JPH0631470B2 - Electroplating energizer for both sides plating - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electroplating energizing device for both single-sided plating and double-sided plating.

(Prior Art) A conventional electroplating energizing device is shown in FIG.
As shown in FIG. 2 of Japanese Patent No. 175), the upper electrode power supply device 1
A (first power supply device) and a lower electrode power supply device 1B (second power supply device) are provided, and the upper electrode power supply device 1A is connected to a three-phase AC power supply and has a three-winding transformer 2A for a rectifier. And a thyristor rectifier 3A connected to one output winding 5A of the three-winding transformer 2A and a thyristor rectifier 3A connected to the other output winding 5A of the other three-winding transformer 2A.
It has and. The same applies to the lower electrode power supply device 1B. Reference numeral 7 is a conductor roll, 6A is an upper surface plated electrode, and 6B is a lower surface plated electrode.

The upper surface plated electrode 6A is the first of the double-sided / single-sided switching device 17.
It is connected to the upper electrode power supply device 1A through the contacts.
The lower surface plated electrode 6B is connected to the lower electrode power supply device 1B and also connected to the upper electrode power supply device 1A via the second contact of the switching device 17. Lower electrode power supply 1
Similarly, B also has a rectifier transformer and a thyristor type rectifier, and the neutral point of the transformer is connected to the conductor roll 7 together with the neutral point of the transformer 2A in the upper electrode power supply device 1A.

When performing double-sided plating on the steel plate 20, the switching device 1
With 7 as the first contact side, the rectifier 3A of the power supply device 1A and the rectifier 3B of the power supply device 1B are ignited to supply a current to both the upper surface plated electrode 6A and the lower surface plated electrode 6B.

When plating only the lower surface of the steel plate 20, the switching device 1
7 is switched to the second contact, and current is supplied to the lower surface plated electrode 6A not only from the power supply device 1B but also from the power supply device 1A. Therefore, in the case of single-sided plating, a double current is supplied as compared with the case of double-sided plating.

(Problems to be Solved by the Invention) Since the electroplating current-carrying device for both single-sided plating and double-sided plating in the prior art generally applies substantially the same current to each of the upper surface electrode and the lower surface electrode during double-sided plating,
The upper power supply and the lower power supply use a three-winding transformer for rectifier and a thyristor rectifier having the same capacity.

For example, when performing double-sided plating, when the upper surface electrode and the lower surface electrode are energized with a DC voltage of 22.5V and a DC current of 30KA, the specifications of the power supply unit in this case are: rated output voltage 22.5V, rated output current 30KA, Output power of 675KW is sufficient.

Then, when performing single-sided plating, two power supply devices are connected in parallel to one electrode as in the prior art, and the DC output voltage is doubled in order to flow a double current, that is, a DC output current of 60KA. That is, 45V is required.

That is, since each power supply device is energized with a DC output voltage of 45 V and a DC output current of 30 KA, the specifications of this power supply device are a rated output voltage of 45 V, a rated output current of 30 KA, and a rated output power of 1350 KW.

Therefore, in the device of the prior art, the specifications of the power supply device are those for single-sided plating having a large rated output voltage. For this reason, when double-sided plating is performed using a power supply device with a rated output voltage of 45 V for single-sided plating, a DC voltage of 22.5 V is applied at half the rated output voltage. When the power is supplied at half of the rated output voltage in this way, the power factor of the power supply device when viewed from the AC side is reduced to almost half, and energy loss occurs.

Theoretically explaining that the power factor of the power supply unit when viewed from the AC side is halved, in the case of the 6-phase half-wave rectification method, the DC output voltage (average value) Ed and the DC output current (average value)
Id is as follows.

Ed = 1.17 Escos α ………… (1) Id ＝ 3.46I s ………… (2) In equation (1) and (2) Es: Phase voltage of the output winding Is: Line current of 〃 α: Thyristor Control firing angle 1.17: voltage coefficient 3.46: current coefficient Further, the capacitance P ₂ of the output winding and the capacitance P ₁ of the input winding are P ₂ = 6. Es ・ Is ………… (3) And the capacitance P ₁ of the input winding is calculated from the equations (1) to (4). From the AC side, the power factor cos θ of the power supply is cos θ = 0.95 · cos α ………… (6) from Eq. (5).

Here, let us consider the output voltage when the upper surface power supply device is fully energized in both the double-sided plating and the single-sided plating.
In the case of double-sided plating, when the rated output current Id is supplied to the upper surface electrode, the output voltage Ed ₁ is Ed ₁ = Id · R ………… (7) (7) R: load resistance One-sided plating , When the rated output current 2 · Id of the upper surface power supply device and the lower surface power supply device is supplied to the lower surface electrode, the output voltage Ed ₂ is Ed ₂ = 2 · Id · R .... (8) Therefore, (8) Output voltage E when plating one side from equations 7) and (8)
d ₂ is twice the voltage Ed ₁ for double-sided plating.

Assuming that the thyristor control firing angle α for one-side plating is α = α ₂ , the output voltage Ed ₂ is Ed ₂ = 1.17 · Es · cos α ₂ ………… (9) where thyristor control point When the arc angle α ₂ = 0, the power factor cos θ ₂ of the power supply viewed from the AC side is cos θ ₂ = 0.95 (10) according to equation (6).

Next, assuming that the thyristor control firing angle α = α ₁ , the output voltage Ed _{1 for} double-sided plating is Ed ₁ = 1.17 · Es · cos α ₁ ………… (11) from equation (1). (7), (8), (9), (11) cos α 1 = cos α 2/2 ............ (12) Thus from equation the power factor cos [theta] ₁ of the power supply device as viewed from the AC side, (6 )
From the equation, cos θ ₁ = 0.475 ………… (13).

Thus, it can be seen from Equation (6) that the power factor of the power supply seen from the AC side is determined by the thyristor control firing angle α (actually, it is low due to reactance drop, resistance drop, etc.). Theoretically, from equations (10) and (13), it drops from 0.95 to 0.475, so
The power factor decrease due to the control firing angle α of the thyristor rectifier is
This is a serious problem in terms of energy saving.

In order to solve such a problem, it is conceivable to provide two sets of power supply devices for single-sided plating and double-sided plating.
Since the power supply device for electroplating has a large structure in order to withstand a high current, it is expensive and disadvantageous in terms of cost.

The present invention provides an electroplating current-carrying device that advantageously solves the above problems.

(Means for Solving the Problem) The present invention relates to a three-winding transformer for a rectifier, which has one set of input windings and two sets of output windings connected to an AC power source, and each of the output windings. A thyristor type rectifier is provided in the
In addition, in the electroplating energization device for both single-sided plating and double-sided plating, which has two power supply devices for the upper surface and the lower surface, the conductor roll is connected to the neutral point of the three-winding transformer for rectifier. One of the power supply devices has three windings on the input side each divided into two, and a switching unit for switching each of the two divided windings into a series coupling and a parallel coupling is provided, and the divided windings are connected as a series coupling. This is an electroplating energization device for both single-sided plating and double-sided plating, which is provided with a control unit for controlling the application of a voltage substantially the same as that of the other power supply device when a voltage is applied.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block connection diagram of an electroplating energizing device.
The upper surface power supply device 1A and the lower surface power supply device 1B are respectively equipped with rectifier 3-winding transformers 2A and 2B and two thyristor rectifiers 3A and 3B. The specifications have a rated output voltage and a rated output current that satisfy the DC voltage and the DC current during double-sided plating. Also, three-winding transformers 2A, 2 for rectifiers
B is one set of input windings 4A and 4B and two sets of output windings 5 respectively.
Equipped with A and 5B.

The upper surface power supply device 1A is connected from the thyristor type rectifier 3A to the upper surface electroplating electrode 6A, and is connected from the conductor roll 7 to a neutral point of the rectifier three-winding transformer 2A. Similarly, the lower surface power supply device 1B is also connected from the thyristor type rectifier 3B to the lower surface electroplating electrode 6B, and is also connected from the conductor roll 7 to the neutral point of the rectifier three-winding transformer 2B.

On the other hand, the connection on the input side is from the AC power supplies 12A and 12B to the control unit 1.
1 through the input cable 9A, 9B through the input winding 4
It is connected to A and 4B. The cable 10 is a cable in which each of the three windings in the input winding 4 </ b> A is divided into two, and the control unit 11 switches between the series coupling and the parallel coupling. The control unit 11 has three windings in the input winding 4A, each of which is divided into two, and has a switching unit for switching each of the divided windings into a series connection or a parallel connection. In plating, the AC power supplies 12A and 12B are turned on and off independently and controlled so as to reach the set rated output voltage while being switched.

FIG. 2 shows a connection diagram centering on the control unit 11 in the electroplating energizing device. Input winding 4 of the upper surface power supply device 1A
A has three windings 13-1 and 13-2 in which three windings 13 are respectively divided into approximately equal parts, and the switching portions 14 and 15 are connected via cables 9A and 10 as shown in the drawing. Connect. On the other hand, the input winding 4B of the lower surface power supply device 1B has three windings 13
And is not divided like the input winding 4A. 16A and 16B are AC power supplies 12A and 12B for the upper and lower surfaces.
This is a power switch that turns on and off.

When switching unit 14 is turned off and switching unit 15 is turned on, FIG. 3 (a)
The winding 13-1 and the winding 13-2 of the input winding 4A are connected in parallel. In this case, the rated output voltage is doubled as compared with the case of series connection.

On the other hand, when the switching unit 14 is turned on and the switching unit 15 is turned off, FIG.
As shown in (b), each winding 13-1 and winding 1 of the input winding 4A
3-2 is connected in series, which is exactly the same as the case of the input winding 4B.

That is, the rated output voltage is 1/2 compared to the case of parallel coupling.
However, the rated output voltages of the upper surface power supply device 1A and the lower surface power supply device 1B are the same.

Although the above description has been made on the upper surface side by single-sided plating, the upper surface power supply device 1 of FIG.
It is sufficient to replace A with the lower surface power supply device 1B.

(Operation of Embodiment) When performing double-sided plating, the connection of the control unit 11 is a changeover switch.
16A and 16B are turned on, the switching unit 14 is turned on, the switching unit 15 is turned off, and the connection shown in FIG. 3 (b) is made. In this way, the upper surface power supply device 1A and the lower surface power supply device 1B have the same capacity, for example, a DC voltage of 22.5V and a DC current of 30KA.
Then, electricity is applied to the upper surface electroplating electrode 6A and the lower surface electroplating electrode 6B, respectively. In this case, the thyristor type rectifiers 3A and 3B each have a rated output voltage of 22.5 V and a rated output current of 30 KA and a rated output power of 675 KW. (In the case of the conventional technology, in consideration of the fact that double-sided current is flown by plating on one side, the rated output voltage is 45 V, the rated output current is 30 KA, and the rated output power is
It is said to be 1350KW. ) When plating on one side, the connection of the control unit 11 is a changeover switch
Turn on 16A and turn off 16B. Switching unit 14 is off, switching unit 1
No. 5 is on and the connection is as shown in Fig. 3 (a). In this way, power is supplied only by the upper surface power supply device 1A,
The windings 13-1 and 13-2 of the input winding 4A are connected in parallel, and the rated output voltage is twice that in the case of series connection. That is, the rated output voltage of the upper surface power supply device 1A is 45V, which is twice the rated output voltage of 22.5V for double-sided plating, which is 45V. A double current of 60 KA flows through.

(Effect) With the device of the present invention, it is possible to energize at the rated output voltage of the power supply device in both double-sided plating and single-sided plating. That is, the power factor of the power supply device in double-sided plating by the conventional technology has been improved from 0.475 to 0.95, and considering the heat loss of the input winding of the three-winding transformer for rectifier, etc. Energy savings of 25% can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block connection diagram of an electroplating energizing device according to an embodiment of the present invention, FIG. 2 is a wiring diagram of a control unit in the energizing device of FIG. 1, and FIG. 3 (a). Is an equivalent circuit diagram of the wiring when the input windings are parallel coupled in FIG. 2, and FIG. 3 (b) is an equivalent circuit diagram of the wiring when the input windings are serially coupled in FIG. The figure is a block connection diagram of a conventional electroplating energizing device. 1A, 1B ... Power supply device, 2A, 2B ... 3-winding transformer for rectifier, 3A, 3B ... Thyristor rectifier, 4
A, 4B: input winding, 5A, 5B: output winding, 6
A, 6B ... Electroplating electrode, 7 ... Conductor roll, 9A, 9B ... Input cable, 10 ... Series connection,
Parallel coupling switching cable, 11 ... Control unit, 12A, 1
2B ... AC power supply, 13, 13-1, 13-2 ... Input winding, 14,
15 ... switching unit, 16 ... power switch, 17 ... switching device, 20 ... steel plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-55-6468 (JP, A) Actually opened 62-118175 (JP, U) Actually opened 59-153380 (JP, U) Actually published 39- 21446 (JP, Y1)

Claims (1)

[Claims] 1. A three-winding transformer for a rectifier, which has one set of input windings and two sets of output windings connected to an AC power supply,
A thyristor type rectifier is provided in each of the output windings, an output side of the thyristor type rectifier is connected to an electrode for electroplating, and a conductor roll is connected to a neutral point of the three winding type transformer for the rectifier. 2 for configured upper surface and lower surface
An electroplating energizing device for two-sided plating, which has one power supply, one of the two power supplies
One is to divide each of the three windings on the input side into two, provide a switching unit for switching each of the two divided windings into a series coupling and a parallel coupling, and apply the voltage by dividing the windings into a series coupling. An electroplating energization device for both single-sided plating and double-sided plating, which is provided with a control unit for controlling to apply a voltage substantially the same as that of one power supply device.