The official ElectronicsWeekly.com website blog, highlighting new features, content, and initiatives on the site.
Only Connect: Charging electric cars (Going Green #6)
As electrically powered cars are made available and we read reports about many more being close to production, debates are still raging about a common standard for the plugs they use for charging.
Isn’t there already a standard?
Back in 2001, SAE International proposed a standard for a conductive coupler which was approved by the California Air Resources Board for electric vehicle charging stations. The connector has five pins for the two AC wires, with ground and signal pins that are compatible with IEC 61851-2001/SAE J1772-2001 for proximity detection and control pilot function.
However, the plug standardization in Europe is part of a process that also includes smart grid elements and battery recharge electronics for cars. In this area there are two broad competing standards.
German connector manufacturer Mennekes has developed a series of 60309-based connectors enhanced with additional signal pins known as CEEplus connectors, which have been used to charge electric cars since the 1990s. When Volkswagen promoted its plans for electric mobility, Mennekes contacted the company about its requirements for connectors.
In 2008, it derived a new connector, known as Type 2, with utility RWE and car maker Daimler, and this was accepted as the standard connector by other car makers and utilities for field tests in Europe.
The connector has received criticism however, with car manufacturer Peugeot comparing it to the IEC 60309 plugs that are readily available. As such, a number of field tests in France and the UK have adopted the campground sockets that are already installed in many outdoor locations.
In 2010, the EV Plug Alliance was formed between electrical companies in France and Italy. Together they created a new connector, known as Type 3, which provides three-phase charging up to 32 Ampere and uses shutters over the socket side pins which is required in 12 European countries but is not included in any other electric vehicle charger plug. Limiting the plugs to 32 Ampere also allows for cheaper plugs and installation costs.
According to the EV Plug Alliance, instead of having a single plug type at both ends of the charger cable, it would be better to choose the best type for each side – its plug is considered the best option for the charger side/wall box leaving the choice for the car side open.
So which option is best?
An ACEA position paper published in June 2010 ruled out a Type 1 connector because of the three-phase charging which is so popular in Europe and China – however, debates remain about whether Type 2 or Type 3 should get the nod as the new industry standard across the continent.
Much of the debate revolves around the shutters used in Type 3 that are absent from Type 2. One argument is that mode three requires the socket to be dead when there is no vehicle attached so there is no hazard that the shutter needs to provide protection from and so the shutters only have advantages in mode two (when the electric car is connected to the supply network not exceeding 32A), allowing for a simpler charging station.
However, a public charging station would expose the charging socket and plugs to a harsher environment and so it is argued that the shutter could easily have a malfunction that is not noticed by the driver.
As such it is expected that the ACEA will adopt Type 2 mode three chargers, which means the charging socket is dead if no vehicle is present. Analysts expect them to be used in home chargers after 2017 while still allowing mode two charging with established plug types that are already available.
Whatever the decision on standardization is, it needs to happen fast. Otherwise the car will be available but with nowhere to charge them except at home.
This all reminds me of just how long it took Cat 6 to get ratified, which was just far too long. The only good thing then was that we had Cat 5e to fall back on. Unfortunately for the environment regarding electric vehicles we have carbon monoxide producing engines to fall back on.
Previous Only Connect entries: