Investigation of energy harvesting circuit using a capacitor-sourced buck converter for a tubular linear generator of a moball: A spherical wind-driven exploration robot

Moball is a spherical wind-driven exploration robot intended for in-situ observation of scientifically important environments, such as Arctic, Mars, and Saturn's moon Titan. Moball has three orthogonal linear generators/actuators to enable both the steering control and energy harvesting. This paper focuses on the energy harvesting circuit for the Moball's linear generator which has non-sinusoidal pulse voltage waveform. Battery charging using a capacitor-sourced buck converter is analytically and numerically investigated. The power transferred to the battery is actively regulated to maintain the stable operation. The simulation results demonstrated that stable constant current charging was achieved.