Dynamic models of real-time markets are important since they lead to additional insights of the behavior and stability of power system markets. The main topic of this paper is the analysis of real-time market dynamics in a novel power system structure that is based on the concept of autonomous networks. The concept of autonomous networks (AN), also briefly presented in the paper, is an approach that enables large-scale integration of dispersed generation in a market-based power system. A realistic, decentralized provision of power imbalance ancillary services is proposed and analyzed. It is based on control of power flow deviations among autonomous networks and is shown to have a stabilizing effect for the real-time energy market.