The transition towards environmentally friendly transportation solutions has prompted a focused exploration of energy saving technologies within railway transit systems. Energy Storage Systems (ESS) in railway transit for Regenerative Braking Energy (RBE) recovery has gained prominence in the pursuit of sustainable transportation solutions. In order to achieve the dual-objective optimization of energy saving and investment, this paper proposes collaborative operation of Onboard Energy Storage Systems (OESS) and Stationary Energy Storage Systems (SESS).