribution room is also very limited. Even if the coil turns that can be accurately matched are calculated, but Every time the gear is changed, the Y-connection and △-connection copper bars on the valve side need to be replaced. Not only is the operation difficult, but there is also space for storing spare copper bars. Due to structural limitations, the △-connection copper bars 485V and 590V cannot be used universally.

Third, the valve side of the rectifier transformer is generally made of copper foil, and the copper bar is led out. The secondary pressure regulation on the valve side will add copper foil and lead out copper bars on the valve side. Due to the occupied position of the copper bars, it will be difficult to calculate the accuracy of the transformer impedance, and it is difficult to ensure that the spatial positions of the low-voltage coil and the high-voltage coil are symmetrical. sex.

Contents of the invention

The invention provides a variable magnetic flux voltage regulating rectifier transformer for trams, which is used to solve the problem that the current two DC traction power supply systems cannot be used in common use.

In order to solve the above-mentioned technical problems, the technical solution of the present invention is: the variable flux voltage regulating rectifier transformer for electric cars, which includes a three-phase coil with a double-split four-coil structure, and the three-phase coil is divided into a valve side coil and a valve side coil Corresponding grid-side coils, the valve-side coils are split into three star-connected first valve-side coils and three delta-connected second valve-side coils, and the grid-side coils are split into three delta-connected first valve-side coils. One grid-side coil and three second grid-side coils connected in delta, in each phase coil, the first grid-side coil and the second grid-side coil are connected in parallel;

The first grid-side coil or the second grid-side coil is provided with a number of turns corresponding to the first gear of the first voltage of the net valve and the second gear of the second voltage of the net valve, and the first voltage is higher than the second voltage , by changing the gear position of the grid-side coil to obtain different turn potentials of the grid-side coil.

According to the characteristics of the transformer, the turn potential of the network side coil is equal to the turn potential of the valve side coil, and the output voltage of the valve side is changed due to the change of the turn potential of the valve side, thereby achieving the purpose of realizing the secondary output voltage conversion of the transformer. In the process of two-turn potential conversion, the magnetic flux density of the transformer also changes, and the magnetic flux density cannot be saturated under the two voltage regulation methods. The transformation of the valve side voltage is realized through the electromagnetic induction change formed by the network side coil and iron core. On the basis of realizing the variable magnetic flux voltage regulation method on the grid side, the turns of the two parallel coils are set separately to avoid the circulation between the upper and lower coils due to the difference in the turns.

Optionally, the gear position is adjusted through a voltage regulating panel, and the voltage regulating panel includes a terminal board, an incoming line terminal drawn from the grid side coil and arranged on the terminal board, a first voltage outgoing line terminal, and a second voltage outgoing line terminal. terminals, and the branch board connecting the terminals; when the branch board connects the first voltage outlet terminal and the second voltage outlet terminal, the voltage regulating coil between the first voltage outlet terminal and the second voltage outlet terminal is short-circuited, and the first The voltage outlet terminal is the first gear; when the connection between the first voltage outlet terminal and the second voltage outlet terminal is disconnected, the voltage regulating coil between the first voltage outlet terminal and the second voltage outlet terminal is connected, The outlet from the second voltage outlet terminal is the second gear.

Optionally, the pressure regulating panel also includes several first tap terminals for regulating the voltage of the first gear and several second tap terminals for regulating the voltage of the second gear. The connecting terminal is led out from the first tap gear coil between the incoming line terminal and the first voltage outlet terminal, and the second tap terminal is led out from the second tap gear coil in the voltage regulating coil.

Optionally, short-circuit the voltage regulation coil and disconnect the second tap terminal, and then connect the corresponding first tap terminal through the tap board to perform first gear voltage regulation; connect the voltage regulation coil and switch the first tap gear Adjust the position to the maximum, and then connect the corresponding second tap terminal through the splitter board to adjust the voltage at the second gear.

Optionally, the voltage regulation range of the first tap terminal or the second tap terminal is ±5% or ±2×2.5%.

Optionally, the number of turns ΔN of the voltage regulating grid side coil is obtained by formula 1:

Wherein _N1 is the number of turns of the grid-side coil corresponding to the first gear, and _N2 is the number of turns of the grid-side coil corresponding to the second gear;

The _N1 and _N2 are obtained by formulas 2.1 and 2.2 respectively:

Wherein U _network is the fixed phase voltage at the grid side, _et1 is the turn potential corresponding to the first voltage, and e _t2 is the turn potential corresponding to the second voltage.

Optionally, the e _t1 and e _t2 values are obtained by formulas 3.1 and 3.2:

Wherein, U ₁ is the first phase voltage on the valve side, U ₂ is the second phase voltage on the valve side, and n is the number of turns of the coil on the second valve side.

Optionally, the number of turns of the first valve-side coil is 26, and the number of turns of the second valve-side coil is 45.

Compared with the prior art, the technical solution provided by the invention has the following advantages:

1) The gear adjustment is convenient and flexible: it can not only easily realize the voltage exchange of 485V and 590V output on the valve side, but also meet the gear adjustment requirements of the primary side network voltage tapping range;

2) Easy maintenance and management: The copper foil on the valve side has no structural changes during the entire voltage conversion, the main structure of the transformer has not changed, the position of the external connection line of the grid side coil has not changed, and there are no redundant structural parts, which is convenient for on-site operation maintenance and management;

3) Cost reduction: In the process of changing the number of turns, it is only necessary to ensure that the magnetic density of the iron core is not saturated, and it can be in the linear working area. Compared with the method of voltage conversion by adding copper foil on the valve side, the cost is greatly reduced.

4) The performance of the transformer is stable: there is no obvious difference between the coil of this structure and the coil of the traditional traction rectifier transformer in terms of the number of turns selection, structural design, electric density, magnetic density selection, etc., which can ensure the no-load line voltage unbalance rate of the two coils on the valve side , half-through impedance unbalance rate, voltage transformation ratio and other characteristic parameters meet the relevant requirements of national standards;

5) The performance of the transformer is stable: the number of turns of the axial double-split parallel grid-side coil is completely consistent, and there will be no circulating current during the operation of the transformer, which improves the reliability of the transformer operation;

6) The product structure of the rectifier transformer is compact: it can be integrated in the DC traction transformer box for use.

Description of drawings

Fig. 1 is a schematic diagram of a valve side coil of a variable flux voltage regulating rectifier transformer for electric vehicles described in an embodiment of the present invention;

Fig. 2 is a schematic diagram of a grid-side coil of a flux-changing rectifier transformer for electric vehicles described in an embodiment of the present invention;

Fig. 3 is the schematic diagram of a kind of variable magnetic flux regulating rectifier transformer for tram described in an embodiment of the present invention;

Fig. 4 is a schematic diagram of a first-voltage down-regulation panel of a variable-flux voltage-regulating rectifier transformer for electric vehicles described in an embodiment of the present invention;

Fig. 5 is a schematic diagram of the second voltage down-regulating panel of a variable flux voltage regulating rectifier transformer for electric vehicles described in an embodiment of the present invention;

Fig. 6 is a schematic diagram of voltage regulation of a variable flux voltage regulation rectifier transformer for electric vehicles described in an embodiment of the present invention.

As shown in the figure:

10-valve side coil; 101-first valve side coil; 102-second valve side coil; 20-grid side coil; 201-first grid side coil; 202-second grid side coil; 301-split plate; 3011-incoming terminal; 3012-first voltage outlet terminal; 3013-second voltage outlet terminal; 3014-first tap terminal; 3015-second tap terminal;

Detailed ways

For ease of understanding, the electric vehicle flux-changing voltage-regulating rectifier transformer will be described below in conjunction with embodiments. It should be understood that these embodiments are only for illustrating the present invention and are not intended to limit the scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation and positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplification of the description, rather than indicating or implying that the referred device or element must have a specific orientation, use a specific orientation construction and operation, therefore, should not be construed as limiting the invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected or integrally connected; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

As shown in Figure 1-2, the variable flux voltage regulating rectifier transformer for trams includes a three-phase coil with a double-split four-coil structure. The three-phase coil is divided into a valve-side coil 10 and a grid-side coil corresponding to the valve-side coil 10. 20. The valve-side coil 10 is split into two parts: three star-connected first valve-side coils 101 and three delta-connected second valve-side coils 102, and the grid-side coil 20 is split into three delta-connected first grid-side coils 201 and three delta-connected second grid-side coils 202, in each phase coil the first grid-side coil 201 and the second grid-side coil 202 are connected in parallel;

Referring to Fig. 2, the first grid-side coil 201 or the second grid-side coil 202 is provided with a first gear with the number of turns corresponding to the first voltage of the net valve and a second gear with the second voltage of the net valve, and the first voltage is higher than the second gear. For the second voltage, different turn potentials of the grid-side coil 20 are obtained by changing the gear position of the grid-side coil 20 .

According to the characteristics of the transformer, the turn potential of the grid-side coil 20 is equal to the turn potential of the valve-side coil 10, that is to say, on the premise that the input voltage remains unchanged, the number of turns of the grid-side coil 20 connected to the circuit can be changed, so that Change the turn potential of the network side coil 20, the turn potential of the valve side coil 10 will also change accordingly, and the number of connected turns of the valve side coil 10 remains unchanged, then the output voltage of the valve side coil 10 will follow the turn potential of both sides. It changes in direct proportion, thus achieving the purpose of realizing the secondary output voltage transformation of the transformer. That is to say, as long as the connected turns of the grid-side coil 20 are well controlled, the output voltage of the valve-side coil 10 can be controlled.

What needs to be explained is that during the process of two-turn potential transformation, the magnetic flux density of the transformer also changes accordingly, and the magnetic flux density cannot be saturated under the two voltage regulation methods. The transformation of the valve side voltage is realized through the electromagnetic induction change formed by the network side coil 20 and the iron core. Since the coils in the present invention have a double-split four-coil structure, on the basis of realizing the variable magnetic flux voltage regulation on the grid side, the turns of the two parallel coils should be set separately to avoid circulating currents in the upper and lower coils due to the difference in the number of turns . With the transformation of the turn potential, the magnetic flux of the rectifier transformer will change. In other words, the transformation of the valve side voltage is realized through the electromagnetic induction change formed by the grid side coil 20 and the iron core. Therefore, this voltage regulation method is called variable magnetic field. Through pressure regulation.

Specifically, its number of turns is calculated as follows:

First determine the turn potential e _t1 corresponding to the first voltage and the turn potential e _t2 corresponding to the second voltage,

The e _t1 and e _t2 values are obtained by formulas 3.1 and 3.2:

Wherein, U ₁ is the first phase voltage on the valve side, U ₂ is the second phase voltage on the valve side, and n is the number of turns of the coil 10 on the valve side.

It is further determined that when the valve side coil 10 remains unchanged, the number of turns N ₁ and N ₂ of the grid side coil 20 under the first voltage and the second voltage are respectively obtained,

_N1 and _N2 are obtained by formulas 2.1 and 2.2, respectively:

Wherein U _grid is the fixed-phase voltage of the grid side. It should be noted that since the grid side coil 20 is connected in parallel with two coils, the number of turns here is the number of turns on one coil.

When the adjustment voltage is finally determined, the number of turns ΔN of the adjustment coil,

The number of turns of the voltage regulating coil ΔN is obtained by formula 1:

ΔN=[N ₂ -N ₁ ] (1)

So far, it is possible to determine the number of coil turns that need to be adjusted when the voltage is switched, and set tap terminals at corresponding positions in the grid-side coil 20 according to the number of turns of the voltage regulating coil, so as to conveniently adjust the voltage.

In a specific embodiment of the present invention, the number of turns of the first valve side coil 101 is 26, and the number of turns of the second valve side coil 102 is 45. Because the turns ratio of the △-connected coil on the valve side and the Y-connected coil is 1:√3, but the number of turns of the coil must be an integer, there must be a no-load voltage difference between the valve-

side coils

101 and 102. According to the national standard, the valve-side The no-load voltage difference between

coils

101 and 102 must not exceed 0.3%, so in the present invention, the number of turns of the valve-side △-connected coil is 45 turns, and the number of turns of the Y-connected coil is 26 turns. The no-load voltage difference (26×√3-45)/45×100%=0.075%, far less than 0.3%, far less than the national standard requirements.

As shown in Figure 3, in the present invention, the gear position is adjusted through the voltage regulating panel, and the voltage regulating panel includes a wiring board, an incoming line terminal 3011 drawn from the grid side coil 20 and arranged on the wiring board, and a first voltage outgoing line terminal 3012, the second voltage outlet terminal 3013, and the branch board 301 connecting the terminals; when the branch board 301 connects the first voltage outlet terminal 3012 and the second voltage outlet terminal 3013, the first voltage outlet terminal 3012 and the second voltage outlet terminal The voltage regulating coil between 3013 is short-circuited, and the first voltage outlet terminal 3012 is the first gear. When the first voltage outlet terminal 3012 and the second voltage outlet terminal 3013 are disconnected, the first voltage outlet terminal The voltage regulating coil between 3012 and the second voltage outlet terminal 3013 is connected, and the outlet from the second voltage outlet terminal 3013 is the second gear.

The valve-side coil 10 in the present invention has no structural changes during the entire voltage conversion, the main structure of the transformer has not changed, the position of the external connection line of the grid-side coil 20 has no change, and there are no redundant structural parts, which is convenient for on-site operation and maintenance. manage.

As shown in Figures 3-5, the voltage regulation panel also includes several first tap terminals 3014 for regulating the voltage of the first gear and several second tap terminals 3015 for regulating the voltage of the second gear. A tap terminal 3014 leads out from the first tap gear coil between the incoming line terminal 3011 and the first voltage outlet terminal 3012, and the second tap terminal 3015 leads out from the second tap gear coil in the voltage regulation coil.

Short-circuit the voltage regulation coil and disconnect the second tap terminal 3015, then connect the corresponding first tap terminal 3014 through the tap board 301 to perform first gear voltage regulation; connect the voltage regulation coil and set the first tap gear Adjust to the maximum, and then connect the corresponding second tap terminal 3015 through the tap board 301 to carry out the second gear voltage regulation.

The voltage regulation range of the first tap terminal 3014 or the second tap terminal 3015 is ±5% or ±2×2.5%.

Specifically, in a specific embodiment of the present invention, the first voltage is 590V, and the second voltage is 485V. Referring to Figures 4-6, the high-voltage ABC three-phase structure of the grid-side coil 20 is completely consistent, and only one phase is selected. To illustrate:

Referring to Figure 4 and Figure 6, 2-5 is the first incoming line voltage regulating terminal 3014, 6-9 is the second incoming line terminal 3015, X1' is the first voltage outgoing line terminal 3012, X1" is the second voltage outgoing line terminal 3013 , A1 and A2 are rectifier transformer incoming line terminal 3011.

When the required voltage is 590V, the required access circuit part is A1-X", which is connected with a cable 302, where X1"-X1' uses a tap copper plate to connect X1" and X1' on the voltage regulating panel The corresponding outlet terminals are short-circuited so that this part of the winding exits the grid-side coil 20. Since the grid-side coil 20 is two completely symmetrical coils connected in parallel, the same wiring can be performed on the other coil.

According to the regulation requirement of ±5% stipulated by the national standard, the voltage can be fine-tuned by adjusting the number of turns of the second incoming line terminal 3011 . Since the coil connected to it is A1-X1' when the output voltage is 590V, the first tap terminal 3014 can be adjusted to adjust the voltage.

Specifically, as shown in FIG. 6, when 6-7 of the first tap terminal 3014 is short-circuited, the coil between the two terminals is short-circuited so as to withdraw from the grid-side coil 20, and the grid-side coil 20 reduces n1 turns; when 7-8 in the first tap terminal 3014 is short-circuited, the coil between the two terminals is short-circuited to withdraw from the grid-side coil 20, and the grid-side coil 20 reduces n2 turns; when the first tap terminal When 8-9 in 3014 is short-circuited, the coil between the two terminals is short-circuited to exit the grid-side coil 20, and the grid-side coil 20 reduces n3 turns, and n1 is greater than n2 and greater than n3. When the input voltage is constant, The turn potentials of the three decrease successively, that is, the regulation within the range of ±5% of the target voltage can be achieved. It should be noted that the positions of several first tap terminals 3014 are calculated in advance, and different short-circuiting methods can obtain different voltages, which are not limited to the above-mentioned three-stage voltage regulation, and terminals can also be added continuously to realize network The requirement of side tap position ±2×2.5% makes it more convenient for users to use.

Referring to Figure 5 and Figure 6, when the user needs to adjust the output voltage to 485V, the number of 10 turns of the valve-side coil remains unchanged, and the potential of the valve-side turns will become smaller, so the potential of the network-side turns will also become smaller. If the input voltage level remains unchanged, more turns need to be connected to the line to meet the demand for voltage reduction on the output valve side.

Here X1'-X1" needs to be connected to the transformer line, so X1' and X1" are disconnected, and the original 590V tap position is adjusted to the maximum tap position, that is, A1-X1', A2-X2' All the coils in between are connected in series, that is to say, the breakout board 301 here is placed at the connecting position of 7-8 on the coils.

Similarly, when the output voltage is 485V, the tap gear adjustment terminals are 2-5, and the voltage can be adjusted in the same way as above to meet the adjustment requirements of ±5%. Side tapping stalls ±2 x 2.5% on demand.

To sum up, the present invention can not only conveniently realize the voltage exchange between 485V and 590V output on the valve side, but also meet the need for gear adjustment in the tap range of the primary side network voltage. Compared with other rectifier transformers that adjust the voltage level, the cost is reduced. In the process of changing the number of turns, it is only necessary to ensure that the magnetic density of the iron core is not saturated, and it can be in the linear working area. Compared with the valve side, the voltage conversion is performed by adding copper foil. , the cost has been greatly reduced. Stable transformer performance: There is no obvious difference between the coil of this structure and the traditional traction rectifier transformer coil in the selection of the number of turns, structural design, electric density, and magnetic density selection, which can ensure the no-load line voltage unbalance rate of the two coils on the valve side, half The characteristic parameters such as through-impedance unbalance rate and voltage transformation ratio meet the relevant requirements of national standards; and the number of turns of high-voltage coils connected in parallel with axial double splits is completely consistent, and there will be no circulating current during transformer operation, which improves the reliability of transformer operation; The rectifier transformer has a compact structure and can be integrated in a DC traction transformer box.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: it can still modify the technical solutions described in the aforementioned embodiments, or perform equivalent replacements for some or all of the technical features, and These modifications or replacements do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

A flux-changing voltage-regulating rectifier transformer for electric cars, characterized in that it includes: a three-phase coil with a double-split four-coil structure, the three-phase coil is divided into a valve-side coil and a grid-side coil corresponding to the valve-side coil, the valve The side coil is split into three star-connected first valve-side coils and three delta-connected second valve-side coils, and the grid-side coil is split into three delta-connected first grid-side coils and three delta-connected The second grid-side coil, the first grid-side coil and the second grid-side coil in each phase coil are connected in parallel; the first grid-side coil or the second grid-side coil is provided with the first grid-side coil with the number of turns corresponding to the first voltage of the grid valve The first gear and the second gear of the second voltage of the network valve, the first voltage is higher than the second voltage, different turn potentials of the grid side coil are obtained by changing the gear of the grid side coil.
The variable flux voltage regulating rectifier transformer for electric vehicles according to claim 1, characterized in that it includes: the gear position is adjusted through a voltage regulating panel, and the voltage regulating panel includes a terminal board, which is drawn from the network side coil and set The incoming line terminal, the first voltage outgoing line terminal, the second voltage outgoing line terminal, and the branching board connecting the terminals on the wiring board; when the branching board connects the first voltage outgoing line terminal and the second voltage outgoing line terminal, the first voltage outgoing line The voltage regulating coil between the terminal and the second voltage outlet terminal is short-circuited, and the wire is output from the first voltage outlet terminal, which is the first gear; when the first voltage outlet terminal and the second voltage outlet terminal are disconnected, the first The voltage regulating coil between the voltage outlet terminal and the second voltage outlet terminal is connected, and the outlet from the second voltage outlet terminal is the second gear.
According to claim 2, a flux-changing voltage-regulating rectifier transformer for electric vehicles is characterized in that it comprises: the voltage-regulating panel also includes a plurality of first tapping terminals for voltage-regulating for the first gear and For several second tap terminals for voltage regulation of the second gear, the first tap terminals are drawn from the first tap gear coil between the incoming line terminal and the first voltage outgoing line terminal, and the second tap The connecting terminal is drawn out from the second tap gear coil in the voltage regulating coil.
According to claim 1, a flux-changing voltage-regulating rectifier transformer for electric vehicles is characterized in that it includes: short-circuiting the voltage-regulating coil and disconnecting the second tap terminal, and then connecting the corresponding first tap terminal through the tap-off board Terminals for voltage regulation at the first gear; connect the voltage regulating coil and adjust the first tap gear to the maximum, and then connect the corresponding second tap terminal through the splitter board to perform voltage regulation at the second gear.
According to claim 4, a flux-changing voltage-regulating rectifier transformer for electric vehicles, characterized in that it comprises: the voltage regulation range of the first tap terminal or the second tap terminal is ±5% or ±2× 2.5%.
A variable flux voltage regulating rectifier transformer for electric vehicles according to claim 1, characterized in that it comprises: the number of turns ΔN of the coil on the side of the voltage regulating network is obtained by formula 1:

ΔN=[N 2 -N 1 ] (1)

Wherein N1 is the number of turns of the grid-side coil corresponding to the first gear, and N2 is the number of turns of the grid-side coil corresponding to the second gear;

The N1 and N2 are obtained by formulas 2.1 and 2.2 respectively:

Wherein U network is the fixed phase voltage at the grid side, et1 is the turn potential corresponding to the first voltage, and e t2 is the turn potential corresponding to the second voltage.
According to claim 6, a variable magnetic flux regulating rectifier transformer for electric vehicles is characterized in that it comprises: the values of e t1 and e t2 are obtained by formulas 3.1 and 3.2:

Wherein, U 1 is the first phase voltage on the valve side, U 2 is the second phase voltage on the valve side, and n is the number of turns of the coil on the second valve side.
According to claim 1, a flux-changing rectifier transformer for electric vehicles, characterized in that it comprises: the number of turns of the first valve side coil is 26, and the number of turns of the second valve side coil is 45 .