Advanced Energy Grid Systems - I

Pithapur MohammedSneha CheruvattathUrvakhshaTavadia

WIND POWER• All renewable energy (except tidal and geothermal power), ultimately

comes from the sun.• The earth receives 1.74 x 1017 watts of power (per hour) from the sun• About one or 2 percent of this energy is converted to wind energy (which

is about 50-100 times more than the energy converted to biomass by all plants on earth

• Differential heating of the earth’s surface and atmosphere induces vertical and horizontal air currents that are affected by the earth’s rotation and contours of the land WIND.

For e.g.: Land Sea Breeze Cycle

• A typical 600 kW wind turbine has a rotor diameter of 40-54 meters, i.e. a rotor area of 1,500-2,200 square meters. • The rotor area determines how much energy a wind turbine is able to harvest from the wind.

• Since the rotor area increases with the square of the rotor diameter, a turbine which is twice as large will receive 22 = 2 x 2 = four times as much energy. • To be considered a good location for wind energy, an area needs to have average annual wind speeds of at least 12 miles per hour.

WIND POWER

POWER PRODUCTION WIND POWER EQUATION

31),(

21 vACPCP tPinp

Power extracted depends on 1. Design factors: Swept area, At 2. Environmental factors:• Air density, ρ (~1.225kg/m3 at sea level)• Cube of wind speed (v3)

3. Control factors: • Tip speed ratio through the rotor speed ω• Pitch θ• The Betz Limit is the maximal possible Cp =

16/27• 59% efficiency is the BEST a conventional

wind turbine can do in extracting power from the wind

WARD HALE MODEL

Wind FarmAssuming a wind farm of 100 Wind Turbines each

whose maximum output is 600KW on bus2.Power obtained from wind energy is intermittent since

speed of wind is variable.Using =1.3kg/mꝬ 3 air densityRotor Blade Diameter of 52m. Area = 2124 sq.m.Power Coefficient, Cp = 0.335.Power produced per Turbine,

P = 1380.265*v³

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0MW OUTPUT OF A WIND FARM

with WIND SPEED

WIND SPEED in m/s

MW

OUT

PUT

FOR

100

TURB

INES

CUT IN SPPED 4.5m/sCUT OUT SPEED 24m/sRATEED SPEED 12m/s

0

20

40

60

80

100

120

140

160

180EFFECT OF WIND SPEED ON MW AND MVAR GENERATION

Wind Power MWBus2 MVarMW Gen1Bus2 Mvar

Wind Speed m/s

Rea

l & R

eact

ive

Pow

er M

W &

MV

ar

0.8700

0.8800

0.8900

0.9000

0.9100

0.9200

0.9300

0.9400

0.9500

0.9600 BUS Voltage vs Wind Speed

Bus 3Bus 4

WIND SPEED m/s

BU

S V

OLT

AG

E PU

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18-10

0

10

20

30

40

50

60

70

80

90

EFFECT OF WIND SPEED ON LINEFLOWS

REAL POWER

Line 1-4Line 1-6Line 2-3Line 2-5Line 4-3Line 4-6Line 6-5

Wind speed in m/s

Real

Pow

er -

MW

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

-10

-5

0

5

10

15

20

25

30

EFFECT OF WIND SPEED ON LINE FLOWS

REACTIVE POWER

Line 1-4Line 1-6Line 2-3Line 2-5

Wind Speed m/s

Rea

ctiv

e Po

wer

MV

ar

Switched Shunt Capacitors Advantages of using shunt capacitors 1. It reduces line current of the system. 2. It improves voltage level of the load. 3. It also reduces system Losses. 4. It reduces load of the alternator. 5. It improves power factor of the source current. 6. It reduces capital investment per mega watt of

the Load. All the above mentioned benefits come from the

fact, that the effect of capacitor reduces reactive current flowing through the whole system.

0.00 0.00 5.00 10.00 15.000.8600

0.8800

0.9000

0.9200

0.9400

0.9600

0.9800Effect of installing Switched shunt on

Bus 5

Bus 3Bus 4Bus 5Bus 6

Mvar

Volt

age

(PU

)

60MW 80MW

Effects on wind speedHeight

Daytime peak occurs at 10 m.

Nighttime peak occurs at 200 m.

Almost flat at 80 m.

Average wind

speed increases

with height.

The weather wrecks havoc with the grid every year. Especially to the overhead lines.

In the form of storms, hurricane. Damage to power lines results in arcing also called as power flash.

Fig: Arcing between lines

Weather related faults in transmission lines

Power flashes were incorrectly termed as exploding transformers.

Power flash is simply an arc caused by short out power line.

Power flash can occur due to- - Collapsing of poles - Wires touching each other - Conducting object between two live wires

Fig- Storm formation causing a power flash

Effect of Transformer tap ratio change on currentC

urre

nt c

hang

e

Transformer tap ratio change

Effect of Transformer tap ratio change on voltage

Transformer tap ratio change

Volta

ge c

hang

e

Effect of Transformer tap ratio change on power (MW & Mvar)Po

wer

Transformer tap ratio change

Effect of Transformer tap ratio change on loss (MW & Mvar)

Transformer tap ratio change

Los

s

Effect of changing real power at Generator 2 on CurrentC

urre

nt

Real Power (Mw)

Effect of changing real power at Generator 2 on Voltage

Real Power (Mw)

Volta

ge

Real Power (Mw)

Cha

nge

in P

ower

Effect of changing real power at Generator 2 on Power (Mw & Mvar)

Effect of changing real power at Generator 2 on Power Loss(Mw & Mvar)

Real Power (Mw)

Cha

nge

in P

ower

Los

s

Different system scenarios

Different system scenarios

POWER FLOWS

• Planning future expansion of power systems• Determining the best operation of existing

systems. • Information obtained is the voltage at each bus

, and the real and reactive power flowing in each line.

CHANGE IN REAL POWER

WARD HALE MODEL

CHANGE IN VOLTAGE

VOLTAGE(p.u)

POWER (MW)

CHANGE IN CURRENT

CURRENT(A)

POWER (MW)

CHANGE IN ACTIVE POWER

ACTIVE POWER(p.u)

POWER (MW)

CHANGE IN REACTIVE POWER

REACTIVE POWER (p.u)

POWER (MW)

CHANGE IN VAR SUPPLY

CHANGE IN CURRENT

CURRENT(A)

POWER (MVar)

CHANGE IN VOLTAGE

VOLTAGE

(p.u)

POWER (MVar)

CHANGE IN ACTIVE POWER

ACTIVE POWER

(p.u)

POWER (MVar)

CHANGE IN REACTIVE POWER

REACTIVE POWER(p.u)

POWER (MVar)

SEPTEMBER 8, 2011 CALIFORNIA-ARIZONA:

Transmission failure in Southern California.

Confliction with generation and transmission outages planned for maintenance.

This outage lasted 12 hours, affecting 2.7 million people.

CASE STUDYJuly 30 and 31, 2012 Northern India:

 High demand, inadequate supply coordination, and transmission outages

Mid-summer demand in the north exceeded local supply, making the imports and transfers from west vital.

Excessive demand tripped a transmission line. Within seconds, ten additional transmission

lines tripped. Conditions and failure repeated again the

following day.

CASE STUDY POWER AND THE AUGUST 14TH BLACKOUT:

• Brush fire in southwest Ohio knocked out a power line

• Redirected power on the system• Changed need for reactive power on

other lines • All links between northern Ohio and

southern Ohio shut down• System shutdown

CYBER ATTACKS

INTRODUCTION

A cyber attack is less predictable in its timing and potentially more difficult to diagnose and address.

A cyber attack could also be combined with a more traditional physical attack to distract authorities and inflict further damage.

A cyber attack could come from many sources and target many potential vulnerabilities.

INTRODUCTION

As cyber attacks become more frequent, energy systems are increasingly being targeted.

The Industrial Control Systems Cyber Emergency Response Team reported 198 cyber incidents in 2012.

Larger costs, triggering sustained power outages over large portions of the electric grid

prolonged disruptions in communications, food and water supplies, and health care delivery.

CYBER ATTACK SIMULATION

GENERATOR SHUTDOWN

SIMULATION CONTINUED:

POWER FLOW REDISTRIBUTION

CASE STUDY NORTHEAST BLACKOUT

  1999 Southern Brazil blackoutAt the time, it was the world's second 

most widespread blackout in historyAffected an estimated 10 million people in

Ontario and 45 million people in eight U.S. states.

The blackout's primary cause was a software bug in the alarm system at a control room of the FirstEnergy Corporation, located in Ohio.

CONCLUSIONDifferent scenarios could lead the system to a Blackout. A minor change might have huge implication on the

given network. Different strategies need to be implemented to mitigate

the effects of disturbances. Cyber and Terror attacks also act as a potential weapon. Hence, System security is a very crucial and a lot of

research is being carried out in the same direction.

THANK YOU