JPH0327504A - Control device of electromagnetic device - Google Patents

Abstract

PURPOSE:To reduce power consumption of an electromagnet, to restrain humming noise, and to prevent enlargement of a device by repeating energized and de-energized modes to an excitation magnetic coil at least twice per half cycle at irregular cycles. CONSTITUTION:When an ac power source 11 is applied to a rectifying device 12, output V2 from a voltage dividing circuit of resistances R1, R2 is input to a comparison amplifier IC1 and is compared with a reference voltage V3 from a voltage dividing circuit of resistor R3, R4. Waveshape V4 is thereby output. An AND element IC2 makes output V5 pass only when output of an amplifier IC1 is a high potential. Pulse V6 which does not synchronize with the voltage V2 is input to an OR element IC3. After the ac power source 11 is applied, a NOT element IC4 excites an electromagnet 14 while pulse from the element IC3 makes TR conductive for a time T0 which is decided by a delay circuit 402. Abnormal noises caused by oscillation of the electromagnetic 14, etc., are prevented by using pulse which does not synchronize with a power source and by making repetition cycle irregular.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for an electromagnet device. In particular, the present invention relates to a control device that can reduce whining noise while reducing power consumption.

In general, single-phase AC electromagnetic devices are compared to DC electromagnetic devices. Although it has the characteristics of being small, lightweight, and fast in operation, it has the disadvantage of generating noise or whirring noise due to alternating magnetic flux. Therefore, the AC electromagnet device
It is configured as shown in the figure.

Figure 1 shows a general single-phase AC electromagnet device, with the left half being a front view and the right half being a cross-sectional view. In the figure, (l) is a fixed core made of a stratified core, (2) is an excitation coil wound around the center pole (3) of the fixed core (1), (4) is a movable core made of a stratified core, and (5)
(6) is the magnetic pole head part of the fixed iron core (1). A shade coil (7) is attached to the magnetic pole head portion (5).

A single-phase AC electromagnet device having such a configuration has a magnetic flux φ6 passing through a magnetic pole head (5) surrounded by a shaded coil (7).
and the magnetic pole head (6) that is not surrounded by the shaded coil (7).
), the minimum value of the combined attractive force of the fixed core (1) attracting the movable core (4) is always greater than the external repulsive force of the movable core (4). This eliminates noise caused by alternating magnetic flux.

Regarding the humming noise, since the attractive force includes a pulsating component with a frequency twice that of the power supply, the difference between the maximum and minimum values of this pulsating component causes the strength and weakness of the compressive stress due to the lightning magnetic attractive force within the iron core. , This results in the generation of a whining sound, which generally occurs with varying degrees of intensity.

Next, an explanation will be given using the results of simulation calculations using an electronic computer as an example.

Figure 2 is a simulation of the characteristics of the general AC electromagnet device shown in Figure 1 in transient attraction and steady attraction states. In the figure, W1 is the voltage waveform of the AC power supply, W2, W3
is the magnetic flux waveform passing through the iron core magnetic pole head, W4 is the composite magnetic flux waveform passing through the iron core, and W5 is the excitation? Current waveform of the coil, Wa is the current waveform of the shaded coil, W7 is the waveform of the overall attractive force, w8
indicates an external counterforce. However, the horizontal axis indicates time. In this general AC electromagnet device, as can be seen from FIG. 2, the minimum value of the attractive force W is w7■. is always the external reaction force W8
, so no noise is generated. but. Suction power W
Because the difference between the maximum value W7max and the minimum value W7■,,, of 7 is large. A humming noise is generated because the strength of compressive stress due to electromagnetic attraction force varies within the iron core. If this growling noise is loud, it will cause discomfort. Furthermore, w9
indicates the displacement (stroke) of the movable core of the electromagnet device. Note that the power supply frequency in FIG. 6 is 60Hz, 240V (maximum value) voltage. On the other hand, pure DC electromagnet devices do not generate whirring noise because the attractive force does not include a pulsating component, but when compared at the same voltage value, after attraction, the current does not alternate as in the case of AC. A constant current flows, and the current is determined only by the resistance of the excitation (electromagnetic) coil. Therefore, if the AC electromagnet device, iron core, and excitation coil are considered to be the same, a larger current will flow than the AC electromagnet device, and the current will be determined by the resistance of the excitation (electromagnetic) coil. The loss increases and the coil will burn out if used for a long time. Therefore, in DC electromagnet devices, the resistance value of the coil is increased, but in this case, the current becomes smaller and the magnetomotive force becomes smaller, so the number of turns of the coil must be increased, which results in a larger coil and AC electromagnetic equipment. The disadvantage is that the overall size of the device is larger.

As shown in Figure 3, a method to prevent such a device from increasing in size is to connect a saving resistor (7) in series with the excitation (electromagnetic) coil (2), and to connect a saving resistor (7) in parallel to this saving resistor (7). Insert the normally closed circuit contact (8) into the coil, and when the normally closed circuit contact is turned on, DC voltage is applied to the excitation (electromagnetic) coil (2), and after the normally closed circuit contact is turned on, the normally closed circuit contact (8) is opened. By applying the current to the excitation (electromagnetic) coil (2) via the saving resistor (7), the current is suppressed to reduce the copper loss of the excitation (electromagnetic) coil (2) and prevent burnout of the excitation (electromagnetic) coil (2). Measures are being taken to prevent this. This method requires the use of normally closed contacts and economical resistors, and requires reliable contact operation and contact. It also has the disadvantage that the total power consumption remains unchanged. Note that (9) is a DC power supply, and (lO) is an on-off switch.

The present invention uses an electronic control method different from the conventional phase control method to improve performance by reducing the power consumption for exciting the electromagnetic device and reducing whirring noise compared to the conventional method and compared to the phase control method. An object of the present invention is to provide a control device for an electromagnet device that can control the operation of the electromagnet device.

Next, the principle of the present invention will be explained using an AC power source.

As shown in Figures 4 and 5, the principle is shown in Figures 4 and 5.
ll is full-wave rectified by a rectifier (l2), and the result is shown in Fig. 5(a).
As shown in the figure, the switches sw, . , sw2. , the terminals (13A) to (13B) are disconnected from the power supply (11) by the switch SW for a certain period of time, and at the same time the switch SW2o is disconnected from the power supply (11).
Terminals (13A) - (13B) are short-circuited to bring the voltage supply to the electromagnet device (l4) to zero. Next, the short-circuit between terminals (13A) and (13B) is opened using SW1 for a certain period of time, and at the same time the switch is turned off. Repeat the operation of supplying voltage to the electromagnet device (l4) using SW2o,
The voltage is supplied as shown in FIG. 5(b). Switch SW,.

and S W 2 0 function as follows. switch SW
The disconnection of the power supply by 1o limits the current increase due to full-wave current and suppresses the temperature upper limit due to copper loss in the coil. Furthermore, if the suction power is sufficiently strong, it is possible to save power consumption. Terminal (13A) by switch SW2o
(13B) short circuit causes the electromagnet device (l4) to convert the accumulated electromagnetic energy into electrical energy and generate an attractive force, and even if the electrical energy supply from the power supply is in a zero state, the attractive force is hold. In other words, it acts like a flywheel of suction force. Depending on the case, the terminals (13A) and (13B) may be opened without being short-circuited.

Next, the results of simulation calculations using an electronic computer will be explained using examples.

Fig. 6 shows an AC electromagnet device having the characteristics shown in Fig. 2, using an AC power source of the same frequency and voltage as Fig. 2, using the principle shown in Fig. 4 according to the present invention, and using the zero point of the voltage as a reference every half wave. , 7th
As shown in the figure, switch SW10 SW2o and switch SW+I-SWt1 are both connected at the same time. 1mS
EC energization -+ 1. A simulation is shown when voltage-free switching is repeated for 6 msec. Second
Comparing FIG. 6 with FIG. 6, the principle of the present invention shows that the characteristics of the suction force W, that is, the maximum value W 7 max and the minimum value W 7 mH of the suction force, are better than in the conventional case. The difference is ``11''
You can see that it has become smaller. In other words, it can be seen that the whining noise is significantly reduced. Also, the maximum value of suction power W
? fflin has increased significantly compared to the past.

Figure 8 shows the case where an AC electromagnet device similar to that shown in Figure 2 is operated using the conventional thyristor phase control method (7 mSec no voltage, 1 mSec energized) using an AC power source with the same frequency and voltage as in Figure 2. Show simulation. Comparing Figures 6 and 8. Maximum value W of suction force according to the present invention
7max and the minimum value W 7 rn +. The difference is the maximum suction force of the conventional Cyrisk phase control method W 7 m
a! and the minimum value W7. It can be seen that the difference is about one-half or less than the difference between , and n. As mentioned above, the whining noise of the iron core is proportional to the difference between the maximum value and the minimum value of the suction force, so the present invention can reduce the whining noise to less than half compared to the conventional phase control method. It can be said that the performance is greatly improved. Figure 9 is. A block diagram of the whirring reduction device for an AC electromagnet device according to the present invention is shown, in which (10) is a sine wave AC power supply, (102) is a general AC electromagnet device, (
1031 is a rectifier, (104) is an electronic control device for reducing whirring noise and power consumption, and is operated for a certain appropriate time T after turning on the switch SWo. Later, as shown in Fig. 10, based on the zero point of the power supply voltage, every half wave, energization for T+ time and no voltage for 2 hours were repeated, and after no energization for T3 hours, energization for TI time and no voltage for T2 hours. is repeated, To , T
r, T2, and T3 are shown in Figure 3 so that they can be adjusted freely.
The functions of the switches shown in FIG. 4 are implemented by electronic circuits.

Note that the times of T I and T2 do not necessarily have to be based on the zero point of the voltage. It may be energized or non-energized using pulse oscillation, but the time of T3 must be a time diagram (chart) symmetrical about the point of the maximum value of the voltage waveform. Desirable based on simulation results. In addition, if the power source is DC, the rectifier (103) is omitted and T+, T
2. Just adjust T3. Figure 11 shows an AC electromagnet device with the characteristics shown in Figure 2. Every half wave using an AC power source with the same frequency and voltage as in Figure 2. 0. 1 msec energization -1 1
mSec no voltage-10. 1mSec energization-J 3
．． 2 mSec no voltage - 0. 1mSec energization-
1 1 msec no voltage - 0. 1 mSec energization - 1ynSec no voltage → 0.1 mSec energization is repeated periodically? The simulation shows the case where the maximum value W, ■ y and minimum value W of the attraction force W7 are shown. III in
The difference between the maximum value W tomax and the minimum value W 70ffiif of the high frequency component is almost the same as that in Fig. 6.
It can be said that the difference in i has become slightly smaller, and therefore the humming noise of high frequency components has become smaller.

Figure 12 shows an AC electromagnet device with the characteristics shown in Figure 2, with an AC power supply of the same frequency and different voltage (340V (maximum value)) as in Figure 2, and a voltage of 0.0V every half wave. 1 msec energization = 1.
6 mSec no voltage -0. 1mSec energization →3.
3mSec no voltage -+0. 1mSec energization -+ 1
．． 6mSec no voltage-*O. lmsec energization 4
1. A simulation is shown in which no voltage is periodically repeated for 4 mSec, and the average value of the attraction force and the copper loss of the coil (power consumption W, .) in the normal adsorption state are almost the same.

From this, as mentioned above, TT 2 in Fig. 10,
By adjusting T3, the electromagnetic coil is the same, but the range of application for using different power supply voltages is widened (for example, the excitation (electromagnetic) coil can be shared from AC 200 to 400 V).

Figure 13 shows T of Figure 1O, (7) 25 mSec between
This shows a simulation under exactly the same conditions as in Figure 12 except that the time is changed from 16.6msec to 16.6msec. Comparing Figures 12 and 13, the displacement 'E3. when the movable core (4) of the electromagnet device is attracted to the fixed core (1). : W
It can be seen that the characteristics of the attraction force W7 after the time point 9o are quite different. In other words, for the 12th cause. The suction force of the movable iron core (4) after suction 7'1 increases rapidly. In FIG. 13, after adsorption, the suction force decreases once and then gradually increases to a constant value. This is because, in Fig. 12, the impact when the movable iron core (4) and the fixed iron core (ll) are attracted is severe, whereas in Fig. 13, the impact is gentler than that in Fig. 12, and many driving operations (for example, 10
(0 to 5 million times), and the impact of the closing operation on devices driven by this electromagnetic device (e.g., electromagnetic contactors, relays) is reduced.
For example, when used in an electromagnetic contactor, the bouncing of the contact is reduced, and therefore the amount of wear is reduced due to the generation of arc at the contact (Ill) point, and the performance advantage of extending the number of electrical lifespans is obtained. become.

In this way, T in FIG. By adjusting the time of It is possible to reduce the impact load when the movable iron core (4) and the fixed iron core (11) are attracted to each other.

As explained above, the present invention has the following advantages.

0) The humming noise can be reduced by reducing the difference between the suction force of 711 degrees and the minimum value.

■ Power consumption during steady adsorption can be saved.

■ The applicable range of power supply (input) voltage ratings can be expanded without changing the excitation (electromagnetic) coil.

■ The impact during adsorption can be reduced.

■ Applicable to both AC and DC power sources.

■ For DC conversion. The shade coil of the conventional AC electromagnet device is abolished.

(l2) ■ Because it converts to DC, unlike conventional AC electromagnet devices, alternating magnetic flux does not pass through the core, and therefore eddy currents do not occur, so there is no iron loss, so instead of using a laminated core made of silicon steel sheets like in the past. too. The core can be made of inexpensive cast steel, formed steel, or the like.

Note that the control device of the present invention may be attached separately to the electromagnet device, or may be built-in in combination with the electromagnet device.

FIG. 14 shows a specific embodiment using the electronic control device [104] of FIG. 9, and its operation will be explained based on FIG. 15.

In Figure 14, (11) is an AC power supply, [12]
is a rectifier, (14) is an electromagnet device, Di, D2 are diodes, Rl-R5 are resistors, TR is a transistor, I
CI is a comparison amplifier, IC2 is an AND element (hereinafter referred to as AND element), IC3 is an OR element (hereinafter referred to as OR element), and IC4 is a negative element (hereinafter referred to as NOT element). In addition, (400
) is a resistance voltage circuit, (401) is an oscillation circuit, (40
2) is a delay circuit.

(l3) In a device configured in this way, the AC power supply (1l)
is applied to the rectifier (l2) (Fig. 15(a)
Resistor R1 connected to the output of the rectifier (l2)
The full-wave rectified waveform V2 output from the voltage divider circuit of R2 and
(see FIG. 15(c)) is manually input to the comparator amplifier ICI. This full-wave rectified waveform ■2 is compared and amplified with the reference voltage V3 (see Figure 15 (b)) output from the voltage divider circuit of resistors R3 and R4, and the waveform V4 (see Figure 15 (d)) is It is output from the comparison amplifier ICI. AND element IC
2 is the output V5 of the oscillation circuit (401) only when the output of the comparator amplifier ICI is at a high potential (see Figure 15 (el)).
To output. A waveform Va (see FIG. 15(f)) is obtained. Furthermore, the knot element IC4 is connected to an AC power source (l1
) after the application of T, determined by the delay circuit (402).

In order to output a high potential between . time T
. During this period, the electromagnetic device (14) is in a conductive state and thus the electromagnetic device (14) is energized. Said time T. The electromagnet device (l4) is. The time T is set longer than the time required for suction.
. Later, the suction operation is completed. Next is time T. After that, according to the output waveform V6 of the AND element IC2, the transistor T
R repeats conduction and cutoff, that is, switching.

If the transistor TR conducts here, the electromagnetic device (l
It goes without saying that a current flows through 4), but when the transistor TR is cut off, the coil energy of the electromagnet device (I4) is circulated by the diode Di, so the current continues to flow through the electromagnet device (I4). . In other words, since the coil current does not become an intermittent current, the attraction state is maintained.

Here, the time T to cut the peak value of the AC power supply (11)
3, by changing the voltage division ratio of resistors R3 and R4,
Needless to say, it can be controlled appropriately. In addition, by appropriately setting the oscillation circuit (401), the conduction time T1
Since the cutoff time and T2 can be varied, the beat can be minimized and
Needless to say, settings can be made to minimize energy consumption.

Also, in this example, the oscillation circuit was explained in an asynchronous manner.
It goes without saying that the effect of the present invention can be expected to be even greater (15) since continuity near the zero point can be reliably guaranteed by synchronizing it with an AC power supply. In addition, although the time T3 for cutting the peak value of the AC power supply is explained in this embodiment as being cut when the voltage exceeds a certain level, the same effect can be achieved even if the voltage at which the cut starts and the voltage at which the cut ends is changed appropriately. Needless to say, it is effective.

Furthermore, when the AC power supply (11) becomes a DC power supply, the peak value cut T cannot be set, but it goes without saying that the same effect can be obtained by appropriately setting the oscillation circuit (4011). In some cases, Dai Sai-do D
A capacitor may be used instead of 1, and the diode DI may be omitted. Furthermore, it is also possible to use a chotsuba made of a thyristor in place of the transistor TR. Note that FIG. 15 is a time chart of each output in this embodiment.

As described above, according to the present invention, it is possible to reduce whirring noise while reducing the power consumption for exciting the electromagnet device, and it is possible to configure the device without increasing its size. Various beneficial (16) effects can be obtained.

[Brief explanation of drawings]

Fig. 1 is a front view showing the schematic configuration of a general single-phase AC electromagnet device, Fig. 2 is a waveform diagram showing the waveforms of various parts when a general AC electromagnet device is supplied with power, and Fig. 3 is a A connection diagram showing the circuit configuration of a general DC electromagnet device, Figure 4 is a circuit configuration diagram for explaining the principle of the present invention, and Figure 5 (a) (
b) is a waveform diagram for explaining FIG. 4, FIG. 6 is a waveform diagram showing waveforms of various parts during operation of the control device in an embodiment of the present invention, and FIG. 7 is a waveform diagram showing an embodiment of the present invention. Circuit diagram,
Fig. 8 is a waveform diagram showing the waveforms of various parts in the conventional control system of the Cyrisk phase, Fig. 9 is a block diagram showing the connection relationship when the present invention is applied to a general AC electromagnet device,
Figure 10 is a waveform diagram to explain the operation of Figure 9.
1 to 13 are waveform diagrams showing waveforms of various parts in other embodiments of the present invention. FIG. 14 is a circuit connection diagram showing a specific embodiment of the present invention configured with an electronic circuit, and FIG.
FIG. 4 is a waveform diagram showing waveforms of various parts for explaining the operation of the circuit shown in FIG. 4; In the figure, (l) is a fixed core, (2) is an excitation (electromagnetic) coil, (4) is a movable core, and (11) (lot) is an AC power supply. (12) (103) is a rectifier, (14) (
102) is an electromagnet device, SWo, SWIO, SW2o,
SWII. SW2 is a switch, and (104) is an electronic control device. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (4)

[Claims] (1) A control device comprising a switch interposed between an excitation coil of an electromagnet device and an alternating current power source and controlling the supply of power to the excitation coil so as to periodically repeat an energized state and a de-energized state, A control device for an electromagnet device, characterized in that the switch is switched so that an output obtained by full-wave rectification of the AC power source is periodically repeated between a energized state and a non-energized state at least twice every half wave. (2) Repeat the energized state and de-energized state at least three times, and switch the switch so that the time in the de-energized state is longer than the time in the de-energized state in the middle of the half-wave of the above output compared to the time in the de-energized state in other repetitions. A control device for an electromagnet device according to claim 1, characterized in that the control device is configured to: (3) Targeting the time when the repetition of the energized state and de-energized state in each half wave reaches the maximum voltage value, the time in the de-energized state is set to be larger than the time in the de-energized state in other repetitions. 3. The control device for an electromagnet device according to claim 1, wherein the switch is configured to perform switching. (4) The control device for an electromagnet device according to claim 1, wherein the time duration between the energized state and the non-energized state is adjusted.