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The microgrid consists of a group of interconnected loads and various energy sources such as wind and solar, which are operated in amalgamation to the main grid for sharing of the connected load. The unified operation of different energy sources increases the overall reliability and overall operational efficiency of the whole system. The microgrid always consists of the main source, which is responsible for supplying the main power. Thus, the microgrid has the primary grid and other DGs connected to it and thus provided the microgrid's various modes of operation, such as grid-connected mode, islanded mode, and dual-mode. The microgrid can be switched to multiple methods, and this switching requires a good pattern. The paper describes modes of operation and control strategies required for the proper switching to various methods. The variation of the Irradiance value affects the active and reactive power at the PCC or the bus. At low Irradiance, the load is fed by both grid and the solar PV. At the high Irradiance, the solar PV's output power increases, and thus the load demand is majority filled up by the solar PV. The variation of the Irradiance value affects the active and reactive ability at the PCC or the bus.

Voltage instability is a major problem in power system it seldom results in voltage collapse and blackout. FACTS devices can be used to maintain voltage stability by controlling active and reactive power and increase voltage stability margin. Optimal location of these devices is also an important issue. In this paper static var compensator (SVC) is used to improve voltage stability. Optimal location of SVC is found by continuation power flow and by finding fast voltage stability index. SVC is placed at optimal location and its effect on improving voltage stability, loadability limit and reducing power losses have been studied under normal as well as contingency conditions. Two types of contingencies are considered, transmission line (N − 1) contingency and generator outage contingency. The proposed work is tested in IEEE 14 bus test system.

The continuous rise in electricity demand leads to adoption of renewable energy sources such as sun, wind for power generation. In order to utilize the electric power obtained from renewable solar energy, inverters are required to inject the electricity into the grid. This paper presents single phase flying capacitor multi-level inverter with help of SPWM technique. The comparison of single phase three-level, five-level and seven-level flying capacitor multilevel inverters is carried out with respect to waveform pattern, output current, output voltage, active power and reactive power waveforms. The simulations are conducted in MATLAB/SIMULINK environment.

In the deregulated power system congestion of transmission network is a key challenge. Any attempt to operate transmission system beyond its line limits leads to congestion. By use of FACTS devices, the power transfer capability of network increases & reactive power compensation is done thereby improving the power system stability and network power quality. This paper presents the optimal placement of Thyristor controlled series compensators (TCSC) to avoid congestion in the transmission network. The optimal placement is figured out by factors like line utilisation factor (LUF), line loading, voltage profile at each bus & real and reactive power losses between buses. An algorithm is presented for finding the optimal location for placing TCSC. The reactance model of TCSC is considered to hike the power capabilities of the line. The potency of the model is tested on IEEE 24-bus system with the standard data using MATLAB-PSAT Simulink.

Deregulation of power sector leads to overloading of transmission lines due to high demand of consumers. To fulfill demand of power, generation companies produce more output, but transmission lines are the conventional ones and they get congested as they carry more power than its capacity. To reduce congestion FACTS devices are used, which control power flow and reduce losses, thus reduces congestion. In this paper Thyristor Controlled Series Compensators (TCSC) has been used, TCSC is a series FACTS device which changes reactance of transmission line and thus controls power flow through that line, leads to reducing congestion. Appropriate location of TCSC has been found out by various indices. TCSC placement is done at these locations under base case and varying load condition and improvement in transmission line loading is observed. Work is carried out on IEEE 30 bus test system.

Transmission congestion occurs in a power system due to increase in load demand. This mainly occurs in restructured power system because of restrictions of transmission line capacity. Due to this power system does not remain in secure condition. Ranking of contingency is done using performance index and critical contingency is found. In this paper, placement of multiple TCSCs for reducing transmission line congestion under single line critical contingency condition is done. Optimal location for placement of TCSCs is found out by using sensitivity analysis. By placing two TCSCs, there is reduction in line loading, improvement in voltage profile and reduction in reactive power loss, thus keeping power system in secure condition under critical contingency. Proposed work is carried out on IEEE 14 bus test system using MATLAB.

Nowadays, congestion management is a major problem in power system deregulation. With the continuous increase in load demand, there is continuous requirement for different new technologies resulting in advanced network operation. This paper presents a solution for congestion management by developing a series smart wire module which operates with the increment in load. The circuitry is bypassed if it does not detects congestion in line else with the detection of congestion series smart wire module is operated. This method improves the reliability of the system by reducing active power losses. The effectiveness of this module is demonstrated in standard IEEE 15 bus system model using MATLAB/Simulink and the results are formulated with graphical representations.

In this paper placement of thyristor controlled series compensators (TCSC) at optimal location of a power system for maintaining voltage stability, improving transmission efficiency, steady state stability limit and mitigating congestion under single line critical contingency condition is discussed. Optimal location is found out by line voltage stability index and sensitivity analysis. Performance index (PI) is used for finding critical contingency. Under critical contingency condition which is single line outage in this case, congested transmission lines are found. TCSC is a FACTS device which can reduce power loss in overloaded transmission lines, increase loadability, reduce system loss and maintain stability of power systems. This work has been tested on IEEE 14 bus test system using MATLAB.

Power flow study is the initial step which provides voltage magnitudes, phase angles, active and reactive power flows at respective buses under normal operating conditions. It helps in analyzing the current state of the power system and effective alternative options for expanding the existing system in order to meet with the increasing load demand. Contingency Analysis is also a major part of study for reliable and planned operation of power system. It is very significant function in modern Energy Management Systems. The objective of contingency analysis is to give operator the information about the static security. There are several factors which may lead to the contingency in power system, for example line outage, transformer outage, generator outage and overloads resulting the extreme situations such as voltage collapse, over loads in other branches and/or sudden system voltage rise or drop. Contingency analysis is used to calculate parameters violations. In this paper, maximum loading parameter is calculated and contingency status of Western System Coordinating Council 3 Machine, 9 Bus test system is done using PSAT toolbox in MATLAB.

In the contemporary world, especially developing countries, the demand for electricity is proliferating continuously and power is not only a criterion for fulfilling the requirement, but it is also the responsibility of engineers to provide the reliable and stable power to the consumers in a satisfactory manner. This paper discusses about the designing and improvement in “Transient Stability of IEEE 9 Bus Test System” using Power World Simulator. The simulation work explain the transients inthe system due to a fault which is an evaluated of the voltage stability, Rotor angle stability, frequency stability, Active power and reactive power. The simulation is done using a GNCLS model in which synchronous machine is represented using classical modelling [3] . This paper used exciter (AC7B) and PSS with AVR for improving transient instability.