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Auxiliary Power Solutions

for EV Chargers

www.cui.com

One of the biggest changes that is already under way is the move from fossil fuel

vehicles to cleaner and more e��cient electrically propelled vehicles (EV). While there

is much work to be done within the vehicles themselves, the provision of a sucient

number of charging stations globally is challenging industry and governments.

Range anxiety – the fear of becoming stranded – and the time taken to charge an EV

are often cited as reasons that sales of EVs are lower than hoped for. Clearly, solving

this challenge is going to have a huge benet for automakers, the driving public, and

the environment.

In this technical article we will take a detailed look at the types of chargers being

developed and rolled out and consider the power needs for each of the key features.

BACKGROUND

Some of the very rst vehicles ever made were electric. However, that changed when the

electric starter was invented. This brought internal combustion engine (ICE) vehicles to the

forefront while electric vehicles were consigned to history. During the oil crisis in the early

1970s and the Californian Zero Emission Mandate during the 1990s, there was renewed

interest in electric vehicles, but they did not become mainstream.

In recent years, new battery technologies have emerged. Coupled with widespread

environmental concerns and a customer base seeking cleaner alternatives to fossil fuels,

electrically powered vehicles are nally becoming a viable technology.

The market is maturing rapidly but remains in its early stages and a variety of vehicle types

are available. Hybrid vehicles contain both ICE and electric motors, which may be designed

such that either one or both are used for propulsion. Pure battery types are wholly electric

and reliant upon the charge stored in the battery to travel. Broadly speaking, the market

can be split into two sections – the hybrid types that charge their own battery using the

ICE(HEV, MHEV) and the types that can be plugged in to charge (BEV, PHEV).

As battery technology improves and EVs become more ecient, their range is increasing

and starting to approach that of an ICE vehicle. Many of the most common journeys, like

the daily commute, can be made without recharging. Nonetheless, range anxiety relating to

making longer trips in an EV remains a hurdle, preventing many customers from adopting

the new technology. When an ICE vehicle runs low on fuel it is simple and quick to refuel

at a traditional gas station. Charging the battery in an electric vehicle, on the other hand,

can take many hours depending upon several factors including the state of charge, battery

capacity, charger type and so on. Clearly, in-journey charging of several hours is hugely

impractical and so EVs are more frequently charged ‘at destination’ – whether that is a

short top-up at the shopping mall, an all-day charge at the workplace, or overnight at home.