Energy Management Strategy of Urban Rail Energy Storage System Considering Life Assessment of Train Converter

The reliability of the bidirectional converter plays an important role in the energy storage system. However, the power devices that make up the converter are prone to failure under complex operating conditions. Therefore, how to extend the service life of devices in this case becomes a tricky problem. Due to the typical intermittent, random, and fluctuating nature of train regenerative braking energy, only relying on capacity allocation to extend device life is easily limited by actual operating conditions. Meanwhile, most energy management strategies tend to focus on only two factors: economic cost and energy savings. Therefore, this paper proposes an energy management strategy that considers the lifetime of the energy storage converter device. The objective function of the energy management strategy including device life and systematic evaluation indicators is then established. Taking the actual line conditions as a case, the bald eagle search (BES) is used to optimize the objective. This method can lengthen the IGBT device lifetime and reduce the economic cost while achieving a good energy saving rate and voltage stabilization rate. Its effectiveness and feasibility are verified by simulations under different arithmetic cases.