Performance Analysis of Non-Isolated DC-DC Boost Converter Topologies in VIPV Systems under Variable Irradiance

The adoption of Vehicle-Integrated Photovoltaic (ViPV) systems into urban electric buses improves sustainability and reduces grid dependency in public transport. However, challenges such as variable irradiance and shading conditions limit their effectiveness. This study evaluates three advanced non-isolated DC-DC converter topologies (Boost Interleaved, Quadratic Boost, and Multi-Input/Single- Output) under MPPT control using the Perturb and Observe (P&O) algorithm. Simulations were conducted in Simulink using irradiance and temperature data collected in Antofagasta, Chile. The system assumed 600 PV cells forming a 350 V string connected to a 540 V DC-Link bus powered by a 50 kWh LiFePo4 battery bank. Key metrics analyzed include voltage gain, efficiency, stability, and current ripple under realistic urban conditions. Results demonstrate that Interleaved Boost exhibits high efficiency under uniform irradiance conditions, achieving stable current distribution with a low ripple of 2%. However, its performance is less robust during rapid irradiance changes. Quadratic Boost maintained a stable voltage gain in steady-state conditions and operated with a low duty cycle, reducing stress on switching components and enhancing long-term reliability. Nevertheless, it underperformed during abrupt transients due to the inherent complexity of its coupled stages, which impacted its ability to adapt to rapid system changes. The Multi-Input/Single-Output (MISO) topology effectively integrated multiple input sources and demonstrated strong performance under partial shading scenarios. However, its overall complexity and ripple management require optimization to improve efficiency in high irradiance conditions. These findings identify Interleaved Boost as the best option for stable conditions, while Quadratic Boost offers advantages in reducing component stress under steady-state operation. MISO emerges as a flexible alternative for scenarios with frequent shading. This research provides modeling insights for designing ViPV systems in urban electric buses, addressing the challenges of dynamic environments and improving sustainability in public transport.