Autonomous Dynamic Adaptability System to Maintain Irradiance Levels in a Steady-State Solar Simulator

Abstract

This paper presents the design of an autonomous dynamic adaptability system (ADAS) for maintaining the irradiance levels of a steady-state xenon arc lamp solar simulator (SS). The solar simulator is used to carry out indoor testing and accelerated age tests on photovoltaic (PV) cells at the Fort Hare Institute of Technology (FHIT). The ADAS was designed primarily for two reasons: Firstly, to maintain a set irradiance level, irrespective of external effects which may cause unintended irradiance drift or fluctuations, while carrying out indoor tests. Secondly, to achieve the solar simulator set point quicker, thus reducing temperature build up on the target area. At a cold start, the SS runs at 20% of its rated current (145 A). At 20% of 145 A, the simulator gave an irradiance of 145.97 Wm⁻² with a non-uniformity of 1.02%, and a cell surface temperature of 24.9 °C. At 50%, the simulator produced irradiance of 501.30 Wm⁻², with a non-uniformity of 1.53% and a cell surface temperature of 25.0 °C. The irradiance of 1000 Wm⁻², with a non-uniformity of 3.26% and a cell surface temperature of 25.9 °C, was achieved at 90% of the rated current. From the results obtained, the ADAS demonstrates that it can reliably operate the SS with very minimal human–machine interaction. Through the autonomous dynamic adaptability, set irradiance levels are maintained in a steady-state solar simulator once the user supplies operational set points via the supervisory control and data acquisition (SCADA) interface.