Robust Optimal Reactive Power Dispatch With Feedback and Correction Against Uncertainty of Transmission Line Parameters

The performance of optimal reactive power dispatch is affected by the uncertainty of transmission line parameters (i.e., resistance, reactance, and shunt admittance). To address this problem, a basic robust optimization (BRO) model is presented, where the uncertainty of transmission line parameters is modeled by using an uncertainty set. However, the BRO model tends to return an overconservative solution. Motivated by this, an improved robust optimization model with feedback and correction (FCRO) is proposed to mitigate the conservativeness of the BRO model. The FCRO procedures replace the excessively strict constraints by the constraints represented by increment, which are less strict, and thus improve the performance of robust optimization. This improvement does not need the detailed information about uncertain data, such as the probability distribution functions. Moreover, indicators are proposed to evaluate the performance of the proposed models in terms of robustness and optimality quantitatively. The simulation results show the robustness of the BRO and FCRO models to the uncertainty of transmission line parameters, and substantiate the benefit of the FCRO model in improving the optimal fitness value. Besides, the results also verify the effectiveness of the indicators on evaluating the models.