EE 4192 – Laboratory Practice VIII
IMPULSE GENERATOR (High Voltage Laboratory)
Instructed by
: Prof. J. R. Lca!
Group Members: #ya$ahe%a #. L. &. V. &e! &e!ha ha'r 'riy iya a &. H. ,. &i$-'ra J. /. 0. /. Jaya!eara Jaya!eara
Name 1 1 9 9" " 111L 121*
: ".".
Index No : 1**4+ Group : Date o Perormance Perormance:: 19 3 1 3
21* ". ". #ya$ahe%a 21*
1**4+
Date o Subm!ss!on
: 2 3 2 3
O"SER#ATIONS a-e I$e5 o 6ro' &ate
: ".". #ya$ahe%a : 1**4+ : : 19 3 1 3 21*
Average unintended triggered voltage with impulse generator sphere gaps
Sphere Gap
Average Unintended
(mm)
Triggered Voltage
* 1 1* 2 2* * 4
.* . 9. 22. 2. 24. 4. 4. 4* 7
* 7
(kV) 5 8 4*. 5 8 4. 5 8 *4. 5 8 12. 5 8 18. 5 8 14.2 5 8 24. 5 8 24.
Oscilloscope graphs for various matching units (5 mm sphere gap)
1* 7 7
8 7
;!cillo!co'e gra'h! of $i$te$e tiggere
* -- ga'
1 -- ga'
1* -- ga'
2 -- ga'
2* -- ga'
-- ga' * -- ga'
•
4 -- ga'
ote: 2$ 'art of thi! 'ractical col$=t be o$e.
RESULTS $% Layout o t&e contro' pane' o t&e !mpu'se test!n( un!t
)% T&e *a+eront t!me, *a+eta!' t!me, e-c!ency and stored ener(y at rated max!mum +o'ta(e
r, r’
C0
C 1 =
C 6
=
- Charging Resistance (20 kΩ) R s1 – Internal Damping Resistance (15 Ω) R s2 – Eternal Damping Resistance (1!0 Ω) R " –#a$e %ail Resistance (2 kΩ) C - &ain Capacitance (0'25 ) – #a$e *haping Capacitance (+ n) 0.25 6
=0.0417 µF
C 2 =C 0 =0.003 µF
R1= R0 =2 kΩ R2= R s 1 x 6 + Rs 2=15 x 6 + 180=270 Ω
Efficiency (η) C 1 0.0417 = =0.9329 =93.29 η= C 1+ C 2 0.0417 + 0.003
Wave front time (t f ) Deining a$e r.nt r.m 10/ t. 0/ an c.nsiering .nl
t f =
1
( 0.9 −0.3 )
etermines the a$e r.nt,
(t −t ) 2
1
¿ 3.243 η R C 2
2
¿ 3.243 x 0.9329 x 270 x 0.003 x 10− ¿ 2.4506 x 10
6
−6
¿ 2. 4506 µs Wave tail time (t t) Deining a$e tail time as the time t. eca t. 50/ . peak an .nl c.nsiering t t =
0.693 R1 C 1
η −6
3
¿
0.693 x 2 x 10
x 0.0417 x 10
0.9329
¿ 6.1953 x 10−
5
¿ 61.9533 µs Stored Ener(y at Max!mum #o'ta(e /a5i-- Voltage Emax =V max
C 1 C 1 + C 2
¿ V max η ¿ 300 x 0.9329 ¿ 279.87 kV
/a5i-- E$ergy 1
2
Pmax = C 1 V max 2
1
1
+ C Emax 2
2
0
1
¿ x 0.0417 x 10− x ( 300 x 10 ) + x 0.003 x 10− x ( 279.87 x 10 ) 2
¿ 1876.5 + 117.4908
¿ 1993.9908 J
6
3 2
2
6
3 2
+' 3l.t the $ariati.n . intene an 4nintene triggering $.ltages ith gap setting an .tain the intene an 4nintene triggering 6.nes'
Un!ntended Tr!((ered #o'ta(e +s% Sp&ere Gap
3.
Sphere
Unintended
Gap
Triggered
(mm)
Voltage
* 1 1* 2 2* * 4
(kV) 4*. 4. *4. 12. 18. 14.2 24. 24.
7nintene %riggere 8.ltage $s' *phere 9ap 9raph 21 2 19 1 1 18 1* 14 1 12 11 Tr!((ered #o'ta(e .0#/ 1 9 8 * 4 2 1
*
1
1*
2
2*
Sp&ere Gap .mm/
*
4
4*
4. Plot the
6a' i! !et to * -- a$ the re!i!ta$ce fter a$aly!i$g ob!er
atio !etween the first pea" and second pea" vs. #atching esistance
/atchi$g Re!i!ta$ce (7) 1* 4* 8 *
7 7 7 7 7
Ratio bet%ee$ the @r!t a$ !eco$ 'ea 2.24 1.12 1.8 1.1* 1.1
1% *. Plot the
234 "rea0do*n #o'ta(e o t&e $)2 mm Sp&ere Gap +s% Gap D!stance
6a' &i!ta$ce (--) * 1 1* 2 24 28 * 4 4* *
Po!iti
egati
** 8 8* * 9 1
14* 1** 184 1 11 19 2 21*
1 148 1*4 181 18 14 1* 19*
50/ :reak.n 8.ltage . 125 mm *phere gap $s' 9ap Distance 9raph 22 21 2 19 1 1 18 1* 14 1 12 "rea0do*n #o'ta(e .0#/
11 1 9 8 * 4 2 1 .* 1 1.* 2 2.* .* 4 4.* * *.* 8 8.* .* .* 9 9.*1 Gap D!stance .mm/ Po!iti
Poly$o-ial (Po!iti
egati
Poly$o-ial (egati
DIS5USSION $% D!6erence bet*een t&e processes o t&!s !mpu'se (enerator and t&e standard Marx !mpu'se (enerator c!rcu!t ,he i!!i$ I-'l!e 6e$erator i! !e for the 'ractical a$ i$ter$al arra$ge-e$t i! a! follo%!.
&ar Imp4lse 9enerat.r
;issin Imp4lse 9enerat.r %here is a trigger p4lse circ4it t. create
*tanar &ar Imp4lse 9enerat.r ;. %rigger p4lse circ4it
reak.n %he am.4nt . capacit.rs 4se are higher than
&ar Imp4lse generat.r (.4le the am.4nt) =ll.s the capacit.r t. e 4ll charge
=ll.s $ariati.ns in the amplit4e . the
ith.4t .cc4rring the reak.n' (c.ntr.lle
imp4lses ith.4t a pr.per c.ntr.l
.perati.n )
mechanism' (4nc.ntr.lle .perati.n )
)% D!6erence bet*een any stated +a'ues, t&eoret!ca' +a'ues and pract!ca''y obser+ed +a'ues dur!n( t&!s exper!ments
I-'l!e Voltage Ba
Theoretical V 2.4*8 C! 81.9* C!
Practical 2 V 2 C! 2 C!
Po!!ible rea!o$! for the e
• •
•
•
•
7% S!(n!8cance o t&e 'ayout o t&e contro' pane' o t&e !mpu'se (enerat!n( e9u!pment 0'ecial i$terloci$g !y!te- i! !e i$ high lar-G btto$ i$ the co$trol 'a$el i! there for the !afety 'r'o!e!. Bhe$ !o-eo$e 're!!e! that btto$ i$ a$ e-erge$cy !itatio$ it %ill e-it a$ alar- !o$ to i$for- the 'eo'le aro$ the te!t area to be a%ay fro- the a$ger. >$ al!o there i! a 'o%er i$icator blb to !ho% %hether the i-'l!e ge$erator i! at F;G !tage or F;G !tage. It i! !efl to ie$tify the !tat! of the ei'-e$t. +rre$t i!'lay i! to !ho% the -a5i-- chargi$g crre$t. +ircit ca$ be o'erate $ot to e5cee the -a5i-- chargi$g crre$t abo. 0afety of the 'eo'le a$ ei'-e$t both ca$ be achie
1% Reasons or t&e de+!at!on o output *a+eorms *&en d!6erent pos!t!ons o t&e matc&!n( un!ts used !n t&e measurement
,o ob!er
High Voltage E$gi$eeri$g by Prof. J. R. Lca!
