Current Research Projects
Links to current research projects that the Power Electronics Group are involved in are as follows:
- Active Filtering
- Electric Cars
The Industrial Power Electronics group currently has 7 postgraduate students enrolled under the supervision of Dr. Paul Gaynor and Associate Prof. Richard Duke. The students are working on a wide variety of projects including power conditioning, electric vehicles, fuel cell generation systems and power supply design.
Distributed Generation
John Bryan (PhD student) is undertaking research into "Distributed and Centralized Control of a Nanogrid and Interaction of Nanogrids with Weak Power Systems". A nanogrid is a small power grid that uses renewable energy to supply small local loads. In the future, nanogrids are likely to be used in rural NZ as they will be more economic than the central power system. Nanogrids can operate independently or be connected to the mains, and the internal voltage can be ac or dc. To control a nanogrid, accurate small signal models of the nanogrid elements must be developed. The control options for a nanogrid are decentralized control using picosource and load controllers, and centralized control using a system controller. Using SIMULINK, these two control options will be evaluated. A laboratory model of the best nanogrid system will be built to verify the simulation results. In addition, the interaction of a nanogrid with a weak network and another nanogrid will be studied.
Cryogenic Power Electronics
Si-Kuok Ting (ME student) has developed a design procedure for making simple switching power supplies operate in liquid nitrogen (-200 deg C). As part of the project he investigated the how the characteristics of the passive components (inductors/ferrites and capacitors) changed when operated at the cryogenic temperatures..
Electric Vehicles
Lisiate Takau (ME Student) is finishing a project to design and build a switched reluctance motor (SRM) plus controller that is suitable for electric vehicles. The SRM has a simple and robust construction and is able to operate at high speeds. This project has included computer finite element modelling techniques as well as the construction and testing of a low voltage 200W SRM.
The electric car also requires auxiliary power supplies to operate the lights, indicators and wipers. The main battery bus is 300V so this voltage has to be converted by efficient means down to 12V. William Chen (ME Student) is working on a high frequency power supply project to do this conversion. The system uses a distributed intermediate voltage (48V) network and will use a CAN bus to provide intelligent communication.
Motor Drives
Perry Field is just completing a ME TIF project with PDL Electronics. The project has been looking at the use of Resonant Link DC Bus technology for use in motor speed drives to reduce the cost of DC capacitors and to reduce the switching losses. The system also allows bi-directional power to flow.
Power Supplies
Irene Ting (ME Student) is completing a project with Invensys Energy Systems that has been investigating the benefits of using a dual, energy-holding state, flyback converter in 500W rectifier systems.
Fuel Cells
Tony Rocco (ME Student) is working on a grid connected fuel cell project that is sponsored by Industrial Research Ltd. This project is looking at the fuel cell control system, a power storage buffer and the inverter that is connected to the grid. A distributed control system will be implemented to improve the performance of the system to load changes.