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C. Voltage )

AC . ,

. AC .

, , , , RMS .

RMS .

RMS .

. Current ) . .

.

. Frequence ) AC .

, 1 .

. Phase Angle and Power Factor ) AC .

(0~360 ) (0~2 ) .

, (volt) 0-360 2 .

.

0-360 2 .

.

( ) ( ) ,

( ) ( ) .

.

(degree) (phase angle).

.

AC , (cos) .

PF = cos 0 90 Radians .

. Watts and Vars ) (P) .

(P=EI).

X X (cos)

. (P=EIcos).

( )

2

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.

X ( ) .

0 ( ) cos 1 P=EI .

.

.

( ) .

.

, ?

. . Watthours) Varhours)

,

. ,

.

.

100 watt 1 100wh .

10,000vars(10Kvars) 24 240KVARHs

.

.

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AC

.

AC

. , , , , ,

.

AC

.

AC , , , AC

.

1. ?

* .

* .

* .

* .

2. ?

*

* PT CT

*

*

*

*

*

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Cccuracy ) : .

pparent Power ) : (Cos ) (VA) verage Value ) :

. , 0.637 .

alanced Load ) : 2 (1 3 , 3 3 , 3 4 ) AC .

Burden : . .

I x Z= VA I =

Z =

. .

E / Z= VA

E =

Z =

.

CT : AC . (Current Transfomer)CT Ratio : 2 1 .Error : ( ) .Frequence : 1 . (cycle/second)Harmonic :

.

Harmonic distortion : .

SCR Triac .

Hertz :High Voltage : 15KV 250KVHorse Power : 1HP = 746Watts .

.

Inductor : ( ) .

. , .

Killowatt : 1000Watt :WKillowatthour : 1 1000wattLagging Current : .

90 . , ,

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.

Leading Current : . 90 .

Low Voltage : 600voltMidium Voltage : 600volt 15kvOhm s Law : DC

V = I R, I = R/V

AC

Power Factor = COS = P/V x I

Z = V/I = P / I x C OS

I = V/Z = P/V x COS

V = IZ = P /I x C OS

P = I x Z x COS = V x I x COS Phase Angle : , . -

0 P.F = 1 .

-

90 P.F = 0 .

0 COS = 1, P=VI .

90 COS = 0, P=0 .

P = V x I x COS . COS power factor .

Power Factor P.F) : P.F AC cosin

VICOS P.F =

VI

P.F :

VICOS :

VI :

V :

I :

Primary : . ( 1 )

Reactive Power : . (VAR )VAR = V x I x SIN

R M S : Root mean square . . RMS ( ) watt .

DC .

RMS = 0.707 x

R T U : Remote Terminal Unit .

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. RTU SCADA SYSTEM .

SCADA : supervisory control and data aquisition.

.

Secondary : . ( 2 )

Sinusoidal Voltage and Current : : 0.707 x = RMS

: 0.637 x

True Power : . watt .WATT = V x I x COS

nbalanced Load ) : 2 (1 3 , 3 3 , 3 4 )

.

V.A : Volt Ampare . volt ampare .

VAR : VA . wattWATT : 1 1

1A 1 .

watt . "W"

Watthour : 1 watt 1 . "WH" .

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C .

.

: ,

, .

AC .

AC .

. .

2 .

(220)volts .

, (220)VAC 110V .

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. 220VAC ,

1/2 . 180 .

.

.

3HP 3 3 .

(A B, B C, A C) 220VAC 440VAC .

(Y) .

AC .

. , 3

.

) : 380VAC (A-B, B-C, A-C) : 380/ 3 = 220VAC (A-N, B-N, C-N)

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) AC

AC .

.

) AC

AC AC .

Ohm's Law : = X (E=IR). ,

.

AC 10ohm 15ohm 110 Volt AC

.

E= IR

110 VAC = I ( 10 Ohm) + (15 Ohm)

110 VAC = I ( 25 Ohm)

110VAC= I

25Ohm

4.4 Amps = I 4.4 A .

:

E= IR

E= ( 4.4 Amps) (10 Ohm) = 44 Volts AC

E= ( 4.4 Amps) (15 Ohm) = 66 Volts AC

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Kirchoff's Voltage Law .

0 .

44 VAC + 66 VAC = 110 VAC ( )

110 VAC .

,

.

( ),

.

. 1 . 1 .

CT AC .

.

CT 2 0-1mA DC 4-20mA DC DC

.

DC , , AC

.

. .

( ) VA VA .

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: 10 : 1 : VAp = Ep x Ip = 1000 VA

Ep = 100 VAC VAs = VAp - = 1000 VA

Ip = 10Amps AC Es = Ep / 10 = 10 VAC

= 0 Is = VAs / 10 = 100 Amps

2 2 .

CT :

2 VA .

. : 0.1 Ohm ( )

VA in = 50000 VA ( 100 V, 500 A ) : 1

E = IR, E = 5 Amps x 0.1 Ohm = 0.5 Volts : 2

CT CT , 0

.

CT CT 2

.

100 VAC x CT

500100 VAC x

5

100 VAC x 100 = 10,000 Volts

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CT (arc)

CT , ,

CT 2 .

.

.

:

Motor

) .

(PT) .

DC

(0 1 mA DC 4~12~20 mA DC) .

. 60Hz 5Hz 1 mA DC

60Hz 0 mA DC . 55 Hz -1 mA DC , 65 Hz

+1 mA DC .

4~20 mA DC . 60Hz 12 mADC

(12 mADC 4 mA DC 20 mA DC ) ,

55 Hz 4 mA DC 65 Hz 20 mA DC

) Watt Transducer ) " " . .

.

1 watt 1ohm 1volt 1 amp 1 volt .

AC

P= V x I x .

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,

.

fullscale

.

. 85-150 VAC 0-5

Amp . 0

150 VAC x 5 Amps x 1 = 750 watts .

, 110VAC 150volts

CT .

, (per element)

full scale 500watts .

. (single element) fullscale 500 watts , .

output range x 0.616 = 308 watts

* 0~1 mA DC

1 mA DC x 0.616 = 0.616 mA DC

* 4~20 mA DC16 mA DC x 0.616 = 9.856 mA DC + 4 mA DC = 13.856 mA DC .

( 0 )

uti-Element Transducer fullscale2 Element Transduce

2 3 3 .

Measured watts 308= = 0.616

fullscale watts 500

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2 2 . 1 500watts

1000 watts .

3 : P = 3EIcos .

, 2

. fullscale 1000watts 951watts

3 Element Transducer

3 3 4 . .

.

full scale 1500 watts . 1666, 2000, 4000watts

.

) . ;

VAR = V x I x sin .

30 (Lagging) .

P= VI x cos (cos ) ,

, .

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watts .

.

.

1, 2 3 . ,

PT's CT's .

.

. motor

0.6 (Lagging)

.

.

.

. , .

, . ,

.

.

, .

) .

.

, 1000 KWH/day .

.

? (

) .

15 . 15

X KWH , Y .

,

.

,

.

, (

) . (Load shedding) .

.

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.

.

( ) ( )

.

) . 1 VARH 1 VAR 0.1

10 VAR

15

.

,

.

, .

.

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C

.

AC

AC .

AC

. , , AC-DC

.

AC . , .

.

.

, .

,

.

.

,

.

, 1

.

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,

.

.

.

90 , 0 .

90 0

.

.

, .

,

.

.

.

.

.

, .

.

, .

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11 .

.

.

,

2% .

50 70 Hz .

AC

.

.

.

5 volt ,

.

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.

?

1. .

2. .

3. .

4. 50 70 Hz

1% 3% .

5. AC 6 7

.