{"691197":{"#nid":"691197","#data":{"type":"event","title":"Ph.D. Dissertation Defense - Zexian Zeng","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ETitle\u003C\/strong\u003E\u003Cem\u003E:\u0026nbsp; Modeling, Stability, and Resilience of Voltage-Source Converters in Hybrid AC\/DC Power Systems\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECommittee:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDr. Maryam Saeedifard, ECE, Chair, Advisor\u003C\/p\u003E\u003Cp\u003EDr. Deepak Divan, ECE\u003C\/p\u003E\u003Cp\u003EDr. Santiago Grijalva, ECE\u003C\/p\u003E\u003Cp\u003EDr. Daniel Molzahn, ECE\u003C\/p\u003E\u003Cp\u003EDr. Qichen Yang, UCF\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EVoltage-source converters (VSCs) are becoming the dominant interface in modern power systems as renewable generation, energy storage, high-voltage DC transmission, medium-voltage DC networks, electric-vehicle charging, and large flexible loads continue to expand. In VSC-dominated hybrid AC\/DC power systems, stability and resilience are increasingly determined by converter controls rather than by the inherent electromechanical behavior of synchronous machines. This dissertation develops modeling, stability-analysis, and resilience-oriented control methods for VSC-based hybrid AC\/DC power systems. The first part of the dissertation investigates small-signal AC\/DC dynamic coupling across different AC- and DC-terminal control roles, including AC grid-forming\/DC grid-following, AC grid-following\/DC grid-forming, and dual-port grid-forming operation. The analysis shows how DC-link dynamics, modulation-reference choices, DC-network dynamics, and dual-port control parameters affect oscillatory modes and stability margins. Modular single-input single-output modeling frameworks and physical damping interpretations are developed to support scalable and design-oriented stability analysis. The second part studies large-signal resilience of P-f droop-based AC grid-forming\/DC grid-following VSCs under faults, unbalanced black start, load pickup, motor startup, and protection-device interactions. Current-limiting methods, generalized three-phase droop control, distributed load restoration, and converter-aware protection behavior are examined to understand how current-limited VSCs can support practical grid functions during severe disturbances. Together, the results provide control-aware modeling tools, stability insights, and resilience-oriented design guidelines for future hybrid AC\/DC grids with high penetrations of VSC-interfaced resources.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Modeling, Stability, and Resilience of Voltage-Source Converters in Hybrid AC\/DC Power Systems "}],"uid":"28475","created_gmt":"2026-07-21 17:34:49","changed_gmt":"2026-07-21 17:36:01","author":"Daniela Staiculescu","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2026-07-23T14:30:00-04:00","event_time_end":"2026-07-23T16:30:00-04:00","event_time_end_last":"2026-07-23T16:30:00-04:00","gmt_time_start":"2026-07-23 18:30:00","gmt_time_end":"2026-07-23 20:30:00","gmt_time_end_last":"2026-07-23 20:30:00","rrule":null,"timezone":"America\/New_York"},"location":"Room 380, Bunger Henry","extras":[],"groups":[{"id":"434381","name":"ECE Ph.D. Dissertation Defenses"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"},{"id":"1808","name":"graduate students"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}