PV array simulator performance evaluation

摘要

This dissertation evaluates the performance of a 25kW PV Array Simulator based on a design from Prof. Heinrich Haberlin and his staff from the PV laboratory of the Berne University of Applied Sciences, in Burgdorf, Switzerland. The simulator was set up and is operated by ResLab, based at Murdoch University. The device has a power rating of 25kW, an open circuit voltage of up to 750V, and a short circuit current of up to 40A. The design and concept of the simulator replicates the operations of an actual PV array. Incorporated in its controls are eight IV curves of different fill factors that were configured to portray different cell technologies. The development of such a test device was initiated when PV applications such as inverters required a device that could repeatedly produce consistent testing conditions, as well as a platform that could perform precise MPPT measurements. ududFirst the study goes into understanding the control options of the simulator in terms of its IV curve production abilities. The initial familiarization stage was conducted with technical manuals and a brief session with Andrew Ruscoe who was involved in the development of the simulator. Through that and further research, it was comprehended that the Main Control, which is the control responsible for all IV curve generations, is designed electronically to follow the single diode model circuit of the PV array. A mathematical aspect has been included in the thesis to confirm the operation of Main Control. Designers of the simulator expanded on this theory by utilising individual sets of diode strings with different configurations, which developed certain fill factors when a voltage is applied. ududOperation of the PV Array Simulator commenced after the understanding of the controls was established. The eight IV curves of varying fill factors were captured and observed. As part of the study, the curves were classified against the three most common cell technologies. The performance of the simulator was evaluated using different test conditions to observe its stability. It was proven through these tests, as well as documentations from past tests that the simulator was very stable even when it was made to operate at its threshold limit.ud udAs the varying fill factors were obtained by the different configuration of diode strings, a study was focused on developing a basis or pattern associated with the formation of different classifications of diodes in series. The diode strings found in the simulator were replicated and reverse engineered.