Two-Level Optimal Scheduling Strategy of Electric Vehicle Charging Aggregator Based on Charging Urgency

Aiming at the demand response of power grid load scheduling, the role of the charging load aggregator is becoming more and more important. A two-level optimal scheduling strategy of electric vehicle charging aggregator is proposed based on the urgency of charging. Firstly, the electric vehicles are divided into different levels based on the charging urgency of electric vehicle, and the scheduling needs of peak shaving and valley filling and new energy consumption are determined; secondly, a two-level optimal scheduling strategy of electric vehicle charging aggregator based on charging urgency is proposed; finally, the effectiveness of the strategy is verified by numerical example simulation. The results show that the two-layer optimal scheduling model can fulfill the scheduling requirements of three scenarios of peak shaving, valley filling and new energy consumption, achieving the scheduling objectives effectively and no deviation.

I. Introduction

One of the goals of power dispatching is to realize the peak shaving and valley filling of the grid load [1], at present, users still have certain problems in responding to the demand for peak shaving and valley filling of the power grid, and the response is difficult to meet the demand [2]. With the development of battery technologies, electric vehicles have emerged in large numbers in recent years. On the one hand, the charging of a large number of electric vehicles has caused a certain impact on the stability of the power grid [3], on the other hand, based on the spatiotemporal response characteristics of electric vehicles, by reasonably guiding and controlling its charging and discharging behavior, while avoiding the impact of large-scale electric vehicle charging on the power grid, it can also participate in the peak shaving and valley filling of the power grid load to assist the safety and stability of the power grid [4]. However, due to the discrete distribution of electric vehicles, and the capacity of a single user cannot meet the access threshold of demand response, in order to effectively utilize the decentralized charging potential of electric vehicles, a specialized demand response supplier-charging load aggregator (LA) is proposed [5]. As an intermediate connecting the power grid and new energy electric vehicles, LA aims to optimize the allocation of resources and the safe operation of the power system. Through the combination of direct control of intelligent equipment and indirect control of market prices, the charging network based on the fusion of cyber-physical systems will be decentralized. The controllable flexible loads of electric vehicles are aggregated, integrated to participate in electricity market transactions and assist the safe operation of the power system, and value distribution is carried out according to the contribution of each aggregated resource and users, which ultimately meets the needs of regional power grids for peak shaving and valley filling. This paper mainly focuses on the interaction between the charging aggregator and the power grid.