JP3987778B2 - Transformer and rectifier using the same - Google Patents

Description

この関係式は線分Ｒ１−Ｒ５、Ｒ５−Ｒ３、Ｒ３−Ｓ２に対応するコイルのみに限らず、これと同様な関係にある他の５箇所のコイルの巻数の決定に適用される。
【００１８】
このように、（２）式の関係に従って各コイルの巻数比を決定することによって、３相電圧のベクトルに対応して作図した六角形の線分の長さからコイルの巻数比を決定した従来の変圧器と比較して、電圧の値及び位相をより正確に決定することができる。
【００１９】
図４は上記の実施形態による変圧器１０を用いて、高調波の少ない直流に変換する１８パルス整流器の構成を示す回路図である。図４において、３相交流電源１１から電力の供給を受ける経路の線路インピーダンスが抵抗１２Ｒ，１２Ｓ，１２Ｔとインダクタンス１３Ｒ，１３Ｓ，１３Ｔとで表されている。この３相交流電源ラインに主３相全波整流器２１が接続されている。主３相全波整流器２１の直流出力端子間に、リアクトル３１及び平滑コンデンサ３２でなる平滑回路が接続され、平滑コンデンサ３２の両端に負荷抵抗３３が接続されている。また、３相交流電源ラインに、変圧器１０の中間タップＲ１，Ｓ１，Ｔ１から導線が引き出されて３相交流の入力端子が接続され、この変圧器１０の中間タップＲ２，Ｓ２，Ｔ２から導線が引き出されて第１の３相交流出力端子に補助３相全波整流器２２の交流入力端が接続され、中間タップＲ３，Ｓ３，Ｔ３，から導線が引き出されて第２の３相交流出力端子に補助３相全波整流器２３の交流入力端が接続されている。補助３相全波整流器２２及び補助３相全波整流器２３の各直流出力端子は主３相全波整流器２１の直流出力端子に並列に接続されている。
【００２０】
図５（ａ）及び（ｂ）は上記（２）式の関係を満たすように各コイルの巻数比ａ，ｂ，ｃを決定した解析数値による入力電流と高調波成分をシミュレーションした場合の波形（太い実線で示す）と、（２）式の値のうち、例えば、ａ（＝１）に対応する値を１．０７として７％の誤差を見込んだ実測誤差数値による入力電流と高調波成分をシミュレーションした場合の波形（細い実線で示す）とを併せて示した波形図である。これらの図から明らかなように、巻数を（２）式に基づいて決定した場合の高調波成分は略ゼロと見なし得るのに対して、（２）式に示す値に７％の誤差を見込んだ場合には５次高調波成分が２％も含まれることが分かる。
【００２１】
このシミュレーション結果から明らかなように、作図による六角形の線分の長さからコイルの巻数比を決定する場合に７％程度の誤差はやむを得ないものとして変圧器を作製し、この変圧器を用いて整流器を構成した場合には、様々な障害を引き起こしやすい５次高調波成分が２％程度になるのに対して、本実施形態のように（２）式の関係を満たすように各コイルの巻数比を決定することにより変圧器の定数調整が容易化され、これに従って変圧器を作製し、この変圧器を用いて整流器を構成した場合には高調波成分を実質的にゼロに抑え込むことができる。
【００２２】
図６（ａ）〜（ｄ）は図４に示した主３相全波整流器２１、補助３相全波整流器２２及び補助３相全波整流器２３にそれぞれ印加される３相交流電圧、Ｒ，Ｓ，Ｔ各相の電流をそれぞれシミュレーションした波形図であり、電気角で２０°の間隔で正、負の最大瞬時値を出力する導電端子が切換わっている。
【００２３】
ここで、図６中に一点鎖線の枠で囲った１導通区間（２０°）での変圧器１０の電流の経路に着目すると、例えば、３相交流入力端子Ｒ１から、主３相全波整流器２１及び補助３相全波整流器２２を経て、３相交流出力端子Ｔ２へ電流が流れる区間には、変圧器１０の３相交流出力端子Ｔ２以外の出力端子には電流は流れない。このとき図７に示すように、次の電流経路を通して電流Ｉ１，Ｉ２，Ｉ３，Ｉ４が流れる。
【００２４】
Ｉ１…Ｒ１←Ｒ４←Ｔ５←Ｔ１
Ｉ２…Ｒ１→Ｒ５→Ｓ４→Ｓ１
Ｉ３…Ｔ１→Ｔ４→Ｔ２
Ｉ４…Ｓ１←Ｓ５←Ｔ２
上述した電流Ｉ１〜Ｉ４によって発生する磁束の方向をＲ相鉄心１の磁束方向に合わせると、Ｒ相鉄心１、Ｓ相鉄心４及びＴ相鉄心７の合成磁束はゼロになるから、次式が成立する。
【００２５】
ａ・Ｉ１＋ａ・Ｉ２＋ｂ・Ｉ３＋（ｂ＋ｃ）・Ｉ４＝０ …（３）
−（２ｂ＋ｃ）・Ｉ１＋ａ・Ｉ２−ａ・Ｉ４＝０ …（４）
ａ・Ｉ１−（２ｂ＋ｃ）・Ｉ２−ａ・Ｉ３＝０ …（５）
ただし、ａ，ｂ，ｃは前述した巻数である。
【００２６】
この（３）〜（５）式に上記（２）式の値を代入して電流比を求めると次式の関係が得られる。
【００２７】
Ｉ１：Ｉ２：Ｉ３：Ｉ４＝１：−３．８７９３９：２５．４０４６７：−１０．１７０２…（６）
上記（６）式の関係で表される電流は３相交流出力端子Ｔ２以外の導通区間にも、導通端子に応じた巻線に流れているが、最も大きい電流Ｉ３に相当する電流は出力端子Ｒ２，Ｓ２，Ｔ２，Ｒ３，Ｓ３，Ｔ３から常に巻線ｂ側に流れ、巻線ｃを通ることはない。このため、巻線ｃに流れる１サイクルでの電流の実効値は他の巻線と比較して大幅に小さくなる。
【００２８】
図８は３相交流出力端子Ｔ２に接続される中間タップＴ２の両側の巻線ｃと巻線ｂの電流をシミュレーションした電流波形図である。この波形図から明らかなように、３相交流出力端子Ｔ２の導通時のみ正側と負側の値が異なり、巻線ｃの電流の実効値は巻線ｂの電流の実効値に対して約５５％になる。一つの鉄心の巻線ｂと他の鉄心の巻線ａとの接続点には外部端子が接続されていないので電流値は全て同じになる。
【００２９】
そこで、変圧器１０の巻線ａ，ｂ，ｃの断面積は全て同じにする必要はないため、本実施形態では電流の実効値に応じて導線の断面積を異ならせたもので、その具体例として、巻数ｃに対応する部分の導線の断面積を、他の部分と比較して小さくしている。
【００３０】
この結果、信頼性を損なうことなく、変圧器及びこれを用いた整流器の小型化が可能になる。
【００３１】
【発明の効果】
以上の説明によって明らかなように、本発明によれば、六角形で表された変圧器ベクトル図に係る電圧の値及び位相を正確に決定することができると共に、一層の小型化を可能にする変圧器及びこれを用いた整流器を提供することができる。
【図面の簡単な説明】
【図１】本発明に係る変圧器の実施形態の具体的な巻線構造を表す変圧器ベクトル図。
【図２】図１に示した変圧器ベクトル図を満たす変圧器の巻線構造図。
【図３】図１に示した変圧器ベクトル図に基づいて、コイルの巻数比を決定するために、幾何学的な解析を行うための拡大図。
【図４】図１の実施形態による変圧器を用いて、高調波の少ない直流に変換する整流器の構成を示す回路図。
【図５】図４に示す整流器におけるコイルの巻数比の解析数値と、実測誤差数値によるに各入力電流と高調波成分をシミュレーションした波形図。
【図６】図４に示した３相全波整流器にそれぞれ印加される３相交流電圧及び３相交流電流のシミュレーション結果を示す波形図。
【図７】図６中に一点鎖線の枠で囲った１導通区間における電流経路を、変圧器ベクトル図と併せて示した図。
【図８】図６中に一点鎖線の枠で囲った１導通区間における中間タップの両側の巻線に流れる電流をシミュレーションした瞬時値及び実効値を示す波形図。
【符号の説明】
１ Ｒ相鉄心
２ Ｒ相第１コイル
３ Ｒ相第２コイル
４ Ｓ相鉄心
５ Ｓ相第１コイル
６ Ｓ相第２コイル
７ Ｔ相鉄心
８ Ｔ相第１コイル
９ Ｔ相第２コイル
１０ 変圧器
１１ ３相交流電源
１２Ｒ，１２Ｓ，１２Ｔ 抵抗
１３Ｒ，１３Ｓ，１３Ｔ インダクタンス
２１ 主３相全波整流器
２２，２３ 補助３相全波整流器
３１ リアクトル
３２ 平滑コンデンサ
３３ 負荷抵抗[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transformer suitable for converting three-phase alternating current into direct current with less harmonics, and a rectifier using the transformer.
[0002]
[Prior art]
When three-phase alternating current is converted into direct current, the most common method is to use one three-phase full-wave rectifier formed by bridge-connecting six rectifier elements. In such a three-phase full-wave rectifier, the rectifying elements that are sequentially energized every 60 degrees are switched to output a DC voltage, but the DC voltage rectified by this method has a cycle that is six times the power supply frequency. A voltage ripple with a large amplitude is included, which becomes a harmonic and causes various obstacles.
[0003]
As a countermeasure, the main three-phase full-wave rectifier that converts three-phase alternating current to direct current and the phase voltage of the three-phase alternating current are represented by a vector diagram of an equilateral triangle, and the other two vertices are drawn around each vertex. Transformer represented by a hexagon formed by straight lines that pass through two points obtained by dividing an arc into three equal parts, and straight lines that pass through the vertices of an equilateral triangle and are parallel to one side facing these vertices Transformer that satisfies the vector diagram, and two auxiliary three-phases that convert the two types of three-phase alternating current output from the transformer into direct current, and the DC output line is connected in parallel with the main three-phase full-wave rectifier An 18-pulse rectifier including a full-wave rectifier has been proposed (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-10646 (page 6, FIG. 8)
[0005]
[Problems to be solved by the invention]
However, since the above transformer determines the coil turns ratio from the length of the hexagonal line segment drawn corresponding to the vector of the three-phase voltage, trial and error is required to obtain a good harmonic reduction effect. Had to repeat. In addition, since a plurality of intermediate taps are provided on the coil wound continuously around the iron core as an output terminal, the conductor having the same wire diameter, i.e., cross-sectional area, despite the presence of a portion with a small coil current. The purpose of downsizing the transformer has not been fully achieved.
[0006]
The present invention has been made in consideration of the above-described circumstances, and the object thereof is to accurately determine the voltage value and phase according to the transformer vector diagram represented by a hexagon, and to enable miniaturization. An object of the present invention is to provide a transformer and a rectifier using the same.
[0007]
[Means for Solving the Problems]
The invention according to claim 1
Each phase voltage of the three-phase alternating current is represented by a regular triangle vector diagram, and passes through two points obtained by dividing the arc drawn by connecting the remaining two vertices with each vertex of the regular triangle as the center. In a transformer satisfying a transformer vector diagram represented by a hexagon formed by a straight line and a straight line passing through each vertex of the equilateral triangle and parallel to one side facing each vertex,
Comprising first and second coils respectively wound around a three-phase iron core;
One end of the first coil is connected to one end of the second coil having the same polarity and sequentially different phases, and the other end of the first coil has the same polarity and sequentially different phases from the one end. Are connected to the other ends of the different second coils,
Each of a, b, and c is a number of 2 or more, the number of turns of the first coil is 2a, a first tap is provided at an intermediate position of the number of turns, and the number of turns of the second coil is 2b + c. a second tap is provided at an inner position by b, and a third tap is provided at an inner position by the number of turns b from the other end,
The first tap for three phases is used as an input terminal for three-phase AC voltage, and the second tap for three phases is used as a first output terminal for three-phase AC voltage. Is the second output terminal of the three-phase AC voltage,
The cross-sectional area of the conductor of the portion between the second tap and the third tap corresponding to the number of turns c of the second coil is made smaller than that of the other portion;
It is characterized by that.
The invention according to claim 2
A main three-phase full-wave rectifier that converts three-phase alternating current to direct current, a transformer that outputs three types of three-phase alternating current that is input by shifting the phase by ± 20 ° in electrical angle, and transformer In the rectifier comprising two auxiliary three-phase full-wave rectifiers, each of which converts two types of three-phase alternating currents output from the direct current into DC, and the DC output line is connected in parallel with the main three-phase full-wave rectifier,
The transformer according to claim 1 is used as a transformer.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the drawings. FIG. 1 is a transformer vector diagram showing a specific winding structure of an embodiment of a transformer according to the present invention. In the figure, the three-phase AC voltage of the power supply is represented by equilateral triangles R1, S1, and T1. Two points obtained by equally dividing the arc drawn by connecting the remaining two vertices S1 and T1 around the vertex R1 of the equilateral triangle as S3 and T2, respectively. Further, two points obtained by equally dividing the arc drawn by connecting the remaining two vertices T1 and R1 with the vertex S1 of the equilateral triangle as the center are defined as T3 and R2, respectively. Furthermore, two points obtained by equally dividing the arc drawn by connecting the remaining two vertices R1 and S1 around the vertex T1 of the equilateral triangle as R3 and S2, respectively.
[0009]
Next, the intersections of the straight line passing through the vertex R1 of the equilateral triangle and parallel to the opposite side and the straight line passing through the two points T3 and R2 on the arc and the straight line passing through the two points R3 and S2 on the arc are R4, respectively. R5. Further, the intersection points of a straight line passing through the vertex S1 of the equilateral triangle and parallel to the opposite side, a straight line passing through the two points R3 and S2 on the arc, and a straight line passing through the two points S3 and T2 on the arc are respectively S4 and S5. And Furthermore, the intersections of a straight line passing through the vertex T1 of the equilateral triangle and parallel to the opposite side, a straight line passing through the two points S3 and T2 on the arc, and a straight line passing through the two points T3 and R2 on the arc are respectively T4 and T5. And
[0010]
As a result, a hexagonal transformer vector diagram formed by connecting the points R4-R5-S4-S5-T4-T5-R4 is formed. Of these, the line segment R4-R5 corresponds to the R-phase first coil 2, the line segment S5-T4 corresponds to the R-phase second coil 3, and the line segment S4-S5 corresponds to the S-phase first coil 5, respectively. T5-R4 corresponds to the S-phase second coil 6, line segment T4-T5 corresponds to the T-phase first coil 8, and line segment R5-S4 corresponds to the T-phase second coil 9, respectively. The length of the line segment corresponds to the number of turns of the coil with respect to the cores of the R, S, and V phases, and “·” added to one end of each line segment indicates that the polarity is “positive”, for example. Represents.
[0011]
FIG. 2 is a winding structure diagram of the transformer 10 that satisfies the transformer vector diagram shown in FIG. 1, and the symbols indicating the dividing points and intersections in FIG. 1 are represented as corresponding winding terminals or taps. Yes. In FIG. 2, an R-phase first coil 2 and an R-phase second coil 3 are wound around an R-phase iron core 1. Among these, an intermediate tap R 1 is provided on the R-phase first coil 2, and an R-phase second The coil 3 is provided with intermediate taps T2 and S3. In addition, an S-phase first coil 5 and an S-phase second coil 6 are wound around the S-phase iron core 4, and among these, the S-phase first coil 5 is provided with an intermediate tap S <b> 1. Are provided with intermediate taps R2, T3. Further, a T-phase first coil 8 and a T-phase second coil 9 are wound around the T-phase iron core 7, and among these, the T-phase first coil 8 is provided with an intermediate tap T <b> 1. Are provided with intermediate taps S2, R3.
[0012]
One end R4 of the R-phase first coil 2 is one end of the S-phase second coil 6, one end of the S-phase first coil 5 is one end of the T-phase second coil 9, and one end of the T-phase first coil 8 is one end. The other end of the R-phase first coil 2 is connected to the other end of the T-phase second coil 9 and the other end of the S-phase first coil 5 is connected to the R-phase second coil 3. The other end of the T-phase first coil 8 is connected to the other end of the S-phase second coil 6. Then, the conducting wire is drawn out from the intermediate taps R1, S1, and T1 to become three-phase AC input terminals R1, S1, and T1, and the conducting wire is drawn out from the intermediate taps R2, S2, and T2, and the first three-phase AC output terminal R2 is drawn. , S2, and T2, and the lead wires are drawn out from the intermediate taps R3, S3, and T3 to form second three-phase AC output terminals R3, S3, and T3.
[0013]
In the following description, the intermediate taps R1, S1, and T1 are also referred to as three-phase AC input terminals, and the intermediate taps R2, S2, and T2, and R3, S3, and T3 are also referred to as three-phase AC output terminals.
[0014]
FIG. 3 is an enlarged view for performing a geometric analysis to determine the coil turns ratio based on the transformer vector diagram shown in FIG. A line segment R1-R5 corresponding to the number of turns a from the tap R1 to the other end R5, a line segment R5-R3 corresponding to the number of turns b from the other end R5 of the T-phase second coil 9 to the intermediate tap R3, and the T-phase It is a figure for demonstrating the relationship with line segment R3-S2 equivalent to the winding | turns number c from the intermediate taps R3 to S2 of the 2nd coil 9, and among these, line segment R3-S2 connects point R1 and point R3. The case where the turns ratio a: b: c of the coil is determined using the fact that it is equal to the line segment R1-R3 is shown.
[0015]
In FIG. 3, the arc R1⌒S1 is divided into three equal parts at points R3 and S2, and the strings R1-R3 are equal to the strings R3-S2. That is, the line segment R1-R3 also corresponds to the number of turns c. Here, ∠R3, R1, S1 is the circumferential angle of the arc R3⌒S1, and is half of the central angle ∠R3, T1, S1. That is, since ∠R3, T1, S1 = 40 °, ∠R3, R1, S1 = 20 °. Moreover, since the line segment R1-S1 and the line segment R5-S4 are parallel, that is, R1-S1 // R5-S4, ∠R3, R1, S1 = ∠R1, R3, R5 (complex angle). Therefore, ∠R1, R3, R5 = 20 °.
[0016]
Next, focusing on the triangles ΔR1, R5, and R3, since ∠R1, R5, and R3 = 120 °, ∠R5, R1, and R3 = 40 °. Therefore, the following equation is established by the sine theorem.
[0017]

This relational expression is applied not only to the coils corresponding to the line segments R1-R5, R5-R3, and R3-S2, but also to the determination of the number of turns of the other five coils having the same relationship.
[0018]
Thus, by determining the turn ratio of each coil according to the relationship of equation (2), the turn ratio of the coil is determined from the length of the hexagonal line segment drawn corresponding to the vector of the three-phase voltage. Compared with the current transformer, the voltage value and phase can be determined more accurately.
[0019]
FIG. 4 is a circuit diagram showing a configuration of an 18-pulse rectifier that converts to direct current with less harmonics using the transformer 10 according to the above embodiment. In FIG. 4, the line impedance of the path that receives power from the three-phase AC power supply 11 is represented by resistors 12R, 12S, and 12T and inductances 13R, 13S, and 13T. A main three-phase full-wave rectifier 21 is connected to the three-phase AC power supply line. A smoothing circuit including a reactor 31 and a smoothing capacitor 32 is connected between the DC output terminals of the main three-phase full-wave rectifier 21, and load resistors 33 are connected to both ends of the smoothing capacitor 32. Further, a three-phase AC power supply line is connected to a three-phase AC input terminal from the intermediate taps R1, S1, and T1 of the transformer 10, and is connected to the three-phase AC power line from the intermediate taps R2, S2, and T2 of the transformer 10. Is pulled out and the AC input terminal of the auxiliary three-phase full-wave rectifier 22 is connected to the first three-phase AC output terminal, and the conducting wire is drawn out from the intermediate taps R3, S3, T3, and the second three-phase AC output terminal. Is connected to the AC input terminal of the auxiliary three-phase full-wave rectifier 23. The DC output terminals of the auxiliary three-phase full-wave rectifier 22 and the auxiliary three-phase full-wave rectifier 23 are connected in parallel to the DC output terminal of the main three-phase full-wave rectifier 21.
[0020]
5 (a) and 5 (b) show waveforms when the input current and the harmonic component are simulated based on the analytical values that determine the turns ratios a, b, and c of each coil so as to satisfy the relationship of the above expression (2). (Shown by a thick solid line) and the input current and the harmonic component based on the actual measurement error value with an error of 7%, for example, assuming that the value corresponding to a (= 1) is 1.07 among the values of equation (2) It is the wave form diagram which showed together the waveform at the time of simulation (it shows with a thin continuous line). As is apparent from these figures, the harmonic component when the number of turns is determined based on the formula (2) can be regarded as substantially zero, whereas the value shown in the formula (2) is estimated to have an error of 7%. In this case, it can be seen that 2% of the fifth harmonic component is included.
[0021]
As is clear from the simulation results, a transformer was manufactured assuming that an error of about 7% is unavoidable when determining the turns ratio of the coil from the length of the hexagonal line segment by drawing, and this transformer was used. When the rectifier is configured, the fifth-order harmonic component that easily causes various faults is about 2%, whereas each coil has a relationship of the expression (2) as in the present embodiment. By determining the turns ratio, the constant adjustment of the transformer is facilitated, and when a transformer is made according to this and a rectifier is configured using this transformer, the harmonic component can be suppressed to substantially zero. it can.
[0022]
6A to 6D show three-phase AC voltages applied to the main three-phase full-wave rectifier 21, the auxiliary three-phase full-wave rectifier 22 and the auxiliary three-phase full-wave rectifier 23 shown in FIG. It is a wave form diagram which each simulated the electric current of each phase of S, T, and the electric conduction terminal which outputs a positive and negative maximum instantaneous value is switched at intervals of 20 degrees by an electrical angle.
[0023]
Here, when attention is paid to the current path of the transformer 10 in one conduction section (20 °) surrounded by a one-dot chain line in FIG. 6, for example, the main three-phase full-wave rectifier from the three-phase AC input terminal R1. No current flows to any output terminal other than the three-phase AC output terminal T2 of the transformer 10 in a section where the current flows to the three-phase AC output terminal T2 via the auxiliary phase 21 and the auxiliary three-phase full-wave rectifier 22. At this time, as shown in FIG. 7, currents I1, I2, I3, and I4 flow through the next current path.
[0024]
I1 ... R1 ← R4 ← T5 ← T1
I2 ... R1 → R5 → S4 → S1
I3 ... T1 → T4 → T2
I4 ... S1 ← S5 ← T2
When the direction of the magnetic flux generated by the currents I1 to I4 described above is matched with the magnetic flux direction of the R-phase core 1, the combined magnetic flux of the R-phase core 1, the S-phase core 4 and the T-phase core 7 becomes zero. To establish.
[0025]
a · I1 + a · I2 + b · I3 + (b + c) · I4 = 0 (3)
-(2b + c) .I1 + a.I2-a.I4 = 0 (4)
a.I1- (2b + c) .I2-a.I3 = 0 (5)
However, a, b, and c are the number of turns described above.
[0026]
Substituting the values of the above equation (2) into the equations (3) to (5) to obtain the current ratio, the relationship of the following equation is obtained.
[0027]
I1: I2: I3: I4 = 1: -3.887939: 25.40467: -10.702 ... (6)
The current expressed by the relationship of the above expression (6) flows in the winding corresponding to the conduction terminal also in the conduction section other than the three-phase AC output terminal T2, but the current corresponding to the largest current I3 is the output terminal. It always flows from R2, S2, T2, R3, S3, T3 to the winding b side and does not pass through the winding c. For this reason, the effective value of the current in one cycle flowing through the winding c is significantly smaller than that of the other windings.
[0028]
FIG. 8 is a current waveform diagram simulating the currents in the windings c and b on both sides of the intermediate tap T2 connected to the three-phase AC output terminal T2. As is apparent from this waveform diagram, the positive and negative values differ only when the three-phase AC output terminal T2 is conductive, and the effective value of the current in the winding c is about the effective value of the current in the winding b. 55%. Since no external terminal is connected to the connection point between the winding b of one iron core and the winding a of the other iron core, the current values are all the same.
[0029]
Therefore, since the cross-sectional areas of the windings a, b, and c of the transformer 10 do not have to be the same, in this embodiment, the cross-sectional areas of the conductors are varied according to the effective value of the current. As an example, the cross-sectional area of the conductor corresponding to the number of turns c is made smaller than that of other parts.
[0030]
As a result, the transformer and the rectifier using the transformer can be downsized without impairing reliability.
[0031]
【The invention's effect】
As is apparent from the above description, according to the present invention, the voltage value and phase relating to the transformer vector diagram represented by a hexagon can be accurately determined, and further miniaturization can be achieved. A transformer and a rectifier using the transformer can be provided.
[Brief description of the drawings]
FIG. 1 is a transformer vector diagram showing a specific winding structure of an embodiment of a transformer according to the present invention.
FIG. 2 is a winding structure diagram of a transformer that satisfies the transformer vector diagram shown in FIG. 1;
FIG. 3 is an enlarged view for performing a geometric analysis to determine the coil turns ratio based on the transformer vector diagram shown in FIG. 1;
FIG. 4 is a circuit diagram showing a configuration of a rectifier that uses a transformer according to the embodiment of FIG.
5 is a waveform diagram in which each input current and harmonic components are simulated based on an analysis numerical value of the coil turns ratio and an actual measurement error value in the rectifier shown in FIG. 4;
6 is a waveform diagram showing simulation results of a three-phase alternating voltage and a three-phase alternating current applied to the three-phase full-wave rectifier shown in FIG. 4, respectively.
FIG. 7 is a diagram showing a current path in one conduction section surrounded by a one-dot chain line in FIG. 6 together with a transformer vector diagram.
8 is a waveform diagram showing instantaneous values and effective values simulating currents flowing through windings on both sides of an intermediate tap in one conduction section surrounded by a one-dot chain line in FIG. 6;
[Explanation of symbols]
1 R-phase iron core 2 R-phase first coil 3 R-phase second coil 4 S-phase iron core 5 S-phase first coil 6 S-phase second coil 7 T-phase iron core 8 T-phase first coil 9 T-phase second coil 10 Transformer 11 Three-phase AC power supply 12R, 12S, 12T Resistor 13R, 13S, 13T Inductance 21 Main three-phase full-wave rectifier 22, 23 Auxiliary three-phase full-wave rectifier 31 Reactor 32 Smoothing capacitor 33 Load resistance

Claims (2)

Each phase voltage of the three-phase alternating current is represented by a regular triangle vector diagram, and passes through two points obtained by dividing the arc drawn by connecting the remaining two vertices with each vertex of the regular triangle as the center. In a transformer satisfying a transformer vector diagram represented by a hexagon formed by a straight line and a straight line passing through each vertex of the equilateral triangle and parallel to one side facing each vertex,
Comprising first and second coils respectively wound around a three-phase iron core;
One end of the first coil is connected to one end of the second coil having the same polarity and sequentially different phases, and the other end of the first coil has the same polarity and sequentially different phases from the one end. Are connected to the other ends of the different second coils,
Each of a, b, and c is a number of 2 or more, the number of turns of the first coil is 2a, a first tap is provided at an intermediate position of the number of turns, and the number of turns of the second coil is 2b + c. a second tap is provided at an inner position by b, and a third tap is provided at an inner position by the number of turns b from the other end,
The first tap for three phases is used as an input terminal for three-phase AC voltage, and the second tap for three phases is used as a first output terminal for three-phase AC voltage. Is the second output terminal of the three-phase AC voltage,
The cross-sectional area of the conductor of the portion between the second tap and the third tap corresponding to the number of turns c of the second coil is made smaller than that of the other portion;
A transformer characterized by that. A main three-phase full-wave rectifier that converts a three-phase alternating current into a direct current; a transformer that outputs two types of three-phase alternating currents that are different in phase by ± 20 ° in electrical angle by inputting the three-phase alternating current; A rectifier comprising two auxiliary three-phase full-wave rectifiers, each of which converts two types of three-phase alternating currents output from a transformer into direct current, and whose DC output line is connected in parallel with the main three-phase full-wave rectifier. In
A rectifier using the transformer according to claim 1 as the transformer.

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