Research Areas

The research team led by SU materials scientist Cleva OW-YANG demonstrated that engineering the electrode/active layer interface by nanostructuring enabled tuning the amount of photo-excited charge collected in a polymer-based solar cell. By applying the technology through solution processing on the industry-standard solar cell, the charge collection efficiency was doubled by as much as two-fold.

Long Persistence Ceramic Phosphors: In this virtual laboratory, we seek to understand the mechanism of extended persistence in long afterglow ceramic phosphor powders. Through using ceramic powder processing routes, we synthesize luminescence converters with structural characteristics that enable the application of spectroscopic and advanced transmission electron microscopy techniques to elucidate the mechanisms of extended afterglow. With this knowledge, we are developing technological applications exploiting these optical properties, such as for earthquake, mines and road safety.

This project examines different control strategies for DFIG machine used as a generator in wind energy system. Renewable energy sources, especially wind energy conversion systems (WECS) are becoming more and more popular due to rapid consumption of fuel resources in recent years. Doubly fed induction generator based wind turbines are very advantageous because of its four quadrant active and reactive power flow capability and reduced power converter sources. For example, stator active and reactive power can be controlled with a 30% power rated rotor side converter at +/-0.25 slip variation. Robustness of any implemented control structure can easily be lost due to nonlinearities, variations in the DFIG parameters and network voltage failures. In this project we examined the controller structures that do not need information on machine parameter dependent terms. Instead we use simple disturbance observer to evaluate compensation terms. In addition we design controller in the stator voltage frame of references what gives us simpler and more reliable structure. The laboratory setup is developed for verification of the results.

Power engineering is concerned with the generation, transmission, and distribution of electricity over electric power network, which is arguably one of the largest engineering systems in the world. The size of electric utility industry exceeds billions of dollars and its utilization in a cost-effective manner while providing reliable accessibility is extremely important.

Power system planning is a hierarchical decision-making environment. We use operations research techniques to obtain fast, reliable and accurate solutions for short, medium and long terms planning problems in power systems optimization.

Selected Publications

• Burak Kocuk, Santanu S. Dey & X. Andy Sun (2018). Matrix Minor Reformulation and SOCP-based Spatial Branch-and-Cut Method for the AC Optimal Power Flow Problem, Mathematical Programming Computation, 10 (4), 557-596.

Renewable energy sources appeared as a viable alternative for environmentally hazardous sources. However, sources of renewable energy have considerably unpredictable and environmental conditions dependent power output and as such can’t be directly incorporated into existing electrical grid. These sources are usually integrated to the electrical grid as part of microgrid or hybrid energy source that consists of two or more energy sources, converters and/or storage devices. In hybrid energy sources, generation and storage elements complement each other to provide high quality and more reliable power delivery. The main work in this project is oriented towards defining a generalization of control problem for power electronics interfaces in hybrid energy source, the development of control for grid connected hree phase switching converters and the development of a maximum power point tracking algorithm that can be easily incorporated into hybrid source control.