Vendoti Suresh, Sekhar A Hema, Bharadwaja A V, Kommula Bapayya Naidu, Sateesh Rayala, Prabhakar S, Arunkumar M, Yaping Cui
School of Engineering, Electrical and Electronics Engineering Department, Godavari Global University, Rajahmundry, A.P., India.
Electrical and Electronics Engineering Department, VEMU Institute of Technology, Chittoor, A.P., India.
Sci Rep. 2025 Apr 16;15(1):13192. doi: 10.1038/s41598-025-96704-1.
In order to increase the utilization rate of regenerative braking energy, reduce the operation cost and improve the power quality of traction power supply system in high-speed railway. This paper presents a grid-connected improved SEPIC converter with an intelligent maximum power point tracking (MPPT) strategy tailored for energy storage systems in railway applications. The proposed system enhances power conversion efficiency and stability by integrating an optimized SEPIC topology with an adaptive MPPT algorithm. The solar PV system supplies voltage to the inverter via an Improved SEPIC converter. A smart MPPT technique is used to regulate the DC bus voltage and control the Improved SEPIC converter. The wind energy conversion system (WECS), featuring a DFIG, performs AC-DC conversion with the help of a PWM rectifier, and the rectifier is managed by a PI controller. The converter's output is fed to the grid through a single-phase VSI, which converts the DC voltage into AC. An LC filter is used to improve the inverter's output. The combined power from the PV and WECS sources is stored in the battery through a bi-directional battery converter. Power from both the battery and the AC output from the single-phase VSI is then injected into the power grid, which supplies energy to the train for its operation. Compared to conventional SEPIC converters, the improved topology reduces voltage stress by 25% and increases efficiency by 97%, ensuring reliable energy storage and grid synchronization. Furthermore, the intelligent MPPT strategy improves tracking speed by 37.5% under dynamic conditions, leading to enhanced energy utilization and reduced response time. Simulation and experimental results (DSPIC30F4011 controller) validate the superior performance, demonstrating its potential for real-world railway applications.
为了提高再生制动能量的利用率，降低运营成本并改善高速铁路牵引供电系统的电能质量。本文提出了一种并网改进型SEPIC变换器，其具有专门为铁路应用中的储能系统量身定制的智能最大功率点跟踪（MPPT）策略。所提出的系统通过将优化的SEPIC拓扑与自适应MPPT算法相结合，提高了功率转换效率和稳定性。太阳能光伏系统通过改进型SEPIC变换器向逆变器供电。采用智能MPPT技术来调节直流母线电压并控制改进型SEPIC变换器。具有双馈感应发电机（DFIG）的风能转换系统（WECS）借助PWM整流器进行AC-DC转换，并且该整流器由PI控制器管理。变换器的输出通过单相电压源逆变器（VSI）馈入电网，该逆变器将直流电压转换为交流电压。使用LC滤波器来改善逆变器的输出。来自光伏和WECS源的组合功率通过双向电池变换器存储在电池中。然后，来自电池的功率和单相VSI的交流输出都注入到电网中，电网为列车运行提供能量。与传统的SEPIC变换器相比，改进后的拓扑将电压应力降低了25%，效率提高到97%，确保了可靠的能量存储和电网同步。此外，智能MPPT策略在动态条件下将跟踪速度提高了37.5%，从而提高了能量利用率并缩短了响应时间。仿真和实验结果（DSPIC30F4011控制器）验证了其卓越性能，证明了其在实际铁路应用中的潜力。
