This thesis presents new techniques for voltage stability assessment and improvement in power system under multi-contingencies. A line-based voltage stability index termed as Static Voltage Stability Index (SVSI) was used to evaluate the voltage stability condition on a line. The value of SVSI was computed to identify the most sensitive line and corresponding weak bus in the system

Abdullah, Nor Rul Hasma

UiTM Institutional Repository (Univ. Teknologi MARA)

6 I n s t i t u t e  o f  G r a d u a t e  S t u d i e s  ( I G S )* (MS) = Main Supervisor   (CS) = Co SupervisorThe Doctoral ResearchAbstractsName	 :		Nor Rul Hasma Bt AbdullahTitle		 :	Computational Intelligence Based Power   System Security Assessment and   Improvement under Multi-   Contingencies ConditionsFaculty	: Electrical EngineeringSupervisor	: Associate Prof. Dr. Ismail Musirin(MS)	 	 Dr. Ahmad Murtadha  (CS)4 This	thesis	presents	new	techniques	for	voltage	stability	assessment	 and	 improvement	 in	 power	 system	 under	multi-contingencies.	A	line-based	voltage	stability	index	termed	as	Static	Voltage	Stability	Index	(SVSI)	was	used	to	 evaluate	 the	 voltage	 stability	 condition	 on	 a	 line.	The	 value	 of	 SVSI	 was	 computed	 to	 identify	 the	 most	sensitive	line	and	corresponding	weak	bus	in	the	system.	The	 results	obtained	 from	the	voltage	 stability	analysis	Name	 :		Nurharniza Bt Abdul Rahman Title		 :	Performance of Wall-Slab Connection   Enhanced with Steel Fibres under   Reversible Cyclic LoadFaculty	: Civil EngineeringSupervisor	: Prof. Ir. Dr. Siti Hawa Hamzah  (MS)	 	 Associate Prof Dr. Nor Hayati Abdul   Hamid  (CS)3The	 most	 critical	 stress	 concentration	 build-up	in	 a	 tunnel-form	 construction	 is	 in	 the	 wall-slab	connection	at	 the	 first	 floor	 level.	A	 total	of	 twelve	(12)	wall-slab	samples	were	cast,	six	(6)	as	anchorage	connection	 and	 another	 six	 (6)	 as	 cross-bracing.	All	 samples	 were	 tested	 under	 cyclic	 load	 using	displacement	 control;	 six	 (6)	 samples	 under	 lateral	and	 the	 remaining	 six	 (6)	 under	 vertical.	 Hooked	end	steel	fibres	(SteFib)	were	added	in	the	concrete	mix	 and	 placed	 at	 various	 locations	 in	 the	 wall-slab	 samples.	 The	 concrete	 grade	 used	 was	 30	 N/mm2.	The	anchorage	connection	with	SteFib	placed	in	 the	 connection	 section	 only	 (L-A-C	 and	 V-A-C)	performed	 better	 in	 ductility,	 energy	 dissipation	and	 crack	 control,	 when	 compared	 to	 cross-bracing	samples	 (L-CB-C	 and	 V-CB-C),	 under	 both	 lateral	and	vertical	cyclic	load	capacities.	The	displacement	increased	more	than	100%	 in	L-A-C	when	compared	to	 L-CB-C.	 Crack	 propagations	 reduced	 by	 50%	with	 major	 cracks	 occurred	 at	 200	 mm	 above	 the	connection.	 Likewise,	 the	 displacements	 increased	by	 75%	 and	 more	 than	 100%	 under	 pushing	 and	pulling	 load	 phases	 respectively,	 in	 V-A-C	 when	compared	 to	 V-CB-C.	 A	 comparative	 study	 using	Ruaumoko	 modelling	 showed	 experimental	 load	in	 the	 anchorage	 connection	 with	 SteFib	 increased	the	 displacement	 by	 39%	 under	 lateral	 cyclic	 load.	Further	 analysis	 using	 PROKON	 showed	 maximum	stresses	 concentrated	 at	 the	 first	 floor	 wall-slab	connection	 section.	 Therefore,	 it	 is	 recommended	to	the	construction	industry	to	adopt	the	anchorage	wall-slab	detailing	with	double	layer	steel	fabric	with	SteFib	 placed	 in	 the	 connection	 section	 to	 provide	good	resistance	under	cyclic	load.(Qwsf),	 that	 comprises	 through	 (nonconflicting	 Qncf)	and	weaving	 (conflicting	Qcf	 )	movements.	These	flow	patterns	 are	 critically	 governed	 by	 the	 available	 gaps	between	vehicles,	thus	time	ideal	safe	gap	(Tisg	)	been	identified	 and	 retrieved.	With	 the	 available	 data,	 data	transformations	and	rigorous	statistical	tests	were	done	during	 the	 model	 development	 process.	 Statistical	tables	and	graph	plots	 revealed	 the	good	correlations,	relationships	 and	 significances	 between	 the	 variables/parameters	 being	 considered.	 The	 developed	 model	(Qwsf	 =	 2700	 +	 0.000028	 Qncf	 3/2.Qcf	 -	 1.22Tisg	.Qcf),	 was	 calibrated,	 verified	 and	 validated	 with	independent	 field	 data	 (new	 data	 set).	 Comparison	of	weaving	 flow	 capacity	 between	 the	 develop	model	and	observed/field	data	was	within	approximately	5%	difference.	 Sensitivity	 analysis	 was	 done	 to	 check	 on	the	 measured	 of	 effectiveness	 (MOE)	 of	 the	 model.	Integration	between	weaving	section	flow	and	practical	capacity	 flow	 enable	 level	 of	 service	 (LOS)	 chart	being	 deduced.	 The	 LOS	 chart	 is	 considered	 another	significant	 contribution	 of	 this	 research	 to	 practising	traffic	 engineers	 and	 academicians.	 Knowledge	 on	the	 mechanics	 of	 traffic	 flow	 interactions	 at	 weaving	section	and	the	developed	model	are	able	to	give	better	prediction	on	weaving	capacity	as	well	as	performance	level	 and,	 hence,	 the	 objectives	 set	 for	 this	 research	works	were	accomplished.7L e a d i n g  Y o u  T o  G r e a t e r  H e i g h t s ,  D e g r e e  b y  D e g r e e* (MS) = Main Supervisor   (CS) = Co SupervisorName	 :		Salina Bt MuhamadTitle		 :	 Schottky Behavior of Novel Synthesized   Aligned Zinc Oxide Nanorod Arrays and   Aligned Carbon Nanotube Arrays for   Mesfet DeviceFaculty	: Electrical EngineeringSupervisor	:  Prof. Dr. Mohamad Rusop    Mahmood (MS)	 		 	Profesor Dr Zaki Awang   (CS)   Profesor Dr Anuar Ahmad  (CS)5This	study	is	carried	out	to	introduce	new	active	layers	in	a	Schottky	diode	for	a	metal-semiconductor	field	effect	transistor	 (MESFET)	 device	 structure,	 which	 are	 novel	aligned	 zinc	 oxide	 (ZnO)	 nanorod	 arrays	 and	 aligned	carbon	 nanotubes	 (CNT)	 arrays.	 Both	 nanomaterials	are	 successfully	 synthesized	 using	 the	 Chemical	 Bath	Deposition	(CBD)	and	Chemical	Vapor	Deposition	(CVD)	methods,	 respectively,	 which	 in	 nanoscale,	 exhibit	1-dimensional	 structure	 and	 quantum	 confinement	effects	 that	 lead	 to	 better	 properties.	 Prior	 to	 the	synthesis	 process,	 the	 novel	 seed	 layer,	 which	 is	 the	Mg0.3Zn0.7O	thin	film,	is	introduced.	In	order	to	obtain	a	well-aligned	and	densely-packed	ZnO	nanorod	arrays,	parametric	studies	are	conducted	during	the	deposition	process	 where	 the	 optimized	 parameters	 are	 finalized	(substrate	at	top	floating	position,	4	hour	deposition	time,	and	molarities	of	0.05	M	or	more).	Further	investigations	reveal	 that	 the	0.1	M	sample	was	 the	most	conductive	sample	 of	 27.75	 Scm-1	 with	 the	 highest	 crystallinity,	which	 then	 becomes	 the	 standard	 parameter	 to	 be	applied	in	the	Schottky	diode.	Then,	the	possible	growth	mechanism	 is	proposed.	 Schottky	behavior	 is	observed	in	all	 samples	with	Au-,	Ag-	and	Pt-gate	contact	where	the	 highest	 barrier	 height	 of	 0.77	 eV	 and	 reasonable	ideality	 factor	are	obtained	 from	the	Au/0.1	M	aligned	ZnO	 nanorod	 arrays/Mg0.3Zn0.7O.	 Applying	 this	 into	the	 MESFET	 device	 structure,	 a	 common	 MESFET	behavior	 is	 then	 obtained.	 This	 strongly	 indicates	 that	the	 proposed	 new	 active	 nanomaterial,	 which	 is	 novel	aligned	ZnO	nanorod	arrays/Mg0.3Zn0.7O,	is	applicable	in	the	MESFET	device	structure	application,	even	though	it	 exhibits	 a	 channel	 length	 modulation	 phenomenon.	Simultaneously,	 the	aligned	CNT	arrays	are	successfully	grown	 on	 the	 Mg0.3Zn0.7O	 seed	 layer	 by	 a	 palm	 oil	precursor	mixed	ferrocene.	The	existence	of	Mg	and	Zn	in	 the	 seed	 layer	 increases	 the	 catalytic	 activity	which	results	 in	 physical	 and	 electrical	 improvement,	 where	a	 conductivity	 of	 more	 than	 100	 kScm-1	 is	 obtained.	However,	 only	 weak	 Schottky-curves	 are	 obtained,	leading	to	 intolerable	application	 in	the	MESFET	device	structure.using	 SVSI	 were	 utilized	 to	 identify	most	 sensitive	 line	corresponds	 to	 a	 load	bus	 and	estimate	 the	maximum	loadability	 and	 operating	 margin	 in	 the	 system.	 The	SVSI	was	consequently	used	as	the	line	outage	severity	indicator	in	the	implementation	of	contingency	analysis	and	 ranking.	 The	 application	 of	 SVSI	was	 extended	 for	the	evaluation	of	the	constrained	power	planning	(CPP)	and	 Flexible	 AC	 Transmission	 Systems	 (FACTS)	 devices	installation	 using	 Evolutionary	 Programming	 (EP)	 by	considering	 multi-contingencies	 occurrence	 in	 the	system.	 The	 minimizations	 of	 SVSI and	 transmission	loss	 are	 used	 as	 two	 separate	 objective	 functions	 for	the	development	of	optimization	technique.	The	effect	of	 reactive	 power	 load	 variation	 on	 transmission	 loss	in	the	system	is	also	investigated.	Consequently,	the	EP	optimization	technique	is	extended	for	the	evaluation	of	the	operating	generator	scheduling	(OGS)	to	be	applied	on	reactive	power	control	in	power	system.	The	results	obtained	from	the	study	can	be	used	by	the	power	system	operators	to	make	a	decision	either	to	achieve	minimal	SVSI,	minimal	 transmission	 loss	 or	minimal	 installation	cost.	 This	 has	 also	 avoided	 all	 generators	 to	 dispatch	power	at	the	same	time.	Finally,	a	novel	multi-objective	Constrained	 Reactive	 Power	 Control	 (CRPC)	 algorithm	using	 the	 state-of-the-art	 of	 EP	 for	 voltage	 stability	improvement	 has	 been	 developed.	 A	 performance	comparison	with	Artificial	Immune	System	(AIS)	in	terms	of	SVSI	and	 loss	minimization	was	made	and	 it	 is	 found	that	 the	proposed	 algorithm	has	 been	 able	 to	 produce	better	 results	as	 compared	 to	AIS.	The	contributions	of	the	 studies	 among	 the	 others	 are	 the	 development	 EP	and	 AIS	 engine	 for	 CPP	 considered	multi-contingencies	(N-m),	the	development	of	EP	and	AIS	engine	for	FACTS	installation	considered	multi-contingencies	(N-m)	for	the	determination	of	FACTS	placement	using	SVSI	and	optimal	sizing	of	FACTS	using	EP	and	AIS,	the	development	of	new	technique	 for	OGS	based	on	EP	optimization	 technique	and	 the	 development	 of	 multi-objective	 EP	 and	 AIS	engines	for	CRPC	considered	multi-contingencies	(N-m).

Computational intelligence based power system security assessment and improvement under multi- contingencies conditions / Nor Rul Hasma Abdullah

http://ir.uitm.edu.my/19149/1/ABS_NOR%20RUL%20HASMA%20ABDULLAH%20TDRA%20VOL%202%20IGS%2012.pdf

Computational intelligence based power system security assessment and improvement under multi- contingencies conditions / Nor Rul Hasma Abdullah

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