tailieunhanh - Lecture Methods of Electric power systems analysis - Lesson 6: Power operations, power flow

Lecture Methods of Electric power systems analysis - Lesson 6: Power operations, power flow provide students with knowledge about three bus powerworld simulator case; basic power control; power flow in transmission line is limited by heating considerations; overloaded transmission line; automatic generation control; . | ECEN 615 Methods of Electric Power Systems Analysis Lecture 6 Power Operations Power Flow Prof. Tom Overbye Dept. of Electrical and Computer Engineering Texas A amp M University overbye@ Announcements Read Chapter 6 from the book The book formulates the power flow using the polar form for the Ybus elements Homework 2 is due on Thursday September 17 1 Three Bus PowerWorld Simulator Case PowerWorld Case Name B3Slow Load with Area Name Home ACE MW green Home Area MW MW Load MW MW Gen MW MW MW Losses MW arrows Bus 2 Mvar A Mvar A Bus 1 pu indicating MW Mvar MVA MVA slack pu amount A A MW Mvar of MW MW AGC OFF MW MVA A A MVA MW 100 MW AVR ON Mvar Mvar flow Mvar MW MVA MVA MW Mvar Other Area Mvar Scheduled Transactions pu MW Bus 3 MW Note the Off AGC MW Mvar power Used Mvar AVR ON AGC ON balance at to control each bus output of Direction of green arrow is used to indicate generator direction of real power MW flow the blue arrows show the reactive power 2 Basic Power Control Opening a circuit breaker causes the power flow to instantaneously nearly change. No other way to directly control power flow in a transmission line. By changing generation we can indirectly change this flow. Power flow in transmission line is limited by heating considerations Losses I 2 R can heat up the line causing it to sag. 3 Transmission Line Limits Power flow in transmission line is limited by heating considerations. Losses I2 R can heat up the line causing it to sag. Each line has a limit many utilities use winter summer limits. 4 Overloaded Transmission Line Area Name Home ACE MW Home Area MW Load MW MW MW Gen MW MW Bus 2 Mvar MW Losses MW Mvar Bus 1 A A pu 112 112 MW MVA MVA Mvar slack pu A A MW MVA Mvar MVA MW MW AGC OFF A A MW