Our Team

The best engineers produce
the best results.

Mohamed Rashwan, Ph.D, P.Eng



Dr. Mohamed Rashwan is a professional engineer with over 40 years of experience in HVDC and FACTS. His expertise is in the areas of equipment specifications and design, economic assessment of projects, project execution, O&M, witnessing of factory tests, commissioning & system tests, and integration of HVDC and FACTS into the power system. After working for Manitoba Hydro for 25 years in the HVDC Engineering Department, Mohamed co-founded TGS in 2002.
Dr. Rashwan is a fellow member of IEEE and the current chair of Cigre study committee B4 “HVDC and power electronics”. In 2010, he was the recipient of the prestigious IEEE PES Uno Lamm HVDC award. This award recognizes outstanding contributions to HVDC technology. The technology has developed into an effective power system tool for long-distance energy transmission, integration of renewable energy sources, ac network interconnections, and system stability enhancement.

Mojtaba Mohaddes, Ph.D, P.Eng

Chief Operating Officer


Mojtaba Mohaddes is a professional electrical engineer with over 25 years of experience in a wide range of activities including academic and international consultancy with a focus on HVDC and FACTS devices.

After seven years of university teaching and five years with Brandt Consultants, Mojtaba co-founded TGS in 2002. Dr. Mohaddes has been involved with numerous HVDC and FACTS projects, ranging from feasibility studies, technical specification preparation and tender review.

Dr. Mohaddes’ main area of expertise is in the development of controls for HVDC and FACTS and power system simulation; particularly in the area of time-domain electromagnetic transient modelling. He is actively involved in Cigre and is the convenor of working group B4.71 “Application guide for the insulation coordination of VSC HVDC stations”.

Rebecca Ostash, P.Eng

Vice President - Business Development


Rebecca Ostash is a professional electrical engineer specializing in power system studies, with a particular focus on HVDC, FACTS, renewable generation and AC system planning studies. Mrs. Ostash also specializes in developing custom stability models for HVDC and FACTS devices, with emphasis on power system stability software packages PSS/E and PSLF. She is the author of several papers on this subject.

Rebecca joined TGS in 2004, after working for Manitoba Hydro in the System Planning department and at the Dorsey Converter station.

Chandana Karawita, Ph.D, P.Eng

Vice President - Studies


Dr. Chandana Karawita is a professional engineer with both industrial and academic experience in power systems. Dr. Karawita joined TGS in 2007 while doing his doctoral research at the University of Manitoba.

He is an expert in power system studies including HVAC, HVDC and FACTS, and inverter based generation (Solar, Wind, BESS). He is also involved in state-of-the-art custom model development for HVDC/FACTS and inverter based generation in both transient stability (PSSE, PSLF, DIgSILENT) and electromagnetic transient simulation (PSCAD) platforms.

Dr. Karawita was instrumental in developing the dynamic phasor based small signal stability analysis package (TGSSR) for analyzing sub-synchronous frequency oscillations in power systems and many other in-house software tools. He actively contributes to various CIGRE working groups, and is the convener of working group C4/B4.52 “Guidelines for Sub-synchronous Oscillation Studies in Power Electronics Dominated Power Systems”. He is also involved in academic research activities as an adjunct professor at the University of Manitoba.

Narinder Dhaliwal, M.Sc, P.Eng

Chief Engineer


Narinder Dhaliwal is a professional electrical engineer specializing in HVDC, FACTS and synchronous condensers. He has over 35 years of experience in commissioning, operating and maintenance of HVDC systems.

He specializes in specification preparation, bid evaluation, design review, factory testing, on-line commissioning and fault analysis of HVDC systems and synchronous condensers. His other specialty is providing HVDC training. After working for Manitoba Hydro for 41 years in the HVDC Engineering Department, Narinder joined TGS in 2015.

Hiranya Suriyaarachchi, Ph.D., P.Eng

Principal Engineer


Dr. Hiranya Suriyaarachchi is a professional engineer with over 15 years of industry and academic experience. Hiranya received the B.Sc. Engineering degree from the University of Moratuwa, Sri Lanka in 2003 and M.Sc. and Ph.D. degrees from the University of Manitoba, Canada in 2008 and 2014, respectively.

He has been with TransGrid Solutions since 2010, where he was involved in a wide range of power system consulting services including power system studies, custom model development, commissioning, test witnessing, specification and bid review, RTDS, event analysis, and training.

Hiranya’s main area of specialization is in power system studies and creating dynamic equivalent AC system models for RTDS and PSCAD. He has led the development of a 20 rack RTDS model of one of the largest synchronized power systems in the world. Dr. Suriyaarachchi is actively contributing to a number of CIGRE and IEEE working groups.