What are the different EV charging protocols?

Building EV charging infrastructure is one of the current challenges for the automobile industry — even as new developments are going on in the charging technology itself. The implementation of regulations and standards for charging stations is also occurring and, as a result, many standards are developing aimed to ensure interoperability among charging facilities. The charging protocols are sure to play a key role in systemizing charging infrastructure.

There are several EV charging industry standards and protocols under development for enabling flexibility and interoperability for the entire EV market. Many EV charging protocols and regulations face hurdles in the international expansion of charge point operators and e-mobility service providers. Still, the development of different standards and protocols is critical to ensuring a future-proof infrastructure. In this article, we will talk about different EV charging protocols and standards.

Why charging protocols?
EV charging protocols are a set of rules and guidelines for data communication among different entities of the electric vehicle industry. The protocols are required to ensure interoperability among charging facilities and encourage EV adoption. Standardization is also important for optimizing costs and improving scalability. There are many protocols and standards that apply to the development of a charging facility. Most notable of these protocols & standards are as follows.

Open Charge Point Protocol (OCPP)
Open Charge Point Interface (OCPI)
Open Automated Demand Response (OpenADR)
Open Smart Charging Protocol (OSCP)
Open Clearing House Protocol (OCHP)
Open Inter-Charge Protocol (OICP)
eMobility Interoperation Protocol (eMIP)
ISO 15118

Open Charge Point Protocol (OCPP)
OCPP is an open-source application layer protocol for data communication between back-end systems and EV charging stations. The protocol is developed and maintained by Open Charge Alliance (OCA). The standard is vendor-independent, and many key players in the EV industry are contributing to its development. It has to be an international standard with interoperability among different charging equipment manufacturers, charging network operators, and systems providers. The protocol enables EVSE-agnostic sharing of charging data between electric vehicles and the electricity grid. Some of the important features of the protocol include smart charging, EV security, transaction handling, messaging, device management & network extensibility.

Open Charge Point Interface (OCPI)
OCPI is a protocol for data communication between charge point operators and eMobility service providers regarding charge points and charging sessions. It is developed to enable automated roaming among several EV charging networks thus providing scalability. The protocol is used to authorize charging sessions by exchanging tokens and rendering charge detail records for billing purposes. It allows sharing session and location information for roaming and handling registrations. It is also used for sending remote commands for reservation and smart charging. The protocol simplifies real-time billing and facilitates mobile access to charging stations.

Open Automated Demand Response (OpenADR)
OpenADR is an open-source standard for two-way data communication between the grid and charging stations to deliver automated demand response (ADR) actions. The standard is developed and maintained by OpenADR Alliance. The protocol is useful in optimizing costs by balancing demand at charging stations and the grid supply. It operates between distribution system operators, energy management systems, and charging facilities to ensure supply during peak hours. It relieves stranded assets letting the energy management system operate with full efficiency. It standardizes the messaging for demand response, distributed energy resources, and DR/DER processes.

Open Smart Charging Protocol (OSCP)
OSCP is an open-source protocol for data communication between the energy management system and charge point management systems of a distribution system operator. The protocol provides a 24-hour forecast of the local electricity grid capacity to the charge point operators. This is extremely useful in enabling smart charging based on grid capacity. The standard is again developed and maintained by Open Charge Alliance (OCA).

Open Clearing House Protocol (OCHP)
OCHP is an open-source protocol for data communication between the charging management system and the clearing house system. The protocol has been developed to enable e-roaming and allow EV drivers to charge at different charging station networks without any trouble. It allows eMobility service providers to maintain interoperability among charging station networks by connecting both charging providers and operators to a common network.

Open Inter-Charge Protocol (OICP)
Like OCPI, OICP is another communication standard for data exchange between charge point operators and eMobility service providers. The protocol is developed and maintained by Hubject and is implemented through its own platform. The protocol aims to facilitate automated roaming by means of information exchange between service providers and charge point operators contracted with the Hubject.

eMobility Interoperation Protocol (eMIP)
eMIP is a protocol for enabling the roaming of charging services among different networks. The protocol operates by maintaining a charging point database and authorizing charging sessions by exchanging tokens between the clearing house system and charging management systems.

ISO 15118
ISO15118 is a communication protocol between electric vehicles and charging stations. The protocol has been developed to enable a plug and a charging facility. It allows authorizing the charging session by just connecting the vehicle to the charging station. The standard is a means to implement bi-directional EV charging, commonly known as Vehicle-to-Grid charging. V2G allows energy feedback from electric vehicles to the grid system. This helps to avoid system peaks and enables smart charging. The standard has been extremely useful in simplifying the charging experience for EV drivers and has a part in accelerating EV adoption.