Research on optimal energy scheduling and control strategy for internal diesel-electric hybrid locomotives

To address the disadvantages of high energy consumption and significant environmental pollution associated with pure diesel locomotives, this paper takes diesel-electric hybrid locomotives as the research object, and investigates hybrid power systems primarily based on diesel generators and supplemented by power batteries, with the goal of enhancing the efficiency of system energy management. Firstly, the system topology and operating principle were analyzed, leading to the establishment of an operating model that accounts for the external characteristics of diesel generators and power batteries. The paper then presented the design of an optimal energy scheduling algorithm aimed at maximizing the service life of batteries, as well as ensuring fuel economy and power demand matching during locomotive operation. This algorithm was transformed into an optimal control model by incorporating the state of charge (SOC) of batteries as a state transition variable. Solving this model yielded the optimal output power of each power source. Furthermore, a unified control strategy of energy converters for the power sources was proposed, to ensure the real-time performance and smoothness of power output. Simulation experiments were conducted on a hardware-in-loop simulation platform for diesel-electric hybrid power locomotives in various scenarios. The results indicate the proposed strategy is effective in enhancing fuel economy, real-time performance and smoothness in dynamic response during locomotive operation. Specifically, compared with traditional rule-based methods, the energy saving index is increased by 7.84%, and the sectional running time is shortened by 4.07%.