DC Transmission Grids: Topology, Components, Modelling, Control, and Protection Challenges (Registration is required, and walk-ins are not permitted. Limited seats are available.)

Registration is required, and walk-ins are not permitted. Limited seats are available.
Event Description
High Voltage Direct Current (HVDC) transmission is evolving rapidly with new technologies like Voltage Source Converters (VSC) and Modular Multilevel Converters (MMC). These advancements are paving the way for the creation of complex, multi-terminal HVDC transmission grids.
This seminar will explore the key components, topologies, control strategies, modeling approaches, and protection challenges associated with the development of HVDC grids. With real-world examples, including China’s Zhangbei four-terminal project and emerging hybrid LCC-VSC systems, the talk will cover the state of the art and the road ahead for high-performance, secure HVDC power systems.
Topics include:
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Hybrid LCC-VSC HVDC systems
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Fast DC circuit breakers
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DC/DC converters for multiport HVDC hubs
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HVDC grid protection coordination and fault handling
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Real-world VSC HVDC projects and multiterminal deployment
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Simulation and control frameworks for dynamic HVDC networks
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Target Audience
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Power system engineers and researchers
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Utility and transmission professionals
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Graduate and senior undergraduate students
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Professionals interested in HVDC, energy transition, and system integration
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Additional Notes
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Certificate of Participation available for $10 (optional), please fill out the evaluation form after the event to receive one for PDH.
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Parking info
Windsor Carpark (WCP)
Location:
(https://www.google.com/maps/search/?api=1&query=53.52890700,%20-113.52957100)
Hours & Notes:
Open 24 hours a day, view (https://www.ualberta.ca/en/parking-services/locations-and-rates/index.html?search0=Windsor%20Car%20Park)
Evening Flat Rate: $6.00 (4:30 p.m. – 6 a.m.)
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Room info
Fred Pheasy Engineering Commons (8-292)
Donadeo Innovation Centre For Engineering (ICE)
Co-sponsored by: Resilient And Clean Energy Systems (RCES) – https://sites.engineering.ualberta.ca/rcesi/
Speaker(s): Professor Dragan Jovcic,
Agenda:
Date: Thursday, September 18, 2025
Time:
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4:30 PM: Doors open for attendees
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5:00 PM – 5:45 PM: Main talk by Prof. Dragan Jovcic (Part 1)
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5:45 PM – 6:30 PM: Social mixer with catering provided by Upper Crust, featuring a variety of assorted sandwiches, potato salad, fresh vegetables, fruit, coffee, tea, and sweets.
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6:30 PM – 7:45 PM: Main talk by Prof. Dragan Jovcic (Part 2) and open discussion
– 7:45 PM – 8:00 PM: Door prizes (USB C fast chargers, water bottles)
Location:
(https://www.ualberta.ca/en/maps.html?l=53.528307,-113.52955&z=17&campus=north_campus&b=ice)
(https://www.ualberta.ca/en/maps.html?l=53.528307,-113.52955&z=17&campus=north_campus&b=ice)
University of Alberta, Edmonton, AB
Capacity: Limited to 60 attendees
Abstract:
High Voltage DC Transmission has seen rapid technology advances in the last 20 years driven by the implementation of VSC (Voltage Source Converters) at GW powers and in particular introduction of MMC (Modular Multilevel Converters). The development of interconnected DC transmission grids requires significant further advance from the existing point-to-point HVDC links. It is widely believed that complex DC power grids can be built with comparable performance, reliability, flexibility and losses as traditional AC grids. The primary motivation for DC grid development is the need for power flow and trading between many DC terminals, as an example in the proposed (350 GW) North Sea DC grid, or EU-wide overlay DC grid. AC transmission is not feasible with long subsea cables, and it is inferior to DC systems in many other conditions. This presentation addresses the options and challenges with DC grid development, referring also to state-of-art technology status.
Zhangbei 4-terminal DC system (China, 2020) represents the first implemented GW-scale meshed DC transmission grid, which employs bipolar ring topology with overhead lines and 16 DC Circuit Breakers. However, multiple studies illustrate advantages of some radial, hub-based or segmented topologies, because of component costs, and challenges with interoperability, ownership, DC markets, operation, security and reliability.
MMC concepts, including half-bridge and full-bridge modules, will underpin DC grid converters and further advances like hybrid LCC/MMC converters have been implemented recently. DC/DC converters at hundreds of MW are not yet commercially available but there is lot of research world-wide, and some lower-power prototypes have been demonstrated. DC/DC converters may take multiple functions including: DC voltage stepping (transformer role), DC fault interruption (DC CB role) and power flow control. Multiport DC hubs can be viewed as electronic DC substations, capable of interconnecting multiple DC lines.
Very fast DC CB circuit breakers (2 ms) have become commercially available recently, but the cost is considerably higher than AC CBs. Slightly slower mechanical DC CBs (5-8 ms) are also available from multiple vendors, while new technical solutions are emerging worldwide for achieving faster operation with lower size/weight/costs.
DC grid modelling will face the new challenge of numerous converters dynamically coupled through low-impedance DC cables/lines. A compromise between simulation speed and accuracy is required, leading to some average-value modelling, commonly in rotating DQ frame, but capturing very fast dynamics and variable structure to represent fault conditions.
The principles of control of DC grids have been developed. DC systems have no system-wide common frequency to indicate power unbalance, and voltage responds to local and global loading rather than reactive power flow. DC grid dynamics are 2 orders of magnitude faster than traditional AC systems and most components will be controllable implying numerous, fast control loop interactions. Because of lack of inertia, and minimal overload capability for semiconductors, DC grid primary and secondary control should be feedback-based (man-made), fast, and distributed. International standardisation efforts have begun.
The protection of DC grids is a significant technical challenge, both in terms of components and protection logic. The selectivity has been demonstrated within 0.5 ms timeframe using commercial and open-source DC relays. Nevertheless, grid operators have expressed concerns with self-protection on various components, back-up grid-wide protection, interoperability, and in general if we can achieve power transfer security levels comparable with AC grids and acceptable to stakeholders.
Bldg: Donadeo Innovation Centre For Engineering (ICE), Fred Pheasy Engineering Commons (8-292), 9211 116 St NW, Edmonton, Alberta, Canada, T6G 1H9