Basic About Magnetic Steel Core

8/2/2019 Basic About Magnetic Steel Core

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NS SAIGON COIL CENTER CO., LTD.

No. 3 Street 8 Vietnam - Singapore Industrial Park, Thuan An, Binh Duong

Tel. : (0650) 3784460~3784464 Fax : (0650) 3784465

BASIC ABOUT MAGNETIC STEEL CORE

(CBN VLI THP TTNH)

---oOo---

PART A : BASIC ABOUT MAGNETIC STEEL

(CBN VTHP TTNH)

I. MAKING MAGNETIC STEEL(SN XUT THP TTNH)

II. TYPE OF MAGNETIC STEEL (PHN LOI THP TTNH)

III. USING MAGNETIC STEEL (SDNG THP TTNH)

IV. FUNCTION OF MAGNETIC STEEL (CHC NNG CA THP TTNH)

PART B : BASIC ABOUT MAGNETIC CORE(CBN VLI TTNH)

I. ELECTRIC TRANSFORMER (BIN P, BIN DNG)

II. INDUCTOR & ELECTRIC MAGNET (CM KHNG & NAM CHMIN)

III. ELCTRIC MOTOR (NG CIN)

IV. POWER GENERATOR (MY PHTIN)

For basic understanding only

Not responsible for content

Not responsible for English translation

Not responsible for copyright

DECEMBER - 2010


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PART A : BASIC ABOUT MAGNETIC STEEL

(CBN VTHP TTNH)

I. MAKING MAGNETIC STEEL(SN XUT THP TTNH)

1. Silicon content (Hm lng silc)

Magnetic steel is an iron alloy with 0~6.5% silicon content, very low carbon, sulfur, oxygen andnitrogen to get high permeability, good magnetic properties.

Thp ttnh l hp kim thp vi 0~6.5% silc, rt t cacbon, lu hunh, oxy v nitt thmtcao, ttnh tt.

Addition of silicon content inhibits Eddy currents and narrows the hysteresis loop of the material,

but it make the grain structure harden and embrittle.

Sbsung silc lm hn chdng tn hao Eddy v lm hp vng lp ttrtrong vt liu, nhngn lm cu trc tinh thcng v gin hn.

2. Thin Lamination with Insulating coating at both side (Cn mng & cch in)

Stacking of many thin laminations with insulation is better than

one column of steel in restriction of Eddy current.

Sghp lp cc l thp mng cch in th tt hn hn dng mtkhi thp trong vic hn chdng Eddy.

Magnetic steel is also called electrical steel or silicon steel

Thp ttnh cn c gi l thp kthutin hay thp silc.

II. TYPE OF MAGNETIC STEEL (PHN LOI THP TTNH)

1. Grain-Oriented Electrical Steel (GO) (Thp ttnh nh hng)

Grain-oriented electrical steel (GO) is produced in such a way that the optimum magnetic

properties are developed in the rolling direction. It is maily used for static cores (transformers,

reactor, ), or some special motors & generators.

Thp ttnh nh hng GO (Grain-oriented Electrical Steel) c sn xutdn tti u nhttheo hng qun (rolling direction). N c dng trong cc li tng yn (bin th, cun cmkhng, ), hoc mt sng c& my phtin c bit.

NS Saigon Coil Center Co., Ltd. Page 2


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2. Non Grain-Oriented Electrical Steel (NO) (Thp ttnh khngnh hng)

Non-oriented electrical steel (NO) usually has similar magnetic properties in all directions. It is

less expensive and is used in applications where the direction of magnetic flux is changing such as

rotating machines (electric motors and power generators).

Thp ttnh khngnh hng NO (Non Grain-oriented Electrical Steel) thng c ttnh tngtnhau theo mi hn, v c dng trong cc ng dng m hng ca t trng thay i nh

trong my in quay (ng c& my phtin).It is also used when efficiency is less important, low cost application, or when there is insufficient

space to correctly orient components to take advantage of the anisotropic properties of grain-

oriented electrical steel.

N cngc sdng khi khng cn hiu sut cao, cc ng dng gi r, hoc khi khng giankhngtn dng li thnh hng ca thp GO.

III. USING MAGNETIC STEEL (SDNG THP TTNH)

1. Making Core (Ghp li t)

Slitting and after that punching, cutting, wounding to make steel cores.

X bng v sau dp, ct, cun to li t.

(i) Stacked Core (li ghp) (ii) Wounded Core (Li qun)

2. Stress Relief Anneal (Khi phc ng sut)

During fabrication of electrical steel, such as slitting, cutting, punching, and especially wounding,

the stresses introduced in steel material degrade the magnetic properties, and must be removed toobtain maximum performance. Therefore, Stress Relief Anneal is required after fabrication. In

some cases, if fabrication is not effected much on steel crystal structure, it is not so need Stress

Relief Anneal.

Trong qu trnh gia cng nhx bng, ct, dp, c bit l qun, cun, sdn nn tinh th thplm gim ttnh ca n. Do , cn phi thc hin vic sau khi gia cnghi phc cu trctinh ththp silic. Trong mt strng hp nu nhvic gia cng t lm dn nn tinh ththp thkhng cn phi .

3. Winding (Qun dy)

Winding copper wire on magnetic cores.

Qun dy trn cc li t.



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IV. FUNCTION OF MAGNETIC STEEL (CHC NNG CA THP TTNH)

Main function of magnetic steel is to make magnetic core to TRANSMIT MAGNETIC.

Chc nng chnh ca thp ttnh l to li tDN T.

ELECTRIC in winding coil shall become MAGNETIC in steel core, MAGNETIC run inside the

core, and become ELECTRIC in another place if there is any winding.

IN trong cun dy chuyn thnh T trong li thp, Tdn trong li thp, v chuyn thnhINv tr khc nu c cun dy.

Some other materials may have the same function, in some application.

Mt vi vt liu khc c chc nng tng t, trong mt sng dng.

---oOo---

http://en.wikipedia.org/wiki/Image:Transformer_flux.gif


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PART B : BASIC ABOUT MAGNETIC CORE

(CBN VLI TTNH)

I. ELECTRIC TRANSFORMER (BIN P, BIN DNG)

Principle : Electric current in primary coil become magnetic in steel core, magnetic come to

secondary coil & become electric current.

Nguyn l hotng : Cho dngin qua cun dy thnht (cun scp), dngin to ra ttrng trong li thp, ttrng chy trong li thp n cun thhai (thcp) lm pht sinh dngin trong cun ny.

In the equation above, ratio of secondary & primary turn number N s / Np decide output voltage Vsand output current Is.

Trongng thc trn t svng dy thcp v scp Ns / Np quytnh in p ra Vs v dngin ra Is.

To get high Vs, low Is : winding Ns > Npc in p Vs ln, dngin Is nh : qun Ns > Np

To get low Vs, high Is : winding Ns < Npc in p Vs nh, dngin Is ln : qun Ns < Np

1. Power transformer (Bin p in lc)

(Distribution transformer, transmission transformer)

http://en.wikipedia.org/wiki/Image:Transformer3d_col3.svg


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(Bin p cng sut, bin p phn phi, bin p truyn ti)

Power Generator Family, Factory

(High Voltage) (Medium Voltage) (Low Voltage)

To transmit power in long distance with little loss, electric from power generation is transformed

to high voltage, for ex. 550KV. On the transmission way, distribution transformers reduce voltage

to medium voltage; coming to family or small factory, voltage is just at low voltage (in Vietnam, 1

phase 220V, 3 phase 380V)

Do truyn ti i rt xa, c t tn hao, dngin to ra cc nh my phtin c a lnin p rt cao, in cao th, ln n 550KV. Khi gn ti ni sdng, cc trm bin p h dnin p ny n trung th, khi n h gia nh hay cc nh my nh, in p chcn mc h th(Vit Nam, 220V 1 pha hay 380V 3 pha).

3 phase 1 phase

Normally, power transformers are made from GO.

Thng thng, bin p in lc c lm tGO.

2. Small transformer (Bin thnh)

Home appliances (for entertaiment, toys, ) use electronic boards, these boards normally work

with low DC voltage (like in a battery, with a permanent + terminal & a permanent - terminal).

Cc thit bin in tgia dng nh (nghe nhn), chi dng trong gia nh thng sdngcc board mch in t, cc mch in t thng lm vic in p DC (mt chiu) nh (nhin nhca pin v c quy, lun c mt cc + v mt cc -).

http://en.wikipedia.org/wiki/Image:Polemount-singlephase-closeup.jpg


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To get low DC voltage, it need to transform voltage from low voltage (family voltage) to very low

voltage (3V~24V), after that rectifying circuit shall transfer AC current to DC current.

c in p DC nh, phi dng bin thhin p t220V xoay chiu vin p xoay chiunh 3~24V, sau mch chnh lu schuyn in p xoay chiu thnh in mt chiu (DC).

in h th(family) in p nh 3~24VMch chnh lu in DC

Low voltage Very low voltage DC Voltage

(i) EI Transformer (Bin thEI)

1. Making EI Core (Sn xut EI Core)

2. Preparing plastic bobbin and winding primary & secondary copper coils on bobbin.

Chun b li cun dy (bobbin) & qun 2 cun dy scp v thcp ln n.

3. Using stacking machine to place bobbin on the center column of E cores.

Sdng my ghp li E & Ing thi t cun dy vo trc gia cc li E.

Because direction of magnetic flux changes in E core, so EI core should be made from NO

steel sheet.

V hng ttrng thay i E core, bin thEI thngc lm bng thp NO.

http://en.wikipedia.org/wiki/Image:Transformer-hightolow_smaller.jpg


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(ii) Toroidal transformer (Bin thhnh xuyn)

1. Wounding steel sheet to make toroidal core.

Qun thp l to li hnh xuyn.

2. Winding primary & secondary coils on toroidal core.

Qun cun dy scp v thcp ln li.

Direction of magnetic flux transmits in rolling direction only, so toroidal core should be made

from GO. NO is also used for low cost, low efficiency application.

Hng dn tchl hng qun nn li xuyn thng dng thp GO. NO c thc dngcho nhngng dng chi ph thp, hiu sut thp.

3. Special Transformers (Cc loi bin p c bit)

(i) Voltage & current transformer for measurement (Bin p v bin dngo lng)

Measuring voltage transformer (VT) : to reduce voltage from high, medium voltage to low

voltage supplying for measuring instruments, relays & automation. Measuring instruments in

secondary part have very high resistor, so it can say VT works at no-load mode.

Bin p o lng (k hiu TU, BU) : dngbin i in p tcao th, trung thxung hthcung cp cho cc dng co lng, rle v tng ha. Cc dng c pha thcpca bin p o lng c in trrt ln nn c thcoi n lm vic ch khng ti.

Measuring current transformer (CT) : to reduce current from high to suitable value (normally

5A, or 1A or 10A) for measuring instruments, relays & automation. Measuring instruments in

secondary part have very low resistor, so it can say CT works at short-circuit mode.

Bin dngo lng (k hiu TI, BI) : dngbin i dngin ttr sln hn xung trs thch hp (thng l 5A, trng hp c bit l 1A hay 10A) cho cc dng co lng,rle v tng ha. Ph ti thcp ca bin dng rt nh v vy c thcoi n lm vic ngn mch.

The reason of voltage or current reduction is seperating measuring instruments from highvoltage or high current for human safety. And for this reason, secondary of VT or CT are

earth-connected.

Mc ch gim dng & p l cho cc dng co lng tch khi in p hoc dnginln v c ni t nn an ton hn cho con ngi.



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(ii) Voltage stabilizer (n p)

A type of transformer can adjust automatically turn number of secondary for stable output

voltage.

L mt dng bin p nhng tngiu chnh svng dy cun thcp to ra in pu ra n nh.

(iii) Transformers for special purpose (Bin thchuyn dng)

- Leakage transformers - Welding transformer(Bin thdng r - Bin thhn) :



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During welding, electric current runs in secondary with very low-resistor welding stick &

welded object as short-circuit current (short-circuit current is very high, can destroy copper

wire system). To reduce & adjust this electric current, it need to add & adjust an inductor in

secondary. Therefore, welding transformer is a transformer with a high & adjustable inductor

in secondary.

Khi hn in, dngin pha thcp chy qua que hn v vt hn in trrt nh nn gingnh l dngin ngn mch (tr srt ln c thph hng h thng dy dn). gim &iu chnh c dngin hn ny theo mun th phi thm & iu chnh cun cm khngtrong mch thcp. Nhvy my hn in l bin thc cun cm khng ln iu chnhc pha thcp.

- Resonant transformers (Bin thcng hng) :

A leakage transformer is added with a capacitor to form resonant circuit at secondary.

Tng tnhbin thdng r (Leakage transformers) nhng mc thm tin to mchcng hngthcp.

---oOo---

II. INDUCTOR & ELECTRIC MAGNET (CM KHNG & NAM CHMIN)

Include a copper wire coil winding on a magnetic core.

Cu to gm mt cun dy qun xung quanh li ttnh.

Principle : when electric current runs in copper coil, copper coil operate as an inductor L, can

create inductive current and stabilize electric current in circuit. Magnetic core inside become

an electric magnet, operate similar to a permanent magnet, can attract iron.

Nguyn l hotng : khi c dngin i qua, cun dy hotng nhcm khng L, c tcdng to sutin ng cm ng, hoc lm n nh dngin khng cho tng gim qu caohoc t ngt. Li thp bn trong cun dy b nhim t(do in ca cun dy chuyn thnh),hotng nhmt nam chm, gi l nam chm in.

1. Inductor, Reactor, Choke, Filter (Cun cm khng, cun cn, cun chn, b lc)

Work as an inductor, to filter high harmonic wave & pulse in electric, electronic and high

frequency system.Dnglc cc sng hi bc cao v cc xung pht sinh trong cc h thngin, in t, caotn ).

http://en.wikipedia.org/wiki/Image:Inductor.svg


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2. Magnetic ballast (Tng ph - chn lu in t)

At first, magnetic ballast operate as an inductor, create high voltage inductive current to

excite flourescent lamp for electric discharge. After excitement, ballast work as an inductor to

reduce electric current for circuit protection.

Tng ph in t(chn lu in t) coi nhl mt cun cm khng to dngin cm ngkch mi cho n hunh quang phngin, khi n hotng ri th tng ph l mt ti cmkhnggim dngin qua n.

Magnetic circuit is made from UT core, with copper coil inside.

Mch tkhp kn bng li UT vi cun dy tbn trong.

http://en.wikipedia.org/wiki/Image:Electronic_component_inductors.jpg


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Another type of ballast without magnetic core is electronic ballast. It increase electric frequency

from 50Hz up to 20~50KHz, create voltage pulse up to 800VPP to excite flourescent lamp for

electric discharge.

Loi tng ph khc khng hotng da trn cm ngin t l tng ph in t (electronicballast). N bao gm b chnh lu v b nghch tn tng tn sln 20~50KHz v do to xungin p ln n 800VPP lm cho n hunh quang phngin.

3. Electric magnet (Nam chm in)



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When electric current runs in copper coil, magnetic core inside becomes an electric magnet,

operates similar to a permanent magnet, can attract iron. It is used in magnetic switches such as

solenoid valve, contactor ; or operated as magnet in electric motor & generator.

Khi c dngin i qua, li thp b nhim tnn c tc dng ht nhnam chm, gi l namchm in (hotng tng tnam chm vnh cu). Dng trong cc ng dng ht trong van

solenoid, contactor (khi ng t), ng dng to ttrng cho ng c, my phtin.

---oOo---

III. ELCTRIC MOTOR (NG CIN)

Principle : location a wire frame in magetic field of a magnet (electric magnet or permanent

magnet). If running an electric current in wire frame, magnetic shall create magnetic force on this

current to turn wire frame (rotor). If magnetic of magnet can change continuously, there shall be

an inductive current in wire frame, and it is not need to run electric current from outside.

Nguyn l : t mt khung dy vo trong ttrng ca mt nam chm (in hay vnh cu). Nut dngin i qua khung dy th ttrng sgy ra lc tht dngin ny, do lm quaykhung dy (rotor). Nu t trng ca nam chm bin i th c th to ra dngin cm ngtrong khung dy m khng cn dngin bn ngoi t vo.

MAGNET (Stator) + ELECTRIC in RotorMAGNETIC FORCE to turn Rotor

(Tca nam chm Stator +INRotorLC Tquay Rotor)

\

http://en.wikipedia.org/wiki/Image:Motors01CJC.jpg


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Inverter Motor (ng cbin tn)Disadvantage of motor :

- Starting : changing speed suddenly from zero, making a shock on load; consuming much

power (6~7 times of normal), it is not good for power source.

- It is difficult to change speed as needed.

Nhc im ca ng c:

- Khi khi ng tngt ngt tc t0 nn b git, tiu thin cao gp 6~7 ln bnhthngnh hngn ngun in.

- Khi chy n nh, kh c thiu chnh tc theo nhu cu.

To improve these disadvantage, Inverter Motor is made by combination an Inverter & a

Motor. Inverter is a device to change & adjust frequency as needed, therefore change &

adjustment of motor speed.

- Starting : inverter decrease frequency to very low, after that, increase slowly to change

speed slowly from zero, restriction of shock & much consumption from power source.

- Inverter can change & adjust speed as needed.

+

khc phc nhc im ny ngi ta chto ng cbin tn (Inverter Motor), l stchhp ca ng c(motor) v bin tn (inverter). Bin tn l thit b dngiu chnh tn sngun in, do lm thay i tc ng c.

- Khi khi ng, bin tn tn snh v tng tttc tng chm ttnn khng bgit v tiu th nhiu in.

- Khi chy n nh, c ththay i tn sc tc hoc ng b tc theo yu cu.

IV. POWER GENERATOR (MY PHTIN)

http://en.wikipedia.org/wiki/Image:Motors01CJC.jpghttp://en.wikipedia.org/wiki/Image:Motors01CJC.jpg


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Principle : similar to motor, location a wire frame in magetic field of a magnet (electric magnet

or permanent magnet). If turning the wire frame, magnetic shall create inductive current in wire

frame. The needed duty is taking out this current for using (rectify, invert, transform, filter to

get needed electric current).

Nguyn l : tng tnh trongng c, t mt khung dy vo trong t trng ca mt namchm (in hay vnh cu). Nu chng quay khung dy th ttrng sgy ra dngin cmng trong khung dy. Nhim v cn lm l ly dngin ny ra sdng (chnh lu, nghch lu,bin p, lc c dngin mong mun).

MAGNET (Stator) + TURNING Rotor ELECTRIC in Rotor

Tca nam chm Stator + QUAY RotorINRotor

Comparation between electric motor & generator :

So snh gia ng c& my phtin :

Electric Motor Electric Generator

Stator(Electric or Permanent)

MAGNET

(Electric or Permanent)

MAGNET

Rotor

ELECTRIC

TURNING

TURNING

ELECTRIC

Turning wire frame depends on type of power generator :

Vic quay khung dy ty thuc vo cc loi my phtin :

1. Engine power generator (My nphtin)

Using engine to pull & turn wire frame.

Sdngng ct trong ko lm quay khung dy.

2. Hydro power generator (Nh my thy in)Stop, keep & run water to turn turbine (turning wire frame)

Chn sau x dng nc lm quay tuabin (lm quay khung dy).



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3. Thermal power generator (Nh my nhitin)

Using coal, natural gas, or heat from nuclear reaction (in nuclear power thermal generator) to

boil water, making water steam to turn turbine.

Dng than , kh thin nhin, hay nhit ca phn ng ht nhn (nh my in ht nhn -nuclear power thermal generator) nu nc to lung hi nc lm quay tuabin.

4. Wind power generator (Nh my phongin)Using wind power to turn turbine.

Dng sc gi lm quay tuabin.



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5. Tide power generator (Nh my in thy triu)

Tide power turn fans, blow air to turn turbine.

Dng thy triu dng lm quay cc cnh qut thi cc lung hi lm quay tuabin.

Another type of power generator without using magnetic core is solar power generator : using

photoelectric cells to convert solar light to photoelectric current.

Mt loi my phtin khng sdng cm ngin t(khng sdng li t) l quangin

- in mt tri (solar power generator) : nh sng mt tri chiu vo cc tbo quangin(pin quangin) gy ra hiu ng quangin to ra dngin.

Photoelectric cell

Power generators (Cc nh my in) :

Documents

Basic About Magnetic Steel Core