Friday, August 9, 2013

National Physical Laboratory (NPL) develops new technology for electric vehicles

A new lead-free, high temperature ceramic capacitor could improve the range and efficiency of electric and hybrid vehicles
A team of scientists from the National Physical Laboratory (NPL) at Teddington, Middlesex, have developed a new capacitor that could extend electric vehicle (EV) range and efficiency. The NPL has been working on the project in partnership with a number of other organisations including Syfer, NanoForce,Valeo, Queen Mary, University of London and Queen's University Belfast.
Power electronics found in today’s vehicles require cooling because of limitations in the temperature range of components such as capacitors, which are used to store electrical energy. However, cooling systems add extra weight to vehicles which in turn reduces efficiency and reliability.
In order to solve this problem, the Technology Strategy Board has funded NPL research aimed at developing a new ceramic capacitor dielectric material with a high energy density, called HITECA, which operates with a stable capacitance at temperatures of 200 °C and above. The use of this material, particularly in hybrid and electric vehicles which rely on high efficiency power conversion and management systems, would reduce the need for cooling and therefore would also help to reduce vehicle weight. The materials high permittivity could enable the development of smaller electronic devices and the reduced loss of capacitance with voltage could also improve overall vehicle performance. Other types of capacitor, for example, barium titan ate capacitors, can lose up to 85% of their capacitance at working voltage.
HITECA capacitors could also improve high temperature electronics in other sectors and in high energy applications such as ‘pulsed power’ where energy is stored over a period of time before being released as a high power ‘pulse’.
“Industrial electronics need to be able to perform in the harsh environments in which they operate” said Tatiana Correia, who led the work at NPL. “The ability of HITECA capacitors to function at higher temperatures than existing capacitors will help make electronic systems more robust and remove barriers for technologies such as electric vehicles that rely on them.”