ANALYSIS OF THE IMPACT OF EV PENETRATION ON PROTECTION COORDINATION

Abstract

The global electric vehicle (EV) market has witnessed significant growth in recent years, driven by concerns over climate change, advances in battery technology, and supportive government policies. To address environmental pollution and the increasing energy consumption associated with conventional transportation systems, the adoption of EVs has emerged as a more sustainable alternative. However, the rapid increase in EV charging loads has raised significant operational challenges for power grids. This research project focuses on the impact of EV integration on relay and protection coordination in distribution systems. Relay and protection coordination plays a crucial role in ensuring the safe and reliable operation of distribution systems by detecting abnormal conditions, such as faults or abnormal load conditions, and isolating the affected section to prevent further damage or outages. With the proliferation of EVs, the increased charging load introduces harmonic currents that can disrupt the operational parameters of the power grid. This study utilizes the IEEE standard 33 bus distribution system as a testbed to evaluate protection coordination using genetic optimization techniques. By adding EV chargers at various nodes of the distribution system, the project assesses the time required for circuit breakers to trip in the event of a fault, evaluating the effectiveness of protection coordination techniques in the presence of EVs. The findings reveal that while the replacement of standard loads with EV chargers leads to a slight increase in the net RMS value of current and introduces harmonic currents, the sequence of relay operation remains unaltered. However, the relay operation time is affected, and in scenarios with bulk penetration of EV chargers, the increased harmonic current can cause overloading and other faults, resulting in relay trips. To ensure the proper protection of the system, it is recommended to increase the pickup current for the relays. By adjusting the pickup current level, the relays will trip at higher current levels, mitigating false tripping caused by harmonic currents from EV chargers. The study emphasizes that meticulous design and planning are essential to maintain the reliability and protection of power distribution systems when integrating EV chargers.