Technology and protocols: OCPP, V1G, V2G, DLM and charging power

Let’s clarify the terminologies associated with electric mobility, in particular as regards the protocols for communication between the charging stations, the functions for regulating the absorbed power, and the charging power.

 

Open Charge Point Protocol (OCPP)

It is a protocol for communication between electric vehicle charging stations and central management systems that allows operators to monitor, authorize or stop a charging.

It is the protocol with which the charging systems communicate with the Back-End or with other intelligent systems.

V1G

For V1G, in the context of mobility, we mean the simple recharging of an electric vehicle with the additional possibility of adjusting the absorbed power (both decreasing and increasing – if possible) according to the network needs.

This feature, which is part of what is known as “Smart Charge“, allows network operators to regularize the electrical load, avoiding blackouts and major investments in the infrastructure.

Vehicle 2 Grid (V2G)

Vehicle 2 Grid introduces a new era in energy management for electric vehicle charging that becomes bidirectional.

It is based on charging systems capable of transferring energy not only from the source to the battery but also in the opposite direction, so that if necessary the cars themselves can be transformed into reserves to draw on in times of emergency to stabilize the network and avoid overloads.

The criteria and methods for disseminating the V2G method are being defined by the regulatory bodies (see Legislative Decree of 30 January 2020 of the Mise).

Dynamic Load Management (DLM)

Dynamic load management (electric) means the possibility, for a recharging system, of modulating (adapting) the instantaneous power absorbed by all connected cars according to the power available at that precise moment to the user.

A trivial example, applied to a domestic recharge, is when, while recharging is in progress, an energy-intensive appliance is switched on: in order not to exceed the contractual power and to trigger the limiter, the recharging power is automatically reduced or cancelled; similarly it occurs in more complex systems with different charging stations.

Usually this functionality requires a power measurement system, or just the current in the simplest systems, absorbed by the electrical network and a management algorithm.

Standard, Fast (or high) and Ultra-Fast power charging

  • Standard power recharging means that available in recharging systems up to 22 kW;
  • Fast over 22 kW and up to 100 kW;
  • beyond this power the term Ultra-fast is used.

This terminology is now in common use, as well as used in sector legislation.