Читать книгу Smart Charging Solutions for Hybrid and Electric Vehicles - Группа авторов - Страница 39

The centralized control system for smart charging systems demands robust communication infrastructure. In a centralized control, necessary data is transmitted from each connected entity to the central controller. The controller performs decision making by determining the optimal solution considering constraints of both the EV user and the utility grid. The solution can be related to the direction of power flow, electricity cost, allowable charging rate, scheduling of charging and discharging of EVs, and power management. The central control, in a few cases, is supported by the necessary algorithms that process the data. The processing of data includes error check, relevant parameter estimations, data storage, and analysis. Nonetheless, the centralized control system determines solutions or makes decisions considering information from the entire system [9, 10]. A schematic of the centralized controller is shown in Figure 1.5. Each of the entities shown connected by dotted lines depicts communication links.

The major drawback of the central controller in a smart charging system is an optimization problem. The optimization problem becomes very large and complex as it involves numerous parameters from different entities. The controller’s failure in the centralized control system will result in a complete halt in operation or incur huge losses to the connected components. Further, scalability is another challenge when the optimization problem exceeds the constraints, such as the maximum number of EVs or charging stations [72-74]. The drawbacks of the centralized controller are outfitted by adopting hierarchical control architecture. Several controllers are deployed to administer a particular function. In contrast, the central controller is given the responsibility to monitor and perform load demand response. The hierarchical architecture resulted in reduced computational requirements [75, 76]. However, the risk of a negative impact on the smart charging system due to centralized control is not largely reduced.

Figure 1.5 Schematic of centralized controller in smart charging architecture.