城轨交通牵引供电系统参数与储能系统容量配置综合优化

Synthetic Optimization of Traction Power Parameters and Energy Storage Systems in Urban Rail Transit

在城轨交通中安装地面式超级电容储能系统将有效回收列车再生制动能量,降低系统运行能耗。各个变电所、牵引/制动列车与储能系统通过牵引网进行实时能量交互,组成一个复杂的多能源耦合系统,因此,为了提高牵引供电系统的整体能量效率,减少投资成本,该文提出供电系统参数与储能系统容量配置综合优化方法。首先建立不同列车运行场景的等效电路模型,分析变电所空载电压和制动电阻启动电压对变电所、牵引/制动列车与储能系统之间能量传递效率与有效传输距离的影响;其次,建立以系统能耗和配置成本为目标的多目标优化问题,将NSGA-II优化算法与城轨牵引供电潮流计算相结合,对供电系统参数与储能系统容量配置进行综合优化;最后,基于北京地铁八通线算例,求解综合优化的帕累托最优解集。结果表明,相比于单一储能系统优化,综合优化在投资成本相近的情况下有效提高了储能系统的节能率。

The installation of stationary supercapacitor energy storage systems in urban rail transit will effectively recover the regenerative braking energy of the trains and reduce the energy consumption of the system.The substations,powering/brake trains and energy storage systems(ESSs)conduct energy interactions in real time through traction networks,and constitute a complex multi-energy coupling system.Therefore,in order to improve the overall energy efficiency and reduce investment costs,a synthetic optimization method for power system parameters and ESS capacity configuration is proposed in this paper.Firstly,the equivalent circuit models for different train operation scenarios are established,and the influence of no-load voltage and the starting voltage of the braking resistor on the energy transmission efficiency and effective distance between the substations,trains and ESSs is analyzed;Secondly,a multiobjective optimization problem considering energy consumption and investment cost is established,and the NSGA-II optimization algorithm is combined with the traction power flow calculation to solve the problem.Finally,a case study based on Beijing Metro Batong line is presented,and the pareto optimal solution is obtained with the synthetic optimization method.Results show that in comparison with ESSonly optimization,the energy saving rate is effectively improved with the synthetic optimization.