JPH1122729A - Magnetic bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic bearing device to simplify a circuit for an inverter and reduce size, and improve reliability and flexibility of abnormality processing. SOLUTION: A magnetic bearing device comprises a control type magnetic bearing having a plurality of electromagnets 11 to support a rotor 10 in a non- contact state; a position detecting device 13 for a rotor 10; an electric motor 14 to rotationally drive the rotor 10; an inverter 15 to drive the motor 14; the number of revolutions detecting device 16 for a rotor 10; and a control part 18 to control the electromagnets 11 based on an output signal from the position detecting device 13 and control the inverter 15 based on an output signal from the number of revolutions detecting device 16. An abnormality detecting device 17 is arranged. The control part 18 is provided with a digital signal processing processor to control the electromagnet 11 and the inverter 15. When abnormality is detected, abnormality is processed by controlling the inverter 15 by a digital signal processing processor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic bearing device for supporting a rotating body in a non-contact manner with a magnetic bearing.

[0002]

2. Description of the Related Art As a magnetic bearing device, a control type magnetic bearing having a plurality of electromagnets for supporting a rotating body in a non-contact manner, a position detecting device for detecting a position of the rotating body, an electric motor for rotatingly driving the rotating body, An inverter that drives the motor, a rotation speed detection device that detects the rotation speed of the rotating body, and control that controls the electromagnet based on the output signal of the position detection device and controls the inverter based on the output signal of the rotation speed detection device There is known one that includes a part.

In such a conventional magnetic bearing device,
The inverter for driving the motor is provided with a protection circuit for performing an abnormality process when an abnormality such as a power failure, an abnormal temperature rise of the inverter, or an overcurrent of the motor occurs.

However, the presence of the protection circuit complicates the inverter circuit and increases the outer shape of the inverter. Further, since the number of parts of the inverter increases due to the protection circuit, the reliability is not high.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic bearing device which solves the above-mentioned problems, simplifies and downsizes an inverter circuit, and has high reliability and flexibility in abnormality processing. Is to do.

[0006]

A magnetic bearing device according to the present invention has a control type magnetic bearing having a plurality of electromagnets for supporting a rotating body in a non-contact manner, and a position detecting device for detecting a position of the rotating body. An electric motor that rotationally drives the rotating body, an inverter that drives the electric motor, and a rotational speed detecting device that detects the rotational speed of the rotating body,
A control unit that controls the electromagnet based on the output signal of the position detection device and controls the inverter based on the output signal of the rotation speed detection device, and detects an abnormality in a required portion. An abnormality detection device is provided, the control unit includes a digital signal processor that controls the electromagnet and the inverter, and when an abnormality is detected by the abnormality detection device, the digital signal processing processor It is characterized in that the inverter is controlled to perform an abnormality process.

[0007] In this specification, a digital signal processor (Digital Signal Processor) refers to dedicated hardware that inputs a digital signal, outputs a digital signal, is software-programmable, and is capable of high-speed real-time processing. . Hereinafter, this is abbreviated as DSP.

When an abnormality occurs, the DSP of the control unit controls the inverter to perform the abnormality processing, so that it is not necessary to provide the inverter with a conventional protection circuit. For this reason, the circuit of the inverter can be simplified and the number of parts can be reduced.
The reliability is improved, and the inverter can be downsized. Further, the abnormal processing control can be freely designed by the software program of the DSP, which is extremely flexible.

[0009]

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

FIG. 1 schematically shows the configuration of a magnetic bearing device.

The magnetic bearing device includes a digital control type magnetic bearing having a plurality of electromagnets (11) for supporting the rotating body (10) in a non-contact manner, an electromagnet driving circuit (12) for driving the electromagnet (11), and a rotating body. A position detecting device (13) for detecting the position of (10), and a rotating body;
An electric motor (14) for rotationally driving the motor (10), an inverter (15) for driving the motor (14), a rotational speed detector (16) for detecting the rotational speed of the rotating body (10), and a magnetic bearing device An abnormality detection device (17) for detecting an abnormality of a required portion of the motor, and an electromagnet (11) is controlled via a drive circuit (12) based on an output signal of the position detection device (13), and a rotation speed detection device (16 ) And the output signal of the abnormality detection device (17).
And a control unit (18) for controlling the control.

The magnetic bearing is driven by a magnetic attraction force of a plurality of electromagnets (11) to move the rotating body (10) in the axial direction (axial direction).
The rotary body (10) is supported in a non-contact manner in the axial control axis direction at two locations, and at two axial locations, the rotary body (10) is provided with two radial (radial) control axes orthogonal to each other. Non-contact support in the direction. One electromagnet drive circuit (12) is provided for each electromagnet (11). Each drive circuit (12) includes a power amplifier and the like, and supplies an exciting current to the corresponding electromagnet (11) based on an electromagnet control signal output from the control unit (18) as described later. FIG. 1 shows only one set of the corresponding electromagnet (11) and drive circuit (12).

The position detecting device (13) detects the position of the rotating body (10) in the axial control axis direction by a plurality of position sensors, and detects the position of the rotating body (10) at two locations in the axial direction. It detects a position in the control axis direction in the two radial directions orthogonal to each other.

The electromagnet (11) of the magnetic bearing, the electromagnet drive circuit (1
2), the position detection device (13), the motor (14), the inverter (15), and the rotation speed detection device (16) can employ any known configurations, and thus detailed description is omitted.

The control section (18) includes a DSP. DS
P outputs an electromagnet control signal to each drive circuit (12) based on the output signal of the position detection device (13). Then, as described above, the excitation current based on the electromagnet control signal is supplied from each drive circuit (12) to the corresponding electromagnet (11), whereby
The rotating body (10) is supported at a predetermined target position in a non-contact manner. The DSP outputs a rotation speed command signal to the inverter (15) based on the output signal of the rotation speed detection device (16). Then, the inverter (15) supplies a drive current based on the rotation speed command signal from the DSP to the motor (14), whereby the rotating body (10) is rotated at a predetermined rotation speed.

The abnormality detection device (17) detects abnormalities such as abnormal temperature rise of the inverter (15), overcurrent of the motor (14), abnormal operation of the magnetic bearing, and power failure. Is provided at the abnormality detection site. When any abnormality is detected, the abnormality detection device (17) sends an interrupt signal corresponding to the content of the abnormality to the DSP of the control unit (18). Upon receiving an interrupt signal from the abnormality detection device (17), the DSP controls the inverter (15) so as to perform abnormality processing corresponding to the content of the abnormality.

Next, referring to the flowchart of FIG.
An example of the DSP processing in the control unit (18) will be described.

In FIG. 2, the DSP first inputs a position detection signal, which is an output signal of the position detection device (13), for each control axis (step 1), and performs a PID calculation based on the signal (step 2). ), And outputs an electromagnet control signal to the corresponding drive circuit (12) (step 3). Next, it is checked whether or not there has been an interrupt signal from the abnormality detection device (17), that is, whether or not an abnormality has been detected (step 4).
If no abnormality is detected, the process returns to step 1. Then, the operations of steps 1 to 4 are repeated while no abnormality is detected. If an abnormality has been detected in step 4, the process proceeds to step 5, where an abnormality process control for causing the inverter (15) to perform an abnormality process according to the content of the abnormality is performed, and the process returns to step 1. For example, when an abnormality such as an abnormal temperature rise of the inverter (15) or an overcurrent of the motor (14) is detected, so-called free-run control is performed in which the output from the inverter (15) to the motor (14) is set to 0. , Inverter (1
5) and protect the motor (14). If abnormal operation such as abnormal operation of the magnetic bearing or power failure is detected, the motor (14)
The inverter (15) is controlled so as to brake and stop immediately.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a magnetic bearing device according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an example of processing of a digital signal processor of a control unit.

[Explanation of symbols]

 (10) Rotating body (11) Electromagnet (13) Position detection device (14) Electric motor (15) Inverter (16) Rotation speed detection device (17) Abnormality detection device (18) Control unit

Claims (1)

[Claims] A control type magnetic bearing having a plurality of electromagnets for supporting a rotating body in a non-contact manner; a position detecting device for detecting a position of the rotating body; an electric motor for rotatingly driving the rotating body; and the electric motor. An inverter for driving the rotor, a rotation speed detection device for detecting the rotation speed of the rotating body, and the inverter based on an output signal of the rotation speed detection device while controlling the electromagnet based on an output signal of the position detection device. A magnetic bearing device comprising: a control unit that controls an electromagnet; and a control unit that controls the electromagnet and the inverter. When an abnormality is detected by the abnormality detection device, the digital signal processor controls the inverter to perform abnormality processing. A magnetic bearing device characterized in that the magnetic bearing device is adapted to be driven.