Quasi-oppositional harmony search algorithm and fuzzy logic controller for load frequency stabilisation of an isolated hybrid power system

The studied isolated hybrid distributed generation (IHDG) model of this paper consists of a wind turbine generator and a diesel engine generator. This work presents a study for improving both frequency and power deviation profiles of the studied IHDG model with the help of capacitive energy storage (CES) unit. A novel derivative-free meta-heuristic method, termed as quasi-oppositional harmony search (QOHS) algorithm, is applied to determine the optimal frequency and power deviation responses by tuning the tunable parameters of the studied IHDG model. The two fuzzy logic controllers (FLCs) are used (one at diesel unit and the other at wind generator side) to generate the output levelling frequency and power command. Each fuzzy control has two inputs, either frequency or power deviation and their respective derivatives. The two proposed FLCs are designed with QOHS algorithm for the studied CES equipped IHDG model. Performance study of the model has been carried out under different perturbation conditions. The results presented in this study demonstrate that minimum frequency and power deviations have been achieved by using the two proposed FLCs for the CES equipped studied IHDG model.