Nowadays the number of dispersed generators (DG) is growing rapidly. This change greatly influence the power system dynamics. A distribution network, where DG are connected to the grid, cannot be considered as passive any more. So in future it will not be possible to use simple equivalents of distribution networks for power system dynamic modeling as it was done before. In dynamic studies the whole power system cannot be represented in detailed manner because of huge system dimension. Therefore special techniques have to be applied for aggregation and order-reduction of distribution networks with DG. In this paper brief review of existing techniques has been given, and after that dynamic reduction using Hankel norm approximation has been performed for a part of a distribution network consisting of DG of different types.@en