JPH025107A - Regulated power unit for exciting electromagnet - Google Patents

Abstract

PURPOSE:To highly accurately control current from a fine current area up to a large current by adding a current sensor for exclusively measuring a small current area and switching an output by a current sensor switching signal synchronizing with the switching of a reference signal outputted from a current reference signal circuit. CONSTITUTION:The current sensor 31 for measuring only the small current area and a current sensor 32 for measuring all current areas are used and a current reference signal only for the small current area and that for the whole current area are also prepared so that the current sensors and the current reference signals are respectively switched and used in accordance with the signal level of each current reference signal. Thus, the current sensor 31 only for the small current area and the current reference signal corresponding to the sensor 31 are used in the small current area, and when the current reference signal exceeds a prescribed level, the current sensor 32 and the current reference signal corresponding to the sensor 32 are used to control the output of a regulated power supply. Thus, the whole current area from the fine current area up to the large current area can be highly accurately detected and controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improving the control accuracy of the output current in the small current range of a stabilized power source for excitation of an electromagnet used in an accelerator or the like.

[Prior art] Figure 3 shows, for example, Hitachi Hyoron VO published in October 1987.
This is a block diagram of a current control circuit including a current sensor of a conventional stabilized power supply for excitation of an electromagnet shown in L, 60 No., pages 1047 to 52, in which fi+ is a cyrisk converter and (2) is a load. An electromagnet, (3) is a current sensor (DCCT), (4) is an electromagnet current reference signal generator, and (5) is a control circuit including a current control, a pulse phase shifter, etc.

Next, the operation will be explained. The current sensor (3) detects the current actually flowing through the electromagnet (2), which is the load, in response to the current reference signal generated by the electromagnet current reference signal generator (4), and controls the deviation from the reference signal. Circuit (5)
The signal is amplified and controlled in the pulse phase shifter, and the SiRISK conversion device is operated to follow the reference signal.

Conventional stabilized power supply devices for excitation of electromagnets are configured as described above, so when continuously controlling from a small current to a large current, the current detection accuracy in the small current range is relatively low, and therefore the current control becomes difficult. The problem is that the accuracy is relatively low, and it is difficult to handle cases where high relative accuracy is required even in the micro current range as with large currents.

This invention was made to solve the above-mentioned problems, and provides a stabilized power supply device for excitation of electromagnets that can detect and control the entire current range from minute current range to large current range with high precision. The purpose is to obtain.

[Means to solve the problem]

The stabilized power supply device according to the present invention uses a current sensor exclusively for small current range measurement and a current sensor for full current range measurement, and also provides current reference signals, one for small current range and one for full current range. The current sensor and the current reference signal are switched and used according to the signal level of the current reference signal.

[Effect]

In the small current range, the stabilized power supply device of the present invention uses a current sensor dedicated to the small current range and a corresponding current reference signal, and when this current reference signal exceeds a predetermined level, a current sensor for measuring the entire current range and a current reference signal corresponding to the current sensor are used. A corresponding current reference signal is used to control the output of the regulated power supply.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (31) and (32) are current sensors for measuring the current range and for measuring the entire current range, respectively, (41) and (42)
are electric 2i1 reference signal generators for small basin use and full current range, (62) and (62) are A/D converters,
7), +8+ is a digital selector, and (9) is a switching control signal.

Next, the operation will be explained. The current reference signal generated by the electromagnetic current base single signal generators (41) and (42) is controlled by the selector (8) to be (
41), but in a current range exceeding this, (42) is selected and output as, for example, a 16-bit current reference signal. On the other hand, the current flowing through the electromagnet (2) is detected by current sensors (31) and (32), and is constantly sent to the selector (7) through A/D converters (61) and (62) (for example, 16 bits). It has been entered. The selector (7) switches the current sensor (31) for small current range in synchronization with the switching of the current reference signal by the switching control signal (9).
, (61) and current sensor for full current range (32) , (
62) Switches the output signal between and outputs it as a current detection signal. Here, the deviation between the current reference signal and the current detection signal is input to the control circuit (5), but since the current detection level in the small current range is several to ten times higher than that of the conventional method, Current detection accuracy, current control j21! Accuracy can be improved several to ten times, and current can be controlled with high precision from minute currents to large currents. 1. In addition, a current sensor (31) dedicated to low current range
Only the current carrying capacity has a value equal to the maximum current of the device, and the sensor actually operates as a sensor and requires accuracy only in a limited range of low frequencies.

FIG. 2 specifically illustrates the output of the current sensor (equal to the current reference signal) in the present invention. When a small current is being energized by the select signal (5) given by the reference signal circuit, the sensor output (2) dedicated to small current range measurement is used, so that the current sensor signal (4) in actual use is free from decomposed dust in the small current range. It can be seen that the current detection accuracy and control current accuracy improve accordingly.

Note that in the above embodiment, the current sensors (31), (32
), the deviation detection process with respect to the current reference signal is performed digitally using an A/D converter, but the basic concept is the same even when analog processing is performed.

Further, although a Sirisk converter is used as a device for controlling current, it goes without saying that a converter using a power semiconductor element such as GTO or BL-MO5 can be substituted.

C Effects of the Invention As described above, according to the present invention, a current sensor dedicated to measuring a small current area is added, the relative accuracy of current detection in the area is improved, and the reference signal from the current reference signal circuit is Since the output is switched by the current sensor switching signal synchronized with the switching of the
Can be controlled with high precision. Further, there is an effect that the disturbance at the time of switching is extremely small.

[Brief explanation of the drawing]

FIG. 1 is a control block diagram of a stabilized power supply for excitation of an electromagnet according to an embodiment of the present invention, FIG. 2 is an operation waveform diagram showing each current sensor signal of the present invention, and FIG. 3 is a diagram of a conventional electromagnet excitation power source. FIG. 3 is a control block diagram of a stabilized power supply for (31) is a current sensor dedicated to small current range measurement, (32) is a current sensor for full current range measurement, (41), (42)
are current reference signal generators for small current range and full current range, f
il, +81 is a selector control signal. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. 11:A10 Konkuguchita Figure 1 Agent Masuo Oiwa Figure 2 Figure 3 Jinrekutoi Fortune 1y

Claims (1)

[Claims] In a stabilized power supply that continuously passes current from a minute current to a large current to an electromagnet, there is a first current sensor that measures the small current range of the output of this stabilized power supply, and a second current sensor that measures the entire current range.
a current sensor, a first switch for switching between the first and second sensors, a first current reference signal generating means for providing a current reference for the small current range, and a first current reference signal generating means for providing a current reference for the entire current range. a second switch for switching between the first and second current reference signal generating means; and a second switch for switching between the first and second current reference signal generating means; control means for controlling the output current of the stabilized power supply by switching the switch to the small current range measuring side, and switching the first and second switches to the full current range measuring side when a predetermined value is exceeded. Stabilized power supply for electromagnet excitation.