Solar Climber: A Problem Solving Approach in Power Electronics and Control Systems Teaching

Solar climber is a model of the elevator powered by solar irradiation. The concept of the solar climber is to take enough energy from the sun to move load to arbitrary height without use of wires to transfer energy. Climbing is performed on the cable realized using the advanced low weight and high strength materials such as carbon nanotubes. Such a system consists of PV (Photo Voltaic) modules, MPPT (Maximum Power Point Tracking) DC-DC converter, and drives. Control system of the solar climber is built by using PLC (Programmable Logic Controller), allowing data transfer from climber to ground SCADA (Supervision Control and Data Acquisition) system and back. During the project student faces some challenges such as power source to weight trade off, power conversion efficiency, energy to climbing speed ratio trade off, data transfer and movement control. Main focus of education is to understand the power transfer concept from renewable energy source to load and use of power electronics in searching for optimum operating point, and to build a control system as well as MPPT algorithm by PLC. PLC software is written by software tools for industrial control system development projects and applications. Control, climb height and key electric parameters of the solar climber are visualized on personal computer by SCADA system. Main teaching outcomes of the project are experience in practical and team work, understanding energy transfer and conversion, and use of modern software process control development tools.