[en] The stabilization of the beams of large-sized multi-beam hybrid mirror antenna (MBHMA), the reflector profile of which is subject to distortion due to changing operational factors, is a complicated technical task. One of the ways to maintain energy efficiency of the satellite communications system in these circumstances is to adapt the amplitude-phase distribution of the clusters of the antenna array to random deformations of the reflector. By statistical modeling, the potentially achievable characteristics of the system are evaluated. Three variants of adaptation of cluster excitation were modeled: a) for fixed clusters, b) for adaptation of excitation, c) for adaptation of weights and position of clusters, d) for adaptation of weights and cluster configurations. For multivariate calculations, we use the simplified model of MBHMA that we have proposed. Comparison with calculations in Ticra Grasp environment confirmed the correctness of the model. Not only radiation patterns, but also focal spots on the antenna array we calculated to determine the rational composition of cluster elements and the vector of their excitation coefficients. Beams gain within the service area for reflector deformations were the subject of analysis. The studies showed that gain decrease can be reduced to 0.1 … 0.2 dB instead of 1.6 dB taking place without adaptation. (paper)