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This project is a massive near-infrared (NIR) search for variable stars inhighly reddened and obscured open cluster (OC) fields projected on regions ofthe Galactic bulge and disk. The search is performed using photometric NIR datain the $J$-, $H$- and $K_s$- bands obtained from the Vista Variables in theV\'ia L\'actea (VVV) Survey. We performed in each cluster field a variabilitysearch using Stetson's variability statistics to select the variablecandidates. Later, those candidates were subjected to a frequency analysisusing the Generalized Lomb-Scargle and the Phase Dispersion Minimizationalgorithms. The number of independent observations range between 63 and 73. Thenewly discovered variables in this study, 157 in total in three different knownOCs, are classified based on their light curve shapes, periods, amplitudes andtheir location in the corresponding color-magnitude $(J-K_s,K_s)$ andcolor-color $(H-K_s,J-H)$ diagrams. We found 5 possible Cepheid stars which,based on the period-luminosity relation, are very likely type II Cepheidslocated behind the bulge. Among the newly discovered variables, there areeclipsing binaries, $\delta$ Scuti, as well as background RR Lyrae stars. Usingthe new version of the Wilson & Devinney code as well as the "Physics OfEclipsing Binaries" (PHOEBE) code, we analyzed some of the best eclipsingbinaries we discovered. Our results show that these studied systems turn out tobe ranging from detached to double-contact binaries, with low eccentricitiesand high inclinations of approximately $80^{\circ}$. Their surface temperaturesrange between $3500$K and $8000$K.

New variable stars discovered in the fields of three Galactic open clusters using the VVV Survey