Coordinated control strategy assessment of a virtual power plant based on electric public transportation

With the rapid development of the public transportation industry in recent years, electric public transportation (EPT) with regular operating times and fixed load demands has considerable potential for energy storage. Aiming to solve the problem of insufficient large-scale energy storage and ensure renewable energy development, this study builds the dynamic simulation model of a virtual power plant (VPP) consisting of EPT groups, large-capacity public distributed generations (PDGs) containing a photovoltaic (PV) unit, and a coal-fired unit. Then, the coordinated control strategy, which includes the time-sharing plan part and execution part with multi-section, is proposed to make a trade-off between maximizing the utilization of EPT and ensuring the operational stability of VPP. The control strategy includes two modes (1) gaining benefits through electricity tariff differences and participation in the carbon trading market and (2) peak shaving the consumption of VPP using off-peak grid power. Moreover, the evaluation model related to the control performance and achievement of targets is established. The influence of the EPT number on benefits and peak shaving capability is compared. Results show that the optimal number of EPT for the system is the value at which the energy storage utilization is maximum at the specific period. The optimal daily benefit is 37,300-83,700 yuan, and the optimal daily discharge value is 117.77 MW.h when the maximum peak demand reduction is 38.31 MW. Overall, the proposed strategy makes full use of the energy storage potential of EPT groups, which provide technical support for maintaining grid security and achieving the dual-carbon target.