Optimal Scheduling of Active Distribution Network Based on Demand Respond Theory

With the increasing penetration of renewable power source into the distribution network, maintaining system reliability has been a challenging issue due to the uncertainty and volatility characteristics of renewable power source. Based on the robust optimization theory, this paper proposed a multi-stage robust optimal scheduling of active distribution to maintain the voltage within the allowed range as well as develop the operation of distribution network. This methodology applies the demand responds method into the model in order to make full advantage of elastic load adjustment. The proposed method is accomplished in three phases. In the first stage, in order to determine the uncertain parameters, renewable energy output uncertainty is described by uncertain set. Meanwhile, the extreme scenario method is adopted to cut down the field of sets. In the second stage, the elastic load is used to moderate the load fluctuation by applying demand respond theory. In the third stage, based on the bi-level planning, distributed generation's (DG's) reactive output adjustment cooperates with traditional voltage regulation method, which reduces the regulating times of switching device operations and system network loss. Furthermore, the economy and stability of system operation improve significantly. Finally, the efficiency of the built model is analyzed using the PG&E 69-bus system.