JPS62277074A - Cycloconverter system - Google Patents

Abstract

PURPOSE: To balance 3-phase output voltages of a cycloconverter by composing to cancel the impedance unbalance of secondary windings. CONSTITUTION:First-third single phase cycloconverters 10a-10c formed by cross connection of a pair of bridge rectifiers 2a-2f connected in cascade or two sets of the bridge rectifiers are composed. Secondary winding having larger impedance of a first input transformer 2a is connected with one bridge rectifiers 2a, 2c, 2e of single-phase cycloconverters 10a-10c, and secondary winding having smaller impedance of a second input transformer 1b is connected with the other bridge rectifiers 2b, 2d, 3f.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] This invention provides a cycloconverter device which obtains an AC output with different direct and direct layer wave numbers from an AC input and supplies it to a three-phase balanced load. It is related to.

[Prior art] Figure 3 shows, for example, B, R, Pe1ly.
This is a circuit diagram of the conventional symmetrical 12-pulse bridge connection non-circulating current type cyclone converter device shown in Figures 5 and 6 of P130 of the Cyclo Converter published by Keifuin, translated by Nishi α Takashige and translated by Nishi α Takashige. In the figure, 1 is a transformer, and 2a to 2f are 6-pulse converters supplied with AC power from the transformer 1. These 6-pulse converters 2a to 2f are composed of 6-pulse anti-parallel bridge rectifier circuits, and pairs thereof, for example, 2a and 2b, 2c and 2d, and 2e and 2f are connected in cascade to form a single-phase cycloconverter 10.
a to 10c, and the output side of each single-phase cycloconverter is connected to each phase of the trisum balanced load 4.

On the other hand, a large-capacity cycloconverter requires an input transformer with a large capacity and many secondary windings. However, manufacturing an input transformer with many secondary windings causes impedance imbalance between the secondary windings. The winding method that aligns these causes problems with electromagnetic mechanical force and is difficult to manufacture.

Therefore, as shown in FIG. 4, if the input transformers 1a to 1c are divided into many input transformers 1a to 1c with a small number of secondary windings, each input transformer 18 to IC and 6 pulse converters 2a, 2b, 2c
・2d, 2e, 2f and single phase cycloconverter 10
a to 10c, and the above-mentioned B, R, Pe
As described in No. 2252 of Cyclo Converter by J. Ily, DC excitation of the input transformer occurs due to ultra-low frequency components or DC components, which causes inconvenience.6 [Problems to be solved by the invention] Conventional cyclo converter Since the device is configured as described above, problems such as impedance unbalance of the input transformer winding will cause the three-phase output voltage that is phase-controlled to become unbalanced, causing three-phase unbalance disturbance to the load. There was a point.

This invention was made to solve the above-mentioned problems, and an object thereof is to obtain a cycloconverter device in which three-phase output voltages are balanced.

[Means for solving problems]

The cycloconverter device +, t according to the present invention consists of a pair of cascade-connected bridge rectifier circuits or two sets of bridge rectifier circuits connected in a cross to form a first side, a second side, and a second side. A third single-phase cycloconverter is constructed, and the high-impedance secondary winding of the first input transformer is connected to one bridge rectifier circuit of each single-phase cycloconverter, and the second winding is connected to the other bridge rectifier circuit. It is connected to the low impedance secondary winding of the input transformer.

[Effect]

In the input transformer of this invention, the impedance imbalance of the secondary winding is canceled out, so that
The unbalance of the three-phase output voltage is reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1, in which the same parts as in FIG. 3 are denoted by the same reference numerals.

In FIG. 1, 1a and 1b are 1st. At the second input transformer, this first . The second input transformers 1a, 1b each have three secondary windings 1a1 to 1a3.

It has 1b-1 to 1b-3.

Now, the secondary windings 1a-1, 1 of the first input transformer 1a
, a-2, L a-3 impedance Z, .

Z 1. ! +21 Z I al and Z , 41
< Z 162 < Z + ay.

Also, the secondary winding 1b-1°1 of the second input transformer 1b
b-2, 1b-: 3 (7) impedance Z1b++Z
xbz+Z,b3toL,,Z-bl<Z 1bt
<Z, j'ff.

Under the above conditions, the secondary winding 1a-1 of the first human-powered transformer 1a is connected to one 2a of a pair of cascade-connected six-pulse converters 2a and 2b, and the secondary winding 1a-1 of the first human-powered transformer 1a is connected to the other 2b of the second input transformer 1b. Connect the next winding 1b-1, and similarly connect 2c and 2d to 1a-2, 1b-2, 2e, and 2f to 1a-2.
By connecting 3 and 1b-3, the secondary windings 2a and 2
The output of b is impedance Z1, Z1b3, and Z2c.
and 2d are the same Z, 47 and Ztbz, and 2e and 2f are the same Z1
．． ．． and Z, b.

The voltage varies depending on the total impedance of each, but
Z tat + Z +b3- Z, a2+ Z1b
2-Z 14. +Zlbu, the unbalance of the output voltage becomes small.

In the above embodiment, a 12-pulse b-flow type cycloconverter device was explained, but as shown in FIG.
2 sets 2a: ' and 2d', 2e and 2f, 2e' and 2f'
・2b and 2a'・2b', 2c ・2d and 2c'
· 2d', 2e, 2f and 2e' · 2f' are connected to each other via axles 3a to 3c to limit the circulating current, thereby forming single-phase cycloconverters 10a to 10c. and,
One bridge rectifier circuit 2a of the single-phase cycloconverter 10a.

2a' is the secondary winding 1a-1 of the first input transformer 1a,
1a-2 and the other bridge rectifier circuit 2b, 2b'
The secondary windings 1b-1, 1b- of the second input transformer 1b
Connect 2, and then connect 20・2d, 20′・2d′ in the same way.
ni1 a-3・1 a-4e 1b-3・lb 4+
2e ・2f+ 2e'・2f' to 1a-5・1
Even if a-6, 1b-5 and 1b-6 are connected to form a 12-pulse three-phase circulating current type cycloconverter device, the same effects as in the above embodiment can be obtained.

In this case, 1. Second input transformer 1a, 1b 2
Impedance Z of the next windings 1a-1 to 1a-6, Lb-1 to 1b-6 +a+ to Z+aG+ Z+bl to Z+b
6 to Z, <, < Z, 4=< Z, aj< Z, a,
<Z, a-< 11a, .

Z. , < Z, b, < Z, , b, < Z, b, <
Assume that Z, b5 < Z, .

〔Effect of the invention〕

As described above, according to the present invention, a pair of cascade-connected bridge rectifier circuits or two bridge rectifier circuits are connected in cascade.
Connect the pairs crosswise and connect them to the first one. Second. A third single-phase cycloconverter is constructed, and the high-impedance secondary winding of the first input transformer is connected to one bridge rectifier circuit of each single-phase cycloconverter, and the second winding is connected to the other bridge rectifier circuit. Since the secondary winding of the input transformer having a small impedance is connected to the input transformer, a balanced three-phase output voltage can be obtained.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing a 12-pulse three-phase circulating current type cycloconverter device according to an embodiment of the present invention;
A is a 12-pulse 3-phase '4a according to another embodiment of the present invention.
A circuit diagram showing a 1A current type cycloconverter, Fig. 3 is a circuit diagram of a conventional symmetrical 12-pulse bridge connection cycloconverter device, and Fig. 4 is a circuit diagram of a conventional cycloconverter using a secondary two-winding transformer. be. la and lb are input transformers, 2a to 2f are bridge rectifier circuits, 4 is a three-phase balanced load, and 10a to loc are single-phase cycloconverters. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] (1) In a cycloconverter device that directly obtains an AC output with a different frequency from an AC input, first and second input transformers have a plurality of secondary windings and transform the AC input;
AC power is supplied from a pair of cascade-connected bridge rectifier circuits or a pair of bridge rectifier circuits, or a first, second, and third single-phase cycloconverter configured by cross-connecting the bridge rectifier circuits, and each of the single-phase cycloconverters. a three-phase balanced load, the secondary winding of the first input transformer having the highest impedance is connected to one bridge rectifier circuit of the first single-phase cycloconverter, and the secondary winding of the first input transformer has the highest impedance to the other bridge rectifier circuit. The secondary winding of the second input transformer with the lowest impedance is connected to one bridge rectifier circuit of the second single-phase cycloconverter with the second highest impedance of the first input transformer. one bridge rectifier circuit of the third single-phase cycloconverter; A secondary winding with high impedance is connected to the third position of the first input transformer, and a secondary winding with low impedance is connected to the third position of the second input transformer to the other bridge rectifier circuit. A cycloconverter device characterized by: