PSCAD
Recently, I found a decent program called PSCAD. It is a fixed-step nodal analysis based simulator which is mostly meant for high voltage power systems. I developed a number of power converter examples which are being made available to the power community on MotorLab.com. Below is a description and link for each. All examples run in the student version. Instructions for downloading the student version are below.
I like PSCAD because it doesn't have some of the limitations that other simulators have. You have to know what you are doing, but PSCAD doesn't give regular convergence problems or connectivity problems when putting components together. One major advantage is that you can create a fairly elaborate simulation in the student version. As you can see in the examples below, the power circuit, modulation, and control all fit in one simulation. This makes PSCAD exceptionally useful for teaching.
Note that many of the examples below use notation and parameters from the book
P.C. Krause, O. Wasynczuk, and S.D. Sudhoff, Analysis of Electric Machinery and Drive Systems, Wiley Interscience, 2002.
If you are not familiar with this book, check it out. It provides rigorous, comprehensive, and relevant information for power conversion systems.
This is a standard six-transistor inverter illustrating sine-triangle PWM with third harmonic terms as well as 180 degree VSI. This example also shows PSCAD controls and meters.
This is a three-level diode-clamped inverter with sine-triangle modulation.
A standard six-transistor inverter with an R-L-C output filter between the inverter and load.
A standard inverter controlled with hysteresis current-regulated modulation.
A three-level inverter made by paralleling half bridges with inductors and interleaved switching.
A single-phase nine-level series connected H-bridge inverter.
Active rectifier with constant modulation index and constant phase shift angle.
A brushless dc drive with 180 degree votlage-source inverter operation.
A brushless dc drive supplied from an ideal inverter.
A brushless dc drive with sine-triangle modulation.
An ideal active filter demonstrating control in the synchronous reference frame.
This example illustrates concepts of reference frame theory applied to a 180 degree voltage source inverter.
This example displays a three-phase set of sinusoidal voltages in the synchronous and stationary reference frames.
Downloading PSCAD
Go to http://www.nayakcorp.com/download/
Download the following files:
PSCAD421_2007_Pro.zip
This is the disk image for PSCAD installation
LM127.zip
This is the license manager
ecgs.zip
This is the free version of GNU Fortran
Unzip these files. For each one, note the directory that the setup.exe file is
in. Run the setup.exe file that came from unzipping PSCAD421_2007_Pro.zip.
When InstallShield asks to choose the products to install, select PSCAD, GNU
Fortran Compiler, and Licence Manager.
It will install PSCAD and then ask for the directory where Licnece Manager is.
Select the directory where setup.exe is located from unzipping LM127.zip. Accept
the default settings when questioned. The license manager will be installed.
Next, InstallShield will ask the directory where the GNU installer is located.
Select the directory containing setup.exe that came from unzipping ecgs.zip.
Restart the computer. Run PSCAD. It will start with a student license unless you
have a dongle.