The Effect of Design Parameters of an Integrated Linear Electromagnetic Motor, At the Process of Pulling Away Anchor, From Its Breakaway Stage

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1 International OPEN ACCE Jornal Of Modern Engineering esearch (IJME) The Effect of Design Parameters of an Integrated Linear Electromagnetic Motor, At the Process of Plling Away Anchor, From Its Breakaway tage Dr. Ginady G. Ugarov 1, Dr. Vladimir Iv. Moshkin 2, Dr. Amer h. Massad 3 1 Department of Power pply of Indstrial Enterprises, aratov tate Technical University, ssia 2 Department of Energy and technological of materials, rgan tate University ssia 3 Department of Electrical & Mechanical Engineering, An-Najah National University, Palestine Abstract: This paper assess the inflence of design parameters of ferromagnetic gide hosing at the possess of plling away the anchor from the holding device which is integrated in the design of the motor. The design of an integrated circit and the eqivalent magnetic circit of the integrated LEMM on breakaway stage was bilt, mathematical models of system were laid ot. An expression for its magnetic indction, with which can set the beginning of satration of the shnt, defining moment of plling away anchor from the holding area. an expression is derived for its magnetic indction, with which can set the beginning of satration of the shnt, define moment of anchor plling away from the holding area, the zone of permissible combinations of cross-sectional area of the pper magnetic shnt and holding area, and the zone of change in the magnetic indction in the ke at the plling away moment of the motor anchor. Index Terms: Linear electromagnetic motor, plling away anchor, breakaway stage, holding force, holding device, ferromagnetic gide hosing. I. Introdction Electromagnetic linear machine generates linear motions directly withot rotation-to-translation conversion mechanisms, which significantly simplifies system strctre and improves system efficiency. It has wide applications in aeronatics [1, 2], transportation [3-5], medical devices [6,7] and so on. linear electric motors are able to accmlate energy for the sage, When the generated force is in opposite direction as the sspension velocity [8]. One way of increasing the specific power and energy performance of these linear motors is to force the accmlating of magnetic energy in the working gaps of plsed electromagnetic linear motors (LEMM) by retaining its anchor, which implement the principle of increasing artificially accmlated magnetic energy of rnning clearances on breakaway stage by motors loading [9]. In this breakaway stage, the anchor artificially creates a static reaction force (holding force F ), which decreases abrptly to zero after the start of the armatre. Conseqently, the anchor will start moving nder the inflence of an increased tractive force [1, 11]. The Integration of the holding device of the anchor (DOA) in the motor design in the magnetic core and MMF proposed in [12, 13], has allowed to simplify the design of plse LEMM at the same time to increase its power and energy performance. Design parameters of both holding device of anchor and ferromagnetic gide hosing of plsed LEMM have an effect on the holding force of the motor's anchor. II. Problem tatement Experimental research of the linear electromagnetic motor is a complicated task reqiring se of special experimental eqipment [14]. As mentioned in [15] experimental stdies of sch integrated LEMM showed that the reglation of holding force is difficlt becase it depends on several design parameters of the motor. Therefore, condcting sch experimental research is not feasible (it is not practically possible),as sch verification will take a long time. The inflence of varying the vale of the holding area,which holds the anchor and creates changes of the holding force F on breakaway stage, is the defined and determined in [16]. The motor which has this design is called integrated LEMM. owever obtained expressions in [16], do not allow s to investigate the inflence of the design parameters of the ferromagnetic shnt dring the process of plling away the integrated LEMM anchor. The IJME IN: Vol. 4 Iss.9 ept

2 flx magnitde of the pper shnt and its cross-section have effect on the magnetization process and determine the moment when the breakaway anchor stage reaches satration of the ferromagnetic gide hosing. As the vale,especially at smaller decreases, the shnt is satrated eventally casing holding force F, to be limited to the tractive force F in the moment of plling away motor anchor. In [17] it st is shown that with increasing F increased energy performance of plsed LEMM is obtained. st The prpose of this paper, is to assess the inflence of design parameters of ferromagnetic gide hosing at the possess of plling away the anchor from the holding device which is integrated in the design of the motor. III. Mathematical Models ystem In sch motor design, anchor on breakaway stage is held by its own magnetic field ferromagnetic gide hosing 2 Fig.1, which is called an pper magnetic shnt relative to the pper rnning clearance. Lower magnetic shnt is a ferromagnetic anchor gide 3. Ths, the LEMM in this design has two working clearances shnted by motor parts design - the pper and lower magnetic shnts. Dring operation in this LEMM with holding device (holding device integrated in design), both shnts satrate an eventally affect motor performance. In this LEMM design, holding force F occrs between mating srfaces, which is formed by the pper part of the flat anchor 1 and the top of the inside of the ferromagnetic shnt (2) when they are in contact or almost in contact the gap. Fig. 1: The design of an integrated circit LEMM In sch a motor design, when we connect the coil to the power spply for the first time and ntil the initial magnetic field has not yet nfolded, both the magnetic shnts are also not satrated and have small magnetic relctance, hence Lsh 1. 2 From the eqivalent of the magnetic circit LEMM and with neglecting the leakage flx Fig.2 which is corresponding to the design scheme in Fig. 1, the magnetic flx ke 5 appears as two components: (1) these two components pass in the anchor LEMM almost entirely throgh the pper shnt ( Lsh L and p ), bypassing the pper working clearances, which in this case have mch bigger relctance compared to the relctance of the pper branch of the b shnt Fig.2 and the technological gap Δ: b (2) p p p ; psh (3) IJME IN: Vol. 4 Iss.9 ept

3 Where, the relctance of the air gap p, creates the holding force and forms mating srfaces of the pper p shnt and the top of the anchor 1. Fig. 2: The eqivalent magnetic circit of the integrated LEMM on breakaway stage at a given moment is mch smaller than shnt p de to minimal vale of air gap ;, which is selected p in the initial state of a retrn spring 4 and smaller than the relctance technological gap. Therefore, the expressions (1) and (2) can be written as: ; b Then by the electromagnetic holding force which occrs between the pper shnt and the pper shnt of part anchor, the anchor is attracted to the stationary shnt, and despite the increase of the crrent in the coil anchor it is held in this position. The magnitde of holding force F in this case depends on the magnitde of the magnetic flx of the pper shnt and its contact area with the flat part of the anchor - (olding area) (in Fig.1 shows a heavy line). The magnitde with a certain satration indction B material of the gide hosing (pper shnt) is determined by its cross-sectional area. Accordingly, the vale of holding force nder these conditions will be a fnction of two design parameters - area and area. With increasing mmf motors winding 6 on breakaway anchors stage, the magnetic flx of the pper shnt also increases. Ths, the holding force increases and satrates this ferromagnetic shnt, and relctance begins to increase. As a reslt, shnt flx slowdown and a simltaneos redistribtion of and occrs according to eqation (1). That is, all the blk of the flx in the ke in particlar the flx component extends throgh pper working clearance (the dotted line in Fig.1) which is represented by element in the eqivalent magnetic circit (Fig.2), that creates additional tractive force down, acting on a combined anchor 1 motor. imilar processes occr in the lower shnt with the difference that it is satrated before the pper shnt, and the relctance of the parasitic air gap Fig.2 remains nchanged when the motor is operated and accordingly the tractive force in the parasitic air gap is not created. To assess the inflence of cross-sectional area at the anchor, at the instance of plling-away, it is first necessary to establish the beginning of satration of the pper shnt. According to the magnetization crve schedles, and particlarly at its tablated vales it is difficlt to find these conditions of satration. By an approximation to the magnetization crve of a magnetic steel of ferromagnetic gide hosing 2 (Fig. 1), these conditions are defined easily. For this prpose, the magnetization crve of the material shnt in satration parts, is approximated by piecewise-linear segments and each segment is represented by polynomial of a certain degree as in the following form: ( ) B (4) B where relative permeability of the material of the magnetic shnt at the part of its satration flx density corresponding to the maximm B, magnetic field strength, permeability of free m space, B magnetic indction vale (magnetic flx density), where satration begins of the pper shnt. pag IJME IN: Vol. 4 Iss.9 ept

4 Eqation (4) is the eqation of the line tangent to the magnetization crve at B B, corresponding to the maximm indction indicated by this crve. The maximm magnetic indction B is sally given in the design of plse LEMM [1, 18]. The vale of B in eqation (4) can be fond by sing power polynomial for the crve the magnetic field strength of the material shnt eqals zero. Then the magnetic flx of the pper shnt is: B ) (5) where ( is the cross sectional area of the pper shnt. To determine the magnetic field strength in the pper shnt Figre 2, which implies that, the pper working clearance with relctance B B, when we se the eqivalent circit shown in and shnt branch b both are nder the same magnetic field strength. By CL (when leakage flx neglected), we obtain for this section of the magnetic circit the following relationship: L L (6) where magnetic field strength in the pper working clearance, magnetic field strength in the air gap (shown as a heavy line between the inner mating srfaces of the pper shnt and the top of the anchor 1 Fig.1), and magnetic field strength in the pper magnetic shnt, L the length of the magnetic line of the pper working clearance, L the length of the magnetic line of the pper magnetic shnt. At breakaway stage of the anchor, the magnetic field strength on the air gap between the inner mating srfaces of the pper shnt and the top of the anchor is very small compared to the magnetic field strength on the pper shnt, therefore can be ignored. Accordingly, eqation (6) can be simplified to : The fact that L L L L L (7), reslt in longer length of the magnetic field line of the pper shnt. Which reslts in magnetic field strength in the pper shnt less than the magnetic field strength the pper working clearances which has shorter magnetic field line as indicated by the following eqation. B Then from eqation (7), and above relationship we got: L L L L Considering the length of the magnetic line of the pper working clearance L and taking L relative to L the following reslt can be obtained L L,and the relative magnitde of L is greater than one. L olving eqation (8) for the magnetic field strength in the material of the pper magnetic shnt, nder the condition implemented in eqation (1) reslts in the following: 1 L L where: (1 ) B L B is the magnetic field density in the motor ke sbstitting eqation (9) in to (5) we obtain the following expression for ( B k ) L (9) (8) : (1 ) B (1) olving eqation (1) for the flx density of the ke magnetic shnt reslts in the following: B as a fnction of design parameters of the pper IJME IN: Vol. 4 Iss.9 ept

5 where B B (1 L The expression for B in (11) on the strctre coincides with the ratio obtained in [19], and shows the indction vale in the ke LEMM above which the anchor will pll away from the holding area and will start moving. This indction in accordance with (11) depends on the cross-sectional area of the pper shnt, its average length of the magnetic line L, the material of the shnt (coefficient ), and early indction satration B. Upper limit for the vale is reqired, as any vale higher than the permissible vale will not case satration, which means that the anchor on the breakaway stage will not pll away from the holding area of the shnt. when the crrent in the coil cases satration in the pper shnt before the ke, then the indction in the pper shnt will be lower than the indction in the ke LEMM, so the B B or: B 1 (12) B Then from eqation (11) nder the condition implemented in eqation (12) the following eqation reslts: (13) 1 (1 ) L Maniplating (13) nder the condition for plling the anchor away : L ) L (1 Withot flfillment of (14), satration of the pper shnt will not occr for any vale of the crrent in the coil LEMM, and the anchor will not pll away (move). Using (14) we obtain the range of possible combinations of parameters and for given vales of the parameters L and. If we se steel t1 as material shnt, and according to [19] B 1. 65T, and 9, L 1. 5, reslting in a simpler form, of eqation (14) as follows: 1 6(1 ) ) (11) (14) (15) From the condition of the plling away anchor from holding area: (16) and by sing (15) we define the varios zones for cross-sectional area of the magnetic shnt and the vale of holding area for this case. This zone is in the form of ineqality (17) as shown in Fig. 4 hatched, and the dotted line shows the bondary of the zone change of flx f ( ), constrcted by (16). IJME IN: Vol. 4 Iss.9 ept

6 Fig. 4: change of zone cross sectional area of the magnetic shnt and its flx at the plling away anchor moment when changing the vales of holding area At the border of the zone, when B B the anchor will not pll away anchor from the holding device. By sing the limitations and recommendations set ot above, we obtain from (11) the dependence of the relative magnetic flx in the ke LEMM at the design parameters of the shnt when 9, L 1. 5 and B 1. 65T when the plling away of anchor happens: 1 (17) and B (18) B 6 (1 ) To do this, we express the flx throgh the shnt design parameter sing (16) and bstitting the flx into (18) we obtain: 1 (1 ) B (19) B (1 6) 1 Figres 5a and 5b show the change in the zones relative to the change in the magnetic indction in the ke LEMM anchor at the moment of plling away for varios zones of design parameters. In the bondaries of these zones a sharp increase in the indction of a ke indicates invalid combination of geometrical dimensions LEMM with ferromagnetic gide hosing. Also Eqality B B is nacceptable becase it occrs dring the satration of the ferromagnetic ke and the gide hosing. More over the tractive force of the plse LEMM falls dawn de to the redistribtion of the magnetic flxes in the motor system. IJME IN: Vol. 4 Iss.9 ept

7 Fig. 5: Change zone of the magnetic indction in the ke LEMM at the plling away anchor moment while changing the design parameters and IV. Conclsion Based on a piecewise linear approximation of the magnetization crve of a ferromagnetic material of the gide hosing (pper magnetic shnt), an expression is derived for its magnetic indction, with which can set the beginning of satration of the shnt, define moment of anchor plling away from the holding area, the zone of permissible combinations of cross-sectional area of the pper magnetic shnt and holding area, and the zone of change in the magnetic indction in the ke at the plling away moment of the motor anchor. Any combination of these design parameters, bend those zones, the integrated plse LEMM doesn't work. EFEENCE [1] tmberger, G., M. T. Aydemir, D. Zarko, and T. A. Lipo, \Design of a linear blk spercondctor magnet synchronos motor for electromagnetic aircraft lanch systems," IEEE Transactions on Applied percondctivity, Vol. 14, No. 1, 54-62, 24. [2] o, B. Q., X. Z. ang,. X. W, and L. Y. Li, \Thrst and thermal characteristics of electromagnetic lancher based on permanent magnet linear synchronos motors," IEEE Transactions on Magnetics, Vol. 45, No. 1, , 29. [3] Thornton,., M. T. Thompson, B. M. Perrealt, and J.. Fang, \Linear motor powered transportation," Proceedings of the IEEE, Vol. 97, No. 11, , 29. [4] Yan L. G., \The linear motor powered transportation development and application in China," Proceedings of the IEEE, Vol. 97, No. 11, , 29. [5] aterina yniova, Antonin tribrsky, Jaroslav onc, Ales rczek " Active spension ystem with Linear Electric Motor" WEA TANACTION on YTEM, Vol. 8,No.2, pp , 29. [6] Yamada,., M. Yamagchi, M. arita, Y. Matsra, and. Fknaga, \Acte animal experiment sing a linear motor-driven total artificial heart," IEEE Translation Jornal on Magnetics in Japan, Vol. 9, No. 6, 9-97, [7] Yamada,., M. Yamagchi,. obayashi, Y. Matsra, and. Takano, \Development and test of a linear motordriven total artificial heart," IEEE Engineering in Medicine and Biology Magazine, Vol. 14, No. 11, 84-9, [8] aterina yniova"experiments Taken on Energy Management in Active spension of Vehicles "WEA TANACTION on YTEM, Vol. 11, No. 8, , 212. [9] Ugarov G.G, Principles of increasing the specific power and energy performance of plsed electromagnetic linear motors / / Plse linear electric machines. Collection of scientific papers. -Novosibirsk: Institte of Mining, Academy of ciences of the U, pp [1] N.P. yashentsev.g.g. Ugarov., A.B. Lvytsin Electromagnetic press, Naka Pblishers, sibirsk branch, Novosibirsk, p. [11] Patent U218652, E21C 3/16. Electric hammer. / A.F Maer, V. I Moshkin, IP Popov (ssian Federation) /3; appl , pbl [12] Patent U28471, O2 33/2. The linear electromagnetic motor / G.G Ugarov. VY Nemann (ssian Federation) /7; appl , pbl [13] Usanov. M, Moshkin V. I, Ugarov GG, Linear electromagnetic plse drive Atonomos power spply, Monograph. - rgan: Pblishing ose of the U Press, p. IJME IN: Vol. 4 Iss.9 ept

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