A static synchronous compensator (STATCOM) is a powerful mechanism for balancing reactive power and uplift voltage stability in a transmission system. Nowadays, the desire to save energy by reducing losses is prioritized as an essential target instead of increasing the power generation for the sustainability of any nation’s growth plans. As a result, power-electronics-based converters are more significant for power savings in transmission systems. STATCOM based on voltage source converters (VSC) are operated to improve on stable performance conditions as well as to minimize the harmonic distortions in a power system. Hence, this paper explores low harmonic distortions of fifteen-level VSC structured STACOM using only one DC-link voltage to balance the reactive power and to manage the voltage profile in large power transmission systems. STATCOM consisting of H-bridge type VSCs and binary weighted transformers was utilized to maintain an AC system voltage at 132 kV, 50 Hz. The three stages of VSCs were operated with meticulous firing angles based on converter levels for controlling THD (total harmonic distortion) and providing system improvement. The proposed model of the fifteen-level H-bridge type voltage source converters with fuzzy logic decoupled control algorithm based STATCOM can be used for large power range applications with a small number of switches. This model attained stable operation of the system with a low harmonic deviation at any dynamical conditions. The simulation results using MATLAB showed that the system’s operation was enhanced, with a smoother response and improved steady state performance.

To ensure dynamic and transient angle and load stability in order to maintain the power system security is a major task of the power Engineer. FACTS Controllers are most effective devices to ensure system security by enhancing the stability margins with reactive power support all over the power system network. The major shunt compensation devices of FACTS are SVC and STATCOM. This article dispenses the modelling and simulation of both the shunt devices viz. Oneis the Static Synchronous Compensator (STATCOM) and the other is Static Var Compensator (SVC). The small signal models of these devices have been derived from the first principles and obtained the transfer function models of weak and strong power systems. The weak power system has the Short Circuit Ratio (SCR) is about less than 3 and that of the strong power system has the SCR of more than 5. The performance of the both weak and strong power systems has been evaluated with time and frequency responses. The dynamic response is obtained with the exact models for both weak and strong systems, subsequently the root locus plots as well as bode plots have been obtained with MATLAB Programs and evaluated the performance of these devices and comparison is made. The Stability margins of both the systems with SVC and STATCOM have been obtained from the bode plots. The dynamic behaviour of the both kinds of power systems have been assessed with time responses of SVC and STATCOM models. All of these results viz. dynamic response, root locus and bode plots proves the superiority of the STATCOM over SVC with indices, viz. peak overshoot, settling time, gain margin and phase margins. The dynamic, steady state performance indices obtained from time response and bode plots proves the superior performance of STATCOM.

The voltage control in transmission systems at both no-load and loaded conditions as well is possible with the Compensation equipment in general FACTS Controllers. This paper deals with the analysis and mitigation of Ferranti Effect and voltage control in the transmission system with fuzzy logic control of Static Var Compensator (SVC). SVC is a shunt compensation device which is connected in shunt to load bus. Test system is built with transmission lines of both nominal-pi line and distributed line models in the Simulink environment. The fuzzy based closed loop control of SVC is developed with park’s and inverted park’s transformations. The test system is simulated in the Matlab Simulink environment without and with Fuzzy logic control of SVC. The simulation results have been presented in this article which proves the effectiveness of Fuzzy control of compensator on mitigation of Ferranti effect as well as voltage control is excellent for both no load and loaded conditions.

Flexible alternating current transmission system (FACTS) controllers are important to enhance the quality of power in power systems. The stability of a system is achieved via a FACTS device (a Static Synchronous Compensator (STATCOM)). This paper aims to control the losses in the transmission system during peak energy demand circumstances with minimal losses in the economical and functional efficiency of the system. The STATCOM operation of a seven level voltage source converter (VSC) with binary-weighted transformers is proposed for controlling the reactive power variations and terminal voltage changes at dynamic circumstances in the transmission system. The STATCOM is operated at 132 kV and is a 50 Hz AC system with a single DC-Link capacitance and two VSC power circuits. Each VSC circuit consists of three H-bridges with specific switching angle control in order to achieve low total harmonic distortion at the fundamental frequency. The coupled control circuit phenomenon is imperative for computing the switching angle for a stable performance. The dynamic functional improvement efficiency is harvested with a minimum number of switches and transformers used in high voltage and high-power applications. The number of switches, transformers, and capacitors for 132 kV are optimized with a proposed STATCOM operation in seven level VSC with binary-weighted transformers. The simulated results prove that the proposed model significantly improved system performance and stability.

Modern Distributed systems are equipped with plenty of non-linear loads viz. Computers, Electronic Loads, SMPS and many more Power Electronics based loads. These loads are injecting both voltage and current harmonics into the utility grid and distribution systems. The presence of harmonics is very damaging to all equipment which has been connected to the point of common coupling (PCC). This article focuses engrossed on the distribution system, incorporated of feeders with Distribution GTO Thyristor controlled Series Capacitor (D-GCSC) fed R and RL loads. This article entrust the simulation results with FFT analysis focused on THD of current and voltage waveforms, in two stages, one is with D-GCSC feeding resistive load and second is RL load. The distribution systems have been simulated without and with DSTATCOM for both the stages of D-GCSC fed loads and presented the results. The DSTATCOM is designed and closed loop control circuit have been developed and simulated the same which is quite effective in mitigating the Voltage as well as Current harmonics in distributed systems comprising of nonlinear Loads.