Example 3.4

Example 3.4 - Example 3.4 Per Unit Calculations Feb-06-2008...

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

Example 3.4 - Per Unit Calculations: Feb-06-2008, by M. Giesselmann Three zones of a single-phase circuit are connected by Transformers T1 and T2. Using base values of 30 kVA and 240 volts in zone 1, draw the per-unit circuit and determine the per-unit impedances and the per-unit source voltage. Then calculate the load current both in per-unit and in amperes. Transformer winding resistances and shunt admittance branches (magnetizing current) are neglected. kVA kW If a transformer nameplate rating differs from the global system base values, the per-unit impedances must be converted according to the Equations below: Z pu.new Z Z Base.new = Z pu.old Z Base.old Z Base.new = using: Z Base V Base 2 S Base = Z pu.new Z pu.old V Base.old V Base.new 2 S Base.new S Base.old =

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

View Full Document
X Line 2j := X Line.pu X Line Z Base.2 := X Line.pu 0.2604j = Z Load 0.9 0.2j + := Z Load.pu Z Load Z Base.3 := Z Load.pu 1.875 0.4167j + = Z
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 3

Example 3.4 - Example 3.4 Per Unit Calculations Feb-06-2008...

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

View Full Document
Ask a homework question - tutors are online