Benchtop Testing Method for MPPT Functionality of Solar Charge Controller

This paper presents a benchtop testing methodology to evaluate the Maximum Power Point Tracking (MPPT) functionality of solar charge controllers using the ratio of solar panel voltage to open-circuit voltage. The approach is designed for laboratory environments where controlled and repeatable conditions can be maintained. Using a solar panel equivalent circuit model and other components, the functionality of the MPPT is checked without requiring an outdoor field setup. The testing setup includes programmable DC power supplies, diodes, resistors, rechargeable batteries to emulate solar panels, multimeters for data acquisition, and a battery for load charging. Experimental results from tests on commercially available solar charge controllers demonstrate the accuracy and reliability of the proposed method, with results showing a ratio k solar model voltage with MPPT to open circuit voltage for MPPT controllers between 0.73 and 0.85, and for PWM controllers between 0.9 and 0.95.