Jonathan Newell discovers how an accurate test and maintenance regime helps to keep electric and plug-in hybrid cars supplied with power across Britain’s roads.
Imagine a world where diesel fuel pumps were few and far between and when you thankfully arrive at one, you find it’s out of order. In such circumstances, would you buy a diesel car? Such was the problem when electric vehicles first came onto the market and in an effort from the Government to make green transport more attractive to mass markets, more charging stations can now be found throughout the country’s road network and in retail outlet car parks.
However, there still aren’t enough of them and to put enough in place to suit future requirements will also need the right infrastructure to maintain and test them to make sure they’re safe and performing correctly.
Trickle or gush
Not all charging stations are created alike. According to the IEA’s recent Global EV Outlook report, nine out of every 10 non-residential charging points installed in the USA, Europe, Japan and China are of the slow-charging types which are installed in residential properties for over-night charging. This figure would indicate that the majority are being installed in such locations as workplaces where the vehicle is likely to stand for a considerable amount of time.
However, to overcome the so-called “range anxiety” experienced by many EV owners about to embark on a long journey, the other type of Electric Vehicle Supply Equipment (EVSE) is required for installation in retail parks and motorway service stations. This type of EVSE provides a faster charge, reducing the dependence on the driver for increasing journey times and having to wait at service areas while a usable charge is established.
Notwithstanding this logical requirement for fast charging stations, the same IEA report predicts that by the end of the decade there will be over 2 million more slow chargers globally but far fewer rapid charging systems.
Both safety and performance are important in the operation of EVSE charging points and for this, they need to conform to IEC 61851-1, which deals with electrical safety and with the characteristics of the vehicle under charge and its requirement to be adequately earthed.
In order for a charging point to be energised, there must be a suitable vehicle connected to it. To recognise such a vehicle, the standard calls for a communication channel to be opened between the EVSE and the vehicle.
From a testing standpoint, this means that a vehicle needs to be connected or simulated in order to check such parameters as earth loop impedance as well as to perform functional performance testing.
Monitoring and maintenance
With the expected growth in charging stations across the network, remote monitoring and customer call centres are being established to keep track of the condition of the infrastructure and deploy service personnel to charging stations that require attention more efficiently.
To help such personnel, electrical test device manufacturer Seaward has produced a field testing device with diagnostic capabilities specifically for use for EV and plug-in hybrid vehicle charging stations.
The EV100 testing device also emulates the presence of an electric vehicle so that the charging station will produce energy when it is plugged into the device, thus enabling charging performance measurements to take place.
Covering basic electrical tests, functional performance tests and electric charging cable insulation tests, the new device provides maintenance engineers with a fast and easy to use tool for keeping the nation’s fleet of EV and plug-in hybrids on the roads and fully charged.