Presentation on

Optimal Load flow control using UPFC

method

The most common power system analysis tool is the power flow (also known sometimes as the load flow):

power flow determines how the power flows in a network

also used to determine all bus voltages and all currents,

because of constant power models, power flow is a nonlinear analysis technique,

power flow is a steady-state analysis tool.

First step in solving the power flow is to create what is known as the bus admittance matrix, often called the Ybus.

The Ybus gives the relationships between all the bus current injections, I, and all the bus voltages, V, I = Ybus V

The Ybus is developed by applying KCL at each bus in the system to relate the bus current injections, the bus voltages, and the branch impedances and admittances.

Determine the bus admittance matrix for the network shown below.

| From | To | R | X | B/2 |

1 2 0.02 0.06 0.06;

1 3 0.08 0.24 0.05;

2 3 0.06 0.18 0.04;

2 4 0.06 0.18 0.04;

2 5 0.04 0.12 0.03;

3 4 0.01 0.03 0.02;

4 5 0.08 0.24 0.05];

This method enables us to define the values of thecurrents , the active and reactive powers, the active andreactive power losses, and the power-factor of theelectrical supply network for different loads. It alsoenables us to determine the degree of stability of thenetwork.

flow chart newton rapson method.docx

programme_5bus\start.m

programme_5bus\ybus.m

programme_5bus\jacobian.m

programme_5bus\newt.m

* *

1 1

1

1

1

( )

(cos sin )( )

Resolving into the real and imaginary parts

( cos sin )

( sin cos

ikn n

ji i i i ik k i k ik ik

k k

n

i k ik ik ik ikk

n

i i k ik ik ik ik Gi Dik

n

i i k ik ik ik ik

S P jQ V Y V V V e G jB

V V j G jB

P V V G B P P

Q V V G B

)k Gi DiQ Q

o UPFC is a FACTS device which enhance power transmission capacity.

o able to control all parameters of power transmission(voltage, impedance, and phase angle).

o UPF provides a consistent format to specify power design .

programme_5bus\upf.m

Tie line ! Active power

without ‘UPF’

Active power

with ‘UPF’

Change

1->2 77.9650 48.8279 -29.1326

1->3 74.1491 97.7007 23.5516

2->3 47.6626 14.1116 -33.551

2->4 47.3599 15.3646 -31.9953

2->5 44.8060 16.5174 -28.2886

3->4 12.0563 89.1578 77.1015

4->5 0.6754 19.7202 19.0448

Total active power

->

304.6698 301.4002

Tie line ! Reactive power

without ‘UPF’

Reactive power

with ‘UPF’

Change

1->2 19.5722 20.4738 0.9016

1->3 20.7756 17.1851 -3.5905

2->3 -14.7529 -20.0050 -5.2521

2->4 14.7751 18.6953 3.9202

2->5 -14.8020 -17.0622 -2.2602

3->4 -4.3399 1.9692 6.3091

4->5 -0.0715 0.1639 0.2354

Total Reactive

power ->

21.1566 21.4201

Control of power flow

Reduce reactive power flows, thus allowing the lines to carry more active power.

Increase the loading capability to their thermal capabilities.

Increase the system security through raising transient stability limit.

Provide greater flexibility in siting new generation.

One large-scale network have been presented.The UPFC model itself showed to be veryflexible, it takes in to account the various UPFCoperating modes.

UPFC is able to control active and reactivepower flow in transmission line.

FACTS Modelling and simulation in Power networks, Enrique Acha.

ELECTRICAL POWER SYSTEM (FIFTH EDITION), C. L. WADHWA.

POWER SYSTEM ENGINEERING (SECOND EDITION) , D. P. KOTHARI & I.J NAGRATH

IEEE 100, The Authoritative Dictionary of IEEE Standards Terms, Seventh Edition. New York: Institute of Electrical and Electronics Engineers, Inc.