UWE Bristol Engineering showcase 2015
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Phan Giang Thai Ngoc<br />
BENG (HONS) ELECTRICAL AND ELECTRONIC ENGINEERING<br />
Project Supervisor<br />
DR. HASSAN NOURI<br />
Investigation into impact of pre-insertion resistors in Circuit breakers<br />
Modelling representation and concept<br />
Once when in use (open / close), switch time break causing<br />
impacts to the circuit, called the overvoltage. The<br />
methodology of analyzing the effects of the pre-insertion<br />
resistor and pre-insertion inductor on the 138 KV<br />
transmission line was modelled and simulated using PSCAD.<br />
The full model of the transmission line circuit with bus line<br />
and all component in PSCAD shown in the figure.<br />
Result:<br />
In this study, the 138 KV transmission line with break<br />
time switch is built in PSCAD. The pre-insertion<br />
impedance is considered in this project. The different<br />
value of components are changed in many case. The<br />
result in PSCAD is shown that:<br />
I. Overvoltage in circuit which has break time switch<br />
II. Uncontrolled overvoltage in transmission line<br />
III. Controlled overvoltage in transmission line<br />
I. Pre-insertion resistors<br />
II. Pre-insertion inductor<br />
IV. Comparison<br />
Project summary<br />
This project present the analyzing of pre-insertion<br />
impedance in a 138V transmission line using<br />
PSCAD/EMTDC. 50 ohm resistors and inductors 20mh<br />
turn is inserted into the circuit. Overvoltage will be<br />
measured at remote bus and capacitor bus what call<br />
phase to phase overvoltage and ground to phase<br />
overvoltage. A comparison is shown to see the best<br />
method for different cases.<br />
Project Objectives<br />
• PSCAD Familiarization<br />
• Understand the 1-phase circuit.<br />
• Understand the 3-phase circuit<br />
• Understand the circuit with break time<br />
switch<br />
• Understand the transmission line<br />
• Analyzing the waves voltage in<br />
uncontrolled and controlled voltage.<br />
• This project will study the analyzing and<br />
the comparison the voltage in circuit.<br />
The complete line model consists of several<br />
sub model representing the following<br />
elements:<br />
1. Transmission line and circuit components.<br />
2. Break time switch are installed the closed<br />
function.<br />
3. Pre-insertion resistors and pre-insertion<br />
inductor with different values<br />
4. Voltage wave table.<br />
Ground to phase uncontrolled overvoltage wave<br />
Ground to phase pre-insertion resistor overvoltage<br />
wave<br />
Project Conclusion<br />
Over 3 study optimal control circuit voltage of<br />
transmission lines with break time switch.<br />
Three ways are: fixed inductor, pre-insertion<br />
resistor and inductor pre-insertion. Each<br />
method has its own advantages and<br />
disadvantages. Finally, pre-insertion inductor<br />
is chosen as the most complete method to be<br />
used.<br />
Phase to phase pre-insertion resistor overvoltage<br />
wave<br />
Pre-insertion inductors.