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A constant worldwide growing load stress over a power system compelled the practice of a reactive power injection to ensure an efficient power network. For this purpose, multiple technologies exist in the knowledge market out of which this paper emphasizes the usage of the flexible alternating current transmission system (FACTS) and presents a comparative study of the static var compensator (SVC) with the static synchronous compensator (STATCOM), inducted in a real electric substation. The aim is to improve the power factor (PF) and power quality and to encounter reliably extreme conditions. A 220 kV electric substation was opted for the analysis, and both the static and dynamic conditions were observed with the help of a power system analysis tool termed PowerFactory-DIgSILENT. Multiple aspects were investigated via software simulations to assess the performance of the aforementioned FACTS devices, such as the voltage profile evaluation via the load flow analysis method (LFA), the harmonic response via the power quality and harmonic analysis tool, and the short-circuit response via the RMS simulation tool. The outcomes were verified and compared with permissible values included in the universal standards, such as IEC and IEEE. The superiority of the STATCOM over the SVC was proven in light of the simulative results. [ABSTRACT FROM AUTHOR]

In recent years, the integration of renewable energy resources (RESs) into the power system is growing rapidly, and it is necessary to analyse and evaluate the effect of RES on transient stability of the power system. In this study, centre of inertia (COI) concept is implemented to analyse and evaluate the integration effects of an auxiliary damping control‐based virtual synchronous generator (VSG) consisting an improved governor. The impact of VSG integration is divided into synchronous generator (SG) linked parts and COI associated parts. Due to VSG integration into the power system, the significant elements which disturb the COI dynamic motion and rotor dynamics of SG are examined in detail. Different cases are considered to evaluate the effectiveness of the proposed method, i.e. VSG's different integrating location and different power capacities. It is observed in simulation results that COI dynamic motion and rotor dynamics of SG are positively affected by VSG integration, and transient stability improves significantly. [ABSTRACT FROM AUTHOR]

Aiming for large-scale renewable energy sources (RES) integrated to power systems with power electronic devices, the technology of virtual synchronous generator (VSG) has been developed and studied in recent years. It is necessary to analyze the damping characteristics of the power system with RES generation based on VSG and develop its corresponding damping controller to suppress the possible low frequency oscillation. Firstly, the mathematical model of VSG in a per unit (p.u) system is presented. Based on the single-machine infinite bus system integrated with an RES power plant, the influence of VSG on the damping characteristics of the power system is studied qualitatively by damping torque analysis. Furthermore, the small-signal model of the considered system is established and the damping ratio of the system is studied quantitatively by eigenvalue analysis, which concluded that adjusting the key control parameters has limited impacts on the damping ratio of the system. Consequently, referring to the configuration of traditional power system stabilizer (PSS), an auxiliary damping controller (ADC) for VSG is designed to suppress the low frequency oscillation of the power system. Finally, simulations were performed to verify the validity of theoretical analysis and the effectiveness of designed ADC. [ABSTRACT FROM AUTHOR]

• Transient stability of virtual synchronous generator (VSG) is discussed. • Active power-frequency loop of VSG is modified. • The modification consist on adding the auxiliary inertia and additional power into the active power-frequency loop. • Equal area criterion is used to analyze the proposed modification. • Simulation results shows that the proposed modification significantly improved the transient stability of VSG. Virtual synchronous generator (VSG) control scheme has received much attention from researchers as the introduction of rotational inertia to inverters. However, maintaining power-angle stability during the transient state of low inertia microgrids consisting of VSG based distributed generation units is a critical challenge. According to the equal-area criterion, the accelerating and decelerating area play an important role in power system stabilisation. Therefore, a new control strategy based on the equal-area criterion is proposed in this paper. According to the proposed control technique, the auxiliary inertia is incorporated into the governor unit of VSG with an additional power loop. The auxiliary inertia term minimises the difference between the governor unit of VSG and the governor unit of the conventional synchronous generator (SG). In contrast, the additional power loop supplies the auxiliary power during the transient process only when a significant fault occurs. Moreover, to enhance the transient stability, auxiliary inertia helps to improve the convergence time and dynamic characteristics of VSG, and additional power helps to shorten the acceleration area and widen the deceleration area. MATLAB/Simulink based simulations analysis and results validate the effectiveness of proposed control. [ABSTRACT FROM AUTHOR]

• Virtual synchronous generator (VSG) and distributed generation is discussed. • Deeply discuss the current progress in distributed power generation and role of VSG. • Overview of the recent development in VSG control operation. • Difficulties and future research directions for VSG are discussed in detail. The renewable energy resources based distributed generation (DG) unit's integration into the power system is growing rapidly, and the power system experiencing low inertia and damping, which causes severe stability and performance issues of the power system. In order to facilitate the integration of DG into the existing power system, improved control schemes for grid-tied electronic converters are necessary to ensure the stability and support to the power system. The virtual-synchronous generator (VSG) control emulates the dynamics of the rotation synchronous generator and enhances the stability of the power system. In this paper, an overview of different topologies to virtual inertia is presented along with a detailed description of the VSG structure. Moreover, VSG control defining active and reactive power control, and voltage and frequency control is explained in detail. The VSG stability analysis methods, such as small signal stability and transient stability are presented in comprehensive manners. Later on, the VSG application fields are described. Finally, the VSG problems and future research directions such as centralised control, stability improvement, reliable modelling, the interface for VSG are discussed. [ABSTRACT FROM AUTHOR]