Modelling of a Solar Array Simulator based on Multiple DC-DC Converters

This paper presents a solar array simulator (SAS) to emulate the actual characteristics of solar arrays under different environmental conditions and load variations. SASs are essential in the evaluation of maximum power point tracking (MPPT) algorithms and their power converters. The proposed SAS adopts a modular structure where multiple voltage-controlled buck DC-DC converters are adopted. An active current distribution control is proposed to achieve a balanced current in the parallel connected converters. The effect of the proposed controller on the circulating current impedance is analysed, and the controller's parameters are designed to obtain excellent current distribution and fast dynamic response. The SAS's performance is explored through a Simulink model with a variable resistor load and at different irradiance levels. The results confiun the validity of the proposal, in which excellent performance was obtained in terns of tracking the desired V-I characteristics and the current distribution between the converters.