## Wednesday, June 29, 2011

### EE2404 ELECTROMAGNETIC TRANSIENTS IN POWER SYSTEMS

ELECTROMAGNETIC TRANSIENTS IN POWER SYSTEMS

AIM:
1. To study and understand the electromagnetic transient phenomena in power systems caused due to switching and fault by using Electromagnetic Transients Program (EMTP).
2. To become proficient in the usage of EMTP to address problems in the areas of over voltage protection and mitigation and insulation coordination of EHV systems.

OBJECTIVES:

(i)                 To study the transients due to energization of a single-phase and three-phase load from a non-ideal source with line represented by Π – model.
(ii)               To study the transients due to energization of a single-phase and three-phase load from a non-ideal source and line represented by distributed parameters.
(iii)             To study the transient over voltages due to faults for a SLG fault at far end of a line.
(iv)             To study the Transient Recovery Voltage (TRV) associated with a breaker for a three-phase fault.

SOFTWARE REQUIRED:             ELECTROMAGNETIC TRANSIENTS PROGRAM –
UBC version module of AU Power lab or equivalent
EXCERCISE:
Prepare the data for the network given in the Annexure and run EMTP. Obtain the plots of source voltage, load bus voltage and load current following the Energization of a single-phase load. Comment on the results. Double the source inductance and obtain the plots of the variables mentioned earlier. Comment on the effect of doubling the source inductance.
Energization of a single phase 0.95 pf load from a non ideal source and a more realistic line representation (lumped R, L, C):

Circuit Diagram:

Exercise
1 Prepare the data for the network given in the Annexure 8.1 and run EMTP. Obtain the plots of source voltage, load bus voltage and load current following the energisation of a single-phase load and obtain the plots

Output

2. Prepare the data for the network given in the Annexure 8.2 and run EMTP. Obtain the plots of voltages of phases a, b, c at the load bus and switch A current of phase a following energisation of the three-phase load by closing the switches simultaneously.

Output

3. Prepare the data for the network given in the Annexure 8.3 and run EMTP. Obtain the plots of voltages at source, Bus 1 and Bus 12 following the energisation of the single phase open ended line represented by distributed parameters. Obtain the plot of voltage at Bus 12 by expanding the time scale by a factor of ten, i.e, plot the voltage for the first 2.5 millisecond.

Output

4 Prepare the data for energisation of a three-phase load fed by a three-phase distributed parameter line as given in the Annexure 8.4 and run EMTP. Obtain the plots of voltages at source, Bus 1 and phase a voltage at Bus 12 following the energisation by simultaneous closing of all the three phases
Output

5 Prepare the data for the network given in the Annexure 8.5 and run EMTP. Obtain the plots of voltages at source, Bus 1 and Bus 2 following a single lineto- ground fault at the far end, Bus 2.

Output

6. Prepare the data for the network given in Annexure 8.6 and run EMTP. Obtain the transient recovery voltage (TRV) in each phase for a three-phase fault at Bus 1. The TRVs are the voltages across the switches between Bus1 and BKR1.

Output

INPUT DATA:

ENERGIZATION OF LOAD-EMTP EXPERIMENT NO: 1
.5E-4     .5E-1 -1     1
SRC  BUS1               .0         6.0       .0
BUS1 BUS12            .05       2.0       .0
BUS1                                     .0         .0         .81
BUS12                                   .0         .0         .84
BUS12BUS13S         .0         6.0       .0
BUS13L                                 22.61               19.72               .0
BUS13SBUS13L       .1E-2  .9999E+4                  1
14   SRC 1                  .5634E+2      .60E+2   .0E+0      -.1E+1  .9999E+4
SRCBUS13L