JPS6041762Y2 - magnetic levitation vehicle - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a magnetic levitation vehicle, and more particularly to an arrangement structure for levitation electromagnets.

Recently, research and development of linear motor cars has been progressing as a high-speed ground transportation vehicle.

In a linear motor car, the running body is lifted off the track by magnetic force.

This traveling body, that is, the magnetically levitated vehicle is powered by a propulsion linear induction motor (hereinafter referred to as Linear Induction motor).
It is propelled by a LIM (abbreviation for n Motor) and travels along a rail in a floating state.

The primary side of the LIM is installed on the running road as a magnetic rail, and the secondary side of the LIM is installed on the magnetically levitated vehicle.

As one method for levitating a magnetically levitated vehicle, a DC electromagnet is installed on the magnetically levitated vehicle side, the gap between the rail and the vehicle body is detected by a gap sensor, and the excitation current of the electromagnet is controlled according to the detected amount, so that the vehicle body can be adjusted to an appropriate level. There is a method that allows it to float.

However, when the above-mentioned method is adopted, conventionally, apart from the propulsion linear motor, a magnetic path rail for the electromagnet for levitation has been provided.

In other words, both the magnetic rail, which is the primary side of the propulsion LIM, and the magnetic path rail for magnetic levitation are required.

However, providing separate rails for propulsion and magnetic levitation not only requires a large amount of material, but also requires high construction costs due to the need to construct both rails with high precision.

Therefore, an IDITE has been proposed that uses the same rails for both propulsion and levitation.

However, they discovered that simply sharing the same rails could make levitation control complicated or unstable depending on the conditions.

The present invention solves this problem and provides a magnetically levitated vehicle that enables shared use of rails.

Hereinafter, the present invention will be explained together with the above-mentioned problems with reference to the drawings.

Fig. 1 is a cross section of the linear motor car, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, showing an example of a short secondary LIM, and Fig. 3 is a cross section of the linear motor car. It is a BB arrow sectional view.

In the drawing, 1 is the LIMI next side (magnetic rail), and a LIM primary coil small coil 1b is attached within an iron core 1a provided on the lower surface of the ground support 3 having a T-shaped cross section and extending in the direction of travel.

2 is a LIM secondary side (moving secondary side), and a LIM secondary coil 2b is installed in an iron core 2a along the traveling direction provided at the inner end of an underframe 4 with a substantially U-shaped cross section that straddles the support body 3. ing.

Reference numeral 5 denotes an electromagnet, which is provided on the underframe 4 on both sides of the LIM secondary side on the same straight line in the traveling direction as the LIM secondary side 2.

The LIM primary side 1 serves as an attraction piece for the electromagnet 5.

The electromagnets 5 constitute one block before and after the LIM secondary side 2, forming a series circuit, and the excitation current is controlled separately for each block.

In addition, by selecting the pole pitch of the electromagnet 5 to be 172, which is the pole pitch of the LIMI secondary side 1, it is possible to prevent the electromagnet 5 from generating power in the LIM primary coil small coil 1b.

In addition, 6 is a vehicle, 7 is a cushion between the vehicle 6 and the underframe 4,
8 is a current collector, 9 is a guiding magnet, and 10 is a guiding attraction iron piece.

Further, arrow C in FIGS. 2 and 3 indicates the traveling direction of the magnetically levitated vehicle.

In such a magnetic levitation vehicle, the levitation is maintained at an appropriate levitation height by controlling the excitation current of the electromagnet 5 for each block based on the amount detected by the gap sensor, as in the usual case.

In addition, propulsion is also performed under the operation control of the LIM, which is composed of the LIM primary side 1 and the LIM secondary side 2, as usual.

However, since the traveling wave magnetomotive force caused by the LIM and the attraction magnetomotive force caused by the electromagnet 5 have relative speeds, the attraction force distribution in the internal traveling direction in each of the front and rear electromagnet blocks changes over time.

In this case, since the pole pitch ratio between the LIM and the electromagnet 5 is set to 2:1, the attractive force per pole of the electromagnet 5 has a time-varying component in addition to the average value.

However, this component is zero when averaged over time.

Therefore, when the number of pole pairs is odd, a time-varying component remains, and since this component is a function of slip, control is required to remove it, causing control complexity and instability. .

However, if the number of pole pairs of the electromagnets in the former and latter blocks is selected to be an even number, the time-varying components within the block are canceled out and become zero, so the problem that occurs when the number is odd does not occur.

Therefore, in the embodiment illustrated in the present invention, two N-polarity electromagnets and two S-polarity electromagnets are arranged at the front and rear of the LIM secondary side 2, and the number of pole pairs of the electromagnets 5 in each block is set to 2. .

Note that it is clear in principle that the pole pitch ratio between the LIM and the electromagnet 5 should be 2:1 or even an even number; 1.

To supplement the above qualitative explanation, a mathematical explanation will be given below with reference to FIG. 2.

First, the LIM secondary side is used as a coordinate reference.

By setting the polar pitch of LIM to τ2, the boundary point −”TAL, −rp/2, dep (2p
-172) and "rop".

(a) Magnetomotive force due to LIM 'LIM is given by the following equation (1).

fuM= (UI U2) ALLcos (v−ξ
)rp + (U3-U4) AL2cos (-π-ξ-p ψ) -(1) However, -xTAIL<XTEHAU1=-XT
For AIL< x, U1=O. For XTOP<X, U2=1. For XTOF<X, U2=O. U4=1 rp (U4=0 in 2p→kuX Also, ALI is the magnetomotive force amplitude on the primary side of LIM, and AL2 is L
Magnetomotive force amplitude on the IM secondary side, p is the number of pole pairs on the LIM secondary side, ξ is the phase difference (function of time and slip) between the LIM secondary side coordinate origin and the LIMI secondary side magnetomotive force maximum value point, φ is the LIM primary side The phase delay angle of the LIMZ side magnetomotive force from the magnetomotive force is:

(b) Under similar conditions, the magnetomotive force fM due to the electromagnet is given by the following equation (2).

fM” (UI U3) AM-1 □ Straddle ball 1fp
π + (U4-U2) AMs+n"x'rop"
W ''' (2) rp However, AM is the magnetomotive force amplitude of the electromagnet.

(c) Therefore, the magnetic flux density distribution b(X) in the air gap is determined from the above two magnetomotive forces ft, XM and fv.

This air gap magnetic flux density b (
) is given by the following equation (3).

b(X)=(U,-U3)(B,,.

. straddle five stomachs πτp Ten B.

os(−π−ξ)) 'rp +(U4-U2) (BM, in”’ xTOj.

'rp +BL1oos (-π-ξ)) dep + (U3-U4) (Bl,tcos (-1ξ)f
p 10BL2co5(=-me9)) ...(
3) fp However, BM is the amplitude of the magnetic flux density due to the electromagnet magnetomotive force, BL□ is the amplitude of the magnetic flux density due to the LIM primary side magnetomotive force, and Bi, 2 is the amplitude of the magnetic flux density due to the LIM secondary side magnetomotive force.

) Next, find the attraction force FM by the electromagnet.

This is obtained by partially differentiating the magnetic energy in the gap in the gap length direction, but it ignores the gap permeance irregularity, and the third term on the right side of equation (3) is the gap magnetic flux density distribution of the LIM that is usually considered. Since it can be expressed as the following equation (4), the attraction force FM is given by the following equation (5).

bg” (U3-U4) Bgcos (-1ψ)
...(4) fp However, bg is the gap magnetic flux density, bg is its amplitude, and φ is the phase difference.

XTALL10P’γ2 FM=-f(BMsInstraddle π+BL□.

os (--Po fp
7pξ)) 2dx TAI L XTOP 10f (BMs, n2x-X,,,π +BLICO
8 (-1μOfp γpξ)
)2dX XTOP P' r p ・
...(5) However, P' is the number of pole pairs of the electromagnet in the l block.

(e) Here, if k is a positive integer (1, 2, 3...) and calculate formula (5) for the cases of P'=2 and P'≠2, then in the case of P'=2 : FM=2P′γpL (BM2 +ZBLt”)/Po
...(6) When P'≠2: FM=2P'7pL (BM" + BL1") /μ
.

-ji〔□(cossu72XTAILπ-ξ) -cos
γp XTAIL (ξ)) fp ten cos (P'π ten ξ) −cosξ +! (cos (terribly ヱπ-ξ) 3 fp -6゜5 (2XTOP-y'γpr-e)'rP +cosξ-cos (P'7+ξ)) /p, o
...(7) However, L is the gap length, and U0 is the magnetic permeability of vacuum.

(v) Considering equations (6) and (7), ξ is not included in equation (6), but ξ remains in equation (7).

Since ξ is a function of time and slip as described above, if ξ exists, an unbalanced oscillatory electromagnetic attraction force will act on the front and rear electromagnet blocks.

On the other hand, if P' = 2, that is, the number of pole pairs of each electromagnet block is an even number, the electromagnetic attractive force does not include the term ξ, so
No vibratory suction force is generated.

As explained above, according to the present invention, even if both propulsion and levitation rails are shared, the electromagnetic attraction force does not have an oscillatory component, so when obtaining an appropriate levitation height by controlling the excitation current of the electromagnet, , its control is simple and stable.

Therefore, by sharing the same rails, it became possible to create rails for linear motor cars using fewer materials and at lower construction costs.

[Brief explanation of the drawing]

The drawings relate to the present invention; Figure 1 is a cross-sectional view of the magnetic levitation vehicle;
2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is a sectional view taken along the line BB in FIG. 1. In the drawing, 1 is the primary side of the propulsion linear induction motor, 1a is its iron core, 1b is the primary coil, 2 is the secondary side of the propulsion linear induction motor, 2a is its iron core, and 2b is the Secondary coil, 3 is a support, 4 is an underframe, 5
is an electromagnet, 6 is a vehicle, 7 is a cushion, 8 is a current collector, 9 is a guiding magnet, and 10 is a guiding attraction iron piece.

Claims (1)

[Scope of utility model registration request] The primary side of a linear induction motor that has an iron core and generates traveling wave magnetic flux for propulsion is also used as a suction iron core, and the secondary side of the moving body part where the secondary side of the linear induction motor is installed. In the magnetic levitation vehicle, the magnetic levitation vehicle is provided with an electromagnet disposed on the same line in the traveling direction and that causes a magnetic attraction force to be generated between the attraction core and the moving body to levitate the moving body, the electromagnet being configured as a block consisting of a plurality of electromagnets forming a series circuit. A magnetic levitation vehicle characterized in that the pole pitch of the electromagnets is a length divided by the number of pole pitches of the linear induction motor, and the number of pole pairs of the electromagnets in the block is an even number.