The intermittency of renewable energy and variable loading yield substantial grid frequency deviations. Electric vehicles (EVs) have been seen as an elegant solution to provide the grid ancillary service of frequency regulation, owing to their capacities and rapid response. Meanwhile, the integration of EVs into the grid for frequency regulation raises critical issues such as - frequency stability and economic revenues, which have been the topic of a significant body of literature. This paper presents an overview of the power control schemes for grid frequency regulation using EVs. First, the system architecture is presented. Then, several strategies of frequency regulation are classified into frequency-aware and economic-aware. Furthermore, the feasibility and efficacy of EVs participating in frequency regulation are concluded. Finally, the possible future research trends are summarized.