In recent months, electricity utility companies, EV fleet managers, and Charge Point Operators (CPO) have increasingly had smart charging and ISO 15118 on their minds. This standard dictates the communication protocols between an EV and an electric vehicle charging station.
The energy market hopes that ISO 15118 will provide an internet-protocol-based communication standard for smart charging. Along with summarizing ISO 15118’s essential applications, Tridens has also analyzed its effects on Smart Charging use cases V1G and V2.
ISO 15118 – User Authorization, Security Layer, and More
ISO 15118 comes with a Plug & Charge facility providing an identification and authorization mode. This mechanism allows an EV driver to plug their vehicle into a charging station without further authorization. This situation is equivalent to the driver of a gas-powered car tipping up at the gas station without a payment method!
ISO 15118 is a similar protocol to that on the World Wide Web, Public Key Infrastructures (PKI). It is being used between EV manufacturers and charging station producers as s means of authentication.
However, there are other advantages to ISO 15118 beyond authentication. It allows message encryption to transfer energy data between EVs and charging stations securely. Whenever an EV plugs into a charging station, it enables the system to optimize load management. This concept is known as Smart Charging.
Increased Data Creates Smarter Charging
The term Smart Charging is used to describe the various concepts and techniques used to control the EVs’ charging process. One such method is reducing peak use times so that charging providers can avoid higher costs.
To control the amount of electricity an EV draws from a charging station, there needs to be communication between EV, charging station, and the grid. This communication is enabled by ISO 15118, as it allows the EV to send its battery’s state of charge to the charging station.
Energy Management Systems can now have an accurate view of the amount of energy (kWh) that each EV needs. The system can then set the Smart Charging output accordingly. Having such s Smart Charging system helps deal with three major issues as follows:
- Inefficient Optimization. Concentrating on one EV and blocking other charging events.
- EV Batteries With No Charge. Missing vehicles with insufficient energy.
- Complicated Workarounds. Using time-consuming alternatives to access information that smart charging provides.
ISO 15118 Reliance On OCPP 2.0
Having received the EV’s charging information, the CPO needs to pass that information on to the charging management system (CMS). Most CMSs support Open Charge Point Protocol (OCPP). OCPP is a communication protocol between an EV charging station and the system’s back office.
OCPP works similarly to many IoT protocols. It is the messaging method that goes on between charging stations and the back-end systems they communicate with for authentication purposes, issuing charging commands, and tracking energy levels.
The majority of charging systems are running OCPP 1.5 or 1.6, the latter of which includes Smart Charging functionality. This capability allows CPOs to transmit charging limits and schedules from the back-end to the charging stations. With OCPP 1.5, a charging process can only be started or stopped.
The latest version, OCPP 2.0, enables the requested energy amount to be sent from an EV at a charging station to the central charging system. This capability is another significant improvement; however, as yet, few manufacturers are supporting it.
ISO 15118, in combination with OCPP 2.0, enables an EV to send its state of charge to the charging point. This information then gets forwarded by the charging point to the back-end. The exactness of the data allows Smart Charging functionality to accurately plan to charge events accordingly.
Can Smart Charging Occur Without ISO 15118 and OCPP 2.0?
Smart charging can still take place without OCPP 2.0 and ISO 15118. Three techniques make this possible:
- EVs can often send information directly to cloud-based systems. These transmissions can be done using APIs or data logging equipment. This practice is useful for vehicle fleet managers of companies such as DHL, GLS, or UPS.
- Despite not sending an absolute value for the requested energy amount, OCPP 1.6 sends the State of Charge (SoC) as a percentage. For instance, sending the EV’s current battery state as 70% would mean that it needs a 30% charge.
- Most charging systems come with a user interface that enables users to communicate with the central management system. This interface can be adapted by CPOs to include necessary fields for users to select at the start of the charging process.
Although these three techniques make it possible to conduct smart charging without OCPP 2.0 and ISO 11158, it is not as effective as having them. OCPP 2.0 and ISO 11158 will take Smart Charging to another level, much like the internet-enabled computers, to communicate with each other. Fleet managers, utility companies, and CPOs now have the opportunity to reduce energy costs, avoid significant investment, and use clean energy by implementing Smart Charging.
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