Method and apparatus for controlling a magnetic bearing

Claim 1

A method of controlling a magnetic bearing, said method comprising: providing an ABS control and N-cross control in coaction.

Claim 2

A method of controlling a magnetic bearing, said method comprising: providing an ABS control and N-cross control in coaction.

Claim 3

A method of controlling a magnetic bearing, said method comprising: ABS control, N-cross control and FF control in coaction.

Claim 4

A method of controlling a magnetic bearing, said method comprising: ABS control, N-cross control and FF control in coaction.

Claim 5

A method of controlling a magnetic bearing, said method comprising: ABS control and N-straight control in coaction.

Claim 6

A method of controlling a magnetic bearing, said method comprising: ABS control and N-straight control in coaction.

Claim 7

A method of controlling a magnetic bearing, said method comprising: ABS control, N-straight control and FF control in coaction.

Claim 8

A method of controlling a magnetic bearing, said method comprising: ABS control, N-straight control and FF control in coaction.

Claim 9

A method of controlling a magnetic bearing, said method comprising: ABS control, N-cross control and N-straight control in coaction.

Claim 10

A method of controlling a magnetic bearing, said method comprising: ABS control, N-cross control and N-straight control in coaction.

Claim 11

A method of controlling a magnetic bearing, said method comprising: ABS control and FF control in coaction.

Claim 12

A method of controlling a magnetic bearing, said method comprising: ABS control and FF control in coaction.

Claim 13

A method of controlling a magnetic bearing based on the prosecution of determining in advance a control activation plan which is a set of control modes, each being any one of or any combination of ABS control, N-cross control, FF control and N-straight control, in relation with rotational speed regions of a rotor supported by said bearing, selecting a control mode in said plan depending on the actual rotor speed, and controlling said bearing in accordance with the selected control mode.

Claim 14

A method of controlling a magnetic bearing based on the prosecution of determining in advance a control activation plan which is a set of control modes, each being any one of or any combination of ABS control, N-cross control, FF control and N-straight control, in relation with rotational speed regions of a rotor supported by said bearing, selecting a control mode in said plan depending on the actual rotor speed, and controlling said bearing in accordance with the selected control mode.

Claim 15

A method of controlling a magnetic bearing, said method comprising: N-cross control, N-straight control and FF control in arbitrary combination.

Claim 16

A method of controlling a magnetic bearing, said method comprising: N-cross control, N-straight control and FF control in arbitrary combination.

Claim 17

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N and produces a second control signal: first power amplifying means which amplifies a differential value between said first control signal and a value proportional to the y N and supplies a resulting exciting current to an electromagnet of said magnetic bearing; and second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the x N and supplies a resulting exciting current to another electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal to the input or output of said first control means: and means of adding a value proportional to said sine wave signal to the input or output of said second control means.

Claim 18

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N and produces a second control signal: first power amplifying means which amplifies a differential value between said first control signal and a value proportional to the y N and supplies a resulting exciting current to an electromagnet of said magnetic bearing; and second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the x N and supplies a resulting exciting current to another electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal to the input or output of said first control means: and means of adding a value proportional to said sine wave signal to the input or output of said second control means.

Claim 19

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N by a proportion factor β and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N by a proportion factor β and produces a second control signal; first power amplifying means which amplifies a differential value between said first control signal and a value proportional to the y N by a proportion factor α and supplies a resulting exciting current to an electromagnet of said magnetic bearing; second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the x N by said proportion factor α and supplies a resulting exciting current to another electromagnet of said magnetic bearing; and means of setting said proportion factors α and β variably in accordance with the rotor speed; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses: means of adding a value proportional to said cosine wave signal by a proportion factor γ to an input or output of said first control means; and means of adding a value proportional to said sine wave signal by said proportion factor γ to an input or output of said second control means, said factor setting means setting said proportion factor γ, variably in accordance with the rotor speed.

Claim 20

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N by a proportion factor β and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N by a proportion factor β and produces a second control signal; first power amplifying means which amplifies a differential value between said first control signal and a value proportional to the y N by a proportion factor α and supplies a resulting exciting current to an electromagnet of said magnetic bearing; second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the x N by said proportion factor α and supplies a resulting exciting current to another electromagnet of said magnetic bearing; and means of setting said proportion factors α and β variably in accordance with the rotor speed; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses: means of adding a value proportional to said cosine wave signal by a proportion factor γ to an input or output of said first control means; and means of adding a value proportional to said sine wave signal by said proportion factor γ to an input or output of said second control means, said factor setting means setting said proportion factor γ, variably in accordance with the rotor speed.

Claim 21

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N and produces a second control signal; first power amplifying means which amplifies a summed value of said first control signal and a value proportional to the x N and supplies a resulting exciting current to an electromagnet of said magnetic bearing; and second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the y N and supplies a resulting exciting current to another electromagnet of said magnetic bearing.

Claim 22

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N and produces a second control signal; first power amplifying means which amplifies a summed value of said first control signal and a value proportional to the x N and supplies a resulting exciting current to an electromagnet of said magnetic bearing; and second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the y N and supplies a resulting exciting current to another electromagnet of said magnetic bearing.

Claim 23

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; first and second control means which produce a first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; first differential means which evaluates a differential value between the x and a value proportional to the x N thereby to produce said first input signal; second differential means which evaluates a differential value between the y and a value proportional to the y N thereby to produce said second input signal; first power amplifying means which amplifies a summed value of said first control signal and a value proportional to the x N and supplies a resulting exciting current to an electromagnet of said magnetic bearing; and second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the y N and supplies a resulting exciting current to another electromagnet of said magnetic bearing.

Claim 24

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; first and second control means which produce a first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; first differential means which evaluates a differential value between the x and a value proportional to the x N thereby to produce said first input signal; second differential means which evaluates a differential value between the y and a value proportional to the y N thereby to produce said second input signal; first power amplifying means which amplifies a summed value of said first control signal and a value proportional to the x N and supplies a resulting exciting current to an electromagnet of said magnetic bearing; and second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the y N and supplies a resulting exciting current to another electromagnet of said magnetic bearing.

Claim 25

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N by a proportion factor β and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N by said proportion factor β and produces a second control signal; first power amplifying means which amplifies a summed value of said first control signal and a value proportional to the x N by a proportion factor δ and supplies a resulting exciting current to an electromagnet of said magnetic bearing; second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the y N by said proportion factor δ and supplies a resulting exciting current to another electromagnet of said magnetic bearing; and means of setting said proportion factors B and δ variably in accordance with the rotor speed.

Claim 26

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N by a proportion factor β and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N by said proportion factor β and produces a second control signal; first power amplifying means which amplifies a summed value of said first control signal and a value proportional to the x N by a proportion factor δ and supplies a resulting exciting current to an electromagnet of said magnetic bearing; second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the y N by said proportion factor δ and supplies a resulting exciting current to another electromagnet of said magnetic bearing; and means of setting said proportion factors B and δ variably in accordance with the rotor speed.

Claim 28

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing, first and second control means which produce first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; first differential means which evaluates a differential value between the x and a value proportional to the x N by a proportion factor β thereby to produce said first input signal; second differential means which evaluates a differential value between the y and a value proportional to the y N by said proportion factor β thereby to produce said second input signal; first power amplifying means which amplifies a summed value of said first control signal and a value proportional to the x N by a proportion factor δ and supplies a resulting exciting current to an electromagnet of said magnetic bearing; second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the y N by said proportion factor δ and supplies a resulting exciting current to another electromagnet of said magnetic bearing; and means of setting said proportion factors β and γ variably in accordance with the rotor speed.

Claim 29

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing, first and second control means which produce first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; first differential means which evaluates a differential value between the x and a value proportional to the x N by a proportion factor β thereby to produce said first input signal; second differential means which evaluates a differential value between the y and a value proportional to the y N by said proportion factor β thereby to produce said second input signal; first power amplifying means which amplifies a summed value of said first control signal and a value proportional to the x N by a proportion factor δ and supplies a resulting exciting current to an electromagnet of said magnetic bearing; second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the y N by said proportion factor δ and supplies a resulting exciting current to another electromagnet of said magnetic bearing; and means of setting said proportion factors β and γ variably in accordance with the rotor speed.

Claim 30

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N and produces a second control signal; first power amplifying means which amplifies a summed value of said first control signal and a value proportional to the x N and supplies a resulting exciting current to an electromagnet of said magnetic bearing; and second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the y N and supplies a resulting exciting current to another electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal to the input or output of said first control means; and means of adding a value proportional to said sine wave signal to the input or output of said second control means.

Claim 31

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N and produces a second control signal; first power amplifying means which amplifies a summed value of said first control signal and a value proportional to the x N and supplies a resulting exciting current to an electromagnet of said magnetic bearing; and second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the y N and supplies a resulting exciting current to another electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal to the input or output of said first control means; and means of adding a value proportional to said sine wave signal to the input or output of said second control means.

Claim 32

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N by a proportion factor β and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N by said proportion factor β and produces a second control signal; first power amplifying means which amplifies a composite value of a differential value between said first control signal and a value proportional to the y N by a proportion factor α and a value proportional to the x N by a proportion factor δ, and supplies a resulting exciting current to an electromagnet of said magnetic bearing; and second power amplifying means which amplifies a composite value of a differential value between said second control signal and a value proportional to the x N by said proportion factor α and a value proportional to the y N by said proportion factor δ, and supplies a resulting exciting current to another electromagnet of said magnetic bearing.

Claim 33

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N by a proportion factor β and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N by said proportion factor β and produces a second control signal; first power amplifying means which amplifies a composite value of a differential value between said first control signal and a value proportional to the y N by a proportion factor α and a value proportional to the x N by a proportion factor δ, and supplies a resulting exciting current to an electromagnet of said magnetic bearing; and second power amplifying means which amplifies a composite value of a differential value between said second control signal and a value proportional to the x N by said proportion factor α and a value proportional to the y N by said proportion factor δ, and supplies a resulting exciting current to another electromagnet of said magnetic bearing.

Claim 39

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; first and second control means which produce a first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; first differential means which evaluates a differential value between the x and a value proportional to the x N (by proportion factor β) thereby to produce said first input signal; second differential means which evaluates a differential value between the y and a value proportional to the y N (by proportion factor β) thereby to produce said second input signal; first power amplifying means which amplifies a composite value of a differential value between said first control signal and a value proportional to the y N (by proportion factor α) and a value proportional to the x N (by proportion factor δ), and supplies a resulting exciting current to a electromagnet of said magnetic bearing; and second power amplifying means which amplifies a composite value of a differential value between said second control signal and a value proportional to the x N (by proportion factor α) and a value proportional to the y N (by proportion factor δ), and supplies a resulting exciting current to another electromagnet of said magnetic bearing.

Claim 40

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; first and second control means which produce a first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; first differential means which evaluates a differential value between the x and a value proportional to the x N (by proportion factor β) thereby to produce said first input signal; second differential means which evaluates a differential value between the y and a value proportional to the y N (by proportion factor β) thereby to produce said second input signal; first power amplifying means which amplifies a composite value of a differential value between said first control signal and a value proportional to the y N (by proportion factor α) and a value proportional to the x N (by proportion factor δ), and supplies a resulting exciting current to a electromagnet of said magnetic bearing; and second power amplifying means which amplifies a composite value of a differential value between said second control signal and a value proportional to the x N (by proportion factor α) and a value proportional to the y N (by proportion factor δ), and supplies a resulting exciting current to another electromagnet of said magnetic bearing.

Claim 41

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N by a proportion factor β and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N by said proportion factor β and produces a second control signal; first power amplifying means which amplifies a composite value of a differential value between said first control signal and a value proportional to the y N by a proportion factor α and a value proportional to the x N by a proportion factor δ, and supplies a resulting exciting current to an electromagnet of said magnetic bearing; second power amplifying means which amplifies a composite value of a differential value between said second control signal and a value proportional to the x N by said proportion factor α and a value proportional to the y N by said proportion factor δ, and supplies a resulting exciting current to another electromagnet of said magnetic bearing; and means of setting said proportion factors α, β and δ variably in accordance with the rotor speed.

Claim 42

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N by a proportion factor β and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N by said proportion factor β and produces a second control signal; first power amplifying means which amplifies a composite value of a differential value between said first control signal and a value proportional to the y N by a proportion factor α and a value proportional to the x N by a proportion factor δ, and supplies a resulting exciting current to an electromagnet of said magnetic bearing; second power amplifying means which amplifies a composite value of a differential value between said second control signal and a value proportional to the x N by said proportion factor α and a value proportional to the y N by said proportion factor δ, and supplies a resulting exciting current to another electromagnet of said magnetic bearing; and means of setting said proportion factors α, β and δ variably in accordance with the rotor speed.

Claim 44

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; first and second control means which produce first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; first differential means which evaluates a differential value between the x and a value proportional to the x N by a proportion factor β thereby to produce said first input signal; second differential means which evaluates a differential value between the y and a value proportional to the y N by said proportion factor β thereby to produce said second input signal; first power amplifying means which amplifies a summed value of a differential value between said first control signal and a value proportional to the y N by a proportion factor α and a value proportional to the x N by a proportion factor δ, and supplies a resulting exciting current to an electromagnet of said magnetic bearing; and second power amplifying means which amplifies a summed value of a differential value between said second control signal and a value proportional to the x N by said proportion factor α and a value proportional to the y N by said proportion factor δ, and supplies a resulting exciting current to another electromagnet of said magnetic bearing; and means of setting said proportion factors α, β and δ variably in accordance with the rotor speed.

Claim 45

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; first and second control means which produce first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; first differential means which evaluates a differential value between the x and a value proportional to the x N by a proportion factor β thereby to produce said first input signal; second differential means which evaluates a differential value between the y and a value proportional to the y N by said proportion factor β thereby to produce said second input signal; first power amplifying means which amplifies a summed value of a differential value between said first control signal and a value proportional to the y N by a proportion factor α and a value proportional to the x N by a proportion factor δ, and supplies a resulting exciting current to an electromagnet of said magnetic bearing; and second power amplifying means which amplifies a summed value of a differential value between said second control signal and a value proportional to the x N by said proportion factor α and a value proportional to the y N by said proportion factor δ, and supplies a resulting exciting current to another electromagnet of said magnetic bearing; and means of setting said proportion factors α, β and δ variably in accordance with the rotor speed.

Claim 46

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N (by proportion factor β) and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N (by proportion factor β) and produces a second control signal; first power amplifying means which amplifies said first control signal and supplies a resulting exciting current to a electromagnet of said magnetic bearing; second power amplifying means which amplifies said second control signal and supplies a resulting exciting current to another electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal (by proportion factor γ) to the input or output of said first control means; and means of adding a value proportional to said sine wave signal (by proportion factor γ) to the input or output of said second control means.

Claim 47

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N (by proportion factor β) and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N (by proportion factor β) and produces a second control signal; first power amplifying means which amplifies said first control signal and supplies a resulting exciting current to a electromagnet of said magnetic bearing; second power amplifying means which amplifies said second control signal and supplies a resulting exciting current to another electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal (by proportion factor γ) to the input or output of said first control means; and means of adding a value proportional to said sine wave signal (by proportion factor γ) to the input or output of said second control means.

Claim 48

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; first and second control means which produce a first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; first differential means which evaluates a differential value between the x and a value proportional to the x N (by proportion factor β) thereby to produce said first input signal; second differential means which evaluates a differential value between the y and a value proportional to the y N (by proportion factor β) thereby to produce said second input signal; first power amplifying means which amplifies said first control signal and supplies a resulting exciting current to a electromagnet of said magnetic bearing; second power amplifying means which amplifies said second control signal and supplies a resulting exciting current to another electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal (by proportion factor γ) to the input or output of said first control means; and means of adding a value proportional to said sine wave signal (by proportion factor γ) to the input or output of said second control means.

Claim 49

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; first and second control means which produce a first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; first differential means which evaluates a differential value between the x and a value proportional to the x N (by proportion factor β) thereby to produce said first input signal; second differential means which evaluates a differential value between the y and a value proportional to the y N (by proportion factor β) thereby to produce said second input signal; first power amplifying means which amplifies said first control signal and supplies a resulting exciting current to a electromagnet of said magnetic bearing; second power amplifying means which amplifies said second control signal and supplies a resulting exciting current to another electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal (by proportion factor γ) to the input or output of said first control means; and means of adding a value proportional to said sine wave signal (by proportion factor γ) to the input or output of said second control means.

Claim 50

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N by a proportion factor β and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N by said proportion factor β and produces a second control signal; first power amplifying means which amplifies said first control signal and supplies a resulting exciting current to a electromagnet of said magnetic bearing; second power amplifying means which amplifies said second control signal and supplies a resulting exciting current to another electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal by a proportion factor γ to the input or output of said first control means; means of adding a value proportional to said sine wave signal by said proportion factor γ to the input or output of said second control means; and means of setting said proportion factors β and γ variably in accordance with the rotor speed.

Claim 51

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which receives a differential value between the x and a value proportional to the x N by a proportion factor β and produces a first control signal; second control means which receives a differential value between the y and a value proportional to the y N by said proportion factor β and produces a second control signal; first power amplifying means which amplifies said first control signal and supplies a resulting exciting current to a electromagnet of said magnetic bearing; second power amplifying means which amplifies said second control signal and supplies a resulting exciting current to another electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal by a proportion factor γ to the input or output of said first control means; means of adding a value proportional to said sine wave signal by said proportion factor γ to the input or output of said second control means; and means of setting said proportion factors β and γ variably in accordance with the rotor speed.

Claim 52

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; first and second control means which produce a first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; first differential means which evaluates a differential value between the x and a value proportional to the x N by a proportion factor β thereby to produce said first input signal; second differential means which evaluates a differential value between the y and a value proportional to the y N by said proportion factor β thereby to produce said second input signal; first power amplifying means which amplifies said first control signal and supplies a resulting exciting current to a electromagnet of said magnetic bearing; second power amplifying means which amplifies said second control signal and supplies a resulting exciting current to another electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal by said proportion factor γ to the input or output of said first control means; means of adding a value proportional to said sine wave signal by a proportion factor γ to the input or output of said second control means; and means of setting said proportion factors β and γ variably in accordance with the rotor speed.

Claim 53

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; first and second control means which produce a first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; first differential means which evaluates a differential value between the x and a value proportional to the x N by a proportion factor β thereby to produce said first input signal; second differential means which evaluates a differential value between the y and a value proportional to the y N by said proportion factor β thereby to produce said second input signal; first power amplifying means which amplifies said first control signal and supplies a resulting exciting current to a electromagnet of said magnetic bearing; second power amplifying means which amplifies said second control signal and supplies a resulting exciting current to another electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal by said proportion factor γ to the input or output of said first control means; means of adding a value proportional to said sine wave signal by a proportion factor γ to the input or output of said second control means; and means of setting said proportion factors β and γ variably in accordance with the rotor speed.

Claim 54

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; first and second control means which produce a first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; power amplifying means which amplifies a composite signal of a differential value between said first control signal and a value proportional to the y N by a proportion factor α and a value proportional to the x N by a proportion factor δ and supplies a resulting exciting current to a electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal by a proportion factor γ to the input or output of said first control means; means of adding a value proportional to said sine wave signal by said proportion factor γ to the input or output of said second control means; and means of setting said proportion factors β and γ variably in accordance with the rotor speed.

Claim 55

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; first and second control means which produce a first and second control signals, respectively; filter means for extracting rotation-synchronous components x N and y N from a first input signal to said first control means and a second input signal to said second control means; power amplifying means which amplifies a composite signal of a differential value between said first control signal and a value proportional to the y N by a proportion factor α and a value proportional to the x N by a proportion factor δ and supplies a resulting exciting current to a electromagnet of said magnetic bearing; a two-phase synchronous oscillator which produces a sine wave signal and cosine wave signal in synchronism with rotation pulses; means of adding a value proportional to said cosine wave signal by a proportion factor γ to the input or output of said first control means; means of adding a value proportional to said sine wave signal by said proportion factor γ to the input or output of said second control means; and means of setting said proportion factors β and γ variably in accordance with the rotor speed.

Claim 57

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which produces a first control signal from the detected displacement value x; second control means which produces a second control signal from the detected displacement value y; first power amplifying means which amplifies a summed value of said first control signal and a value proportional to the x N (by proportion factor δ) and supplies a resulting exciting current to a electromagnet of said magnetic bearing; and second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the y N (by proportion factor δ) and supplies a resulting exciting current to another electromagnet of said magnetic bearing.

Claim 58

An apparatus for controlling a magnetic bearing comprising: displacement detection means which detects displacement values x and y from reference positions on two orthogonal axes perpendicular to the rotational axis of a rotor supported by said bearing; filter means for extracting rotation-synchronous components x N and y N from the detected displacement values x and y; first control means which produces a first control signal from the detected displacement value x; second control means which produces a second control signal from the detected displacement value y; first power amplifying means which amplifies a summed value of said first control signal and a value proportional to the x N (by proportion factor δ) and supplies a resulting exciting current to a electromagnet of said magnetic bearing; and second power amplifying means which amplifies a summed value of said second control signal and a value proportional to the y N (by proportion factor δ) and supplies a resulting exciting current to another electromagnet of said magnetic bearing.