能源互联网框架下多端口能量路由器的多工况协调控制

多端口能量路由器是整合光伏、储能以及电动汽车充电桩的有效拓扑结构。在不同端口进行能量路由时,涉及多工况运行,无缝工况切换是一大难点。在能源互联网框架下,采用分层控制,使得能量路由器在电网调度、并离网、电动汽车接入切除等工况下都能够协调运行,从而实现工况的无缝切换。微网控制层采用集中式控制,维持各工况下系统整体能量平衡,既能与上层调度层交互,响应调度;也能与下层本地控制层通信,即采样各端口的状态信息,计算储能、充电桩的充放电电流给定值。本地控制层中光伏、电压源型变换器端口采用分布式控制,降低通信带宽;储能、充电桩端口采用所提的基于电流跟踪的新型下垂控制方法,精准传输所需功率,并控制直流母线电压稳定。最后,通过MATLAB仿真验证了所提统一协调控制策略的有效性。

Coordinated Control of Multiple Operation Conditions for Multi-port Energy Router in Energy Internet Framework

Multi-port energy router is an effective topology structure of integrating photovoltaic, energy storage and charging pile of electric vehicle. When energy routing is performed at different ports, the energy router involves multiple operation modes. Therefore, seamless mode transition is a major difficulty. In the Energy Internet framework, hierarchical control of multi-port energy router enables coordinated operation to achieve seamless mode transition in power grid dispatching, grid-connected/off-grid conditions or in the condition that electric vehicle is integrated or cut off. The control layer of micro-network adopts centralized control to maintain the overall energy balance of the system with various operation modes, which interacts with the upper-level scheduling layer to respond to scheduling, communicates with the lower-level local control layer by sampling the state information of each port, and calculates the references current of energy storage and the charging pile. In the local control layer, ports of photovoltaic and voltage source converter adopt distributed control to reduce the communication bandwidth. Ports of energy storage and the charging pile adopt the proposed new droop control strategy based on current tracking to accurately transmit the required power and control the voltage stability of DC bus. Finally, the effectiveness of the proposed unified coordinated control strategy is verified by MATLAB simulation.