SUBSTATION & SWITCHYARD STRUCTURE’S

(1)

HOW ELECTRICITY IS

DELIVERED TO YOUR

HOME

HOW ELECTRICITY IS

DELIVERED TO YOUR

HOME

GENERATION _{TRANSMISSION 230kV} DELIVERY POINT SUBSTATION SUB-TRANSMISSION DISTRIBUTION

(2)

DEFINATION’S

SUBSTATION:-AN ASSEMBLAGE OF EQUIPMENT THROUGH WHICH

ELECTRICAL ENERGY IN BULK IS PASSED FOR THE PURPOSE OF SWITCHING OR MODIFYING ITS CHARACTERISTICS

SWITCHYARD:-AN ASSEMBLAGE OF SWITCHES, POWER CIRCUIT

BREAKERS, BUSES AND AUXILIARY EQUIPMENT THAT IS USED TO COLLECT POWER FROM THE GENERATORS OF A POWER PLANT AND DISTRIBUTE IT TO THE TRANSMISSION LINES AT A LOAD POINT.

AS FAR AS STRUCTURES ARE CONCERNED, THE TERMS SUBSTAION AND SWITCHYARD WILL BE USED

(3)

Switchyard Type

• Conventional Air Insulated Type.

• Gas Insulated type.

(4)

Switchyard Type

AIR INSULATED SUBSTATION

:-• AN AIR INSULATED SUBSTATION OR SWITCHYARD HAS THE INSULATING MEDIUM OF AIR

GAS INSULATED

SUBSTATION:-• SULFUR HEXAFLUORIDE (SF6) GAS INSULATED SUBSTATION

(5)

SUBSTATION & SWITCHYARD

STRUCTURE’S

• TO SUPPORT ELECTRICAL EQUIPMENTS SUCH AS • CABLE BUS,

• RIGID BUS,

• STRAIN BUS CONDUCTORS; • SWITCHES;

• SURGE ARRESTERS; • INSULATORS

(6)

SUBSTATION & SWITCHYARD

STRUCTURE’S

• COMMON MATERIALS USED ARE; » CONCRETE

» STEEL

» ALUMINUM » WOOD

(7)

SUBSTATION & SWITCHYARD

STRUCTURE’S

• LATTICED ANGLES ( CHORDS & TRUSSES) • WIDE FLANGES

• TUBES (ROUND, SQUARE & RECTANGULAR) • PIPES

(8)

(9)

(10)

(11)

EQUIPMENT SUPPORTING BOX / TUBE TYPE STRUCTURE

(12)

BUSWORK SYSTEM

• RIGID BUS SYSTEM

:-An Extruded Metallic Conductor. The conductor material is usually an aluminum alloy / also be Copper

.

• STRAIN BUS

SYSTEM:-A stranded wire conductor installed under tension.

• CABLE BUS

SYSTEM:-Low-tension, stranded conductors supported on station post insulators

.

(13)

ELECTRICAL CLEARANCE

ELECTRICAL CLEARANCES PROVIDE THE

PHYSICAL SEPRATION NEEDED FOR

PHASE-TO-PHASE, PHASE-TO-STRUCTURE

AND PHASE-TO-GROUND AIR GAPS TO

PROVIDE SAFE WORKING AREAS AND TO

PREVENT FLASHOVERS.

(14)

SHORT-CIRCUIT FORCE

SHORT-CIRCUIT FORCES ARE STRUCTURE

LOADS THAT ARE CAUSED BY

SHORT-CIRCUIT CURRENTS.

SHORT-CIRCUIT CURRENTS ARE THE

RESULT OF ELECTRICAL FAULTS CAUSED

BY EQUIPMENT OR MATERIAL FAILURE,

LIGHTNING OR OTHER WEATHER-RELATED

CAUSES, AND ACCIDENTS

(15)

ELECTRICAL EQUIPMENT AND

SUPPORTS

POWER TRANSFORMER & AUTOTRANSFORMER

– SUPPORT :- THE POWER TRANSFORMER AND

AUTOTRANSFORMER ARE SUPPORTED DIRECTLY ON A FOUNDATION.

SHUNT REACTOR

– SUPPORT :- THE SHUNT REACTOR IS SUPPORTED DIRECTLY ON A FOUNDATION

(16)

GENERAL DEFINITION:

TRANSFORMER IS AN ELECTRICAL DEVICE THAT TRANSFERS ENERGY FROM

ONE CIRCUIT TO ANOTHER BY MAGNETIC COUPLING WITH NO MOVING PARTS

TRANSFORMERS ARE USED TO CONVERT BETWEEN HIGH AND LOW VOLTAGES, TO CHANGE IMPEDANCE, AND TO PROVIDE ELECTRICAL

(17)

(18)

(19)

ELECTRICAL EQUIPMENT AND

SUPPORTS

CURRENT-LIMITING INDUCTOR OR AIR CORE REACTOR

– SUPPORT :- THE SUPPORTING PEDESTALS ARE BOLTED DIRECTLY TO THE FOUNDATION.

LINE TRAP / WAVE TRAP

– SUPPORT :- THE LINE TRAP CAN BE MOUNTED

VERTICALLY OR HORIZONTALLY ON EITHER A SINGLE OR MULTIPLE PEDESTAL SUPPORT STRUCTURE. THE LINE TRAP CAN ALSO BE SUSPENSION MOUNTED FROM A STRUCTURE.

(20)

ELECTRICAL EQUIPMENT AND

SUPPORTS

COUPLING CAPACITOR VOLTAGE TRANSFORMER

– SUPPORT :- THE CCVT IS USUALLY SUPPORTED ON A SINGLE PEDESTAL.

DISCONNECT SWITCH (VERTICAL BREAK, CENTER BREAK, SINGLE SIDE BREAK OR DOUBLE SIDE BREAK)

– SUPPORT :- THE DISCONNECT SWITCH IS

SUPPORTED ON A COMMON STRUCTURE FOR VOLTAGE LESS THAN 500kV.

(21)

(22)

ELECTRICAL EQUIPMENT AND

SUPPORTS

LOAD INTERRUPTER SWITCH / CIRCUIT SWITCHER / LINE CIRCUIT BREAKER

– SUPPORT :- THE CIRCUIT SWITCHER SUPPORTED ON A COMMON STRUCTURE FOR VOLTAGE LESS THAN 500kV.(DYNAMIC LOAD ON OPENING OR CLOSING .

CIRCUIT BREAKER

– SUPPORT :- CIRCUIT BREAKERS, INCLUDING THEIR SUPPOTING FRAMES, ARE ANCHORED DIRECTLY ON THE FOUNDATION.

(23)

ELECTRICAL EQUIPMENT AND

SUPPORTS

POTENTIAL AND CURRENT TRANSFORMERS

– SUPPORT :- PTs & CTs ARE USUALLY SUPPORTED ON A SINGLE PEDESTAL OR LATTICE STAND STRUCTURE.

CAPACITOR BANK

– SUPPORT :- USUALLY SUPPORTED ON A SINGLE PEDESTAL OR LATTICE STAND STRUCTURE.OUTER PERIPHERY OF THE BANK SHOULD BE ENCLOSED

INSIDE A FENCE FOR PROTECTION OF PERSONNEL; IF ELECTRICAL CLEARANCE IS NOT PROVIDED.

(24)

(25)

ELECTRICAL EQUIPMENT AND

SUPPORTS

SHUNT CAPACITOR

– SUPPORT :- THE SUPPORT IS PROVIDED BY A METAL PLATFORM.THE PLATFORM MUST BE MOUNTED ON

INSULATORS THAT ARE BOLTED TO THE FOUNDATION. SURGE ARRESTER – SUPPORT :- SURGE ARRESTER CAN BE SUPPORTED ON A SINGLE PEDESTAL OR LATTICE STAND STRUCTURE OR DIRECTLY MOUNTED ON TRANSFORMER.

(26)

(27)

ELECTRICAL EQUIPMENT AND

SUPPORTS

NEUTRAL GROUNDING RESISTOR

– SUPPORT :- RESISTORS ARE SOMETIMES MOUNTED ON SEPARATE STRUCTURES BUT ARE USUALLY MOUNTED ON THE TRANSFORMER TANK.

CABLE TERMINATOR / POTHEAD

– SUPPORT :- SUPPORT

STRUCTURES OF CABLES

TERMINATORS OF INDIVIDUAL PHASES CAN BE COLUMNS

RESTING ON A FOUNDATION. A STRUCTURE SUPPORTING

THREE PHASES CAN ALSO BE USED.

(28)

ELECTRICAL EQUIPMENT AND

SUPPORTS

INSULATOR

(PORCELAIN,GLASS &

COMPOSITE MATERIALS

ARE USED FOR

SUSPENSION & POST

INSULATORS)

– SUPPORT

:-INSULATORS CAN BE

SUPPORTED ON A

SINGLE-PHASE OR

THREE PHASE

STRUCTURE.

(29)

LOADING CRITERIA FOR SUBSTATION

STRUCTURES

• DEAD LOADS

• EQUIPMENT OPERATING LOADS

• TERMINAL CONNECTION LOADS FOR

ELECTRICAL EQUIPMENT

• WIRE TENSION LOADS

• WIND LOADS

• COMBINED ICE AND WIND LOADS

• EARTHQUAKE LOADS

• SHORT CIRCUIT LOADS

(30)

9,81.mi

fs

SAG DUE TO CONDUCTOR

fs = w.Lc2

8.T

fs = maximum conductor sag (m) wi = weight of conductor (kg/m) Lc = conductor span length (m) T = tension per conductor (kg)

T

(31)

Construction and commissioning of

sub station

Construction and commissioning of sub station is a subject describing the actual execution details.

• These sub station land is initially selected and the final level to be kept for construction of substation is decided on the basis of contour survey of the sub station land. So that the land development is carried out economically.

• The land development is then carried out accordingly • The sub station equipments and gantry foundations are

then cast.

(32)

(33)

(34)

(35)

Construction and commissioning of

sub station

• The construction of sub station includes some of following activities.

• The arrangement of 3 phase supply up to 200 KVA • Erection of sub station columns and beams.

• Stringing of various buses in the sub station.

• Erection of equipment structures and equipments • Erection of equipment in control room

• The earthing mesh and earthing electrodes work

• The equipments are connected to each other, to bus, etc. by carrying out jumpering work as specified in the lay out .

(36)

(37)

(38)

(39)

Construction and commissioning of

sub station

• Commissioning of breakers, isolator alignments are

carried out.

• Battery charging, charger commissioning making DC

supply available for testing purposes.

• Commissioning of C & R panels relays etc.

• The transformer erection filtration and testing

Lightening in control room and switch yard.

• Metal spreading

(40)

(41)

(42)

(43)

(44)

-: Design Example

:-Design a Single Phase Bus Support for a Substation in Nagpur, given the following information,

– Height of Bus Centerline above foundation = 5.5 m

– Schedule 40 aluminum bus = 100 mm (mass = 5.51 kg/m) – Maximum Short Circuit force = 550 N/m

– Short Circuit reduction factor = 0.66 – Bus Support Spacing = 6.0 m

– Insulator Height (hi) = 2.0 m – Insulator Diameter (Di) = 0.28 m – Insulator Weight (Wi) = 140 kg

– Basic Wind Speed (Vb) = 33 m/sec (Zone = 1)

– Reliability level = 2 (Return period of design loads 150 yrs) – Terrain Category = 2

(45)

LATTICE STRUCTURE

DETAILS:-Main Leg = ISA65x65x6 @ 5.8kg/m

Bracing,

Inclined = ISA45x45x5 @ 3.4kg/m

Plan = ISA45x45x5 @ 3.4kg/m

Part of Structure = 04

Each Part Length = 850 mm

Inclined Length = 931 mm

(46)

• Short-Circuit

Loading:-• Fsc = 6.0 m x 0.66 x 550 N/m • Fsc = 2178 N

• Mom @ Base = 5.5 m x 2178 N • Mom @ Base = 11979 N.m

(47)

Wind Loading

:-• IS 802 (Part 1 / Sec 1) :1995,

• Basic wind speed Vb = 33 m/sec

• Metrological Reference wind speed V

_R

is,

• V

_R

= Vb / K

₀

, where K

₀

= 1.375 (cl. 8.2 pg 3)

• V

_R

= 33 / 1.375 = 24 m/sec

• Design wind speed Vd = V

_R

x K1 x K2,

• Where K1 = Risk Coeff. (cl. 8.3.1)

• K1 = 1.08 (Table 2)

• Where K2 = Terrain roughness coeff. (cl.8.3.2)

• K2 = 1.00 (Table 3)

(48)

Wind Loading

:-Design wind pressure Pd = 0.6 Vd2 _{(cl. 8.4)}

Pd = 0.6 x 25.92 x 25.92 = 403.11 N/sq.m

============================================== Wind load on Conductor Fwc (cl 9.2)

Fwc = Pd x Cdc x L x d x Gc, Where,

Cdc = Drag coeff, taken as 1.0 for conductor

L = wind span, being sum of half the span on either side of supporting point in meters

d = diameter of cable / tube

Gc = gust response factor (Table 7) = 1.83 Fwc = 403.11 x 1.0 x 6 x 0.1 x 1.83

(49)

Wind Loading

:-• Wind load on Insulator Strings (Fwi) :- (cl 9.3)

• Fwi = Cdi x Pd x Ai x Gi

• Where,

• Cdi = drag coeff to be taken as 1.2

• Ai = 50 % of the area of insulator string projected on

a plane which is parallel to the longitudinal axis of

the string

• Gi = Gust response factor (Table 6) = 1.92

• Fwi = 1.2 x 403.11 x 0.5 x 2 x 0.28 x 1.92

• Fwi = 260.1 N (928.8 N/sq.m)

(50)

• Wind on structure Fwt = Pd x Cdt x Ae x Gt

• Where,

• Cdt = Drag coeff for panel under consideration

against which the wind is blowing . Values of Cdt

for different solidity ratios are given in Table 5.

• Solidity ratio (Φ) is equal to the effective area of

a frame normal to the wind direction divided by

the area enclosed by the boundary of the frame

normal to the wind direction.

• Solidity ratio (Φ) = Aeff / Agross

• Ae = Total net surface area of the legs, bracing,

cross arms and secondary members of the

panel projected normal to the face in m

2

• Gt = Gust response factor, Table 6

(51)

:-Solidity Ratio (Φ) = Ae / Ag Φ = 0.678 / 1.292 = 0.525

Drag Coeff Cdt = 2.0 (Table 5) Gt = 1.92 (Table 6)

Fwt = 403.11 x 2 x 0.678 x 1.92 Fwt = 1049.50 N (1547.92 N/sq.m)

0.678

Total Net Surface Area Ae =

0.068 0.045 0.38 4 3,5,7 & 9 1.292

Gross Surface Area Ag = 3.4 m x 0.38 m

0.168 0.045 0.931 4 2,4,6 & 8 0.442 0.065 3.4 2 1 Area (sq.m) Width (m) Length (m) Nos Member

(52)

Wind load summary

:-5363.00 1752.22 Totals 1784.15 1.7 1049.5 Wind on Structure (Fwt) 1144.44 4.4 260.1 Wind on Insulator (Fwi)

2434.41 5.5 442.62 Wind on Bus (Fwc) Moment @ Base (N.m) Lever Arm (m) Force (N) Description

(53)

Earthquake

Loading:-IS 1893 (Part 1) : 2002

Design Horizontal Acceleration Coeff (Ah), Ah = Z I / 2R * Sa/g

Z = Zone factor = Zone II = 0.10 (Table 2) I = Importance factor = 1.5 (Table 6)

R = Response reduction factor = 4 (Table 7)

Sa/g = Avg. response acceleration coeff for rock or soil sites as given by fig 2 & Table 3 based on

appropriate natural periods and damping of the structure.

Fundamental Natural Period Ta = 0.085 h0.75

Ta = 0.085 x 3.40.75 _{= 0.213 sec}

Sa/g = 2.5

(54)

Earthquake

Loading:-IS 1893 (Part 1) : 2002

Design Seismic Base Shear V_B = Ah W W = Seismic weight of the structure

508.92 162.78 Totals 141.08 1.7 180kg x 9.81 x 0.047 = 82.99 EQ on Structure 284.02 4.4 140kg x 9.81 x 0.047 = 64.55 EQ on Insulator 83.82 5.5 6m x 5.51 kg/m x 9.81 x 0.047 = 15.24 EQ on Bus Moment @ Base (N.m) L.A (m) Force (N) Description