EELE5431 Advanced Power Electronics
Project 1: 18-pulse Diode Rectifier
To develop simulation models for the 18-pulse series-type diode rectifiers; and
To investigate the harmonic performance of multipulse rectifiers.
Build your Simulink model for the six-pulse diode rectifier shown in Fig. 3.2-3 in the textbook (either first
edition or second edition). The rectifier power rating is 1MW, its supply voltage is 2300V (line-to-line,
60Hz), and the line inductance Ls is 0.05pu. It is assumed that the value of the dc capacitor Cd is very large
such that the capacitor and the load resistor can be replaced by a voltage source. Run your Simulink model
and adjust the load voltage source such that the rms value of the fundamental-frequency line current Ia1 is
equal to 0.2pu and 1.0pu, respectively. Verify the waveforms, harmonic spectrum and THD of the line
current shown in Fig. 3.2-7. Proceed with the following tasks only if you obtain the same waveforms,
harmonic spectrum, and THD as shown in Fig. 3.2-7. Do not include your simulation results of this part
in your report.
• Rectifier Configuration
The 18-pulse series-type diode rectifier as shown in Fig. 1 is investigated in this project.
Fig. 1 18-pulse series-type diode rectifier.
• System Parameters
Transformer Nameplate Data:
Rated Power/Frequency: 2MVA/60Hz
Rated Primary Voltage: 6000V (rms, line-to-line)
Rated Secondary Voltage: 3000V (rms, line-to-line, each three-phase winding) for the 18-pulse rectifier
Diode Rectifiers: Ideal (no power losses, no voltage drop)
DC Filter Capacitor: Cd = ∞ (dc voltage is ripple free).
Note: since the DC filter capacitor is very large, the capacitor and dc load can
be replaced by a voltage source as shown in Fig. 1.
Line Inductance Ls: 0 mH
Leakage inductance Llk: 0.05 pu
• Phase-Shifting Transformers
Use multiple units of ideal single-phase transformers to build Simulink models for the phase-shifting
transformers used in the 18-pulse diode rectifier as shown in Fig. 1. The turns ratio for the 18-pulse
transformer is given in Table 5.2-1 of the textbook (note that since the conditions of Table 5.2-1 are different
from the ones given in this project, you may need to re-calculate the turn ratios).
For the single-phase ideal transformers, it is assumed that 1) the primary and secondary winding resistances
are very small, and they are equal to 0.036Ω each, 2) the primary and secondary winding leakage
inductances are zero, 3) the magnetizing inductance is infinite, and 4) the magnetizing resistance (the
resistance in parallel with the magnetizing inductance) on the primary side of the transformer is equal to
1.1 Build a Simulink model for the 18-pulse phase-shifting transformer using 9 units of the ideal single-
phase transformers discussed earlier.
1.2 Build and run your Simulink model for the 18-pulse series-type diode rectifier shown in Fig. 1 and
adjust the load voltage such that the fundamental line current IA1 is equal to 1 pu (rms).
1.3 Plot the waveforms of ai , ai , ai , and ai¢ , ai¢ , ai¢ , and iA, and their harmonic spectrum. Find THD of these
currents. Use the format as shown in Fig. 2. For example, the current waveforms should be in per unit
with two fundamental cycle each, and the current harmonics should be divided by its fundamental
component, and its frequency range should be from zero to 1500Hz (you can generate this spectrum in the
Simulink model, please contact the TA if you did not know how to perform THD analysis using Simulink).
Fig. 2 Sample/template for the simulated waveforms and harmonic spectrum.
• Project Report
1) Cover page (including course/lab title, your name, student ID, date)
2) Abstract (Up to 200 words)
3) Introduction (Up to one page)
4) Theoretical analysis and calculations
5) Simulation results and discussions/explanations.
8) Appendix: Simulink models
❖ Format/Font/Size: Single space/Times New Roman/12pt
• Project Submission
1) One report (pdf version) + simulation model
2) Due date/time: 6pm, February 11, 2022 (easter time zone)
2) Where to submit: D2L
• Evaluation: 20 marks
❖ Your submitted simulation model should reproduce the same results as presented in the report.
Otherwise, the mark for this project will be zero.
❖ Marks will be deducted for submissions not following the previous guidelines.
❖ Late submissions/any additional content submitted after the deadline will not be accepted.
❖ Please refer to the course outline for further information regarding academic integrity. Plagiarism
and Cheating will automatically receive 0 and will be reported to the department and university.