An excellent operating point tracker of the solar-cell power supply system

When the solar array is used as an input power source, the excellent operating point tracker is often employed to exploit more effectively the solar array as an electric power source and to obtain the maximum electric power at all times even when the light intensity and environmental temperature of the solar array are varied. Usually, the excellent operating point is determined by computing the electric power from the solar-array power supply with a microcomputer, digital signal processor, etc. However, such a method has the following problems: 1) complex control-circuit configuration; 2) high cost; and 3) low control speed. From this viewpoint, this paper proposes a new excellent operating point tracker of the solar-cell power supply system, in which inexpensive p-n junction diodes are used to generate the reference voltage of the operating point of the solar array. Using the proposed method, the high degree of the solar-array excellent point tracking performance can be obtained even when the light intensity and environmental temperature of the solar array are varied. Furthermore, this paper provides the operation principle, design-oriented analysis, etc., of the proposed solar-cell power supply system.