L7 - ECE 524: Transients in Power Systems Session 7; Page...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
ECE 524: Transients in Power Systems Session 7; Page 1/9 Spring 2012 Transient R-L Circuit Example Given a 230kV:34kV, -Ygrounded, 100MVA transformer supplied supplied by a source with a short circuit MVA of 2000. The transformer has a per unit reactance of 0.1pu on its ratings base. Both the transformer and the source impedance have an X/R ratio of 12. Calculate the complete phase A fault current if a fault occurs on the LV side of the transformer at 70 degrees past the voltage peak. Define Units: MVA 1000kW  S BASE 100MVA  pu 1  Transformer parameters: S rated 100MVA  XoverR 12  V hv 230kV  V lv 34.5kV  X trans 0.1pu  R trans X trans XoverR  R trans 0.01 pu Find the transformer impedances referred to the LV side since the fault occurs on that side. Z BLV V lv 2 S rated  Z BLV 11.9 Ω R transLV R trans Z BLV  R transLV 0.0992 Ω X transLV X trans Z BLV  X transLV 1.19 Ω L transLV X transLV 2 π 60 Hz  L transLV 3.157 mH
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
ECE 524: Transients in Power Systems Session 7; Page 2/9 Spring 2012 Source impedance MVA sc 2000MVA  V pu 1.0pu  MVA sc_pu MVA sc S BASE  MVA sc_pu 20 pu mZ source V pu 2 MVA sc_pu  mZ source 0.05 pu η atan XoverR ()  η 85.24 deg Z source mZ source e j η  Z source 0.0042 0.0498i
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 9

L7 - ECE 524: Transients in Power Systems Session 7; Page...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online