A coordination frequency control strategy for electric vehicles and air conditioners based on the load assessment index

In order to enhance the frequency response capability of the power systems, the EV (electric vehicle) clusters and AC (air conditioner) clusters are used as response resources to maintain the system frequency within an acceptable range. The frequency control strategies of the EV clusters and AC clusters are given respectively. A load assessment index is proposed to evaluate the available response capability of the EV/AC loads in real time. Then an EV-AC coordination frequency control strategy is developed. The control sequence of the two controllable loads is determined by their impacts on the comfort level of EV/AC users. In the case study, a simplified frequency regulation model is used to investigate the effectiveness of the proposed strategy under two frequency events, the simulation results show that utilizing the EV/AC loads to stabilize the system frequency can reduce the frequency deviation to some extent without serious impact on the comfort level of users.