High-Reliability Solar Array Regulator Proposal for Harsh Environments

This paper presents a fault-tolerant solar array regulator intended for isolated applications where reliability is critical. For this, it is proposed an architecture similar as the one used in the space sector, in which reliability and fault tolerance are essential. The proposed regulator is composed of six phases, each one powered from a string of 20 solar cells. Each of these phases has a Buck converter controlled by a double control loop, that can control both the voltage in the batteries and the power generated in the solar arrays. To maximize this extracted power, each phase has a maximum power point tracker (MPPT) circuit. In addition, the converter has a redundant over voltage protection (OVP) system that powers off all the converters in case of battery overvoltage. In addition, this regulator is tolerant to the failure of any of its components. This work describes the design of each of the developed subsystems that compose the regulator, as well as the implementation of a 60W prototype and the tests carried out.