Electrification of the means of transportation, known as electric mobility, has been consolidated worldwide as an important mechanism to reduce greenhouse gas emissions and face global warming. Large cities also see electric mobility as a solution to mitigate the pollution problems caused largely by the internal combustion engines of conventional vehicles.
Government and private sector investments are being made not only to meet this need, but also to seek the economic benefits that should accompany the trend of electric mobility. Traditional vehicle manufacturers, as well as new companies entering the auto market, are announcing the production of electric vehicles (EV), however, electric models are still costly compared to combustion vehicles.
Increasing supply is expected to lead to a reduction in prices which, coupled with other factors such as tax incentives (eg the exemption from automobile taxes for EV, already adopted in some Brazilian states), should boost demand for electric vehicles. However, the popularization of EVs still depends on other important factors, such as the existence of an adequate recharging infrastructure.
Recharging Electric Vehicles
Electric vehicles can be recharged at public refueling points (such as highways, refueling stations, shopping malls, etc.) or privately (at home). Despite the residential recharge offer, the existence of a public supply network is understood as essential to ensure safety and reliability to drivers, reducing the effect known as range anxiety, the fear that the vehicle load being insufficient to reach its destination.
Authorized public and private recharge models, as well as the rules and conditions for their commercial exploitation, are defined by the regulations of each country. In Brazil, ANEEL (National Electric Energy Agency), through Normative Resolution 819/2018, established among other points that any interested party is allowed to carry out activities related to the recharging of electric vehicles, including for commercial exploitation, to freely negotiated prices.
Thus, according to the standard, both energy distributors and other interested parties (such as gas stations, shopping malls, commercial establishments, etc.) may provide electric vehicle recharge services, which encourages the expansion of electricity infrastructure. public recharge.
The electric vehicle recharge market may have multiple players, with public recharge points being offered by various types of establishments, something quite different from the combustion vehicle supply system, where fueling is basically done at gas stations.
Other actors also play an important role in the recharging ecosystem, for example: Original Equipment Manufacturers (OEMs); the manufacturers of charging stations (CS); Charge Station Operators (CSOs) operating companies; electric utilities, which must provide electric power; payment companies, which must enable models for consumers to pay for energy consumed, etc.
The existence of various actors, different types of equipment and electronic systems can pose practical problems for the end consumer. Imagine a driver who needs to recharge publicly (for example, while traveling), but when he reaches an electric charging station, he identifies that his EV connector is not compatible with the charging station connector.
Standardization of connectors may solve the above problem, but other issues may arise in this context. Imagine now that the driver has managed to get to a charging station with a connector compatible with his EV, but the supply control system does not allow him to enable charging. This problem may occur, for example, because the driver does not have an account with the CSO at that reload point.
In addition, there are also different payment mechanisms for the energy consumed – for example through prepaid RFID cards, credit cards, smartphone apps, etc. – which can also be a hindrance for the driver to recharge his vehicle.
Not only the standardization of equipment (such as connectors), but also the definition of standard communication protocols, are essential to avoid compatibility problems and enable the creation of flexible charging solutions for drivers.
Reload Standards and Protocols
A charging station has at least one EVSE (Electric Vehicle Supply Equipment) that, connected to the EV via a connector, will communicate with the EV’s Battery Management System (BMS) to perform the loading operation.
Recharging stations can be of 2 types: slow recharging, which use alternating current (AC) and can take up to 8 hours or more to charge a vehicle, typically used at residential recharging points; and fast recharge, which use Direct Current (DC) and can recharge in 20 or 30 minutes, usually used in public electroposts.
The table below shows some of the connector standards adopted in some regions (reference). As the table shows, connector standardization initiatives already exist, although there are still differences between regions, these initiatives seek to minimize connector-related problems.
Communication between the charging station (EVSE) and the electric vehicle (BMS) can be done through the Power Line Communication (PLC) or Controller Area Network (CAN) protocol, however these protocols are only related to the physical layer (low communication). not including specific standardization of the recharge process and payment mechanisms (high-level communication).
To meet this demand for compatibility, industry players and standardization bodies have been organizing to create specific charging protocols for electric vehicles that ensure interoperability between equipment and software systems. Two of these high-level protocols that have been widely adopted are ISO 15118 and OCPP, which has a slightly different focus, as illustrated in the figure below.
ISO 15118 is an international standard of the International Organization for Standardization (ISO), which defines a high level protocol for communication between the charging station and the VE.
The standard supports various recharge mechanisms, ensuring LV users flexibility, among which is the “Plug & Charge”, in which the electropost automatically recognizes the connected EV, authorizing the recharge process and performing the collection electronically.
The standard also enables the development of smart charging solutions, where EV recharges are designed to avoid overloading the electrical system (or grid). In addition, the standard should also include, in future versions, the sending of energy from the vehicle to the grid (a concept called V2G).
Open Charge Point Protocol (OCPP) is a protocol defined by the Open Charge Alliance (OCA) for the communication of charging stations with the charging operators management (CSO) systems. VE
Thus, OCPP allows CSOs to remotely manage multiple charging stations, regardless of the charging point manufacturer, through systems called Charging Station Management System (CSMS).
The latest version of the protocol (OCPP 2.0) addresses a large number of use cases related to charging station management and control of charging transactions, as well as supporting Plug & Charge and smart charging in accordance with ISO 15118.
Electric vehicles are still a new modality in the market, but with great growth possibilities and benefits. However, as it is a new modality, linked to new technologies, there are still many difficulties in its adoption and massification. One of them is the standardization of the recharging mechanism, which is not yet uniform, from EV connectors to the protocols used for recharging.
ISO 15118 and OCPP are two important standards related to electric vehicle recharging that can solve equipment and solution mismatch problems, enabling the creation of solutions that bring flexibility and convenience to electric vehicle users and enabling the operation of these systems by of CSOs. Protocols can also be essential for creating smart charging solutions, which in turn can be critical for integrating charging stations with the electrical system, avoiding problems such as grid overload and ensuring more efficient use of energy.