Supervisor:
Professor Frede Blaabjerg

Co-Supervisor:
Saeed Peyghami
Ariya Sangwongwanich

Assessment Committee:
Yajuan Guan(Chair)
Prof. Brad Lehman, North Eastern University, USA
Prof. Alessandra Parisio, University of Manchester, UK

Moderator:
Amjad Anvari-Moghaddam

Abstract:

Grid modernization and extensive integration of renewable energy-based generation accompanied by supporting technologies are some of the actions motivated by humanity's need for a sustainable future. While the power system is undergoing the transitioning process to accommodate sustainable energy solutions, it is pivotal to assure an adequate level of reliability. This entails accounting for the new power system functionalities, as well as the introduced challenges in the system planning and operation. Failure-prone power electronics are indicated as one such component, which can impact system reliability to a large extent. Hence, to facilitate reliable and cost-effective design and operation of the modern power electronics-based power system, it is crucial to redefine the existing design guidelines to enable power electronics investigation.
Accordingly, in this Ph.D., the power electronics long-term impacts (reliability) and operational impacts (control-based grid support functionalities) on the power system are discussed. Power electronics reliability is integrated into long-term power system planning, where new guidelines for forecasting and sizing are developed. The novel forecasting model can be utilized to predict power converter lifetime with higher accuracy than the state-of-the-art methods. The results of the forecasting model can be used in long-term power system sizing with included power electronics reliability information. As a result, an optimization procedure for a multi-generation system sizing which accounts for this aspect is developed. The main forecasting and sizing results can be utilized to further strengthen the modern power system reliability during long-term planning. Power electronics grid support functionalities (i.e., smart inverters) are investigated for grid contingency events including load shedding. The developed guidelines provide information on how to account for a range of events with different impact magnitudes and probability of occurrence to systematically assess the smart inverter-based benefits. The results of such assessment are of great value to aid power system reliability during operation. Therefore, the main outcomes of this Ph.D. study serve as a step forward in planning a reliable and cost-effective modern power electronics-based power system.