ECE – 590 I POWER & ENERGY SYSTEMS SEMINAR
WHEN: Monday, October 23, 2023
WHERE: ECEB 4070, 3:00 – 3:50 p.m.
SPEAKER: Iven Guzel, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign
TITLE: "Fast and Certifiably Correct Power System State Estimation via Nonconvex Phase Synchronization"
ABSTRACT: Power system state estimation (PSSE) uses noisy system power measurements to determine the values of the voltage phasors at each bus. The ability to provide high-quality state estimates is of critical importance, as the PSSE results form the basis of the utilization of the functions of the energy management system, including security assessment, contingency analysis and optimal power flow. The conventional approach used in the PSSE solution is to minimize the sum of the squares of the errors under the assumption that all the measurements contain white noise only. Typically, first and second order smooth numerical optimization methods are deployed. While such approaches are fast and scalable to large-scale systems, the reliance on local search techniques may result in convergence to suboptimal values rather than global solutions. We reformulate the PSSE problem as the simultaneous estimation of the voltage magnitudes and the voltage angles of a phase synchronization problem to provide guaranteed globally optimal solutions.
SPEAKER: Arjit Bali, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign
TITLE: "Inverter Topology Investigation in High-Frequency,
Low-Inductance Motors"
ABSTRACT: Electric vehicle and electric aviation applications require lightweight electro-mechanical energy conversion, but passive components in the drive system can constrain the power density. Slotless machine construction can attain high power density, but such designs result in very low per-phase machine inductances. The reduced inductance imposes additional filtering requirements between the inverter and motor, which lower the power density benefits gained from the slotless design used. Furthermore, the dc-link capacitor within the inverter increases significantly the overall weight and volume. We discuss the advantages of the deployment of interleaved, multi-level topology in such systems. We propose an Interleaved Hybrid Active Neutral Point Clamped (I-HANPC) converter to reduce output filter sizes with smaller dc-link capacitors. We demonstrate the design with a 10-kW, 3-phase, 7-level I-HANPC hardware prototype that attains a peak efficiency of 98.8 % with low output THD.
