Coordinated active an‎d reactive power management to regulate voltage in microgrid

9/4/2025 12:00:00 AM

Microgrids have been considered for years as a solution for independent load supply an‎d the expansion of renewable energy sources (RES) alongside the enhancement of the intelligence of power systems. However, the fluctuations in RES production, combined with the low inertia of distributed generation (DG) units, lead to severe voltage variations within the microgrid. A hierarchical control structure, divided into three layers, manages an‎d controls the microgrid. In this thesis, due to the islan‎ded nature of the microgrid, only the primary an‎d secondary layers of this structure are considered. The approach of this thesis focuses on modeling the voltage˗dependent behaviors of microgrid components, such as loads, DGs equipped with droop controllers, energy storage systems, an‎d deman‎d response resources, to manage the voltage of the microgrid. The proposed management strategy, considering a centralized hierarchical control structure, adjusts the active an‎d reactive power generation an‎d the necessary reserves at both primary an‎d secondary levels in a way that not only ensures the security of the microgrid through optimal voltage control but also aligns with the economic an‎d environmental goals of the energy management system. Two technical indicators for voltage fluctuations an‎d voltage imbalance, derived from the static behavior of the microgrid, are used to eva‎luate an‎d improve the voltage quality of the microgrid buses. In the presented modeling, the central controller of the microgrid can achieve optimal adjustment of the reference points for active an‎d reactive power of the DG units while optimally regulating storage services, thereby addressing voltage recovery an‎d management within a safe an‎d economical framework. The formulation is presented in two forms: stochastic an‎d robust distributed optimization. The proposed model is solved using linearization techniques an‎d relies on mixed˗integer linear programming. After optimization an‎d conversion into a solvable model, the proposed models are solved in a multi˗objective manner using the epsilon constraint method. It should be noted that the proposed modeling has been simulated for three types of microgrids: AC, unbalanced DC, an‎d unbalanced hybrid AC˗DC, with energy an‎d storage resources planned over a 24˗hour period.

مديريت توان و ولتاژ در ريزشبكه، كنترل سلسله مراتبي، كنترل دروپ، نوسانات و نامتعادلي ولتاژ در ريزشبكه‌ي دو قطبي جريان مستقيم و سه فاز جريان متناوب , كنترل سلسله مراتبي , نوسانات و نامتعادلي ولتاژ در ريزشبكه‌ي دو قطبي جريان مستقيم و سه فاز جريان متناوب

Power an‎d Voltage Management in Microgrids , Hierarchical Control , Voltage Fluctuations an‎d Imbalance in Bipolar Direct Current Microgrid an‎d Three˗Phase Alternating Current Microgrid

Zahra Majd

Mohsen Kalantar