We propose four different models of three-terminal quantum dot thermoelectric devices.From general thermodynamic laws,we examine the reversible efficiencies of the four different models.Based on the master equation,the expressions for the efficiency and power output are derived and the corresponding working regions are determined.Moreover,we particularly analyze the performance of a three-terminal hybrid quantum dot refrigerator.The performance characteristic curves and the optimal performance parameters are obtained.Finally,we discuss the influence of the nonradiative effects on the optimal performance parameters in detail.