Institute Of Elect. Electro. & Comp. Engineering
Course Code: EE—5106
Advance Power Systems
Credit Hours: 3
MSc Electrical Engineering ( Semester No; 1)
Teacher: Dr Tabrez Aslam Shami
University of the Punjab, L
Course Description
1) Power System Analysis & Planning
2)Principles and limitations of AC transmission lines.
3)Fault Calculations and Circuit Breaker Selection
4)Load Growth Estimation.
5)Power Generation & Economics of Locating Stations.
6)Load Flow Studies Fundamentals.
7) Stability of Power Systems
8)HVDC Systems
BOOKS
1)Xi-F Wong, et-al
Modern Power System Analysis
2)Glover I.D. , et-al.
Power System Analysis & Design
3)Nasar, S.A.
Electric Power Systems
HELP BOOKS
1) Stevenson , W.D., Elements of Power System Analysis.
2) Weedy, B.M.,
Electric Power Systems
Pakistan's
High
Voltage
Grid
Under
National
Transmissi
on
and
Dispatch
Matiari - Lahore Transmission Line Project - Belt and Road Initiative
Micro Grid
A small network of interconnected users with distributed
Energy resources within clearly defined electrical boundaries
that act as a single controllable entity with respect to the grid meaning
thereby that it is a grid within a grid.
Smart Grid
Smart Grid is an Electrical Grid with Automation ,Communication, and
IT systems that can monitor Power flows from points of generation to
points of consumption (Even down to appliances level). It has
the capability to control the power flow or curtail the load to match
generation in real time or near real time.
THE KEY FEATURES OF A SMART GRID ARE.
1) Load Handling
2) Demand Response Support
3) Decentralization of Power Generation
4) Reduced Peak Demand Thereby reduction in
consumer bill
Main Components of Smart Grid
Electrical power generators and Substations
Transmission lines ( Overhead and/or Cables)
Distribution lines with control centers
Collector Nodes with Sensors
Smart Meters.
Three Phase Systems Analysis
• Three Wire Balanced Systems.
• Such systems may be treated as comprising of three single phase
systems. This simplifies the calculations. However Total 3 Phase
power and reactive power are three times the single phase values.
• Three wire Unbalanced Systems.
• In more complex networks method of symmetrical components is
used.
• In simple situations conventional network theory e.g. loop analysis
can be applied.
Three Phase Connections
1) Star Connection 2) Delta Connection
Relation between Phase and Line Voltages
V(line)=√3*V(phase) … Star Connection
I(line) = √3*I(phase)…… Delta Connection
Two Examples
• No1. A 3 phase transmission line 1000KVA at 11KV. When operating
at rated load the total resistive and reactive voltage drops in the line
are respectively 2.5% & 3.6% of the rated voltage. Determine the
input power and power factor when the line delivers 600 KW at 0.8
PF.
• No2. The line below delivers a load of 50MW,P.f 0.8 lag at 30KV. The
ratings and reactances are shown alongwith nominal line voltages.
Calculate the terminal voltage at generator end.
Class Problem : A wye connected load shown below is
supplied from a transformer with grounded neutral and
line voltage = 400V.Determine a) line current and b)
Voltage of Star point of load. Solve using 1) Loop
Equations 2) Nodal Analysis.
Performance Of AC Transmission Lines
• A very important problem in the design and operation of any power
system is the maintenance of voltages within specified limits at
various points in the system. Thus Formulae need to be developed by
which the voltage, current, power etc. can be calculated at a given
point provided the values of these parameters are given at one end of
the line.
• For analysis of circuits parameter of interest for a transmission line
are a) Inductance (L), b) Capacitance (C) , c) Resistance (R), and d)
Leakage Resistance (G). The derivation of formulae for the
calculations of these parameters is given in Chapter 3 (pp 37-65) of
Book by Stevenson. Another reference is ;EHV Transmission Line
Reference by EEI.
Representation of Transmission Lines
• Lines are represented are classified into three categories depending upon
the length of line and the accuracy of results required i.e..
• A) Short Line (50KM) 2) Medium Line ( upto 200KM)
• 3) Long line> 200 KM
• For Medium & Short lines the parameters Resistance, Inductance, and are
Capacitance are lumped together to give lumped constant circuit.
• The actual line has distributed constants so these methods do introduce an
error in the calculations.
• For short line capacitance is neglected. For Medium is either concentrated
1) at the two ends ( Pi Circuit) or 2) at the center to give a ( T circuit)
Medium Length Lines ( upto 200KM)