CN101242151A - Suspending magnetic stagnant compensation method - Google Patents

Abstract

The invention discloses a compensation method for magnetic suspension hysteresis, comprising the following steps of: using a sensor to measure offset; using a controller to generate a differential control signal, and judging a demagnetization control signal; processing weighing treatment for the demagnetization control signal; using a power amplifier to generate excitation current of generating magnetization and demagnetization respectively; wherein, the excitation current enables the increasing amount equal to the decreasing amount of magnetic strength generated by the differential electromagnet; or making the increasing amount equal to the decreasing amount of a magnetic strength generated by the differential electromagnet by increasing the compensation current for increasing compensation coil and corresponding compensation power amplifier. The invention compensates magnetic hysteresis. The invention is simple and convenient, stable and reliable. The invention makes the increasing amount equal to the decreasing amount of magnetic strength generated by the differential electromagnet. The invention carbonizes and equalizes magnetization and demagnetization. The invention guarantees the suspended matter restore to balancing position, so as to improve stability of the magnetic suspension system.

Description

The compensation method of suspending magnetic stagnant

Technical field

The present invention relates to maglev electromagnetic force control, more particularly, relate to a kind of compensation method of suspending magnetic stagnant.

Background technology

The operation principle of magnetic suspension bearing and electromagnetism band steel systems stabilisation is basic identical, see also shown in Figure 1, can be departed from original equilbrium position by suspended matter 1 under external disturbance, bias is measured by transducer 3a and 3b, and controller 5 produces differential control signal (u according to bias ₀+ Δ u) and (u ₀-Δ u), power amplifier 4a and 4b convert control signal to the exciting current (I of coil 6a and 6b ₀+ Δ i) and (I ₀-Δ i), exciting current makes electromagnet 2a and 2b produce differential magnetic field respectively, is subjected in differential magnetic field under the force action of magnetic field by suspended matter 1, and the direction point towards equilibrium positions returns to the equilbrium position thereby make by suspended matter 1.But have hysteresis in real process, see also shown in Figure 2ly, when being departed from the equilbrium position by suspended matter, electromagnet coil current in the differewntial electromagnet increases Δ i, and corresponding magnetic field intensity has increased Δ H, magnetic flux density has increased Δ B; And another electromagnet coil current reduces Δ i, corresponding magnetic field intensity reduces Δ H, because the B-H characteristic curve is a closed curve with directivity, the variation of magnetic induction density B always lags behind the variation of magnetic field intensity H, so B increases with H and reduces not to be along same curve, therefore corresponding magnetic flux density does not reduce Δ B, but reduced Δ B ', the increase of magnetic flux density and reduce unequal meeting cause two differewntial electromagnets produce respectively add magnetic with the demagnetization asynchronous on phase place, difference is arranged in size, cause magnetic force that increases and the magnetic force that reduces unequal, can't guarantee to be returned to the equilbrium position by suspended matter.

At present, usually the general employing soft magnetic material that coercive force is little, saturation flux density is high is made differewntial electromagnet, because the area of hysteresis loop of this kind material is little, the non-linear of B-H characteristic weakens, the magnetic flux density that makes differewntial electromagnet produce is basic identical, make add magnetic with the demagnetization also accomplish easily to equate, so this method can satisfy the compensation of the magnetic hysteresis of most of magnetic suspension bearing.But for magnetic suspension band steel etc., because air gap is big in the magnetic circuit, the non-linear enhancing of B-H characteristic, the magnetic flux density that differewntial electromagnet produces is difficult to protect just equal, make that to add magnetic asynchronous, unequal with demagnetization, cause the increase of electromagnetic force and reduce unequally, can't guarantee to be returned to the equilbrium position by suspended matter, thereby increased the control difficulty, reduced the stability of magnetic suspension system.

Summary of the invention

Add magnetic and demagnetize asynchronous, unequal at what the above-mentioned differewntial electromagnet that exists in the prior art produced, can't guarantee that suspended matter returns to the equilbrium position, increased the control difficulty, reduced the shortcoming of maglev stability, the purpose of this invention is to provide the compensation method of suspending magnetic stagnant, this method is simple and convenient, and the stability of magnetic suspension system is strengthened.

For achieving the above object, the present invention adopts following technical scheme:

Scheme one, the compensation method of this suspending magnetic stagnant may further comprise the steps:

A. use transducer to measure side-play amount;

B. use controller to produce differential control signal, and judge the control signal that needs demagnetization;

C. the control signal that the needs that produce among the step B are demagnetized is weighted processing;

D. use power amplifier to produce and produce the exciting current that adds magnetic and demagnetization respectively;

E. the exciting current that produces among the step D makes the magnetic flux density recruitment of differewntial electromagnet generation equate with decrease.

Preferably, the weighted among the described step C is for multiply by weighted factor with control signal.

Preferably, the calculation procedure of described weighted factor is as follows:

C1. draw the magnetization B-H characteristic curve of the core material of differewntial electromagnet;

C2. magnetization B-H characteristic curve is carried out linearization process in quiescent point, obtain the slope that adds magnetic and demagnetization of differewntial electromagnet respectively;

C3. calculate weighted factor.

Preferably, the computing formula of weighted factor is among the described step C3:

$k=\frac{k_1}{k_2},({\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="A20071003719700101.png,A20071003719700121.png"\; state="\{\{state\}\}">k</figure-callout>}}_1>k_2)$

Wherein k is a weighted factor, k ₁Add magnetic slope, k for iron core ₂Demagnetization slope for iron core;

Preferably, the recruitment of the exciting current that adds magnetic and demagnetization among the described step D is different with decrease.

Scheme two, the compensation method concrete steps of this suspending magnetic stagnant are as follows:

A. on two differewntial electromagnets, increase bucking coil and corresponding compensation power amplifier respectively;

B. use transducer to measure side-play amount;

C. use controller to produce differential control signal, and judge the control signal that needs demagnetization;

D. use controller to produce compensating signal;

E. use the corresponding compensation power amplifier will convert the offset current of bucking coil to the compensating signal that produces among the step D;

F. offset current produces the compensation electromagnetic induction, and the magnetic flux density recruitment that differewntial electromagnet is produced equates with decrease.

Preferably, the calculation procedure of the offset current among the D of described step is as follows:

D1. draw the magnetization B-H characteristic curve of the core material of differewntial electromagnet;

D2. magnetization B-H characteristic curve is carried out linearization process in quiescent point, obtain the slope that adds magnetic and demagnetization of differewntial electromagnet respectively;

D3. calculate offset current.

Preferably, the computing formula of offset current is among the D3 of described step:

${\mathrm{\&Delta;i}}^{\&prime;}=\frac{k_1-k_2}{k_2}\mathrm{\&Delta;i},({\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="A20071003719700101.png,A20071003719700121.png"\; state="\{\{state\}\}">k</figure-callout>}}_1>k_2)$

Wherein Δ i ' is an offset current, k ₁Add magnetic slope, k for iron core ₂Be the demagnetization slope of iron core, Δ i is the increment of the exciting current of respective differences motor magnet.

Preferably, described offset current is opposite with the exciting current direction of respective differences motor magnet.

In technique scheme, the compensation method of suspending magnetic stagnant of the present invention has used transducer to measure side-play amount; Use controller to produce differential control signal, and judge the control signal that needs demagnetization; Control signal to the needs demagnetization is weighted processing; Use power amplifier to produce and produce the exciting current that adds magnetic and demagnetization respectively; The magnetic flux density recruitment that exciting current produces differewntial electromagnet equates with decrease.The compensation method of suspending magnetic stagnant of the present invention has also increased bucking coil and corresponding compensation power amplifier respectively on two differewntial electromagnets; Use transducer to measure side-play amount; Use controller to produce differential control signal, and judge the control signal that needs demagnetization; Use controller to produce compensating signal; Use the corresponding compensation power amplifier will convert the offset current of bucking coil to the compensating signal that produces among the step D; Offset current produces the compensation electromagnetic induction, and the magnetic flux density recruitment that differewntial electromagnet is produced equates with decrease.Adopt the compensation of the present invention to suspending magnetic stagnant, simple and convenient, reliable and stable, the magnetic flux density recruitment that differewntial electromagnet is produced equates with decrease, make to add magnetic and demagnetization synchronously and equate, guarantee to be returned to the equilbrium position, thereby improved the stability of magnetic suspension system by suspended matter.

Description of drawings

Fig. 1 is the maglev operation principle schematic diagram of prior art;

Fig. 2 is the maglev B-H characteristic curve of a prior art schematic diagram;

Fig. 3 is the solution of the present invention one principle schematic;

Fig. 4 is the solution of the present invention one a flow process schematic block diagram;

Fig. 5 is the B-H characteristic curve schematic diagram of the solution of the present invention one;

Fig. 6 is the solution of the present invention two principle schematic;

Fig. 7 is the solution of the present invention two flow process schematic block diagrams;

Fig. 8 is the B-H characteristic curve schematic diagram of the solution of the present invention two.

Embodiment

Further specify technical scheme of the present invention below in conjunction with drawings and Examples.

Embodiment 1

The control signal that employing is demagnetized to needs is weighted the method for processing, i.e. software method.

Please, when under external disturbance, being departed from original equilbrium position, use transducer 3a and 3b to measure bias, use controller 5 to produce differential control signal (u then according to bias by suspended matter 1 in conjunction with Fig. 3, shown in Figure 4 ₀+ Δ u) and (u ₀-Δ u), therefrom judge the control signal that needs demagnetization and be (u ₀-Δ u), to control signal (u ₀-Δ u) is weighted processing, multiply by a weighted factor k and obtain to be (u ₀-k Δ u) control signal uses power amplifier 4a with control signal (u ₀+ Δ u) converts the exciting current (I of coil 6a to ₀+ Δ i), use power amplifier 4b with control signal (u ₀-k Δ u) converts the exciting current (I of coil 6b to ₀-k Δ i), please again in conjunction with shown in Figure 5, because it is unequal to add the decrease k Δ i of magnetic flux density of the differewntial electromagnet 2b that recruitment Δ i and needs of magnetic flux density of the differewntial electromagnet 2a of magnetic demagnetize, just can make the electromagnet magnetic flux density recruitment of generation equate to be Δ B with decrease, make that two differewntial electromagnet 2a and 2b produce respectively add magnetic and demagnetization on phase place synchronously, at equal and opposite in direction, equate with the electromagnetic force that reduces thereby differewntial electromagnet is increased, guarantee to be returned to the equilbrium position by suspended matter 1.Please consult shown in Figure 5 again, the calculation procedure of weighted factor k is: research by experiment earlier, draw out the magnetization B-H characteristic curve of the outstanding material of iron of differewntial electromagnet, then magnetization B-H characteristic curve is carried out linearization process in quiescent point, obtain the slope k that adds magnetic of differewntial electromagnet respectively ₁Slope k with demagnetization ₂, calculate weighted factor k by computing formula at last.The formula that calculates weighted factor k employing is $k=\frac{k_1}{k_2}$ , wherein k is a weighted factor, k ₁Add magnetic slope, k for iron core ₂Demagnetization slope for iron core adds the magnetic slope k ₁Greater than the demagnetization slope k ₂

Embodiment 2

Employing increase bucking coil and corresponding compensation power amplifier increase the method for offset current, i.e. hardware method.

Please in conjunction with Fig. 6, shown in Figure 7, on differewntial electromagnet 2a, increase a bucking coil 7a and with bucking coil 7a corresponding compensation power amplifier 4c; On differewntial electromagnet 2b same increase a bucking coil 7b and with bucking coil 7b corresponding compensation power amplifier 4d.When under external disturbance, being departed from original equilbrium position by suspended matter 1, use transducer 3a and 3b to measure bias, use controller 5 to produce differential control signal (u then according to bias ₀+ Δ u) and (u ₀-Δ u), therefrom judge the control signal that needs demagnetization and be (u ₀-Δ u), use power amplifier 4a and 4b respectively with control signal (u ₀+ Δ u) and (u ₀-Δ u) converts the exciting current (I of coil 6a and 6b to ₀+ Δ i) and (I ₀-Δ i); Use controller 5 to produce a compensating signal Δ u ' then, use corresponding compensation power amplifier 4d converts compensating signal Δ u ' to the offset current Δ i ' of the bucking coil 7b on the electromagnet 2b that needs demagnetization, owing to the exciting current (I of offset current Δ i ' with respective differences motor magnet 2b ₀-Δ i) direction is opposite, please in conjunction with shown in Figure 8, the induction of offset current Δ i ' generation compensation electromagnetic, just can make the electromagnet magnetic flux density recruitment of generation equate to be Δ B with decrease, make to need the decrease of magnetic flux density of the electromagnet 2b of demagnetization equal to add the recruitment of magnetic flux density of the electromagnet 2a of magnetic, make that two differewntial electromagnet 2a and 2b produce respectively add magnetic and demagnetization on phase place synchronously, at equal and opposite in direction, equate with the electromagnetic force that reduces thereby differewntial electromagnet is increased, guarantee to be returned to the equilbrium position by suspended matter 1.Please consult shown in Figure 8 again, the calculation procedure of offset current Δ i ' is: research by experiment earlier, draw the magnetization B-H characteristic curve of the core material of differewntial electromagnet, then magnetization B-H characteristic curve is carried out linearization process in quiescent point, obtain the slope k that adds magnetic of differewntial electromagnet respectively ₁Slope k with demagnetization ₂, calculate offset current Δ i ' by computing formula at last.The formula that calculates offset current Δ i ' employing is ${\mathrm{\&Delta;i}}^{\&prime;}=\frac{k_1-k_2}{k_2}\mathrm{\&Delta;i},$ Wherein, wherein Δ i ' is an offset current, k ₁Add magnetic slope, k for iron core ₂Be the demagnetization slope of iron core, Δ i is the increment of the exciting current of respective differences motor magnet, adds the magnetic slope k ₁Greater than the demagnetization slope k ₂

The compensation method of suspending magnetic stagnant of the present invention, easy to use, reliable and stable, by to the compensation of exciting current or increase the method for offset current, the magnetic flux density increase that differewntial electromagnet is produced equates with the amplitude that reduces, add magnetic and demagnetization synchronously and equate thereby make, that guarantees to hang magnetic floating system in the high-precision applications occasion is returned to the equilbrium position by suspended matter, has improved the stability of magnetic suspension system.

Claims (9)

1. the compensation method of a suspending magnetic stagnant is characterized in that,

These method concrete steps are as follows:

A. use transducer to measure side-play amount;

B. use controller to produce differential control signal, and judge the control signal that needs demagnetization;

C. the control signal that the needs that produce among the step B are demagnetized is weighted processing;

D. use power amplifier to produce and produce the exciting current that adds magnetic and demagnetization respectively;

E. the exciting current that produces among the step D makes the magnetic flux density recruitment of differewntial electromagnet generation equate with decrease.

2. the compensation method of suspending magnetic stagnant as claimed in claim 1 is characterized in that,

Weighted among the described step C is for multiply by weighted factor with control signal.

3. the compensation method of suspending magnetic stagnant as claimed in claim 2 is characterized in that,

The calculation procedure of described weighted factor is as follows:

C1. draw the magnetization B-H characteristic curve of the core material of differewntial electromagnet;

C2. magnetization B-H characteristic curve is carried out linearization process in quiescent point, obtain the slope that adds magnetic and demagnetization of differewntial electromagnet respectively;

C3. calculate weighted factor.

4. the compensation method of suspending magnetic stagnant as claimed in claim 3 is characterized in that,

The computing formula of weighted factor is among the described step C3:

$k=\frac{k_1}{k_2},(k_1>k_2)$

Wherein k is a weighted factor, k ₁Add magnetic slope, k for iron core ₂Demagnetization slope for iron core.

5. the compensation method of suspending magnetic stagnant as claimed in claim 1 is characterized in that,

The recruitment of the exciting current that adds magnetic and demagnetization among the described step D is different with decrease.

6. the compensation method of a suspending magnetic stagnant is characterized in that,

These method concrete steps are as follows:

A. on two differewntial electromagnets, increase bucking coil and corresponding compensation power amplifier respectively;

B. use transducer to measure side-play amount;

C. use controller to produce differential control signal, and judge the control signal that needs demagnetization;

D. use controller to produce compensating signal;

E. use the corresponding compensation power amplifier will convert the offset current of bucking coil to the compensating signal that produces among the step D;

F. offset current produces the compensation electromagnetic induction, and the magnetic flux density recruitment that differewntial electromagnet is produced equates with decrease.

7. the compensation method of suspending magnetic stagnant as claimed in claim 6 is characterized in that,

The calculation procedure of the offset current among the D of described step is as follows:

D1. draw the magnetization B-H characteristic curve of the core material of differewntial electromagnet;

D2. magnetization B-H characteristic curve is carried out linearization process in quiescent point, obtain the slope that adds magnetic and demagnetization of differewntial electromagnet respectively;

D3. calculate offset current.

8. the compensation method of suspending magnetic stagnant as claimed in claim 7 is characterized in that,

The computing formula of offset current is among the D3 of described step:

$\mathrm{\&Delta;}{i}^{\&prime;}=\frac{k_1-k_2}{k_2}\mathrm{\&Delta;i},(k_1>k_2)$

Wherein Δ i ' is an offset current, k ₁Add magnetic slope, k for iron core ₂Be the demagnetization slope of iron core, Δ i is the increment of the exciting current of respective differences motor magnet.

9. as the compensation method of the suspending magnetic stagnant of claim 6-8 described in each, it is characterized in that:

Described offset current is opposite with the exciting current direction of respective differences motor magnet.

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