JP2803728B2 - Power converter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter used for a load supplied with a large direct current, such as an electric plating tank or an anodizing tank. [Prior Art] FIG. 4 shows, for example, JP-B-55-1997 or JP-B-55-1997.
FIG. 5 is a connection diagram showing a conventional power converter shown in Japanese Patent Publication No. 1998-1998, and FIGS. 5 and 6 are a plan view and a front view of the power converter shown in FIG. In the figure, reference numeral 1 denotes a processing tank as a load, and 2A and 2B are arranged opposite to each other with the processing tank 1 interposed therebetween, and a pair of thyristors having the same configuration for supplying a large DC current to a current terminal of the processing tank 1. Rectifiers, 3
A and 3B are transformers in thyristor rectifiers 2A and 2B, 4A and 4B are thyristors connected to the secondary side of transformers 3A and 3B, and 5A and 5B are gates that provide control signals to the gates of thyristors 4A and 4B. A control device, 6A and 6B are current detectors for detecting a large DC current output from the thyristors 4A and 4B, and 7 is a bus bar connected to the plus terminal and the minus terminal thereof for flowing the large DC current to the processing tank 1. Reference numeral 8 denotes an output setting device for setting the amount of current output from the thyristors 4A and 4B of the thyristor rectifiers 2A and 2B. Reference numerals 9 and 10 denote the primary of the transformers 3A and 3B of the thyristor rectifiers 2A and 2B. The power cables 11 and 12 are control cables connecting the gate control devices 5A and 5B of the thyristor rectifiers 2A and 2B and the output setting device 8, and 13 is the power cable connected to the thyristor rectifiers 2A and 2B. Gate control devices 5A and 5B are connected to each other to connect both thyristor rectifiers 2A and 2B. Period is operating, also a control cable which Intarotsuku signal and the correction signal for outputting the same amount of current to the treating tank 1 flows. Next, the operation will be described. AC power is supplied from the power cables 9 and 10 to the respective transformers 3A and 3B of the thyristor rectifiers 2A and 2B, and a large direct current is supplied from the thyristors 4A and 4B to the processing tank 1 via the bus bar 7. The adjustment of the current amount at this time is performed by the operator operating the output setting device 8 and the operation signal is transmitted to the respective gate control devices 5A and 5B of the thyristor rectifiers 2A and 2B via the control cables 11 and 12. It is done by doing. In this case, since the thyristor rectifiers 2A and 2B need to perform a synchronous operation with respect to the processing tank 1, the control cable 13
Transmit the interlock signal to each other. further,
Since the same amount of current needs to be supplied from the thyristor rectifiers 2A and 2B to the treatment tank 1, the control cable 13
Is also used for transmitting a correction signal. [Problems to be Solved by the Invention] Since the conventional power converter is configured as described above, there are the following problems. That is, first of all, the environment around the processing tank 1 is a poor environment in which toxic gas is generated and various processing liquids are scattered. However, in the configuration shown in FIGS. The two thyristor rectifiers 2A and 2B, including the gate controllers 5A and 5B, which are the weakest and most likely to cause trouble, are arranged at a distance from each other with the processing tank 1 interposed therebetween. Therefore, the operator can always directly monitor the operation state of only one of the thyristor rectifiers 2A (or 2B), and cannot monitor the other at the same time, so that sufficient maintenance and management cannot be performed. That is, for sufficient maintenance management, operators must be assigned to both the thyristor rectifiers 2A and 2B one by one. Second, the control cables 12, 13 and the power cable 10 are laid for a long distance in a space that is not so large, which is not only uneconomical but also reduces the risk of corrosion due to toxic gas. It has increased. In addition, it is not preferable that such a large number of cables are densely laid from the viewpoint of reducing noise in transmitting the operation signal, the interlock signal, and the correction signal. The present invention has been made in order to solve the above-described problems, and is intended for a case where a plurality of devices, such as thyristor rectifiers 2A and 2B, that are vulnerable to toxic gas and the like and must be constantly monitored by an operator are used. In addition, an object of the present invention is to provide a power conversion device that can collectively arrange these components close to an operator and further reduce the amount of cable laying as much as possible. [Means for Solving the Problems] The power converter according to the present invention has a transformer having a rectifier connected to the secondary side, and is installed at one end and the other end of the load, respectively. And a plurality of rectifiers for supplying a large DC current to the rectifier, and an AC power regulator installed at one end of the load connected to the primary side of the transformer in the rectifier and regulating the amount of AC power. It is a thing. [Operation] Since the AC power regulator of the power converter according to the present invention is installed only at one end of the load, whereas the rectifier is installed at one end and the other end of the load, Even when two or more power converters are used for a load, only this AC power regulator is collectively disposed at a location where an operator is present. An embodiment of the present invention will be described below with reference to the drawings. 1 to 3, reference numeral 1 denotes a processing tank as a load;
A and 14B are rectifiers of the same configuration, which are disposed opposite to one end side and the other end side of the processing tank 1 and supply a large direct current to the current terminal of the processing tank 1 through the bus bar 7;
A transformer 15B constitutes the rectifiers 14A and 14B, and 16A and 16B constitutes the rectifiers 14A and 14B.
Diode as rectifier connected to the secondary side, 17A, 17
B has the same configuration including the gate control devices 5A and 5B and the current detectors 6A and 6B, and is installed at one end of the processing tank 1 for adjusting and supplying AC power to the rectifiers 14A and 14B. AC power regulators, 18A and 18B are gate controllers 5A and 5B
A thyristor as an AC power adjusting element controlled by the thyristors 19A and 19B are switches connected to the thyristors 18A and 18B,
20, 21 are power cables connected to the switches 19A, 19B, 22 is a power cable connecting the transformer 15A and the thyristor 18A,
23 is a power cable connecting the transformer 15B and the thyristor 18B, 24 is a control cable connecting the gate control device 5A and the output setting device 8, and 25 is a control cable connecting the gate control device 5B and the output setting device 8. , 26 is the AC power regulator 17
In order for A and 17B to perform synchronous operation with respect to the processing tank 1,
This is a control cable connecting between the gate control devices 5A and 5B for mutually transmitting interlock signals between the gate control devices 5A and 5B. Next, the operation will be described. The AC power from the power cables 20 and 21 is adjusted by AC power regulators 17A and 17B, respectively, and the transformers 15A and 15B of the rectifiers 14A and 14B, respectively.
Is input to At this time, the AC power is adjusted by transmitting an operation signal of the output setting device 8 by an operator, an interlock signal, a correction signal, and the like to the respective gate control devices 5A and 5B via the control cables 24, 25 and 26. Further, the thyristors 18A and 18B are controlled in phase based on the control signals of the gate control devices 5A and 5B. Then, the respective transformers 15A, 15B of the rectifiers 14A, 14B
AC input to the primary side of the transformer is connected to transformers 15A and 15B.
It is output as a direct current by the rectifying action of the diodes 16A and 16B connected to the next side and supplied to the processing tank 1. With the above configuration, as apparent from FIG. 3 in particular, the AC power regulators 17A and 17B including the gate controllers 5A and 5B, which are weakest against toxic gas, etc., are collectively placed near the operator's presence. Can be arranged. Therefore,
The operator can perform the same and sufficient maintenance and inspection work on both of the AC power adjusting devices 17A and 17B. In addition, since the AC power adjusting devices 17A and 17B can be disposed collectively, protection against toxic gases and the like can be more easily performed. As is clear from the comparison of FIG. 3 with FIG. 6, the cable laid around the processing tank 1 is only the power supply cable 23, so that it is economical and danger of corrosion. In all aspects, such as reliability and signal transmission reliability, it is superior to the conventional one. Further, the gate control devices 5A, 5B and the thyristors 18A, 18B
And so on are separately disposed from the transformers 15A and 15B, so that the rectifiers 14A and 14B including the transformers 15A and 15B are provided.
Can be significantly reduced in size compared to the conventional thyristor rectifiers 2A and 2B, and can be advantageous in terms of space. In the above embodiment, thyristors 18A, 18B are used as AC power adjusting means in AC power adjusting devices 17A, 17B.
Although an example using a triac is shown, a triac may be used, and an induction voltage regulator may be used instead of a semiconductor device such as a thyristor or a triac. Furthermore, although an example is shown in which diodes 16A and 16B are used as rectifying means connected to the secondary sides of transformers 15A and 15B of rectifiers 14A and 14B, this rectifying means is a semiconductor rectifying element other than diodes. Alternatively, a rotary rectifier or the like may be used instead of a semiconductor rectifier. [Effects of the Invention] As described above, according to the present invention, the power conversion device
A plurality of rectifiers each having a transformer connected to a rectifier on the secondary side and installed at one end and the other end of the load to supply a large direct current to one load from both ends; When using two or more power converters, the system includes an AC power regulator installed at one end of the load connected to the primary side of a transformer in the device to regulate the amount of AC power. In addition, all the AC power regulators, including those that are vulnerable to toxic gases, can be placed close to the operator to constantly monitor their operation, and the length of the cable laid around the load can be increased. Can be reduced. Therefore, there is an effect that the maintenance and inspection work of the operator becomes easy, and the economy, the danger of corrosion, the reliability of signal transmission, and the like relating to the cable laying can be further improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a connection diagram showing a power converter according to an embodiment of the present invention, FIG. 2 is a plan view of the power converter of FIG. 1, FIG.
FIG. 4 is a front view, FIG. 4 is a connection diagram showing a conventional power converter, FIG. 5 is a plan view of the power converter of FIG. 4, and FIG. 6 is a front view. 1 is a load (treatment tank), 14A and 14B are rectifiers, 15A and 15B are transformers, 16A and 16B are rectifiers (diodes), and 17A and 17B are AC power regulators. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] A plurality of rectifiers comprising a transformer and rectifying means connected to the secondary side of the transformer, and each being provided at one end and the other end of the load and supplying a large direct current to the load from both ends; A plurality of AC power regulators connected to the primary side of a transformer in the rectifier and installed at one end of the load for adjusting the amount of AC power input to the transformer; A power converter comprising: a common output setting device that is installed on the same side and sets output current amounts of a plurality of AC power regulators.