This point of view was originally published in Auto Tech Review - Source Link
The trend of vehicle electrification has caught the automotive ecosystem's eye for quite some time. While automakers are investing millions of dollars on various technologies that support xEVs (Battery Electric Vehicle, Electric Vehicle, Hybrid Electric Vehicle and Plug-in Hybrid Electric Vehicle), Tier 1 suppliers and battery manufacturers, too, have come up with various technologies that support the development of next-gen electric vehicles.
Though the ecosystem has embraced vehicle electrification, charging infrastructure has remained a prevailing question throughout. Clearly, the success of EV adoption in the country depends on getting this piece of the puzzle answered. Building a robust public charging infrastructure is key to growing the electric vehicle market. Providing the right infrastructure with updated technology will play a vital role in increasing adoption of EVs in India.
There are several changes taking place in the EV market but charging infrastructure still suffers from fragmentation, inconsistent data availability, and a lack of consistent standards to follow. Standards for vehicle-charge point communication and payment systems should be secure and easy to follow so that it will reduce the issues of interoperability between charging networks, increasing innovation and competition, and reducing costs to EV drivers.
A typical layout of an EV charging system is shown in (1). Charging speed is another aspect that has taken paramount importance. EV Charging levels based on speed are shown in (2).
As India aims to have battery-powered vehicles by 2030, the charging landscape is very interestingly poised. There have been a lot of debates on whether to adopt already existing charging standards or create a new charging standard that resonates well with the Indian market. Globally, different charging standards have evolved over a period of time, including:
- Combined Charging Standards (CCS) followed widely in Europe and US;
- CHAdeMO followed in Japan; and
- GB/T followed in China.
Latest developments suggest that India will have Bharat Standard for AC charging and follow the guidelines of CCS (for high voltage), and CHAdeMO (for low voltage) for DC charging. This will continue till the time we have our own set of standards for vehicle charging. The major areas of focus for India specific charging station system include the appended:
- Charging station connector;
- Communication protocol; and
- Architectural design of charging station.
This article particularly focuses on communication protocol and the technology behind it.
In the rapidly evolving charging infrastructure industry, communication of right data in terms of state of charging, payment mode, battery health, etc are deciding factors for adoption of charging station. Intelligent charging uses smart communication protocol to talk to the battery management system (BMS) and fetch consumer related information promptly as per need. Intelligent charging uses Time of Day (TOD) tariff to communicate to consumer before charging the vehicle through mobile app or relevant interface to make charging operation cost effective.
Bidirectional communication between the electric vehicle and the grid operator is one of the crucial steps in the EV charging operation and grid communication. This communication makes it possible to dynamically respond to changes in grid condition. The interface of communication is commonly indicated as V2G. The basic building block behind this V2G communication is the ISO 15118 standard.
IS0 15118 is the building block for charging communication and protocol. It specifies the handshake between xEV and Electric Vehicle Supply Equipment (EVSE), and is divided into five parts:
- ISO 15118-1 introduces the overall flow of communication;
- ISO 15118-2 deals with the requirements of messages exchanged by EV and EVSE;
- ISO 15118-3 consists of physical and data link layer requirements;
- ISO 15118-4 includes the conformance tests for ISO 15118-2; and
- ISO 15118-5 consists of the conformance tests for ISO 15118-3
The remaining part of standard deals with wireless communication.
The objective is to achieve a user-friendly mechanism for authentication, authorisation and billing at the charging station without any additional interaction with the user. Integration of an EV in the smart grid allows flexible load control, which further provides valuable grid services without compromising on the driving habits of consumers.
Charging equipment should be able to communicate with the BMS of a battery pack in a xEV, to enable it to charge at the right rate for maintaining State of Health (SoH) of batteries. Embedded software plays a key role in ensuring a safe and secure supply of energy for battery charging.
KPIT Technologies has a readily available stack and testing framework that enables seamless communication between vehicle and grid for the aforementioned use cases. The conformance test suite developed by KPIT using industry standard tools is easy to use and can be easily customised or extended to include additional test cases, apart from the ones mentioned in the standard. KPIT's V2G charging solutions have enabled leading global automotive manufacturers and suppliers to jump onto the electric mobility bandwagon.
As the India specific charging standards are taking shape, it is imperative that governments and private sector coordinate their deployment activities to ensure that convenient, affordable, and reliable public charging infrastructure is available to all EV consumers. Deployment of public charging should factor latest advancements and be flexible enough to adopt next-gen technologies.
The future EV vision for India lies in global interoperability, which requires standardisation, test procedures, compatibility enabling technologies including communication controllers, messaging protocols, metering and plugs. Vehicle manufacturers, charging infrastructure providers and consumers owning passenger cars, commercial vehicles, two-wheelers will benefit through this.