Microgrids can be used as platforms for the development of renewable energy-based distributed generation (DG) if they have a suitable design and an efficient control system. Microgrids have low inertia because their structure is small and their tolerance for change is low, which makes maintaining voltage and frequency stability difficult, especially in island mode. Unlike power systems, microgrids are primarily powered by inverter-based DG. Although the DG has an efficient control system, the primary energy sources are slow to respond, which makes it impossible for it to maintain the stability of the microgrid on its own. DG, D-STATCOM, and electrical energy storage systems (ESS) are used to develop a multilevel and interactive structure for microgrid frequency and voltage stability. The interactive control system of this microgrid greatly increases its response speed to disturbances. MATLAB has been used to implement and evaluate the proposed structure on a microgrid with two connection modes and an islanding mode. The final goals are as follows: The D-STATCOM increases reactive power generation in the microgrid by interacting with ESS. This, in turn, maintains the voltage stability of the microgrid. The power control of DGs is used to investigate microgrid voltage stability and frequency in the presence of renewable units. It is demonstrated that the microgrid performs well in all operating modes. It is shown how the control system operates correctly in the event of a severe short circuit in a part of the microgrid and how it maintains the microgrid's stability after a fault. As the microgrid transitions from the state of being connected to the main grid to the state of being an island, the control system is shown to maintain voltage and frequency stability. D-STATCOM improves power quality indicators by maintaining voltage stability and reducing voltage sag. D-STATCOM is recommended for close loads with rapid changes, such as factories and industrial complexes, and places with sensitive electrical loads, such as hospitals.

This paper proposes a combination approach termed combined approach for dynamic available transmission capacity (CDATC) for the quick and accurate computation of ATC. In this regard, the suggested model makes use of the static enlarged downhill and Newton–Raphson-Seidel algorithm. In this paper, the boundary surface of potential energy and the maximum point of potential energy are also estimated in a manner to ascertain transient stability. A CDATC calculation was developed by combining the static method, transient stability, and online state estimate. When compared to existing DATC approaches, the simulation results on a large-scale real-world system confirm the suitability of the suggested method with faster speed and tighter accuracy. Simulation results on the East Iran network, IEEE 118 bus, and Iowa State 145 bus, all of which have a high penetration of wind farms-showed that the developed CDATC is robust at all operating conditions and can be used online with fewer computational resources. The unique application of state estimation in DATC computation, which enabled the study to produce a more realistic answer even in the face of ambiguity, is an additional value.

In this chapter, DIgSILENT PowerFactory software is used to simulate and analyze power systems as industrial software. DIgSILENT software's classic power network modeling, reactive power compensation with a capacitor, reactive power compensation with a transformer tap changer, short circuit calculations, and transient stability analysis, are covered. The next section shows that parallel wind generators in wind farms increase calculation speed without significantly affecting transient stability. In the following, reliability and contingency ranking analyses are discussed. Then "Energy Not Supplied (ENS)" is calculated from "Load Point Energy Not Supplied (LPENS)". At the end, a combined network of wind power plants and photovoltaic power plants is examined within 24 h. This section aims to investigate two wind and solar power plants using DIgSILENT's toolbox "Quasi-Dynamic Simulation". Furthermore, students and engineers interested in simulating the power system in DIgSILENT can repeat the simulation results by following the files given in the reference.