一定温差下，热电模块( TEM) 的最大输出功率可以通过开路电压和短路电流进行估算．但开路和短路之间存在开路到短路及短路到开路两种切换模式，必有两组开路电压和短路电流． 相同温差下，两种切换模式估算出的TEM 最大输出功率存在差异，且差值随TEM 冷热端温差变化．文中对此现象进行了理论分析，指出造成此差值的主要原因在于两种切换模式下的电流不同，从而导致TEM 产生的电动势不同，并提出了减小该差值的计算方法．经实验验证，该计算方法提高了TEM 最大输出功率的估值准确度．

The maximum output power of a thermoelectric module ( TEM) can be estimated according to the opencircuit voltage and the short circuit current under certain temperature difference. As there are two switch modes,namely the mode from open to short circuit and the mode from short to open circuit,there may exist two groups ofopen circuit voltage and short circuit current.Consequently,under identical temperature difference,the maximumoutput powers of TEM in the two modes are different from each other,and the difference varies with the temperaturegap between the hot and the cold sides.This paper deals with such power difference based on theoretical analysisand points out that the power difference is due to the variable electromotive potential caused by the current varyingwith the switch mode.Moreover,a computation method to reduce the power difference is put forward.Experimentalresults show that the proposed method greatly improves the estimation accuracy of maximum output power of TEM.