Investigation of High Frequency AC Power Distribution Benefits for the Automobile Auxiliary Electrical System 2010-01-1322

This paper aims to indicate the advantages and any drawbacks of high frequency alternating current (HFAC) power for vehicle auxiliary electrical systems. Generally, benefits of HFAC include efficient power distribution and transformation, space and weight saving and load galvanic isolation. In addition, HFAC bus topologies are distributed to the point of use, lending the system to easy fault detection. The paper is structured as follows: first, the main findings of the most relevant automotive HFAC studies are outlined. Next, an HFAC architecture is proposed which is compared to the existing 14V and proposed 42V centralised DC networks in terms of power distribution efficiency and wiring harness weight saving. For this analysis, the case study of a medium-sized passenger vehicle is considered, and a group of intermittent and continuous auxiliary loads with a cumulative power of 2.8kW. The calculations over a 1200s drive cycle show that the power distribution efficiency for a 50kHz, 100V AC power bus increases by 90 per cent and 80 per cent compared to 14V and 42V DC topologies, respectively, and the wiring copper weight drops significantly by 70 per cent and 30 per cent, respectively.