Frequency and voltage support of EV connected to an AC charging station – a practical application based on a smartcable

The increasing penetration of electric vehicles (EVs) raises new challenges for power system stability and flexibility. In particular, uncontrolled charging could amplify frequency and voltage fluctuations in future grids with high shares of renewable energy. This paper introduces a novel “Smartcable” device, an intelligent EV charging cable designed to autonomously adjust charging power based solely on local grid measurements, without requiring communication with the charging station or modifications to existing infrastructure. The proposed device exploits the control pilot (CP) signal defined in IEC 61851, enabling a “man-in-the-middle” control strategy that dynamically limits charging current according to measured frequency and voltage. A dedicated algorithm combining droop control with frequency and voltage thresholds has been implemented on a microcontroller and tested on a laboratory platform. Experimental results on several EV models, including Renault Zoé, Tesla Model Y, MG4, and CUPRA Born, demonstrate the ability of the Smartcable to accurately reproduce a 1% droop response with minimal delay. These findings confirm that embedding flexibility at the cable level represents a promising, scalable, and user-transparent solution to enhance system stability in future EV-dominated power systems.