JPH02177306A - Pulse magnetizing current controller - Google Patents

Abstract

PURPOSE:To prevent deterioration, burning, and breaking of a coil so as to lengthen the life of the coil by introducing unnecessary currents flowing to a yoke coil to a shunt circuit when letting pulse currents flow to the yoke coil for magnetization being load. CONSTITUTION:An input terminal 7 is connected to the output terminal 5 of a magnetizer, and a yoke coil 6 is connected to an output terminal 10 being load, and when the currents of the magnetizer flow, controlled currents are let flow to the coil 6. In this constitution, a + input terminal 7 connects directly with at + output terminal 10, and a - output terminal 10 connects with a - input terminal 7 through a shunt 11. On the other hand, a dividing circuit is constituted by serial connection of a dividing thyristor protective coil 8 and a dividing thyristor 9, and the cathode side of the thyristor 9 is connected to the -output terminal 10, while the protective side is connected to the + output terminal 10. When currents begin to flow by the voltage signal of the magnetizer which is input through the shunt 11 to which a gate pulse generating control board 12 is connected, the points, where the maximum value and counter-electromotive fourth occur, are detected and respective lapse times are measured, and the time when the temperature rise of the coil is the smallest is set to pulses.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention applies a pulse current (hereinafter referred to as current) to a magnetizer current tllf#L to a magnetizing yoke coil (hereinafter referred to as yoke coil) which is a load. The output circuit of a conventional magnetizer of this type is as shown in Fig. 4, and the output circuit of the conventional magnetizer is as shown in Fig. 4. 1. Thyristor 3. A thyristor 3. A thyristor 3. A thyristor 3. A thyristor 3. A reflux diode 4. A reflux diode 4. A reflux diode 4. Consisting of an output terminal 5 that outputs current,
By applying a pulse voltage to the gate of the thyristor 3, the thyristor 3 is turned on, and a current is caused to flow through the yoke coil, thereby generating magnetic force. The current waveform is shown in Fig. 5.1 The electrical energy required for magnetization by the magnetomotive force of the coil is approximately from the start of current flow to to the peak passing point t1 of the current value in Fig. 5 (strictly speaking, In addition to this, a minimum amount of time is required for the domain wall movement of the magnetic material.The current after this is mainly loss energy that is converted into heat, but in the conventional technology, this current Since all the current from to to t3 is passed through the yoke coil, its temperature rises, and this results in deterioration, burnout, disconnection, etc. of the yoke coil, and shortens its lifespan. It causes.

In addition, changes in coil resistance due to this temperature rise directly result in changes in the magnetizing current characteristics, which can lead to a drop in magnetization level and variations, which can be detrimental to the product, so forced cooling methods such as air cooling or water cooling must be used, or At present, the current countermeasures are to set intervals between energizations or to do one of the following. However, this is only an indirect measure and cannot be called a fundamental measure, and was not effective as a method for preventing the linear expansion and heat generation of the coil itself caused by passing a large current through the coil. In addition, stronger materials such as rare earth magnets have recently been developed, and their shapes have become smaller and smaller, requiring larger currents for magnetization, and this problem has become a major obstacle in the magnetization process.

(Embodiment) Pulse magnetizing current control device This device was made to solve the above-mentioned disadvantages, and its structure is as shown below (FIG. 1).

7. Input terminal (+/-') This is a terminal to input the current of the magnetizer.

8. Shunt thyristor protection coil Di/dt characteristics of shunt thyristor This is the protective coil (L).

9. Shunt thyristor This is for shunting the current of the magnetizer at a set time.

(G) It is a gate.

10, Output terminal (+/-) This is a terminal that outputs a controlled current.

11. Current transformer or current transformer (hereinafter referred to as a current transformer) This is for extracting a voltage signal from the current of the magnetizer.

12. Gate pulse generation control board While analyzing and measuring the magnetizer voltage signal input through the shunt 11, generates a gate pulse voltage and applies it to the gate CG of the shunt thyristor 9 at a set time. I! It is a board with functions.

(in) This is a terminal for inputting the voltage signal of the magnetizer from the shunt 11.

(out) This is a terminal that outputs gate pulse voltage.

(VR) This is a volume for setting the application time (from tl to t2) of the gate pulse voltage for turning on the shunt thyristor.

13. f! of gate pulse generation control board! ! This supplies power to the source gate pulse generation control board.

The above is the configuration. This input terminal 7 is connected to the output terminal 5 of the magnetizer, and the yoke coil 6, which is a load, is connected to the 5 output terminal 10. When the current of the magnetizer flows, it is controlled by the yoke coil 6. Current flows.

The principle operation of this device and its results are shown in Figures 1 and 2.
This will be explained with a diagram. In Fig. 1, input terminal 7 (
+) is directly connected to the output terminal 10(+). The output terminal 10(-) is connected to the input terminal 7(-) via a shunt 11. On the other hand, the shunt circuit connects a shunt thyristor protection coil 8 and a shunt thyristor 9 in series, and connects the cathode side of the shunt thyristor 9 to the (-) output terminal 1o.

Shunt thyristor protection coil side (+) of output terminal IO
12 connected to the current shunt 11 connected to the current shunt 11 is a gate pulse generation control board. 1 The voltage signal of the magnetizer inputted through the current shunt 11 determines the current flow start to, its maximum value tr, and the back electromotive force. The three points t3 where the (kick puck) is generated are detected, and the elapsed time at each point is measured. and tl
An appropriate time (a time in which the required generated magnetic field is obtained and the temperature of the yoke coil does not rise much) is set using the gate pulse voltage application time setting knob 4 in the time range from t2 to t2. This causes the current from the magnetizer to flow to the shunt thyristor at the set time.

As a result, the cut current flows through the yoke coil as shown in FIG.

A (■■■) and B (■■) are different lid loads (yoke coils), and their respective waveforms are obtained by dividing the current at different times.

(Effects of the invention) Due to the above-mentioned action, the unnecessary current flowing through the yoke coil is guided to the shunt circuit, thereby directly suppressing the heat generation of the yoke coil.As a result, deterioration, burnout, and disconnection of the yoke coil are prevented. This significantly improves the life of the yoke coil. Further, since the change in resistance value of the yoke coil due to temperature rise is reduced, extremely stable magnetizing current characteristics can be obtained, and uniform magnetization can be achieved. This practical IUT exhibits a remarkable effect on yoke coils for rare earth magnets that require large currents, multipolar yoke coils, and yoke coils that use thin windings.

Therefore, there is no need for a complicated cooling device such as water cooling or air cooling conventionally used for this type of yoke, and most yoke coils do not require cooling by using this device.

Furthermore, there is no lost time in work due to intervals between energizations, leading to improved work efficiency. FIG. 3 is a graph of temperature rise comparison test data using the same yoke coil under the same conditions.

[Brief explanation of the drawing]

(First @) It is a block #F diagram of the present device. (Fig. 2) When using this device, the current from tl to t2 can be freely controlled by changing the time at which the 0 minute flow starts, which is the output waveform of the current. (FIG. 3) This is a graph of temperature rise comparison test data of the same yoke coil under the same conditions when this device is used and when it is not used. (FIG. 4) This is an outflow output ryJ path diagram of a conventional magnetizer. (Fig. 5) This is the current waveform of Fig. 84. Figure 1 (Block circuit diagram of this device)

Claims (1)

[Claims] Connected to the output circuit of a conventional magnetizer using pulsed current, it controls the current from the maximum value (peak value) of the pulsed current to the point where back electromotive force (kickback) is generated. A device that suppresses the heat generation of the magnetizing yoke coil, which is the load, and maintains appropriate and stable magnetizing current characteristics by appropriately dividing the current into a current dividing circuit consisting of the following: