Optimal AGC with redox flow batteries in multi-area restructured power systems

This paper attempts to investigate the effect of Redox flow batteries (RFB) in Automatic Generation Control (AGC) of multi-area restructured power systems. Initially, a two-area restructured thermal power system is investigated. For the analysis, optimal AGC regulators (OARs) are designed employing performance index minimization criterion. The advantages of the OARs are shown by comparing the results with Genetic Algorithm (GA) based integral controllers for the same restructured system. MATLAB simulation results further demonstrate significant improvements in the dynamic performance of the system with RFB. System stability enhancement with OARs/RFB is outlined by conducting the system modes study. The study is additionally extended to a more realistic two-area multi-source thermal-hydro-gas restructured system with/without RFB. To add nonlinearities, appropriate generation rate constraints (GRCs) are considered for the thermal, hydro and gas plants. Results verify that OARs are able to satisfy the AGC requirement under varied power transactions taking place in an open power market. The robustness of OARs is demonstrated by sensitivity analysis, which is carried out with wide variation in initial loading, system parameters and magnitude/position of the uncontracted power demands. Finally, the study is extended to a two-area multi-source thermal-hydro power system with/without considering RFB.