JPH035925Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a current control circuit for a power supply unit used, for example, to demagnetize or magnetize materials.

[Conventional technology] Conventionally, there are various types of current control circuits in power supply sections.
A method suitable for each purpose is used.

Among them, the induction voltage regulator changes the output voltage by changing the rotation angle, and is similar to the slider in this respect, but the two differ in structure and characteristics.

That is, the slider changes the voltage due to its rotation by bringing a sliding brush into contact with a coil wound around an iron core, and extracting current through the sliding surface, and the input phase and output phase are in the same phase without any change.

On the other hand, an induced voltage regulator uses voltage changes due to induced voltage, so even if rotation occurs, current is extracted without contact. However, the output phase relative to the input appears as a varying phase that deviates depending on the rotation angle.

As mentioned above, the slider and the induced voltage regulator have different characteristics, and it is possible to control the slider using a thyristor on the secondary side because it does not cause a phase shift. Using a thyristor on the secondary side of the device is not possible due to the phase shift.

[Problem to be solved by the invention] The problem of the invention is to create an induction voltage regulator that is highly durable, can be used semi-permanently, and requires very little maintenance and inspection, and that prevents phase shift and allows the use of thyristors. It is an object of the present invention to provide a current control circuit that has a longer service life, is easier to handle, and is less expensive than a conventional slider.

[Means for Solving the Problems] The means of the present invention connects an induction voltage regulator and a phase regulator that drive a thyristor in parallel and interlock them, and connects the thyristor to the secondary side of the induction voltage regulator. However, the signal generator is connected to the secondary side of the phase adjuster.

[Example] In FIG. 1, 1 indicates an induction voltage regulator, and 2
is a phase adjuster, and the phase adjuster 2 is connected in parallel to the induced voltage regulator 1 and interlocked therewith.
3 is a transformer connected to the output side of the induction voltage regulator 1, and a thyristor 4 is connected to the output side. The thyristor 4 is provided with an output terminal 5. A signal generator 6 is connected to the secondary side of the phase adjuster 2.

Next, in the present invention, the induced voltage regulator 1 (hereinafter referred to as
The reason for combining the thyristor 4 (abbreviated as IVR) and the thyristor 4 will be explained.

In order to make it easier to understand the output waveforms of the present invention, FIGS. 2 and 3 show only one output waveform of three-phase full-wave rectification. In the three-phase full wave, one wave is simply superimposed on six waves, and there is no change in the waveform of each wave, and they show similar changes.

First, in Fig. 2, when the load is constant, if the firing phase of thyristor 4 is started from 0 point, I' will flow, and if the voltage is increased, I'' will flow, and if it increases further, I' will flow.
A sine wave flows. At the maximum current value I', the current value becomes Ip', and as the voltage increases, the current value increases to Ip'' and Ip.

Now when a constant current is passed through the load, and the current value is Ip', as shown in Figure 3, in (a), I,
If Ip′ requires t ₁ second and I″ in (b) is added, it will take t ₂ seconds to obtain the current value of Ip′, which is less than half of (a). Also, if I in (c) It will take at least ₃ seconds to obtain the current value of Ip′. (In both cases, the current value is shown as the peak value.) In other words, the IVR and thyristor combination is a coil with a large load impedance. It takes time for the current flowing through the coil to reach its maximum value after it starts flowing, and the closer it gets to the maximum value, the longer it takes.In order to quickly flow current through the coil, increase the voltage and quickly increase the current. When the current reaches a certain value, the current can be quickly cut off by applying a reverse voltage to the thyristor.

A thyristor is responsible for turning this current on and off. This is a combination of an IVR and a thyristor in order to adjust the voltage using an IVR.

IVRs that use IVR as voltage regulators include sliders and tap transformers, but both have electrical contact points that wear out and lack durability. On the other hand, IVR is characterized by being contactless or can be used semi-permanently.

Also, as mentioned earlier, IVR is contactless, but
Because it is an induction rotation type voltage regulator, there is a phase shift between the input and output. This deviation changes with the rotation angle of the IVR. If the input of the signal generator (gate signal circuit) 6 is taken directly from the RST, the phase applied to the thyristor 4 from the transformer 3 and the firing phase output from the signal generator 6 do not match, so the second
The phase control shown in FIGS. 3 and 3 becomes impossible.

If the input of the signal generator 6 is taken from the primary side of the transformer 3, the phases will match, but since the voltage changes there, it cannot be used for the signal generator 6.

That is, when using IVR, it has conventionally been considered impossible to use IVR and thyristor at the same time.

This invention uses a phase adjuster to adjust the phase difference, and by rotating IVR1 and phase adjuster 2 in parallel and synchronously, transformer 3
Since the phase difference between the input of the signal generator 6 and the input of the signal generator 6 remains constant, phase control becomes possible as shown in FIGS. 2 and 3.

In the phase adjuster 2, even if the rotation angle of the movable coil is changed, only the phase changes on the primary side and the secondary side does not change the output, which is a constant voltage. Therefore, it can be used as a power source for the signal generator 6, and its phase angle is
It changes in conjunction with IVR1. As the phase adjuster, for example, a phase shifter can be used.

As described above, the IVR's non-contact voltage adjustment and thyristor-based output waveform turning ON/OFF have the characteristics of both, and high-speed performance that allows the maximum value to be obtained in a short time even with a high-impedance coil with a large load. You can obtain a power source for magnetization and demagnetization.

[Effects] This invention connects a phase adjuster in parallel to an induced voltage regulator and makes them work together, and uses a thyristor, so a non-contact current extraction method is adopted, and it is highly durable and can be used semi-permanently. This enables current control that does not cause

[Brief explanation of the drawing]

Figure 1 shows a power supply circuit showing an embodiment of the present invention;
3 and 3 are output waveform diagrams.

Claims (1)

[Scope of utility model registration request] An induction voltage regulator that drives the thyristor and a phase regulator are connected in parallel and interlocked, the thyristor is connected to the secondary side of the induction voltage regulator, and a signal generator is connected to the secondary side of the phase regulator. Connected current control circuit.