V‐I droop‐based distributed event‐ and self‐triggered secondary control of AC microgrids

Abstract

In this study, distributed event‐and self‐triggered (ST) control methods are proposed for accurate load sharing and voltage control in islanded AC microgrids with resistive line impedances. The proposed control framework is comprised of a two‐level control structure. At the primary level, the V‐I droop control method is adopted. In this method, the distributed energy resources (DERs) are synchronised to a common synchronous reference frame and load sharing is accomplished through voltage‐current droop characteristics in this frame. The secondary level, which has a distributed structure, mitigates the voltage deviations induced by the primary level and eliminates the current sharing error caused by the line impedances. The data exchange among the DERs is controlled using event‐ and ST algorithms. In order to reduce the communication burden, the feedback control laws are realised using estimated variables, which are updated at certain event times. The event times are extracted based on Lyapunov stability analysis and by consideration of the V‐I droop characteristics. Comparison of event and ST algorithms shows that while the event‐triggered strategy offers superior dynamic response, the ST approach requires lower network traffic. The efficacy of the proposed scheme is verified through real time simulation results.

Enhancing microgrid performance with AI‐based predictive control: Establishing an intelligent distributed control system

“…Secondary control (SC) frameworks come in two primary forms. The centralized framework, despite its prevalence, faces challenges due to heavy communication and computation loads [5]. In contrast, the distributed control framework, based on local information exchanges, has gained significant attention.…”

“…FIGURE5 An intelligent distributed control scheme for each distributed generation unit in a microgrid.…”

Conservation Voltage Reduction Strategy for Autonomous Microgrid with Improved Voltage-CurrentDroop-Based Inverter Control Framework

“…An improved droop control is designed based on dual ascent algorithm to maintain an optimal allocation of power [16]. Te reported literature discussed communication-less framework which modifed the algorithm to accurately track the voltage and frequency, but the modifed droop technique still dependent on active and reactive power to computes the frequency and voltage parameter and hence, the work reported in [17,18] discussed the V-I droop control method to regulate the voltage and it utilizes the alternative approach which shifted the power sharing approach to current sharing based droop control technique. In addition to it, one of the key characteristics of the V-I droop control described here is that it sets voltage proportional to the feedback current received from the output of the flter.…”

“…Decentralized droop control features poor dynamics and therefore, the droop method based on voltage-current characteristics is being introduced to exploit the advantages of inverter's fast dynamics characteristics [18]. Te simpler structure of V-I droop control method leads to problem such as nonsynchronization of VSIs due to elimination of power loop.…”

“…It characterizes the drooping of the output voltage of the VSI corresponding to the output current of the inverter [20]. Although various literature [18][19][20] is concentrated on the accurate distribution of power by modifying the V-I droop algorithm but almost none of them discussed the appropriate method to determine the V-I droop gain applicable to multifeeder network.…”