Multiphase Interleaved DC-DC Converters for Impedance Spectroscopy in Photovoltaic Diagnostics: Findings from SPICE Simulations

The effective and low-cost diagnosis of photovoltaic (PV) systems is essential for ensuring their long-term reliability and efficiency. Impedance Spectroscopy (IS) has emerged as a promising tool for PV diagnostics. For IS to be a cost-effective solution, its implementation should minimize additional hardware, rendering the utilization of existing power converter topologies ideal. This paper investigates the integration of IS into DC-DC converters, specifically focusing on multiphase interleaved designs. These converters regulate energy harvesting around the Maximum Power Point (MPP) while simultaneously generating sinusoidal stimuli to acquire impedance spectra. Various configurations were analyzed to assess their behavior and control strategies for minimizing measurement interference. A detailed SPICE model was developed to evaluate design options, and a prototype was implemented to validate the practical feasibility of IS integration. Preliminary simulations and prototype testing confirm that IS can be successfully integrated into interleaved boost converters, demonstrating its potential for accurate spectral acquisition. Future research will focus on refining converter behavior, optimizing IS signal generation, and developing application-specific designs to further enhance performance.