The Future of Transient Analysis is Bright

Yes, or at least, it’s brightening.
We make this bold observation after attending the 2012 users’ group meeting for the PSCAD/EMTDC software, held March 27-20 at a little gem of a coastal town named Castelldefels in Spain. About 60 participants (eyeball count) from universities, manufacturers, utilities, sysops, sales reps and consultants gathered together for techno-talk on the decidedly geeky subject of power system transients and PSCAD applications.


With 22 countries represented, one would have to be positively polyglot to communicate in all the languages spoken by the attendees. But power system analysis and mathematics make for a universal medium. Just stay on topic or risk invoking a Tower of Babel event.
Three and a half days of immersion in all things PSCAD led us to our main observation and takeaway from the conference. Electromagnetic transient analysis is resurgent. Our basis:

  • The proliferation of fast controllers embedded in solar photovoltaic inverters, wind turbines, direct-current converter stations and sundry other power system equipment.
  • Broadening of power system issues requiring transient analysis as operators, planners, designers and analysts grapple with an increase in high-frequency events.
  • Pioneering work as presented during the conference: including (hopefully, this includes most, if not all, presentations) multi-run simulations, optimization of design parameters (Dr. Ani Gole- University of Manitoba), modeling for sub-synchronous resonance, transients with underground cables (Lei Wu, Einhoven University of Technology, Netherlands), Smart Grid applications and HVDC capacity sharing (Bogdan-Ionut Craciun​, Aalborg University, Denmark), operating limits in systems with multiple series-compensated lines (Toumas Rauhala, Fingrid Oyj, Finland), protection equipment design (Janne Leminen, ABB Finland), power system short circuit and transient applications (Jianping Wang, ABB Sweden), and user modeling for wind turbines (Francisco Jimenez Buenda , Gamesa) and solar inverters (Oliver Glitza, SMA Solar Technology AG).


PSCAD offers an excellent platform, in our honest opinion, for trying out innovative ideas in transient analysis as it provides for different levels of customization, from raw code (Fortran) to building composite models. We would have like to have seen more representation from power companies at the event, but realize that this will come in due course as high-frequency events increasingly impact day-to-day power system operations.

Thoughts About the PSCAD Software

PSCAD is one of those products that we talked about in our article, “On Engineering Software.” It’s development team exemplifies the characteristics we look for in a provider of mission-critical engineering software. Pterra did have some suggestions for improving the software:

  • Adding capability to import data from other software such as Aspen OneLiner, Siemens’ PSS/E and General Electric’s PSLF. (The reasons for this are discussed in a forthcoming article on this Blog. So please stay tuned or subscribed.)
  • Add organizing features to the model layout to facilitate de-cluttering and prepare for the documentation phase of any study.

Our internal alert rang up only twice during the conference. (It makes a noise like a fire truck on steroids inside the head and is difficult to ignore.) These instances came about during two presentations, both from equipment manufacturers who provide PSCAD user-models for their products. To preserve proprietary information, the user models include or are provided in the form of dlls (dynamic link libraries). These are essentially blackboxes that take input from PSCAD and send output back to the software without revealing anything about their internal processes. We’ve documented the issues and concerns relating to this practice in a previous article, “Open Source or Proprietary Data: the Model Dilemma.” What we’ve reported then still applies today. For example, the PSSe stability database for the Eastern Interconnection (North America) includes oodles of blackbox models noted to be the cause of all nature of issues from longer simulation times to debugging brain trauma (Ok, this last one was an exaggeration). Though PSCAD does not require a large database for its simulations, there are lessons to be learned from how the GE product, PSLF, enforced open-source user models, facilitating a community effort to develop standard models for new equipment such as wind and solar photovoltaic inverters.

Future Development

One of the perceived challenges for PSCAD is the exponential increase in simulation time as the model size increases. Craig Muller, development manager, presented a plan for implementing distributed processing; i.e., using computer time on enterprise networks to run multiple instantiations of PSCAD. This is an important development which we note is being tried with other engineering software.
Dharshana Muthumuni, the engineering manager, constantly reminded the attendees about the target frequency range for transient studies in general, and PSCAD, specifically. But we had the sense that users will keep pushing the envelop on the applications, especially if models become more broadly available and industry operations demand more studies in this field. So, our prognostication for future development is that as more users get involved and applications expand, software, such PSCAD, will need to be light-footed and adapt. As we said, the future is bright.

Acknowledgments

Overall, the meeting was well-organized and coordinated. From our perspective, it is rewarding to get out of the office once in a while and meet other practitioners to share ideas and experiences. Many thanks to those who made this an informative and rewarding event: to Vicente Aucejo of INDIELIC, the local host, to the onsite PSCAD team, Dharshana, Craig Muller, Alyson Teterenko, and Rohitha Jayasinghe, to the presentors (listed above) and instructors, including Ozge Oz, of CEDRAT S.A. and most of all to all the friendly folks we shared this time with — Jianping, Oyvind, Dejan, Katja, Agusti, Bogdan, Bharti, In-Hong, Mauricio, Christian, Wei and others who will remain nameless. Until next time.