Evolution of Power Capacitors for Electric Vehicles

Evolution of Power Capacitors for Electric Vehicles
Written By: Gilles Terzulli

Electric vehicles are in widespread use. Hybrid cars are now a common sight on our roads as people look to find more environmentally-friendly forms of personal transport, and there are many other commercial and public electric vehicles, such as trains, trams, buses and industrial trucks and equipment in everyday use. The electronic systems and components that have enabled the realisation of such a wide variety of electric vehicles have all experienced a major evolution, including the DC link power capacitor.

The purpose of capacitors in electric vehicles is to prevent ripple currents from reaching back to the power source, and to smooth out DC bus voltage variations. Capacitors are also used to protect semiconductors – originally thyristors, but now IGBTs. Metallised film has become the capacitor technology of choice for electric vehicle and other medium and high power applications; this article explains why using worked examples.