JPS6040820A - Control method for magnetic bearing device - Google Patents

Abstract

PURPOSE:To perform stable control of a magnetic bearing by multiplying, the number of rotation detection signal multiplied by coefficient, by each torque command value and adding an integral value of this signal to the torque command of one side and subtracting the same from the torque command of the other side. CONSTITUTION:Electromagnets 1(a)-1(h) are provided on both end parts of a rotary shaft A and support the rotary shaft in the air. Command torque Ttheta, Tpsi are given for control in theta direction and psi direction, however, since gyro action is generated due to this torque, a detection signal from rotation speed detector is multiplied by the coefficient by means of a coefficient instrument. Respective torque command values TpsiS, TthetaS are multiplied by the value obtained as abovementioned by means of a multiplier and the value thus obtained is integrated by means of an integrator and added to the torque command TthetaS of one side, while it is subtracted from the torque command TpsiS of the other side and control is performed by a value obtained through such processes of operation. Thus, gyro action in the orthogonal direction is negated.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method of controlling a magnetic bearing device.

[Background technology]

7. Magnetic bearings use magnetic force to support the rotating body in a completely non-contact manner, are free from lubrication problems, can be used even in special environments, and have M-stops.

Magnetic bearing devices are being actively researched to put them into practical use because they have the advantage of being able to operate at ultra-high speeds because they have no or very little problems with wear and M noise.

The sailor previously discovered that, in a magnetic bearing device in which both ends of a rotating shaft are supported in the air by magnetic rack supports, as specified in JIA 1982-217082, the magnetic attraction forces acting on both ends of the self-rotating shaft are mutually equal. We proposed a control method for a magnetic bearing device that prevents interference from occurring.

However, it has been found that this method has the disadvantage that it takes a long time to set foot due to the gyroscopic effect when the motor rotates at a still high speed.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a control method for a magnetic bearing device that predicts whirling due to gyroscopic action and attempts to suppress its occurrence.

[Summary of the invention]

The present invention is a 4-axis suction control type magnetic bearing device that consists of two radial bearings, and detects displacement in the 4-axis directions to determine the displacement of the center of gravity and the deflection angle around the center of gravity, and to keep them constant. When performing such control, multiply the 5-rotation speed detection signal by a coefficient and each torque command 1 shift, integrate this signal, apply it to one torque command, and subtract it from the other torque command. It was designed to do so.

[Embodiments of the invention]

Hereinafter, specific embodiments of this invention will be described using figures.

First, in order to facilitate the ti solution, the gyro effect (occurrence of pitching and yawing) of the magnetic bearing system will be explained.

Such gyroscopic action is described in Public Corporation Document 1, "Basic method of horizontal axis type I air bearing and side-tilt system design" (Fumio Matsumura, Journal of the Institute of Electrical Engineers, 56-019), Fig. 1. It is represented by the block diagram shown in .

In the figure 2 &'Zl l ftm l 'Z31'
Z41' r I* fr * *fr8. fr4 is the magnet H surrounding the rotating shaft as shown in Figure 2 (a).
a), Hb), Hc), 1(d), He).

H-r), Hg), Hh), gZI I
gZ21g41 gZ41 g r t r g r
z r g r s r g r 4 c. As shown in FIGS. 21 (b) and (c), K is the gap at the location corresponding to the attraction force = bp, and w is the gap in the equilibrium state. Also, P is the rolling angular velocity, Jx and J,'
ri is the moment of inertia around the X-axis and the y-axis, respectively.

Figure 3 shows the central part of Figure 1.

The command torques Tθ and Tψ in the θ direction and ψ direction are respectively expressed by the following equations. However, for easy VC-)-11-1□-
1 and 3. From the figure, equation (2) of first order holds true.

However, in Figure 3, 8 is a Lagras operator, so It is.

In Equation (2), if we set ψ=O2ψ=0.

The relationship between Tψ and Tθ is expressed by the following equation.

Similarly, in equation (2), θ=0. If we set θ=0.

The relationship between 1Tψ and Tθ is expressed by the following equation.

Above Me, Equation (3) is the relationship between Tψ and Tθ such that ψ = ψ - 0, so when controlling θ, that is, when giving a command for Tθ, Tψ also changes according to Equation (3). This means that ψ will not change if a command is given.

Also, since equation (4) is the relationship between Tψ and Tθ such that θ = θ = 0, when controlling ψ, that is, when giving a command for Tψ, a command is also given to Tθ according to equation (4). This means that if θ is given, θ will not change.

Therefore, the embodiment of the present invention shown in FIG. 4 incorporates a control method based on equations (3) and <4).

The feature of the present invention is that when a torque command is given to control θ and ψ, it is known that a gyroscopic action is caused by the torque, so at the same time as the torque command is given, a torque command that cancels the gyroscopic action in the orthogonal direction is given. By giving the same value, the part surrounded by the one-dot chain line in the 5g diagram is the fc part, which is the fc part according to the present invention.

The rest is the above-mentioned magnetic bearing control device proposed by the present applicant; 16 to 19 and 16' to 19' are N-power converters; 24 to 27, 24' to 27', 30 to 32, and 30
' to 32' are coefficient units, 28, 28', 29 and 29' are PID controllers, and 33, 33', 34 and 34' are linearization controllers.

In the present invention, the detection signal W of the rotational speed detector 2 is multiplied by a coefficient by a coefficient multiplier 3, and then multiplied by a multiplier ◆ to each torque index value Tψ8. Multiply Tψ8 and integrate it by integrators 5, 5, respectively, and add it to one torque command Tθ3 and subtract it from the other torque command Tθ8,
By controlling with the calculated value, the gyro effect in the orthogonal direction is canceled.

〔effect〕

According to the present invention, since the swing caused by the gyroscopic action is predicted and calculated, the settling speed during high-speed rotation is quickly achieved.
, a cheap and short cape can be realized.

[Brief explanation of drawings]

Figure 1 is a block diagram that affects the gyro effect of the magnetic bearing system, Figure 2 is an explanatory diagram showing the arrangement of electromagnets in the magnetic bearing device, their iron attraction, and the valley gap, and Figure 3 is the same diagram as Figure 1. FIG. 4 is an enlarged block diagram showing an example of the present invention.
Coefficient unit, cow, 4'... multiplier, 5, 5'... integrator tube j circle 3rd jH

Claims (1)

[Claims] Among magnetic bearing devices, electromagnets are provided at both ends of the rotating shaft, and the rotating shaft is supported in the air by the magnetic attraction of the electromagnets.
In the Dou JJ4fJg & pull control type magnetic bearing device that constitutes two radial bearings, the displacement deviation of the center of gravity of the rotating shaft and the deflection angle of the rotation of the center of gravity are determined from the displacement deviation of the rotating shaft at the points of application of the magnetic attraction force at both ends of the rotating shaft. When the electromagnets provided at both ends are controlled to control the force acting on the center of gravity and the torque of the rotation of the center of gravity so that the displacement deviation of the center of gravity and the deflection angle of the rotation of the center of gravity become 0. One time & several tests
A magnetic bearing device whose percentage sign is to multiply the kJ signal multiplied by a coefficient and each torque command value, then integrate this signal and add it to one torque command and subtract it from the other torque command. control method.