Hardware Implementation and Performance Analysis of a Current Sensor Free MPPT for High Performance Vehicle Solar Arrays

Abstract

A Maximum Power Point Tracker has been previously developed for the single high performance triple junction solar cell for hybrid and electric vehicle applications. The Maximum Power Point Tracking MPPT) control method is based on the Incremental Conductance (IncCond) but removes the need for current sensors. This paper presents the hardware implementation of the Maximum Power Point Tracker. Significant efforts have been made to reduce the size to 18 mm x 21 mm (0.71 in x 0.83 in) and the cost to close to $5 US. This allows the MPPT hardware to be integrable with a single solar cell. Precision calorimetry measurements are employed to establish the converter power loss and confirm that an efficiency of 96.2% has been achieved for the 650-mW converter with 20-kHz switching frequency. Finally, both the static and the dynamic tests are conducted to evaluate the tracking performances of the MPPT hardware. The experimental results verify a tracking efficiency higher than 95% under three different insolation levels and a power loss less than 5% of the available cell power under instantaneous step changes between three insolation levels.