Presentation of an H _∞ based frequency control for islanding provisional microgrid consisting of hybrid AC / DC microgrid

Abstract

Provisional microgrids create by the connection of two beside microgrids to achieve economic benefits. So far, there have been many reviews on AC microgrids. However, due to the many advantages of DC microgrids, they cannot be ignored. To achieve the advantages of both AC and DC microgrids, hybrid structures were considered. The subject of controlling hybrid microgrids is relatively more complex. Due to the variable nature of the distributed generation resources, this complexity in islanding conditions is even greater than normal conditions. This paper proposes a robust frequency control for islanding provisional microgrid including hybrid AC/DC part as a master microgrid and AC conventional part as a slave microgrid. As authors are aware, there are no scientific reports for frequency control of the proposed microgrid. One of the issues affecting the performance of this controller is the choice of weighting functions. To achieve optimal controller, an algorithm is used to determine the best weighting functions according to the way the controller works, and by examining the sensitivity functions. Finally, simulations were performed to investigate the performance of the controller and the results of using this controller for this microgrid were examined. K E Y W O R D Shybrid microgrid, islanding mode, robust frequency control, uncertainty parameters, weighting functions | INTRODUCTIONA microgrid is one of the categories in which the generation process, consumption, and energy storage are practicable and useful simultaneously. In this context, generation and storage operations are mixed. 1 Electric loads, generators, and storages can be AC or DC type. Over the years, power grids have evolved to use AC structure. However, with the

Recent control techniques and management of AC microgrids: A critical review on issues, strategies, and future trends

“…In addition, without communication control links are important to connect remote inverters. This control level aims to maintain output voltage regulation and active power 107,116‐118 . The droop control levels are classified in subsections are discussed below.…”

“…The optimization control technique is also known as MPC which resolves the uncertain problem in both the load and DG units. However, this technique is used for small‐microgrid for a limited number of load‐shedding, allowing cost‐saving and better performance with a simplified calculation 116 . The existing control level consist of important features like improved power quality, restored frequency, minimized average voltages, and increased output voltage amplitude due to primary‐level actions in MG.…”

Control strategies for permanent magnet synchronous generator‐based wind turbine with independent grid‐forming capability in stand‐alone operation mode

“…In the stand-alone microgrids with high renewable penetration, existing studies [13][14][15][16] adopted the classical droop-based control methods for enhancing the frequency and voltage stability. Moreover, previous studies [17][18][19] also proposed effective nonlinear controllers suitable for stand-alone microgrids. However, the coordination designs between RSC and GSC of PMSG-based WT were not given in References 17-19.…”

“…The researchers continued to explore the possibility of PMSG-based WT integrating into stand-alone microgrids in References 20 and 21. Unfortunately, in above so-called stand-alone microgrids, [13][14][15][16][17][18][19][20][21] there still exist external power supplies or the energy storage system (ESS) 22,23 to build the robust PCC voltage. Thus, the above control strategies [13][14][15][16][17][18][19][20][21][22][23] still implemented typical PLL-dependent grid-following 24 controls, which cannot avoid PLL-associated instability issues [6][7][8] and cannot build the AC voltage independently in SAOM.…”

Variable converter Pulse Island test in integrated distributed generation of electrical energy system

“…[21,22] will cause variation in amplitude and frequency of the load voltage when the utility is interrupted, so that immediately detect the islanding operation. Comprehensive 23 analysis of ROCOF fuzzy tune PID/H ∞ , 24,25 power synchronization control, 26 and vector surge relays for distributed generation applications are given with all standards 27‐29 of voltage and frequency are used for grid integration 30,31 of power system island detection. Inverter control based on ROCOV, ROCOF, impedance variations, and some of techniques are used drift/dual frequencies to find islanding of system.…”