JP3226051B2 - DC power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power supply for obtaining a low-voltage, large-current DC required for aluminum surface treatment and electrolysis.

[0002]

2. Description of the Related Art FIG. 3 is a circuit diagram of a DC power supply. In this figure, three-phase AC power obtained from a three-phase power supply 1 having a commercial frequency of 50 Hz or 60 Hz is rectified by a rectifier 2 to obtain DC power, and the DC power is converted into a high-frequency single-phase AC of several kHz by an inverter 3. Then, the voltage is reduced to a predetermined low voltage by the rectifier transformers 41 and 42 whose primary sides are connected in parallel and rectified by the rectifiers 51 and 52. Is obtained and supplied to a load (not shown) by the DC leads 61 and 62. The unit transformer rectifier 101 is composed of the rectifier transformer 41 and the rectifier 51, and the rectifier transformer 42 and the rectifier 52.
Constitutes the unit transformer rectifier 102, and in a DC power supply device requiring a larger capacity, it can be dealt with by increasing the number of unit transformer rectifiers.

The inverter 3 controls on / off of the four power transistors 32 by a control pulse output from a control circuit (not shown) to obtain a high-frequency alternating current of which polarity is alternately changed. Alternatively, it has a feature that the current can be controlled at high speed and with high accuracy. The rectifier transformer 41 has an unlabeled primary winding and two secondary windings 411 and 412.
And a single-phase two-leg iron core described later,
U 1 terminal as shown, o _u, the terminal of the secondary winding 412 o _v, and v. The o _u and o _v are collectively connected to the DC lead 62 to form a connected to the neutral point terminal o as shown. Since the polarity of each winding is reduced as shown, the voltages induced at the terminals u and v are opposite in polarity with respect to the neutral terminal o, that is, 180 degrees different in phase. ing. Therefore, one of the rectifiers 511 and 512 connected to these terminals u and v always receives a forward voltage, and the rectifier 51 outputs a full-wave rectified waveform. Unit transformer rectifier 1
02 is the same.

As is well known, in the process in which the rectifying element 511 changes from on to off and the rectifying element 512 changes from off to on, there is a period in which both the rectifying elements 511 and 512 are on and a circulating current flows. It is called the flow period. The same applies to the process in which the rectifying element 512 is turned on from the rectifying element 512 being turned on. The circulating current flowing during this commutation period has a waveform that changes abruptly from a DC current value of one polarity to a DC current value whose sign is inverted. When the circulating circuit starts from the terminal u, the rectifying element 511 and the rectifying element 512 , Terminal v, secondary winding 412, neutral point terminal o, secondary winding 411
And returns to the terminal u. A voltage drop corresponding to the product of the inductance of the circulating circuit and the time derivative of the circulating current occurs, which reduces the DC voltage as the output voltage of the DC power supply, and furthermore, the leakage magnetic flux generated by the circulating current that changes rapidly with time. Causes stray loss in the connection lead and the nearby metal structure due to the electromagnetic induction, which causes a reduction in efficiency and a reduction in device life due to local heating.

FIG. 4 is a two-sided view of a conventional DC power supply, FIG. 4 (a) is a front view of a rectifier transformer 41, and FIG. 4 (b).
Is a side view of the same. In these figures, DC leads 61 and 62 are formed of rectangular conductors and are arranged in parallel with each other. The DC lead 62 on the upper side of the figure is an N pole, the DC lead 61 on the lower side is a P pole, and the rectifier transformers 41 and 62 are shown. Reference numeral 42 is arranged between these two DC leads 61 and 62 in parallel with their longitudinal direction. The rectifiers 511 and 512 of the rectifier 51 have a configuration in which a semiconductor element is molded into a rectangular shape and both terminals are pulled out on one surface and connected to connection leads by bolting. The rectifying element 511 is mounted on the opposite surface with the rectifying element 512 having the same polarity.
Since the mold resin portion is attached, the DC lead 61 and the rectifying elements 511 and 512 are electrically insulated.
In the drawing, each of the rectifiers 511 and 512 indicates that four rectifiers are arranged in parallel. The number of rectifiers is determined by the relationship between the rated current and the current capacity of the rectifier employed, and is not limited to four.

The rectifier transformer 41 is a single-phase two-leg iron core 410.
The secondary windings 411 and 412 and the primary winding which is not shown because they are inside these are disposed on the two iron legs. Lead leads 413, 414, 415, 416 drawn from these secondary windings 411, 412.
And the secondary windings 411 and 41 arranged on the two core legs of the single-phase two-leg core 420 of the rectifier transformer 42, respectively.
2 lead wires 423, 424 and 4
25, 426 (423, 425 are hidden and not shown), rectifiers 51, 52 and DC leads 61, 62
Are connected by connection leads indicated by reference numerals 71 to 76 as shown in the figure. The connection between them is made by bolting. In FIG. 4A, the tightening bolts of these connecting portions are indicated by dashed-dotted lines, and in FIG. 4B, their positions are indicated by + marks. Illustration of the connection of the high voltage terminals U and V is omitted.

In such a configuration, since the neutral terminal side and the rectifier are separated at the top and bottom in the figure, the connection and assembly work is easy, and the rectifying element 511 arranged with the DC lead 61 interposed therebetween. Since the currents flowing to the rectifiers 512 and 512 are in opposite directions, there is a feature that the imbalance of the current sharing of the rectifiers connected in parallel due to the leakage magnetic flux is small. In this figure, the rectifier transformer 41 includes connection leads 71,
Although shown in the configuration as being fixedly supported on the DC leads 61, 62 via 74, 75, 76, the structure is actually fixedly supported by steel (not shown) including the rectifier transformer 42. Has been adopted. In FIG. 3, two unit transformer rectifiers 101 and 102 are shown, and in FIG. 4, only rectifier transformers 41 and 42 and rectifiers 51 and 52 are shown. The number is determined in accordance with the formula (1), and is not limited to two. If the number is larger, they are arranged side by side on the left and right in FIG.

[0008]

By the way, in these figures, the path through which the circulating current flows during commutation as described above is indicated by arrows in the figures, from the terminal u to the connection lead 71 and the rectifying element 51.
1, connection lead 72, DC lead 61, connection lead 7
3, the rectifying element 512, the connecting leads 74, terminal v, the secondary winding 412, terminal o _v, connection leads 76, the DC lead 6
2, the connection leads 75, terminals o _u, a path back to the terminal u via the secondary winding 411, has an approximate rectangular peripheral shape except for secondary windings 411 and 412, well known As described above, the larger the area surrounded by the current path, the larger the inductance of the circuit and the amount of leakage magnetic flux. Therefore, there is a problem that the inductance of the path through which the circulating current flows during commutation is also large. As described above, when the inductance of the circulating circuit is large, the commutation period is increased, the voltage drop value of the DC voltage is increased, and since the leakage flux is large, the surrounding metal structures, especially the transformer 4 for the rectifier shown in FIG.
1, 42 single-phase two-leg iron cores 410 and 420 (in FIG. 4 (a), opposite to the single-phase two-leg iron core 410 and hidden by the connecting leads in FIG. 4 (b), none of them are shown). There is also a problem that current flows and local heating occurs.

It is an object of the present invention to solve such a problem and to reduce the DC voltage drop by reducing the inductance of the circulating circuit of the circulating current flowing during commutation and to locally heat the surrounding metal structures. It is an object of the present invention to provide a DC power supply device having a secondary circuit of a rectifier transformer capable of suppressing the above.

[0010]

According to the present invention, in order to solve the above-mentioned problems, a primary winding to which a high-frequency alternating current generated by an inverter is input and a primary winding having a phase of 18 degrees with each other.
A first secondary winding and a second secondary winding that respectively output an AC of a first phase and an AC of a second phase that differ by 0 °, and the first secondary winding and the second secondary winding. A rectifier transformer having a single-phase two-leg iron core having a secondary winding wound on each leg; and a first rectifier for half-wave rectifying the first-phase alternating current and the second-phase alternating current, respectively. A plurality of unit transformer rectifiers each including a rectifier having a rectifier and a rectifier having a second rectifier are provided, and the P pole side and the N pole side of the DC side outputs of these unit transformers are P pole DC leads and In a DC power supply device connected in parallel to an N-pole DC lead, the number of unit transformer rectifiers is an even number, two unit transformer rectifiers are one set, and these two unit transformer rectifiers are identical to each other. As the configuration and the same shape, the two Of the respective rectifier transformers in the potential transformer rectifier, one of the rectifier transformers has a lead secondary lead of a rectangular conductor and the other rectifier transformer has a second secondary winding. An extraction lead made of a rectangular conductor is directly opposed to each other, and an extraction lead made of a rectangular conductor of the second secondary winding of one rectifier transformer and a first secondary winding of the other rectifier transformer are connected. The rectifier transformers are arranged so as to face each other in line symmetry so that the lead leads made of a rectangular conductor are directly opposed to each other. The width faces of the P-pole DC lead and the Q-pole DC lead made of parallel rectangular conductors whose pole sides are connected in parallel, respectively, and the plane common to each leg of the single-phase two-leg iron core of the rectifier transformer are parallel. Even if you arrange And
The width faces of the P-pole DC lead and the Q-pole DC lead, which are parallel rectangular conductors on which the P-pole side and the Q-pole side of the DC side output of the unit transformer rectifier are connected in parallel, respectively, and the single-phase two legs of the rectifier transformer A common plane is arranged at right angles to each leg of the iron core.

[0011]

In the configuration of the present invention, the number of unit transformer rectifiers is even and two units are formed as a set, and these two rectifier transformers are connected to each other by a lead wire made of a flat rectangular conductor of a secondary winding. Are arranged so as to be directly symmetrical with each other, so that the lead leads and the connection leads for connecting the DC lead and the rectifier can also be arranged with their width faces directly opposed to each other. In addition, since the rectifier transformer is arranged in line symmetry, the circulating currents flowing in the directly facing lead and connection leads are in opposite directions,
Both the inductance of the circulating circuit through which the circulating current flows and the amount of leakage magnetic flux are reduced.

The two rectifier transformers are arranged so that the width faces of the two parallel DC leads and the plane common to each leg of the single-phase two-leg iron core of the rectifier transformer are parallel. Alternatively, it may be configured to be arranged vertically.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
FIG. 1 is a three side view of a DC power supply device showing an embodiment of the present invention. The same components as those in FIG. FIG. 1 (a) is an elevation view of one side,
1 (b) is a side view, and FIG. 1 (c) is an elevation view on the opposite side to FIG. 1 (a), and the figure itself is exactly the same as FIG. 1 (a). In this figure, the secondary winding 4 of the rectifier transformer 41 is shown.
Lead lead 41 pulled out from the upper part of 11, 412
5,416 and the secondary windings 421, 421 of the rectifier transformer 42.
Leader leads 425 and 42 pulled out from the upper part of 422
The rectifier transformers 41 and 42 are disposed so as to directly face the rectifier 6. The lead leads 413 and 414 which are drawn out from the lower part along with this, and the secondary winding 4 of the rectifier transformer 42
Pull-out lead 42 pulled out from the lower part of 21, 42
Similarly, 3,424 are also arranged to directly oppose each other. Leader leads 413, 414, 41 of such arrangement
Connection leads 81, 84, 85, 8 to 5,416
6 and connected to the DC lead 62 and the rectifier 51.
The connection leads connected to the rectifier transformer 42 are not denoted by reference numerals, but have the same configuration as that of the rectifier transformer 41 as shown.

In FIG. 1A, a rectifier transformer 41 is shown.
4 is 9 relative to the DC leads 61 and 62 in FIG.
0 ° different. As shown in FIG. 1B, this is straightforward without twisting the connection lead 86 for connecting the extraction leads 416 and 425 and the DC lead 62 and the connection lead having no reference numeral opposite thereto. The same applies to the lower part.

The connection leads 81, 8 on the side shown in FIG.
The path of the circulating current including 4, 85, 86 is similar to the periphery of the rectangle similar to FIG. On the other hand, FIG. 1 (c) is exactly the same as FIG. 1 (a) as described above, and the layout is the rectifier transformer 41 of FIG. 1 (a), and the connection leads 81, 84, 85, 86 connected thereto. Rectifier 5
1. FIG. 1 (c) shows that the same electrical and geometrical dimensions as the connection leads 72 and 73 are repeatedly arranged.
Rectifier transformer 42, rectifier 52, and the like. Therefore, the circulating current also flows in exactly the same direction as in FIG.
In FIG. 1B, when the connection leads 84 are directly opposed to each other and the corresponding connection leads without reference numerals are opposite in direction of current, the magnetic flux generated by each other is canceled. They are in a good relationship. Strictly speaking, the circulating current flows independently in FIG. 1A and FIG. 1C, but the magnitude and waveform of each current may be substantially the same. ) Shows reciprocating connection leads and series leads 61 and 6 connecting both ends thereof.
4, the area surrounded by the circulating circuit in which the circulating current flows becomes very small, as is clear from the comparison of FIG. 4, and the inductance decreases and the amount of generated leakage magnetic flux also decreases. .

FIG. 2 is a two-sided view of a DC power supply device showing another embodiment of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals, detailed description is omitted, and the functions are the same. The relationship is clarified by adding a suffix A to the constituent elements of. FIG. 2A is a front view, and FIG. 2B is a side view, which is the same as the relationship between FIGS. 1A and 1B. 2 is different from FIG. 1 in the arrangement of the DC leads 61 and 62 and the rectifier transformers 41 and 42. In FIG. 1, the two rectifier transformers 41 and 42 are paired with the DC leads 61 and 42.
62 is arranged in a direction perpendicular to the longitudinal direction, whereas FIG. 2 is arranged in a direction parallel to the longitudinal direction.
Due to such an arrangement, the connection leads 81A, 84
Each of A, 85A, and 86A has a shape provided with a portion bent at a right angle on the way. For example, in the case of the connection lead 84A, a portion having a bolt hole connected to the rectifying element 512 when a portion on the side of the secondary winding 412 whose width surface is perpendicular to the DC lead 61 reaches the DC lead 61 is perpendicularly formed. It is bent so as to be parallel to the DC lead 61. Similarly, the connection lead 86A has a shape in which a portion having a bolt hole connected to the DC lead 62 is bent at a right angle.

Since it is easy to bend the connection leads at right angles, it is not possible to determine which of the different embodiments of FIGS. 1 and 2 is advantageous within the scope of this embodiment alone. Taking into account factors other than the present invention, such as the fixed structure of the rectifier transformers 41 and 42 and the allowable dimensions of the DC leads 61 and 62 in the longitudinal direction and the direction orthogonal thereto, it is determined which configuration to adopt. You.

In the embodiments of FIGS. 1 and 2, only two transformers 41 and 42 are shown as rectifier transformers. However, when the required DC capacity is larger, the DC capacity is determined according to the capacity. A configuration in which a plurality of sets of such transformers are provided in the longitudinal direction of the DC leads 61 and 62 is adopted. Therefore, it is inevitable that the number of unit transformer rectifiers in the present invention is an even number.

[0019]

As described above, according to the present invention, the number of unit transformer rectifiers is set to an even number to form a pair of two transformer rectifiers, and these two unit transformer rectifiers have exactly the same configuration and shape. By arranging the lead conductors made of a rectangular conductor with their width faces directly opposed to each other, the connection leads made of a rectangular conductor for connecting the drawer lead, the DC lead, and the rectifier can also be arranged with their width faces directly opposed to each other. Therefore, a rapidly changing circulating current flowing at the time of commutation flows in opposite directions to the connection leads directly opposed to each other, so that the inductance and leakage magnetic flux of the circulating circuit through which the circulating current flows are reduced. This inductance is a value proportional to the voltage drop of the DC voltage.Because this inductance is small, the voltage drop due to the load DC current is reduced, and the capacity of the rectifier transformer and the inverter to which it is connected is reduced accordingly. The effect of reducing the price of the power supply device can be obtained. In addition, as a result of reduced leakage flux, eddy currents generated by electromagnetic induction in surrounding metal structures, especially iron cores, are reduced and efficiency is improved, and local heating of the iron cores caused by these eddy currents is reduced, resulting in reliability. Is also improved.

[Brief description of the drawings]

FIG. 1 is a three side view of a DC power supply device showing an embodiment of the present invention.

FIG. 2 shows a DC power supply device 2 according to another embodiment of the present invention.
Front view

FIG. 3 is a circuit diagram of a DC power supply device.

FIG. 4 is a two-sided view of a conventional DC power supply.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Three-phase AC power supply 2 Rectifier 3 Inverter 101 Unit transformer rectifier 41 Rectifier transformer 410 Single-phase two-leg iron core 411 Secondary winding 412 Secondary winding 413 Leading lead 414 Leading lead 415 Leading lead 416 Leading lead 51 Rectifier 511 Rectification Element 512 Rectifier 81 Connection lead 82 Connection lead 83 Connection lead 84 Connection lead 85 Connection lead 86 Connection lead 81A Connection lead 82A Connection lead 83A Connection lead 84A Connection lead 85A Connection lead 86A Connection lead 102 Unit transformer rectifier 42 Transformer for rectifier 420 Single-phase two-leg iron core 421 Secondary winding 422 Secondary winding 423 Lead lead 424 Lead lead 425 Lead lead 426 Lead lead 52 Rectifier 521 Rectifier 522 Rectifier 61 DC lead 62 DC lead

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02M 7/04 H01F 38/34 H02J 1/00 H02M 7/06

Claims (3)

(57) [Claims] 1. A primary winding to which a high-frequency alternating current generated by an inverter is input, and a first secondary winding which outputs a first-phase alternating current and a second-phase alternating current whose phases are different from each other by 180 °. A rectifier transformer comprising a wire and a second secondary winding, and a single-phase two-leg core having the first and second secondary windings wound on respective legs; A plurality of unit transformer rectifiers each comprising a rectifier having a first rectifier and a rectifier having a second rectifier for respectively half-wave rectifying the first-phase alternating current and the second-phase alternating current; P of DC output of unit transformer rectifier
The pole side and N pole side are P pole DC lead and N pole respectively.
In a DC power supply device connected in parallel to a pole DC lead, the number of unit transformer rectifiers is an even number, two unit transformer rectifiers are one set, and these two unit transformer rectifiers have the same configuration. And of the same shape, out of the respective rectifier transformers in the two unit transformer rectifiers, an extraction lead made of a rectangular conductor of the first secondary winding of one rectifier transformer and the other rectifier transformer And the extraction lead made of the rectangular conductor of the second secondary winding is directly opposed to each other, and the extraction lead made of the rectangular conductor of the second secondary winding of one rectifier transformer and the other rectifier transformer are used. The rectifier transformers are arranged so as to be line-symmetrically opposed to each other so that the lead leads of the first secondary winding made of a rectangular conductor are directly opposed to each other. . 2. The width of a P-pole DC lead and a Q-pole DC lead made of parallel rectangular conductors whose P-pole side and Q-pole side of the DC-side output of a unit transformer rectifier are connected in parallel, respectively, and a rectifier transformer. 2. The direct-current power supply according to claim 1, wherein a common plane is arranged in parallel with each leg of the single-phase two-legged iron core. 3. The width of the P-pole DC lead and the Q-pole DC lead made of parallel rectangular conductors whose P-pole side and Q-pole side of the DC-side output of the unit transformer rectifier are connected in parallel, respectively, and a rectifier transformer. 2. The DC power supply according to claim 1, wherein a common plane is arranged at right angles to each leg of the single-phase two-legged iron core.