- Email: [email protected]
Flux distribution, power losses and harmonics of magnetizing current in three-limb amorphous magnetic circuit
~
ELSEVIER
Journal of Magnetism and Magnetic Materials 196-197 {1999) 930-932
Journalof magnetism and magnetic 4P~ materials
Flux distribution, power losses and harmonics of magnetizing current in three-limb amorphous magnetic circuit R. K o l a n o a'*, I. Pinkiewicz b, N.
W6jcik ~
;'Institute of Non-Ferrous Metals, u/. Sowit~skiego 5, 44-100 Gliwice Pohmd ~'Institute o/Power Engineering, D. Tr. L6d-'-, Poland
Abstract The three-limb magnetic circuit consisting of three single rectangular cores with overlapping joints has been investigated. The cores were wound from 142 mm wide and 23 lam thick Metglas 2605 TCA ribbon. Flux distribution. harmonics of magnetizing current and losses were measured by means of a wide band power analyser D6133TE for different B from 1.1 to 1.4 T. ~, 1999 Elsevier Science B.V. All rights reserved. Keywords. Three-limb amorphous magnetic circuit
2. Experimental
lapping joints: the two smaller ones (l and Ill, surrounded by a third larger one (IIIIlEig. 1). The cores were wound from 142 mm wide and 23 gm thick Metglas 2605 TCA amorphous ribbon. After formation, the cores were heat treated at 640 K for 2 h in a longitudinal lnagnetic field of 15 A / c m , and then cooled at a rate of about 2 K/min. Geometrical parameters and magnetic propelties of the cores are shown in Table 1. The measurement of no-load characteristics of 3-phase, three-limb MC were made by means of wide band power analyser D6133TE. For this purpose the primary and secondary windings (32 turns each} were wound on the limb, both in a Delta configuration. For the measurement of flux distribution in the tree-limb MC, 9 search coils were wound on the limb iFig. l) and the magnetic flux was measured for different B from 1.1 to 1.4T. The no-load loss Pc =.fiB) and the exciting power P~{B) were measured. Moreover, the measurement of up to eight harmonics of the magnetizing current for B froln 0.5 to 1.4 T were carried out.
The three-limb magnetic circuit model ~Fig. 1) was produced from three single rectangular cores with over-
3. Result and discussion
* Corresponding author. Tel.: Lk + 48-32-380-312: fax: + 4832-316933: e-mail: [email protected],gliwice,pl.
The values of localised magnetic flux of the three-limb MC, are listed in Table 2. As we can see, an homogeneons
1. Introduction Up to now, for building three-phase amorphous distribution transformers (AMDTs), five-limb magnetic circuits (MC) are generally used [1]. Such kind of MC require the dimensions of A M D T s to be much bigger in comparison with classic transformers (FeSi). Using a three-limb M C eliminates such an unprofitable situation [2]. The results of a study of 3-phase five-limb M C were presented in Ref. [3]. However, a similar investigation was not made for three-limb M C which will soon be used in AMDTs. The aim of the present work was an elaboration and preparation of a three-limb Metglas 2605 TCA M C model and measurements of the flux distribution, power losses and harmonics of the magnetizing current of the 3-phase, three-limb MC.
0304-8853/99/$ - see front matter c, 1999 Elsevier Science B.V. All rights reserved. PII: $ 0 3 0 4 - 8 8 5 3 ( 9 8 ) 0 0 9 9 3 - 7
931
R. Kolano et al. / Journal of Magnetism and Magnetic Materials 196-197 (1999) 930-932
magnetic flux appears both in a single and double limb. Such a flux distribution favours to obtain low losses in the transformer. Fig. 2 shows the loss dependence of Pet and the exciting power P= on the magnetic induction B. The ratio of P~t of three-limb M C from Fig. 2 and P ~ single core from Table 1, Pct/Pes is about 1.4. In the case of five-limb M C the ratio is about 1.8 I-3]. Fig. 3 shows the three-phase of magnetizing current harmonics diagram for induction B = 1.3 T. It was found that the 5th harmonic gives the biggest (30% of first harmonic - H01 = 0.65 A) contribution to the current,
from among the remaining harmonics. The harmonic diagram for B = 1.3 T is typical for B > 0.5 T but for B = 0.5 T the 3-harmonic equals 4% of H01 (H01 = 0.1 A) and it gives the main contribution (beyond H01) to the magnetizing current. The higher harmonics (H05, H07) play a predominant role in the magnetizing current for 3-phase magnetic circuit. On the other hand, the 3 harmonic plays the main role (56% HOD for single phase core [4]. This fact and the presence of a rotating magnetic field in a knot zone of the middle limb can explain the relation Pc~ ~ 1.4 P~. 2
0,3
1,8 0,25
I ~Pz
1,4
0,2
1,2 ~ 015
0,8 ~ 0,1
v
\,
"\-~.
j
0,6 ~.
//
Fig. 1. The three-limb magnetic circuit and nine search coils placed on it.
0 t0,3
0 0,4
0,5
06
0,7
0,8
0,9
1
Magnetic induction
Table 1 The main geometrical parameters and magnetic properties of the 3-limb magnetic circuit cores
0,4 ",~ "~
~
005
1,1
1,2
1,3
1,4
BIT]
Fig. 2. The three-limb no-load loss Pc, and exciting P= power dependence on magnetic induction B.
Core number 3o
Mean path Lvo (cm) Cross section Ave (cm 2) Bs0 (T) B, (T) Hc (A/cm)
I
II
III
110 63 1.5 1.21 0.071
109 63 1.5 1.2 0.07
200 63 1.5 1.22 0.069
25 .o
20
g s ~
0 1
P~s (50 Hz) (W/kg): 1.3 (T) 1.4 (T) Weight (kg)
0.16 0.19 47
0.158 0.189 46.7
0.161 0.195 86
2
3
4
5
6
7
8
Number of harmonic
Fig. 3. The three-phases of the magnetizing current harmonics diagram, for B = 1.3 T, H01 = 0.82 ARMS.
Table 2 The values of localized flux of three-limb magnetic circuit. The cipher at q~ denotes number of search coil (I)1
(I)2
(I)3
(~4
(~5
(~)6
(~7
(1)8
~9
B (T)
(Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) 7.05 7,77 8.4 8.93
7.31 8.09 8.9 9.64
14.05 15.33 16.62 17.88
7.37 8.14 8.93 9.61
7.35 8.15 8.96 9.64
14.05 15.34 16.61 17.87
7.32 8.12 8.94 9.69
7.09 7.81 8.44 8.99
14.06 15.32 16.6 17.88
1.1 1.2 1.3 1.4
932
R. Kolano et al. / Journal o f Magnetism and Magnetic Materials 196-197 (1999) 930-932
A general conclusion which can be drawn from the present study is that the three-limb magnetic circuit model has 0.22 W / k g no-load loss at 1.30 T and very homogenous magnetic flux in the limb. We hope that this new kind of magnetic circuit will be applied successfully in AMDTs.
Acknowledgements The work was supported by a grant No. 8 9876 95C/2365 from Scientific Research Committee in Poland.
References [1] A.J. Moses, in: Proc. Seminar oi1 the THERMIE project, University of Wales, Cardiff, February 1995. [2] R. Kolano, N. Wdjcik, W. Gawior, J. Magn. Magn. Mater. 160 (1996) 213-214. [3] A. Basak, A.J. Moses, M.R. Yasin, J. Magn. Magn. Mater. 160 (1996) 210-2t2. [4] 1. Pinkiewicz, T. Szymaflski, The report of Institute of Power Engineering, No, OTB1/2-15/96.
ELSEVIER
Journal of Magnetism and Magnetic Materials 196-197 {1999) 930-932
Journalof magnetism and magnetic 4P~ materials
Flux distribution, power losses and harmonics of magnetizing current in three-limb amorphous magnetic circuit R. K o l a n o a'*, I. Pinkiewicz b, N.
W6jcik ~
;'Institute of Non-Ferrous Metals, u/. Sowit~skiego 5, 44-100 Gliwice Pohmd ~'Institute o/Power Engineering, D. Tr. L6d-'-, Poland
Abstract The three-limb magnetic circuit consisting of three single rectangular cores with overlapping joints has been investigated. The cores were wound from 142 mm wide and 23 lam thick Metglas 2605 TCA ribbon. Flux distribution. harmonics of magnetizing current and losses were measured by means of a wide band power analyser D6133TE for different B from 1.1 to 1.4 T. ~, 1999 Elsevier Science B.V. All rights reserved. Keywords. Three-limb amorphous magnetic circuit
2. Experimental
lapping joints: the two smaller ones (l and Ill, surrounded by a third larger one (IIIIlEig. 1). The cores were wound from 142 mm wide and 23 gm thick Metglas 2605 TCA amorphous ribbon. After formation, the cores were heat treated at 640 K for 2 h in a longitudinal lnagnetic field of 15 A / c m , and then cooled at a rate of about 2 K/min. Geometrical parameters and magnetic propelties of the cores are shown in Table 1. The measurement of no-load characteristics of 3-phase, three-limb MC were made by means of wide band power analyser D6133TE. For this purpose the primary and secondary windings (32 turns each} were wound on the limb, both in a Delta configuration. For the measurement of flux distribution in the tree-limb MC, 9 search coils were wound on the limb iFig. l) and the magnetic flux was measured for different B from 1.1 to 1.4T. The no-load loss Pc =.fiB) and the exciting power P~{B) were measured. Moreover, the measurement of up to eight harmonics of the magnetizing current for B froln 0.5 to 1.4 T were carried out.
The three-limb magnetic circuit model ~Fig. 1) was produced from three single rectangular cores with over-
3. Result and discussion
* Corresponding author. Tel.: Lk + 48-32-380-312: fax: + 4832-316933: e-mail: [email protected],gliwice,pl.
The values of localised magnetic flux of the three-limb MC, are listed in Table 2. As we can see, an homogeneons
1. Introduction Up to now, for building three-phase amorphous distribution transformers (AMDTs), five-limb magnetic circuits (MC) are generally used [1]. Such kind of MC require the dimensions of A M D T s to be much bigger in comparison with classic transformers (FeSi). Using a three-limb M C eliminates such an unprofitable situation [2]. The results of a study of 3-phase five-limb M C were presented in Ref. [3]. However, a similar investigation was not made for three-limb M C which will soon be used in AMDTs. The aim of the present work was an elaboration and preparation of a three-limb Metglas 2605 TCA M C model and measurements of the flux distribution, power losses and harmonics of the magnetizing current of the 3-phase, three-limb MC.
0304-8853/99/$ - see front matter c, 1999 Elsevier Science B.V. All rights reserved. PII: $ 0 3 0 4 - 8 8 5 3 ( 9 8 ) 0 0 9 9 3 - 7
931
R. Kolano et al. / Journal of Magnetism and Magnetic Materials 196-197 (1999) 930-932
magnetic flux appears both in a single and double limb. Such a flux distribution favours to obtain low losses in the transformer. Fig. 2 shows the loss dependence of Pet and the exciting power P= on the magnetic induction B. The ratio of P~t of three-limb M C from Fig. 2 and P ~ single core from Table 1, Pct/Pes is about 1.4. In the case of five-limb M C the ratio is about 1.8 I-3]. Fig. 3 shows the three-phase of magnetizing current harmonics diagram for induction B = 1.3 T. It was found that the 5th harmonic gives the biggest (30% of first harmonic - H01 = 0.65 A) contribution to the current,
from among the remaining harmonics. The harmonic diagram for B = 1.3 T is typical for B > 0.5 T but for B = 0.5 T the 3-harmonic equals 4% of H01 (H01 = 0.1 A) and it gives the main contribution (beyond H01) to the magnetizing current. The higher harmonics (H05, H07) play a predominant role in the magnetizing current for 3-phase magnetic circuit. On the other hand, the 3 harmonic plays the main role (56% HOD for single phase core [4]. This fact and the presence of a rotating magnetic field in a knot zone of the middle limb can explain the relation Pc~ ~ 1.4 P~. 2
0,3
1,8 0,25
I ~Pz
1,4
0,2
1,2 ~ 015
0,8 ~ 0,1
v
\,
"\-~.
j
0,6 ~.
//
Fig. 1. The three-limb magnetic circuit and nine search coils placed on it.
0 t0,3
0 0,4
0,5
06
0,7
0,8
0,9
1
Magnetic induction
Table 1 The main geometrical parameters and magnetic properties of the 3-limb magnetic circuit cores
0,4 ",~ "~
~
005
1,1
1,2
1,3
1,4
BIT]
Fig. 2. The three-limb no-load loss Pc, and exciting P= power dependence on magnetic induction B.
Core number 3o
Mean path Lvo (cm) Cross section Ave (cm 2) Bs0 (T) B, (T) Hc (A/cm)
I
II
III
110 63 1.5 1.21 0.071
109 63 1.5 1.2 0.07
200 63 1.5 1.22 0.069
25 .o
20
g s ~
0 1
P~s (50 Hz) (W/kg): 1.3 (T) 1.4 (T) Weight (kg)
0.16 0.19 47
0.158 0.189 46.7
0.161 0.195 86
2
3
4
5
6
7
8
Number of harmonic
Fig. 3. The three-phases of the magnetizing current harmonics diagram, for B = 1.3 T, H01 = 0.82 ARMS.
Table 2 The values of localized flux of three-limb magnetic circuit. The cipher at q~ denotes number of search coil (I)1
(I)2
(I)3
(~4
(~5
(~)6
(~7
(1)8
~9
B (T)
(Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) (Wbx 10 -3) 7.05 7,77 8.4 8.93
7.31 8.09 8.9 9.64
14.05 15.33 16.62 17.88
7.37 8.14 8.93 9.61
7.35 8.15 8.96 9.64
14.05 15.34 16.61 17.87
7.32 8.12 8.94 9.69
7.09 7.81 8.44 8.99
14.06 15.32 16.6 17.88
1.1 1.2 1.3 1.4
932
R. Kolano et al. / Journal o f Magnetism and Magnetic Materials 196-197 (1999) 930-932
A general conclusion which can be drawn from the present study is that the three-limb magnetic circuit model has 0.22 W / k g no-load loss at 1.30 T and very homogenous magnetic flux in the limb. We hope that this new kind of magnetic circuit will be applied successfully in AMDTs.
Acknowledgements The work was supported by a grant No. 8 9876 95C/2365 from Scientific Research Committee in Poland.
References [1] A.J. Moses, in: Proc. Seminar oi1 the THERMIE project, University of Wales, Cardiff, February 1995. [2] R. Kolano, N. Wdjcik, W. Gawior, J. Magn. Magn. Mater. 160 (1996) 213-214. [3] A. Basak, A.J. Moses, M.R. Yasin, J. Magn. Magn. Mater. 160 (1996) 210-2t2. [4] 1. Pinkiewicz, T. Szymaflski, The report of Institute of Power Engineering, No, OTB1/2-15/96.