Integration of electric vehicles (EVs) into the power systems has been a concern for distribution system operators due to their impacts on several aspects of power system operation, such as congestion management, power quality, voltage regulation, and peak time changing. In this paper uncertainty parameters such as charging time, traveled distance, and plug-in location of EVs are considered and their effects on the optimal daily operation of microgrids (MG) are discussed. A power system, including geographically-adjacent quasi-independently controlled MGs, each of which has a different operation objective function (OF) is modeled in this paper. A set of socioeconomic OFs i.e. minimum purchase power from the main grid, maximum usage of green power, and minimum Expected Energy Not Supplied (EENS) are considered for each MG which appear in the optimization process with different weights based on the MG policy. The effect of EV integration into the Multi Microgrid System (MMS) is also investigated in this paper and the performance effectiveness of different operation management policies against EV integration is discussed.