Vol.:(0123456789) 1 3 Journal of Control, Automation and Electrical Systems https://doi.org/10.1007/s40313-019-00562-y Design and Analysis of 2dof‑PID Controller for Frequency Regulation of Multi‑Microgrid Using Hybrid Dragonfy and Pattern Search Algorithm Sonalika Mishra 1  · Ramesh Chandra Prusty 1  · Sidhartha Panda 1 Received: 28 September 2019 / Revised: 13 December 2019 / Accepted: 29 December 2019 © Brazilian Society for Automatics--SBA 2020 Abstract This research work proposes a hybrid dragonfy algorithm and pattern search (hDA-PS) technique to optimize the parameters of two-degree-of-freedom proportional integral derivative controller (2dof-PID) for load frequency control of multi-microgrid (MG) system. The multi-MG contains power pool of photovoltaic (PV), wind turbine (WTG) and diesel engine generator along with diferent energy storage devices like battery energy storage system and fywheel energy storage system. The fre- quency control problem under the infuence of stochastic disturbance condition is formulated as an optimization problem, and hDA-PS is implemented to search for the optimal controller parameters. To demonstrate the supremacy of the proposed 2dof-PID controller, the performances of 2dof-PID controller are compared with conventional PID and PI controllers. A comparative study with particle swarm optimization, genetic algorithm and dragonfy algorithm is done to justify supremacy of hDA-PS algorithm. Keywords Microgrid · Load frequency control · Two-degree-of-freedom PID controller · Hybrid dragonfy and pattern search algorithm 1 Introduction Microgrid is an interconnected power system of several distributed generators. It is established especially in remote areas where electricity supply using utility grid is too costly and unreliable. Due to its environmental benefts, electrical power generation from renewable energy sources is encour- aged (Olivares et al. 2014; Davison et al. 2017). These renewable energy sources include wind energy, solar energy, tidal energy, fuel cell, geothermal energy, diesel engine gen- erators, etc. Wind energy and solar energy depend on climate condition; thus, they cannot participate in MG control (Díaz 2013). Besides this, energy storing elements such as battery energy storage systems (BESS) and fy wheel energy storage systems (FESS) are equipped in the microgrid to consume power more judiciously (Faisal et al. 2018; Blaabjerg and Ionel 2017). MG can operate in two modes, i.e., islanded mode and grid-connected mode. In grid-connected mode, the voltage and frequency variations are controlled by util- ity grid whereas in isolated mode regulation is done through solar and wind energy compensation which is a highly trou- blesome task (Karami et al. 2016). This results in generation demand mismatch which may lead to MG black out. In order to achieve a reliable operation of MG, it is highly essential to maintain the balance between generation and demand, for which intelligent controllers are required (Khorsandi et al. 2016). The performance of practical real-world microgrid systems sufers due to the presence of noise causing volt- age and frequency deviations. Thus, a controller should be designed in sight of these disturbances to continuously monitor the load frequency distraction of MG. For second- ary load frequency control, intelligent control, adaptive control, model predictive control and H ∞ control have been developed in the literature (Bevrani et al. 2012; Khooban et al. 2016; Pahasa and Ngamroo 2014; Goya et al. 2011). For a two-area system with nonlinearity, type II fuzzy PID controller was tuned with I-SSO technique in Sahu et al. (2018). In a recent work, Jaya algorithm-optimized fuzzy PI-PD controller was proposed for microgrid load frequency control (Gheisarnejad and Khooban 2019). The literature * Ramesh Chandra Prusty ramesh.prusty82@gmail.com 1 Department of Electrical Engineering, VSSUT, Burla, Odisha 768018, India