Over the past decade, pq regulation schemes for a single-controllable active distribution network (adn) using coordination among a network of virtual synchronous generators (vsgs) have been proposed. However, considering the variable nature of intermittent renewable energy sources (iress), coupling a cluster of iress with the point of common coupling (pcc) of adn could inflict transient issues for the power management of the whole adn. To counter these challenges, the proposed study has three main objectives: 1) to propose a modified mathematical model that represents the apparent resistance-reactance at the pcc of adn in relation to the pq coordination among the network of vs.Gs; 2) to utilize the proposed model for deriving a $\mu$ synthesis-based robust controller that overcomes the uncertainty in the moment of inertia response of all the vs.Gs; 3) and to present the stability and performance analysis of the proposed controller validated under model uncertainty. Validation of the proposed method and its comparison to the state-of-the-art methods in matlab/simulink environment confirms that the proposed method significantly minimizes the impact of disturbances on the power management of the whole adn.