Project: Design, Modeling and Control of High Efficiency and High
Power Density Multi-port Power Electronics Module for Hybrid Energy Systems

Project Objective: The primary objectives of this project are to develop high efficiency, high power density, and low cost multi-port bidirectional DC-DC converter to integrate energy storage elements with alternative energy sources such as fuel cell, photovoltaic (PV) and rectified wind. 

In this project, a novel multi-phase interleaved bidirectional DC-DC converter topology and its extensions were developed. Fig.1 shows the 6 kW prototype built in the laboratory with 96% efficiency over a wide operation range. A current-fed port is provided in the proposed topology to deal with wide voltage variation of input such as PV or ultracapacitor (UC). Different variations of proposed topology were derived and analyzed. An improved soft-switching operation was achieved by developing combined phase shift control and duty cycle regulation. The optimized soft-switching operation range was derived as the guide line to operate the converter. The circuit was built and tested in the laboratory. The power density and the efficiency have met the research requirements. When multi-port bidirectional dc-dc converter is applied in a system and dynamic environment, a power management control was developed to regulate the power distribution between different ports to reduce circulation energy, meet the load requirement and improve system efficiency. Special design has been derived to reduce the coupling effect between the ports. In addition, the optimized fuel economy design has been achieved and implemented for multi-port dc-dc converters applied in a fuel cell vehicle. Although a real system test bed was built in the laboratory to test and verify the dc-dc converter performance, another research approach using Real Time Digital Simulator (RTDS) was also investigated.  In this new approach, a complicated system can be modeled and simulated in RTDS, the dc-dc converter is the hardware built in the laboratory and connected externally to the virtual system using Power Hardware-In-the-Loop (PHIL) concept. The key to an effective PHIL is the interface called Simulation-Stimulation (Sim-Stim) interface between the simulated system and the real hardware. An effective and stable bidirectional Sim-Stim interface was developed in this research. The theoretical analysis and experimental results proved that PHIL method provides another accurate, fast, safe and economic method to test power electronics modules under a system environment.

　

References:

Lei Wang, Hui Li, “Maximum fuel economy-oriented power management design for a fuel cell vehicle using Battery and Ultracapacitor,” IEEE Trans. Ind. Appl., Vol 46, No.3, pp. 1011-1020, May/June, 2010.

Lei Wang, E. G. Collins Jr., and Hui Li, “Optimal design and real time control for energy management in plug-in hybrid electric vehicles,” to appear in IEEE Trans. of Vehicular Technology, 2011.

Zhan Wang, Hui Li, "Three-phase bidirectional DC-DC converter with enhanced current sharing capability,” IEEE ECCE 2010, Sept. 2010, Page(s): 1116 – 1122

 

CONTACT:                                     SPONSOR:

Dr .Hui Li, Associate Professor          NSF Award number: 0641972

hli@caps.fsu.edu  (850) 644-8573