OCPP is a short form for Open Charge Point Protocol and as the name suggests, it is an open-source communication standard used in networked electric car chargers. The main objective of OCPP is to ensure any electric vehicle charger functions with all charger management software systems even if the software developer and the EV charger manufacturer have never met and are working from different continents.
From the definition, we can see that not all charging station networks are OCPP-compliant. In fact, only open network charging stations can be OCPP compliant.
In addition to open networks, we also have closed networks and no-networked charging stations.
Closed networks EV chargers use trademarked standards to communicate with the networks and will require an entire system overhaul in order to switch to other types of networks. A good example is the Tesla Chargers.
Non-Networked charging station functions as self-sufficient units without any network connectivity. It uses the standard power rates provided by the grid supplier. A good example of the non-networked system is residential chargers.
OCPP has both software and hardware benefits. In terms of software, you gain access to functionalities that noncompliance software can offer. For instance, OCPP-compliant makes your station visible to a broader audience, provides a top-notch user experience, and manages all your electric vehicle charging hardware in a single place.
In terms of hardware benefits, you can easily switch your EV software anytime you wish and encourage competition in the industry.
Here are the key benefits of OCPP:
The following are key considerations before you implement the OCPP standard:
Older versions like OCPP 1.5 were based off of SOAP that depends on XML to characterize data, which is not reliable for charge stations with weak internet connectivity. But later versions of OCPP are based on JSON-over-WebSocket, which, unlike SOAP, is a modern technology that streamlines communications using client-server equipment. The most advanced version of OCPP such as OCPP 2.0.1 is compatible with several options including remote transactions, PIN, and Plug and Charge. It is also the go-to option for implementations that require ISO 15118 certification and integration with EMS (energy management systems).
After completing the OCPP implementation, it is advisable to test different communication outcomes as well as interoperability between the backend (server) and the charger (client). This may involve operations started by the charger such as heartbeat, metering, start or stop, authorize, status, boot, etc., and electric vehicle users through mobile applications.
One should painstakingly consider migration despite the improved features of the latest version of OCPP, because of inconsistent standard interpretation. For an effective migration, one should first check if the server (back-end) infrastructure is compatible with 2.0.1, migration cost, modification in the naming regulations, as well as proof of concept (POC) before migration.
OCPP in electric vehicle charging systems (both software and hardware) has become unavoidable due to the increasing need for interoperability. Looking forward, this protocol has a promising future and great potential for adoption as a key ISO standard, and EV charging manufacturers should begin seeking expert opinion and help in the implementation and testing of OCPP as well as developing a product roadmap that is future-ready.
RCD (residual current device) is a safety production device used to check and prevent electrical leakage in EV chargers. Electrical be cut down to prevent accidents when RCD detects electricity abnormality.
DIN 70121 is an early CCS DC fast charging communication protocol that provides basic vehicle-charger communication but it has no advanced authentication and security cryptography.
OTA（Over-The-Air）, means it can remotely upgrade software by the wireless network. It has become an important menthol to improving EV charger performance and user’s experience.
