Simultaneous Optimization of Virtual Synchronous Generators (VSG) Parameters in Islanded Microgrids Supplying Induction Motors

Abstract

The growing importance of Microgrid in future power systems highlights critical challenges like microgrid control and stability. An islanded microgrid including distributed generations (DG), energy storage systems (ESS), and different types of loads (static or dynamic) is prone to instability. The whole microgrid system must be analyzed and designed to operate within stable regions. This study models an inverter-interfaced microgrid which supplies different types of loads such as static loads and symmetrical induction machines (SIM) by virtual synchronous generators (VSG). Afterwards, a generalized small-signal stability analysis framework is proposed for an islanded microgrid. This model is applied for stability analysis of an arbitrary islanded microgrid including several VSGs, lines, static loads, and SIM loads. Subsequently, permissible intervals for VSG parameters are drawn according to the microgrid smallsignal stability analysis. These permissible intervals are compared for static and SIM load. Finally, a novel optimization platform is introduced which utilizes the particle swarm optimization (PSO) algorithm to draw optimal values for virtual impedances (VI), virtual inertia (Jv), virtual damping (D), and current statefeedback factor (F). The proposed optimization platform enhances the microgrid stability, minimizes voltage drops on the buses, the reactive power mismatches, and the frequency Nadir, simultaneously.INDEX TERMS Current state-feedback factor (F), microgrid, symmetrical induction motors (SIM), smallsignal stability, virtual synchronous generator (VSG), virtual impedance (VI).

Review on Virtual Inertia Control Topologies for Improving Frequency Stability of Microgrid

“…Furthermore, different VSG control strategies have been introduced to enable the inverter to emulate the properties of an SG [41,52]. As a result, every VSG implementation entails an approximately direct mathematical model of an SG [4]. Many solutions presented in the literature show that selecting any SG model and its parameters primarily depends on a random design choice.…”

“…In recent years, many RES, such as wind farms and photovoltaic (PV), have been integrated into the conventional power system. RES based on power electronic converters (PECs) is expected to have a significant impact on a sizeable power grid in the near future [4,5], as the PEC-based generations would be substituted for the substantive portions of traditional SGs in power systems [4]. The RES-based PECs have no rotating mass and damping effects compared with traditional power with SG.…”

An online identification method for establishing a microgrid equivalent model based on the hybrid particle swarm optimization butterfly algorithm

“…Modeling can be classified into mechanism and identification modeling. Mechanism modeling corresponds to building an accurate mathematical model of a microgrid system with known data regarding its topological structure and line parameters 2–4 . The main advantage of this method is its high accuracy, while its disadvantage is the complexity of the modeling process.…”

A Virtual Synchronous Generator Control Strategy for Microgrid Based on Harmonic Current Bypass Control

“…Various researchers [18][19][20] have proposed several VSG models based on the electromagnetic transient equation and rotor equation of motion for synchronous generators. Reference [21] established an inverterinterfaced microgrid model that supplied different types of loads using a VSG and proposed a generalized small-signal stability analysis framework for an islanded microgrid. e proposed optimization platform enhanced the microgrid stability, and it minimized voltage drops on the buses, reactive power mismatches, and the frequency, simultaneously.…”