JPS63138711A - Control system for magnet power supply apparatus - Google Patents

Abstract

PURPOSE:To enable a power supply apparatus to supply current with high precision and to produce stable magnetic field in response to a current command rising or falling abruptly, by providing a constant-voltage-control minor loop connected to the later stage of an ordinary constant-current-control loop so as to control a transistor of a series regulator. CONSTITUTION:A power supply apparatus assembly 1-5 is provided for supplying current as desired to a magnet 6. A constant-current-control loop is provided as a control device, so that it detects output current of a series regulator 4 and turns ON or OFF the transistor of the series regulator 4 via a current amplifier 8 on the basis of a result of comparison between the detected value and a set value of a current setting device 7. Further, a constant-voltage-control feed-back loop for detecting a loaded voltage of the magnet 6 is provided on the later stage of the ordinary constant-current-control loop, so that the transistor of the series regulator 4 is controlled from an output of the feed-back loop. By providing two-stage loop control in this manner, current can be supplied with high precision and high stability in response to a current command rising or falling abruptly.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides low voltage and high Control method for a high-precision pulsed current power supply device that supplies a stable current [Conventional technology] Both normal-conducting and superconducting types of magnets are used in such devices, and both types of magnets ensure highly accurate magnetic field generation. Therefore, a constant current supply is required.

This typically requires accuracy and stability of 103 to 1.

As a power supply device for generating this kind of magnetic field, a device as shown in FIG. 2 is known.

In the figure, 1 is an isolation transformer connected to an AC power source, 2 is a diode rectifier, 3 is a DC smoothing filter, 4 is a series regulator using a transistor, and 5 is a shunt for current detection.

From the AC power supply to the diode rectifier 2 via the isolation transformer 1
The current converted to direct current is supplied to the magnet 6 as a load by the series regulator 4 as a highly accurate and highly stable variable adjustable direct current.

Note that when a large-capacity power source is used, a silicate rectifier may be used in place of the diode rectifier 2 because the loss generated in the series-relay regulator 4 becomes a problem.

Such a power supply device is required to stably and reliably raise the current supplied to the magnet 6, which has a large inductance, from zero amperes at a certain current rising rate or fall at a certain current falling rate. Therefore, the output current of the series regulator 4 is extracted and the transistor of the regulator 4 is controlled by a constant current control loop using a regulator. In the figure, 7 is a current setting device forming such a control loop, and 8 is a current amplifier (ACR).

[Problem that the invention seeks to solve]

In such a control system, if precision and stability of 10'' to 1σ5 are required in a steady state with the aim of generating a magnetic field relatively slowly, this can be achieved using a high gain amplifier 8. When performing pulse-like intermittent operation, it is not possible to cope with the sudden rise and fall of the current, and the
It was difficult to achieve high accuracy of σ3 to 1σ5.

An object of the present invention is to provide a control system for a power supply device for a magnet, which eliminates the disadvantages of the conventional example and can supply a highly accurate current even in response to a current command with rapid rise and fall due to pulsed intermittent operation. Our goal is to provide the following.

[Means for solving problems]

In order to achieve the above object, the present invention provides a power supply device that obtains a variable DC current from an AC power source through an isolation transformer, a rectifier, a DC smoothing filter, and a series regulator, and supplies this to a magnet as a load. In a method in which the output current of the regulator is detected and controlled by a constant current control loop, the load voltage of the magnet is detected, and a constant voltage control feedback loop is provided after the constant current control loop to control the output. The gist of this is to control the transistors of a series regulator using the following methods.

[Effect]

According to the present invention, by controlling the transistors of the series regulator with a constant voltage control minor loop connected after the normal constant current control loop, high precision supply current,
A stable magnetic field can be generated.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

Figure 1 shows one of the control methods for the magnet power supply device of the present invention.
This is a block diagram showing an embodiment, and the same reference numerals are given to the same components as in FIG. 2 showing the conventional example.

That is, 1 in the figure is an isolation transformer connected to an AC power supply,
2 is a diode rectifier that converts the alternating current from the transformer 1 into direct current, 3 is a smoothing filter, 4 is a series regulator using a transistor, and 5 is a shunt, and these constitute a power supply device that supplies the desired current to the magnet 6. configured.

Also, as a control device, the output current of the series regulator 4 is detected, and by comparing this detected value and the setting value of the current setting device 7, the output current is transmitted to the series regulator 4 via the current amplifier 8.
It is also the same as the conventional example shown in FIG. 2 in that a constant current control loop is provided to control on/off of the transistor.

In addition to the conventional circuit shown in FIG. 2, the present invention detects the load voltage of the magnet 6, and also provides a constant voltage control feedback loop inside (later stage) of the normal constant current control loop. , the transistor of the series regulator 4 is controlled by the output of this regulator.

In the figure, reference numeral 9 denotes a voltage amplifier (A VR) forming this constant voltage control loop, which receives the load voltage output of the magnet 6 and the output of the current amplifier 8 of the constant current loop, and sends the output to the series regulator 4. This is to be introduced.

[Effects of the Invention] As described above, the control method of the magnet power supply device of the present invention obtains a variable DC power source from an AC power source through an isolation transformer, a rectifier, a DC smoothing filter, and a series regulator, and uses this as a load. In the method of controlling the transistor of a series regulator in a power supply device that supplies a magnet with a constant current control loop by detecting the output current of the regulator, a constant voltage control loop is further implemented based on the detection of the magnet voltage of the load. Since this is a new addition, the two-stage loop control prevents currents from rising and falling sharply, not only during steady operation where relatively slow magnetic field generation occurs, but also during intermittent operation. It is possible to realize highly accurate and highly stable current supply.

[Brief explanation of the drawing]

Figure 1 shows one of the control methods for the magnet power supply device of the present invention.
A block diagram showing an embodiment, and FIG. 2 is a block diagram showing a conventional example. 1... Isolation transformer 2... Diode rectifier 3.
...DC smoothing filter 4...Series regulator 5...Shunt 6...Magnet 7...Current setting device 8...Current amplifier 9...Voltage amplifier Fig. 1 1 (*3斤@,') 6(
77 “Kiba” 2 (Gu°Io F now ii record)
7 (1 deficiency; power; 2, 5,) 5 (phosphorus μ
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Claims (1)

[Claims] A variable DC current is obtained from an AC power supply through an isolation transformer, a rectifier, a DC smoothing filter, and a series regulator, and this is supplied to a magnet as a load.In the power supply device, the transistor of the series regulator detects the output current of the regulator. , in a control method using a constant current control loop, the load voltage of the magnet is detected, a constant voltage control feedback loop is provided at the latter stage of the constant current control loop, and the transistor of the series regulator is controlled by the output of the feedback loop. A control method for a power supply device for magnets.