Baling Fang

Synergistic and priority control for electric vehicles power allocation in participating in AGC

Large scale integration of electric vehicles (EVs) provides new ideas for power system stability and control. Connected to power grid, EVs can be taken as distributed energy storage and thus cooperate with traditional automatic generation control (AGC) units to help stabilize the system frequency and achieve energy saving. On the basis of previous researches, taking into account the influence of battery state of charge (SOC) on the maximum charging/discharging power and the charging demand of EVs users, this paper firstly expounds the AGC control system framework with the contribution of EVs. Then, coordination and priority control scheme for multiple EVs power allocation during the charging/discharging processes is discussed and the main constraints are formulated. Finally, simulations for EVs participating in a two-area interconnected power system AGC are performed. The results show that rational power allocation and effective utilization of EVs resources can be fully achieved by implementing the proposed method, so as to better improve power system stability and achieve energy saving.

Review of the impact of electric vehicles participating in frequency regulation on power grid

Electric vehicles (EVs) can act as distributed storages and loads while they are connected to the grid. Vehicle-to-grid (V2G) system can provide active power support and frequency regulation services to mitigate the intermittence of renewable energy sources (RES), and balance the loads in the grid. Through V2G technologies, EVs can provide power to the grid, which significantly improves the performance of the stability, efficiency, and reliability of power grid operation. Moreover, the participation of sufficient EVs in power grid will help diminish greenhouse gases. This paper reviewed the current studies on the participation of EVs in frequency regulation from different perspectives. The impact of V2G technologies on different power systems, and control strategies, management, incentive policy and challenges of both small-scale EV and large-scale EV were simply reviewed. At last, the future research prospect of frequency regulation with EVs was discussed.

Fractal Characteristics Analysis of Blackouts in Interconnected Power Grid

The power failure models are a key to understand the mechanism of large scale blackouts. In this letter, the similarity of blackouts in interconnected power grids (IPGs) and their subgrids is discovered by the fractal characteristics analysis to simplify the failure models of the IPG. The distribution characteristics of blackouts in various subgrids are demonstrated based on the Kolmogorov–Smirnov (KS) test. The fractal dimensions (FDs) of the IPG and its subgrids are then obtained by using the KS test and the maximum likelihood estimation. The blackouts data in China were used to demonstrate the similarity of distribution characteristics and FDs of the IPG and its subgrids. The results are consistent with the development of the power grids.

Procedure and Model of Antidisaster Differentiated Planning for a Power Distribution System

AbstractPhysical topology is essential for antidisaster and disaster recovery abilities of power systems. Focusing on preparedness of physical topology, differentiated planning has been proposed, which refers to supplying power continuously to important special loads under disaster conditions by upgrading the construction standard of the selected subsystem, as well as installing distributed generation, microgrid, or movable generation. In this paper, the specific procedure of differentiated planning in distribution system is proposed, which includes identification and prediction of special loads, analysis of current status, measures of power supply for special loads, and high-standard power grid planning. The construction standard in the procedure not only depends on the voltage class but also the power supply for special loads. Then the model is established to select the subsystem components with minimum cost increment over general planning considering disaster scenario and general scenario. To solve the...

Consumer electrical equipment asynchronous and coordinating response for frequency regulation

Demand response plays an important role in smart grid. In this paper, an asynchronous and active demand response strategy for consumer electrical equipment (CEEs) is proposed, aiming at power system frequency regulation. CEEs, if the load is non-rigid, can response to power system frequency deviation by adjusting operating parameters and power consumption actively. It is very helpful for frequency regulation of power system, especially with high intermittent power source penetration rate. The strategy adopts asynchronous response and coordinated control mode. High coordination and asynchronous response (without communications) guarantee the frequency regulation in various disturbances and avoid the secondary impact. Moreover, the more CEEs participate in response, the more advantages will achieve. According to the proposed control strategy, corresponding simulation schemes have been designed. The feasibility and effectiveness of the control strategy has been proved by simulations and contrastive analysis, such as big disturbance and continuous random disturbances in power system.