terça-feira, 1 de julho de 2014
Design and development of a battery cell voltage monitoring system. Master’s Thesis Nick Prinsloo Department of Electrical Engineering Cape Peninsula University of Technology
Design and development of a battery cell voltage monitoring system.
Department of Electrical Engineering
Cape Peninsula University of Technology
A Thesis for
The Department of Electrical Engineering in fulfilment of the requirements for the
Magister Technologiae degree in electrical engineering,
at the Cape Peninsula University of Technology.
The purpose of this thesis was to design and develop a measurement system that would allow accurate measurement of individual cell voltages in a series cell stack. The system was initially proposed to be used in conjunction with an active cell balancer. This would allow for the efficient equalising of cells as well as provide detailed information on the cell stack and how the stack operates over time. Having a system that measures voltages accurately, with which the active cell balancer can be controlled would allow for peak cell lifetime and performance. Current battery management systems are large, complex and inefficient and a new way of battery management had to be investigated. To accurately measure individual cells in a series stack, the high common mode voltage must be negated. Different techniques that are currently used to create galvanic isolation were reviewed; circuits were designed and were simulated to find the most suitable design. The traditional methods used to create galvanic isolation did not provide adequate results. The methods were too inefficient and not accurate enough to be used. The methods that had the required accuracy were too complicated to connect in a useable system.