Rating Of Static Var Compensator Research Articles

Probabilistic optimal reactive power planning with onshore and offshore wind generation, EV and PV uncertainties

This article proposes a probabilistic optimal reactive power planning keeping in view the uncertainties in renewable generations (wind and photovoltaic systems), loads, and electric vehicle charging. High voltage direct current based on voltage-sourced converters is an important part in the connection between offshore wind farms and grid. In this article, a probabilistic ac–dc load flow method is used, which includes the connection between the offshore wind farms and grid. For the reactive power planning, capacitor and static Var compensator (SVC) banks have been used. A strategy has been adopted to find the rating of SVCs and capacitor banks. The extensive simulation studies have been performed on a modified IEEE-118 bus system and the results obviates the aptitude of proposed method.

Synchrophasors assisted protection scheme for the shunt‐compensated transmission line

This study presents synchrophasor assisted protection scheme for the protection of long transmission line compensated with shunt flexible AC transmission system (FACTS) device. With the advancement in synchrophasor technology, data communication medium, and wide area measurement system for transmission line protection, the differential protection scheme is a most suited scheme over the over-current, distance and directional protection schemes. The proposed scheme discriminate between internal and external fault using the time synchronised voltages and currents of both the terminal of the transmission line. The performance of proposed scheme has been evaluated on IEEE 12 bus FACTS benchmark power system model implemented in PSCAD/EMTDC. The measured voltage & current signals are pre-processed and phasors are estimated through DFT algorithm in MATLAB. The performance remains unaffected during wide variation in fault and system parameters including different line length and static var compensator rating. The test results confirm the selective, simplicity, high speed, sensitivity, and robustness of the proposed protection scheme. This scheme is also able to distinguish the faulty phase(s) from healthy phases, which enables the single-pole tripping option. Finally, comparative evaluation of the proposed technique with the existing protection schemes clearly shows its superiority.

The voltage profile improvement using static var compensator (SVC) in power system transmission

In transmission system named ‘Subsistem Bandung Selatan dan New Ujungberung’ there are the voltage drop which relatively high and the voltage profile at the receiving ends below 0.95 p.u. Therefore, this research proposed a method to improve the voltage profile in the transmission system using one of Flexible Alternating Current Transmission System (FACTS) technology which is Static Var Compensator (SVC) and ‘Subsistem Bandung Selatan and New Ujungberung’ as the object. This research aims to get the voltage profile in ‘Subsistem Bandung Selatan dan New Ujungberung’ before and after connected to SVC and to set optimal location and rating of SVC to maintain the voltage profile at the system that has desire range (0.95 p.u – 1.05 p.u). To get the result in accordance with these objects, Newton –Raphson power flow solution is applied to the system. The result of Newton- Raphson power flow solution of the system shows the voltage profile before connecting to SVC are averagely 140.95 kV or 0.94 p.u while after connecting to SVC are 145.28 kV or 0.97 p.u. The SVC installation is connected to ‘Bandung Utara I’ as the weakest bus, and the SVC rating is -250 Mvar to 300 Mvar.

A Study on Integrated Performance of Tap-Changing Transformer and SVC in Association with Power System Voltage Stability

Abstract—Electricity market activities and a growing demand for electricity have led to heavily stressed power systems. This requires operation of the networks closer to their stability limits. Power system operation is affected by stability related problems, leading to unpredictable system behavior. Voltage stability refers to the ability of a power system to sustain appropriate voltage levels through large and small disturbances. Steady-state voltage stability is concerned with limits on the existence of steady-state operating points for the network. FACTS devices can be utilized to increase the transmission capacity, the stability margin and dynamic behavior or serve to ensure improved power quality. Their main capabilities are reactive power compensation, voltage control and power flow control. Among the FACTS controllers, Static Var Compensator (SVC) provides fast acting dynamic reactive compensation for voltage support during contingency events. In this paper, voltage stability assessment with appropriate representations of tap-changer transformers and SVC is investigated. Integrating both of these devices is the main topic of this paper. Effect of the presence of tap-changing transformers on static VAR compensator controller parameters and ratings necessary to stabilize load voltages at certain values are highlighted. The interrelation between transformer off nominal tap ratios and the SVC controller gains and droop slopes and the SVC rating are found. P-V curves are constructed to calculate loadability margins.

Thyristor-controlled voltage regulators for critical induction motor loads during voltage disturbances

The transient stability of a critical induction machine load group during momentary as well as continuing voltage sags can be enhanced by using a fast-response voltage regulator in the form of a static VAr compensator (SVC) or a thyristor controlled tap changer (CTC). A procedure is presented for determining the minimum SVC rating or CTC off-nominal turn ratio including control of the SVC admittances or CTC taps to meet dynamic and steady-state specifications. The limitations of their effectiveness to preserve operation continuity are also shown. >