ECE 476 POWER SYSTEM ANALYSIS Lecture 5 Power System Operation, Transmission Lines M.E.E. Muhammad Al-Badri Department of Electrical and Computer Engineering

Reading and Homework 1st Exam moved to Oct 11 (in class) For lectures 4 through 6 please be reading Chapter 4 we will not be covering sections 4.7, 4.11, and 4.12 in detail though you should still at least skim those sections. HW 1 is 2.9, 22, 28, 32, 48; due Thursday 9/8 For Problem 2.32 you need to use the PowerWorld Software. You can download the software and cases at the below link; get version 15. http://www.powerworld.com/gloversarma.asp Direct PowerWorld download page is http://www.powerworld.com/DemoSoftware/GloverSarmaSimdwnldv15.asp

Substation Bus

Power Transactions Power transactions are contracts between areas to do power transactions. Contracts can be for any amount of time at any price for any amount of power. Scheduled power transactions are implemented by modifying the area ACE: ACE = Pactual,tie-flow - Psched

100 MW Transaction Scheduled 100 MW Transaction from Left to Right Net tie-line flow is now 100 MW

Security Constrained ED Transmission constraints often limit system economics. Such limits required a constrained dispatch in order to maintain system security. In three bus case the generation at bus 3 must be constrained to avoid overloading the line from bus 2 to bus 3.

Security Constrained Dispatch Dispatch is no longer optimal due to need to keep line from bus 2 to bus 3 from overloading

Multi-Area Operation If Areas have direct interconnections, then they may directly transact up to the capacity of their tie-lines. Actual power flows through the entire network according to the impedance of the transmission lines. Flow through other areas is known as “parallel path” or “loop flows.”