Precise Estimation of Solar Cell Temperature using a Validated Solar Array Thermal Simulation Tool and a New Technology of using Solar Cell as Temperature Measuring Device

摘要

Solar array operating temperature is one of the most important parameter for the evaluation of the power output of the solar array throughout its mission life. For designing an efficient solar array, accurate knowledge of the temperature of the solar cell during the various phases and modes of operation of the spacecraft is necessary. This paper presents in detail the development of a Microsoft Excel based solar array thermal simulation tool. This specialized software is tailor made for solar array thermal simulation; versatile enough to simulate different operating conditions of array with a very fast response time. This tool is validated with on orbit data of various missions including Mars Orbiter Mission (MOM). The estimated temperatures are matched within 5 ℃ with the observed on-orbit temperatures. This simulator is a significant step towards the convergence between thermal and electrical models, as the inputs and assumptions used in both the models are dependent on each other. Further improvement in the temperature estimation can be achieved by validating thermal simulation tool with direct measurement of solar cell temperature. This paper also presents in detail a new technology of using solar cell itself as a temperature measuring device. In this scheme, the solar cell open circuit voltage (V_(oc)), which strongly depends on temperature, is measured. Then temperature is derived from this information of solar cell open circuit voltage (V_(oc)).