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LOVELY S. PAULINO

BSECE-4

1. Explain the principle of ON-OFF control. Derive the expression for rms

value of output voltage.

PRINCIPLE OF ON-OFF CONTROL TECHNIQUE (INTEGRAL CYCLE CONTROL) The

basi !"i#i!$e %& %#-%' %#"%$ eh#i*e is e+!$ai#e, ih "e&e"e#e % a si#$e

!hase &*$$ a/e a /%$ae %#"%$$e" i"*i sh%# be$%. The h0"is%" sihes T1

a#, T2 a"e *"#e, %# b0 a!!$0i# a!!"%!"iae ae "ie" !*$ses % %##e he

i#!* a s*!!$0 % he $%a, &%" 3# #*5be" %& i#!* 0$es ,*"i# he i5e i#e"/a$

ON ON. The h0"is%" sihes T1 a#, T2 a"e *"#e, %' b0 b$%6i# he ae "ie"

!*$ses &%" 35 #*5be" %& i#!* 0$es ,*"i# he i5e i#e"/a$ OFF OFF. The a

%#"%$$e" ON i5e ON *s*a$$0 %#siss %& a# i#e"a$ #*5be" %& i#!* 0$es.

Fig.: Single phase full wave A voltage controller circuit

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!O DE"#$E AN E%&"ESS#ON FO" !'E "(S $A)*E OF O*!&*! $O)!A+E

 N% ON 7 A# i#e"a$ #*5be" %& i#!* 0$es8 He#e

ON7 T9 2T9 :T9 4T9 ;T9 <.. = >ON 7 2?9 4?9 @?9 ?9 1?9<<

he"e T is he i#!* s*!!$0 i5e !e"i%, (T 7 i#!* 0$e i5e !e"i%,). Th*s e #%e

ha si# 2>ON 7

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2.

,. Compare the full wave and half wave AC controllers.

Full Wave Controller

• Both the half cycles of supply are controlled.

• These controllers generate symmetric voltage and currents across load.

• Supply current is symmetric.

• Complete range of supply voltage can be controlled.

• Full wave controllers are preferred for large loads.

Half Wave Controller

• O#$0 ha$& 0$e %& he s*!!$0 %#"%$$e,.

•  These %#"%$$e"s e#e"ae as055e"i /%$ae a#, *""e#s a"%ss

$%a,.

• S*!!$0 *""e# is as055e"i.

• C%5!$ee "a#e %& s*!!$0 /%$ae a##% be %#"%$$e,.

• Ha$& a/e %#"%$$e"s a"e !"e&e""e, &%" s5a$$ $%a,s.

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LOVELY S. PAULINO

BSECE-4

1. E+!$ai# h% s%$a" !a#e$ %#/e"s s*#$ih % e$e"ii0D

•  The s%$a" !a#e$s a"e 5a,e %& s%$a" e$$s. A e$$ is a s5a$$

,is6 %& a se5i%#,*%" $i6e si$i%#. The0 a"e aahe, b0

i"e % a i"*i. As $ih s"i6es he se5i%#,*%"9 $ih

is %#/e"e, i#% e$e"ii0 ha %s h"%*h he i"*i.

As s%%# as he $ih is "e5%/e,9 he s%$a" e$$ s%!s

!"%,*i# !%e".• Light striking a silicon semiconductor causes electrons to flow, creating electricity. Solar

power generating systems take advantage of this property to convert sunlight directly intoelectrical energy.

2. E+!$ai# he %#s"*i%# %& a s%$a" !a#e$.

• Solar modules use light energy (photons) from the sun to generate electricity through

the photovoltaic effect. The majority of modules usewafer -ased crystalline

silicon cells or thin-film cells ased on cadmium telluride or  silicon. The structural

(load carrying) memer of a module can either e the top layer or the ack layer.

!ells must also e protected from mechanical damage and moisture. "ost solar

modules are rigid, ut semi-fle#ile ones are availale, ased on thin-film cells.These early solar modules were first used in space in $%&'.lectrical connections

are made in series to achieve a desired output voltage andor in parallel to provide a

desired current capaility. The conducting wires that take the current off the modules

may contain silver, copper or other non-magnetic conductive transition metals. The

cells must e connected electrically to one another and to the rest of the system.

#ternally, popular terrestrial usage photovoltaic modules use "!* (older) or "!+

connectors to facilitate easy weatherproof connections to the rest of the system.

ypass diodes may e incorporated or used e#ternally, in case of partial moduleshading, to ma#imie the output of module sections still illuminated.

Some recent solar module designs include concentrators in which light is focused

y lenses or mirrors onto an array of smaller cells. This enales the use of cells with

a high cost per unit area (such as gallium arsenide) in a cost-effective way.

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:. ha 0!e %& bae"ies is *se, i# s%$a" e#e"0 %#/e"si%#D

•

4. Uses %& s%$a" ha"e, %#"%$$e".

• Solar charge controller  is charge controller  that is used in the solar application and also called solar

battery charger . ts function is to regulate the voltage and current from the solar arrays to the attery in

order to prevent overcharging and also over discharging. There are many technologies have een

included into the design of solar charge controller.

;. Uses %& i#/e"e" i# s%$a" e#e"0 %#/e"e". Is i esse#ia$ ih %" ih%* he

i#/e"e"D h0 a#, h0 #%D

•  / solar inverter , or PV inverter , or Solar converter , converts the variale direct

current (0!) output of a photovoltaic (12)solar panel into a utility

fre3uency alternating current (/!) that can e fed into a commercial electrical grid or

used y a local,off-grid electrical network. t is a critical 4S 5component ina photovoltaic system, allowing the use of ordinary /!-powered e3uipment. Solar

inverters have special functions adapted for use with photovoltaic arrays,

including ma#imum power point tracking and anti-islanding protection.