# System Analysis ELEN3001 / ELEN6009

{`Curtin University Department of Electrical and Computer Engineering Power System Analysis ELEN3001 / ELEN6009 Assignment 1 `}

**Assignment PART A **

The one-line diagram of a three-phase power system in Figure 1has the following data:

Transformer: 100 MVA, 23/115 kV, X=0.2 Transmission line: 0+j66.125 Ω

Load at bus 2: S_{2}=184.8+j6.6 MVA Load at bus 2: S_{3}=0+j20 MVA

It is required to hold the voltage at bus 3 at 115 kV. Working in per-unit, determine the voltage at buses 2 and 1. Use a base of 100 MVA and neglect the transformer resistance, and phase shift

**Figure 1 **

**Assignment PART B **

**B.1)** Show that the generalized circuit constants of all three transmission-line models (short, medium and long) satisfy the condition below:

AD−BC=1

**B.2)** A 60 Hz three-phase transmission line is 300 mi long and serves a load of 400 MVA, with 0.8 lagging power factor at 345 kV. The *ABCD* constants of the line are:

*A*= *D*= 0.818∠1.3°

*B*=172.2∠84.2° Ω

*C *= 0.001933∠90.4° *S*

- Determine the sending-end line-to-neutral voltage, the sending-end current and the sending-end active power.
- Percent voltage regulation
- Transmission line efficiency at full load
- Determine the line propagation constant
_{γ}and the Characteristic impedance*Z*_{c} - Calculate the total series impedance and total shunt admittance of the line
- Draw the equivalent π-circuit and calculate its parameters (
*Z*^{\ }*and*\ ) 2__Y__ - Calculate the wavelength
*λ*and velocity of propagation - If the line is lossless (i.e.
*R*=*G*=0); Calculate the surge impedance - If the line is loaded with the surge impedance; Calculate the SIL
- Re-calculate the
*ABCD*parameters for the lossless TL - Re-calculate the line efficiency and voltage regulation for the lossless line.