No abstract

Abstract-A procedure for measuring the overheating temperature (AT) of a p-n junction area in the structure of photovoltaic (PV) cells converting laser or solar radiations relative to the ambient temperature has been proposed for the conditions of connecting to an electric load. The basis of the procedure is the measurement of the open-circuit voltage (Voc ) during the initial time period after the fast disconnection of the external resistive load. The simultaneous temperature control on an external heated part of a PV module gives the means for determining the value of Vb c at ambient temperature. Comparing it with that measured after switching OFF the load makes the calculation of AT possible. Calibration data on the Voc = f(T) dependences for single-junction AlGaAs/GaAs and triple-junction InGaP/GaAs/Ge PV cells are presented. The temperature dynamics in the PV cells has been determined under flash illumination and during fast commutation of the load. Temperature measurements were taken in two cases: converting continuous laser power by single-junction cells and converting solar power by triple-junction cells operating in the concentrator modules.

Abstract.A new method has recently been proposed by us for accurate measurement of the solar cell temperature in any operational regime, in particular, at a maximum power point (MPP) of the I-V curve ( - . In the present work, we have considered a practical case, when a solar cell is heated not only by absorption of light incident upon its surface (called "photoactive" absorption of power), but also by heat transferred from structural elements surrounding the cell and heated by absorption of direct or diffused sunlight ("non-photoactive" absorption of power with respect to a solar cell). This process takes place in any concentrator module with non-ideal concentrators. Low overheating temperature of the p-n junction (or p-n junctions in a multijunction cell) is a cumulative parameter characterizing the quality of a solar module by the factor of heat removal effectiveness and, at the same time, by the factor of low "non-photoactive" losses. MPP

No abstract

No abstract