Smart Grid Security in the presence of plug-in electric vehicles

Smart Grid is the modernization of the existing power grid using digital technology in order to derive a number of benefits such as energy efficiency, security and reliability of power supply, and integration of electricity generated from renewable sources. It will be able to co-ordinate the needs and capabilities of all generators, grid operators, end users and electricity market stakeholders in such a way that it can optimize asset utilization and operation and minimize both costs and environmental impacts while maintaining system reliability, resilience and stability.

One of the anticipated applications of Smart Grid is the introduction of the plug-in Electric Vehicle (EV). The mass adoption of EVs could serve as a back-up source of power grid with EV's big battery capacity. They will allow for both the possibility of storing electricity, which might otherwise go unused (ideally from renewable), and of feeding stored energy back into the electric grid, in periods of high demand. On the other hand, we face two challenges in this application. One is the impact of potential peaks (either accidental or malicious) on Smart Grid caused by connecting so many new and very large appliances to the grid. Another challenge is finding a way to take advantage of these new sources of distributed power storage, such that grid operators can draw upon this new power supply when needed. This requires a secure and reliable communication infrastructure to support monitoring, control and management of the EV charging infrastructure in Smart Grid.

Smart Grid security has received significant focus in the recent years. In part, this is due to the increasing awareness of vulnerabilities of the existing grid and well publicized incidents of both real and simulated attacks on the grid as well as other critical infrastructure around the world. In NISTIR 7628 "Guidelines for Smart Grid Cyber Security", it is stated that “cyber security is one of the key technical areas where the state of the art falls short of meeting the envisioned functionality, reliability and scalability requirements of the Smart Grid”.

A compromised electrical grid and EV charging infrastructure can have serious implications on the normal operation of the grid and the EV population. For example, the following scenarios may happen.

• The addition of EVs poses a significant load to the grid. A coordinated attack on the compromised system may synchronize the charging of all the EVs in one locality to coincide with the peaking of the grid load, thereby overloading and tripping an entire region causing a black out, resulting in economic and social costs.
• A denial of service attack may be carried out to prevent all EVs and charging infrastructure from communicating with the grid. This will prevent the EVs from charging, or to provide ancillary services to the grid.
• Cyber thieves may hack into the system to gain account information, or to steal credits.
• An attacker may hack into the system to manipulate the EV charging stations to overcharge the batteries of EVs (especially for the case of overnight charging at home) which may damage the EVs or even cause fires.
• An attacker may hack into the system to trace the EV driver by searching the location the EV is charging.

We are doing research on cyber security for the EV ecosystem in Smart Grid, funded by the Energy Market Authority (EMA), Singapore. The objectives of this project are

• To conduct cyber security risk assessment and analyze the security impact of the impending addition of many EV equipped with Intelligent Electronic Devices (IEDs) to the Smart Grid.
• To design a scalable and cost effective security system architecture for integrating IEDs into Smart Grid.
• To design a cost effective tamper resistant IED for the EV charging infrastructure and in the vehicle unit.
Overall, a comprehensive security solution for the EV charging infrastructure will be delivered, which secures all the communication involved and provides virtual isolation for legacy communication systems of the power grid. As a result, it will not only boost the confidence of utility operators, but also add incentives for consumers to purchase electric vehicles, which could have a potentially profound impact on the reduction of carbon dioxide emission and other pollutants.
 

Dr. Jianying Zhou, Institute for Infocomm Research, Singapore