DOGPHOSS is a project dedicated to the development of methodologies and devices for the online diagnosis of photovoltaic generators and energy storage systems, with the aim of transferring Impedance Spectroscopy (IS) from a technique mainly used in laboratory settings to a tool suitable for real operating conditions.
Impedance spectroscopy makes it possible to obtain information on the internal state of a device by applying small perturbations. In the DOGPHOSS project, this technique was applied to the diagnosis of energy systems, with particular attention to state-of-health estimation (SoH), early anomaly detection, and support for predictive maintenance.
Objectives
The overall aim of the project is to develop a high-performance diagnostic tool for estimating the state of health of energy devices, capable of operating without modifying the original architecture of the system and with minimal impact on its normal operation. The tool is conceived as a modular platform composed of a measurement and acquisition module, an excitation module, a management unit, and configurable diagnostic algorithms.
Expected results
The most significant outcome of the project is the transition from a diagnostic technique typically confined to the laboratory to a solution that can be used in the field, where photovoltaic generators and energy storage systems operate under load and in variable conditions. From a technological standpoint, the project aims to develop a modular, scalable diagnostic device with low operational impact.
The contribution of the Electrical and Electronic Measurements research group at Politecnico di Bari focused on the measurement chain and, in particular, on the Front-End Module as the metrological core of the platform: a module capable of accurately measuring voltage and current, ensuring synchronization between signal generation and acquisition, operating over frequency ranges compatible with impedance spectroscopy, and producing reliable data for diagnosis.
Results achieved
The Politecnico di Bari unit defined the measurement requirements for photovoltaic systems and batteries, assessing through models and simulations the effect of measurement errors on impedance spectra and experimentally verifying voltage and current transducers suitable for detecting small signal components superimposed on higher DC levels.
On this basis, a prototype based on the AD5941 analog front end and ESP32 microcontroller was developed and validated. The firmware enables the configuration of measurement sequences, waveform acquisition, frequency-domain processing, and communication with a supervisory system.
Tests on rechargeable LiPo batteries demonstrated the system’s ability to generate suitable excitation signals, acquire voltage and current measurements, perform repeatable sweeps, and produce data useful for reconstructing impedance spectra.
The developed prototype and its firmware therefore represent a directly reusable result for experimental measurement campaigns on batteries and photovoltaic devices.
The expected impact of the project lies in making advanced diagnosis of energy systems more accessible, reducing dependence on expensive laboratory instrumentation that is not well suited to field installation.
In perspective, DOGPHOSS results can contribute to improving the reliability, safety, and lifetime of plants, supporting a more efficient management of renewable energy sources and storage systems.