Controlled Shunt Reactor for UHVAC System Reactive Power Control

2020 ◽  
Vol 13 (3) ◽  
pp. 417-425
Author(s):  
Satyadharma Bharti ◽  
Satya P. Dubey
Keyword(s):  
Transmission Line ◽  
Power Management ◽  
Reactive Power ◽  
Voltage Profile ◽  
Voltage Level ◽  
Shunt Reactor ◽  
Three Phase ◽  
Power Frequency ◽  
Controlled Shunt Reactor ◽  
Ac Transmission

Background: In this paper, a novel technique for reactive power management of the Ultra High Voltage (UHV) lines having voltage level of 1200 kV line and above is suggested. The UHV power grid has to frequently face the problems associated with the power- frequency and switching over-voltages. Methods: The technique involves the use of three-phase UHV Transformers as a Controlled Shunt Reactor (CSR) in combination with the use of a fixed reactor. The performance of the UHV AC transmission line is studied using PSCAD software and working of CSR is evaluated. Results: Standard parameters of the proposed Wardha-Aurangabad 1200 kV transmission line in India are considered for simulation model. The use of CSR has been found to be effective in mitigating system problems. Conclusion: The system can be used for maintaining voltage profile, resulting in enhancement of the reliability of the UHV transmission system.

ANN-Based Relaying Algorithm for Protection of SVC- Compensated AC Transmission Line and Criticality Analysis of a Digital Relay

2020 ◽  
Vol 13 (3) ◽  
pp. 381-393
Author(s):  
Farhana Fayaz ◽  
Gobind Lal Pahuja
Keyword(s):  
Transmission Line ◽  
Failure Modes ◽  
Reactive Power ◽  
Circuit Breaker ◽  
Research Work ◽  
Back Propagation ◽  
Static Var Compensator ◽  
Data Set ◽  
Ac Transmission ◽  
Criticality Analysis

Background:The Static VAR Compensator (SVC) has the capability of improving reliability, operation and control of the transmission system thereby improving the dynamic performance of power system. SVC is a widely used shunt FACTS device, which is an important tool for the reactive power compensation in high voltage AC transmission systems. The transmission lines compensated with the SVC may experience faults and hence need a protection system against the damage caused by these faults as well as provide the uninterrupted supply of power.Methods:The research work reported in the paper is a successful attempt to reduce the time to detect faults on a SVC-compensated transmission line to less than quarter of a cycle. The relay algorithm involves two ANNs, one for detection and the other for classification of faults, including the identification of the faulted phase/phases. RMS (Root Mean Square) values of line voltages and ratios of sequence components of line currents are used as inputs to the ANNs. Extensive training and testing of the two ANNs have been carried out using the data generated by simulating an SVC-compensated transmission line in PSCAD at a signal sampling frequency of 1 kHz. Back-propagation method has been used for the training and testing. Also the criticality analysis of the existing relay and the modified relay has been done using three fault tree importance measures i.e., Fussell-Vesely (FV) Importance, Risk Achievement Worth (RAW) and Risk Reduction Worth (RRW).Results:It is found that the relay detects any type of fault occurring anywhere on the line with 100% accuracy within a short time of 4 ms. It also classifies the type of the fault and indicates the faulted phase or phases, as the case may be, with 100% accuracy within 15 ms, that is well before a circuit breaker can clear the fault. As demonstrated, fault detection and classification by the use of ANNs is reliable and accurate when a large data set is available for training. The results from the criticality analysis show that the criticality ranking varies in both the designs (existing relay and the existing modified relay) and the ranking of the improved measurement system in the modified relay changes from 2 to 4.Conclusion:A relaying algorithm is proposed for the protection of transmission line compensated with Static Var Compensator (SVC) and criticality ranking of different failure modes of a digital relay is carried out. The proposed scheme has significant advantages over more traditional relaying algorithms. It is suitable for high resistance faults and is not affected by the inception angle nor by the location of fault.

Combined Test of Capacity Regulating in 1100kV Controlled Shunt Reactor Valve-Control System

2014 ◽  
Vol 977 ◽  
pp. 334-337
Author(s):  
Xi Lei ◽  
Gui Zhi Xu ◽  
Ke Zheng Xing
Keyword(s):  
Control System ◽  
Test Method ◽  
System Stability ◽  
Shunt Reactor ◽  
Flexible Ac Transmission ◽  
Flexible Ac Transmission System ◽  
Combined Test ◽  
Controlled Shunt Reactor ◽  
Ac Transmission ◽  
Valve Control

As a flexible AC transmission system equipment, controlled shunt reactor is becoming increasingly important in the grid with the development of EHV / UHV transmission systems. Since currently rated voltage of controlled shunt reactor has developed to 1100kV, as its capacity control system, or valve-control system, stability and reliability test is very important. In this paper, the test circuit and method for the valve-control system in the laboratory or the test station for combined adjustment test is put forward. By adjustment of power supply and the device parameter, the valve-control system can put the voltage and current of the device to be the same as the on-set operation. Actual test of the world's first 1100kV controlled shunt reactor valve-control system shows that, the test method in this paper is correct and feasible, and the objective of assessment can be achieved.

scholarly journals MODELING AND SIMULATION OF STATCOM FOR POWER QUALITY IMPROVEMENT

2021 ◽  
Vol 9 (2) ◽  
pp. 217-229
Author(s):  
Ch. Umamaheswararao, Et. al.
Keyword(s):  
Power Quality ◽  
Distribution Systems ◽  
Reactive Power ◽  
Reactive Power Compensation ◽  
Voltage Profile ◽  
Inductive Load ◽  
Linear Load ◽  
Three Phase ◽  
Quality Aspects ◽  
Wide Range

In power system, reactive power compensation is one of the important action to maintain better voltage profile, stability and decrease losses. STATCOM is feasible in terms of cost effective in wide range of problem solving capabilities among all Flexible AC Transmission system (FACTS) in both transmission and distribution levels. In this paper the synchronous rotating frame theory algorithm is used since it is easy to implement i.e. the rotating three phase quantities are converted into stationary components. So it requires less number of PI controllers and also calculations on the stationary quantities are easy than to do calculations on instantaneous quantities and the modeling of STATCOM is done.  This project focuses on improvement of power quality in a three phase three wire system with a non-linear load i.e., three phase bridge rectifier and a parallel inductive load. Some power quality aspects like reactive power compensation of linear load, better Total Harmonic Distortion (THD) performance and the power factor improvement are achieved. The result shows the THD of input current achieved as per the IEEE 519-1992 standard. It is observed that STATCOM gives effective compensation for reactive power variation and hence the power quality of distribution systems improved.

scholarly journals Mal-Operation of Mho Relay In Transmission Line Due To Presence of TCSC

2019 ◽  
Vol 8 (3) ◽  
pp. 4328-4333
Keyword(s):  
Transmission Line ◽  
Fault Location ◽  
Reactive Power ◽  
Power Transmission ◽  
Transmission System ◽  
Simulation Software ◽  
Normal Operation ◽  
Distance Protection ◽  
Voltage Profile ◽  
Angle Variation

Distance protection is simple and it provides fast response to clear the fault. Distance protection is also providing primary and remote backup function depending upon distance of transmission line. Distance protection uses various relays like mho relay/admittance relay, impedance relay and reactance relay. In power transmission system, Flexible AC Transmission System (FACTS) controllers are used to increase power transfer capability and reactive power control, but distance relay get affected due to presence of FACTS devices. This may create the stability issues, security and it may affect on voltage profile. The changes in impedance level would affect the accuracy of distance protection. This paper represents the effect of TCSC on operation of mho relay in transmission line. The work presented here emphasis on the interaction of TCSC on distance protection and their performances under different condition i.e., load angle variation, variation of SCL, different fault location. Design and control performance of MHO relay during normal operation as well as during variation in different condition is verified by using PSCAD simulation software.

Cotrolling Characteristic Analysis of Magnetically Controlled Shunt Reactor Based on Field-Circuit Coupled

2013 ◽  
Vol 860-863 ◽  
pp. 2236-2239
Author(s):  
Jun Qiang Xing ◽  
Lei Chen ◽  
Zuo Xia Xing
Keyword(s):  
Finite Element ◽  
High Voltage ◽  
Transmission Lines ◽  
Demonstration Project ◽  
Characteristic Analysis ◽  
Harmonic Current ◽  
Shunt Reactor ◽  
Controlled Shunt Reactor ◽  
Ac Transmission ◽  
Shunt Reactors

In order to restrict over-voltage and compensate line charging power, there is a need to install high compensation shunt reactors in ultra-high voltage AC transmission lines. Due to the saturation characteristic of core limb during the working progress in the magnetically controlled shunt reactor (MCSR), the current higher harmonics exist in the high voltage winding. Based on finite element, the method which analyzes the controlling characteristic of high voltage winding with 500kV MCSR demonstration project in the Jiangling converter station is presented in this paper. The magnitude and frequency of harmonic current in the high voltage winding current is derived by this method. Through the comparison with the measured results of 500kV MCSR, the validity of method is proved.

scholarly journals A New Adaptive Control Strategy of active and reactive power sharing in Islanded Microgrids

2016 ◽  
Vol 19 (4) ◽  
pp. 14-34
Author(s):  
Phuong Minh Le ◽  
Duy Vo Duc Hoang ◽  
Hoa Thi Xuan Pham ◽  
Huy Minh Nguyen ◽  
Dieu Ngoc Vo
Keyword(s):  
Transmission Line ◽  
Distributed Generation ◽  
Reactive Power ◽  
Active Power ◽  
Power Sharing ◽  
Droop Control ◽  
Active And Reactive Power ◽  
Three Phase ◽  
Islanded Microgrid ◽  
Adaptive Control Strategy

This paper proposes a new control sharing method for parallel three-phase inverters in an islanded microgrid. The proposed technique uses adaptive PIDs combined with the communication among the parallel inverters to accurately share active power and reactive power among the inverters via adjusting the desired voltage if there is a distinct difference between line impedance and the load change in the microgrid. Moreover, the paper also presents the response ability of the inverters to maintain the error within the allowed limits as the transmission line is interrupted. The proposed technique has been verified in a microgrid with three parallel distributed generation-inverter units using Matlab/Simulink. In the simulation, as the droop control using the communication information among the inverters, the sharing errors for active power and reactive power are around 0.2% and 0.6%, respectively. As the connection between the microgrid and transmission line is interrupted, the sharing errors for active power and reactive power increase to 0.4% and 2%, respectively. The simulation results have indicated that the proposed technique is superior to the traditional droop control in terms of the accuracy and stability. Therefore, the new proposed technique can be a favor alternative model for active power and reactive power sharing control of parallel inverters in an islanded microgrid.

The Influence of Distributed Photovoltaic Access to Distribution Network on Voltage Profile

2014 ◽  
Vol 1070-1072 ◽  
pp. 68-73
Author(s):  
Cun Xiang Yang ◽  
Hui Juan Yang ◽  
Ping He ◽  
Yun Long Niu
Keyword(s):  
Theoretical Calculation ◽  
Reactive Power ◽  
Distribution Network ◽  
Voltage Profile ◽  
Shunt Reactor ◽  
Load Center ◽  
Voltage Violation

The generated photovoltaic located at load center has a significant impact on feeders' voltage profile. Firstly, considering the reactive power and the line reactance, after theoretical calculation and simulation, it is proved that the influence on voltage profile of generated PV access to distribution network has a great relationship with its access position and access capacity; when there are multiple PV access to distribution network, the influence on voltage profile is different when combined capacity and location is different. Then the maximum alternative capacity at each node is calculated. Al last, it is illustrated through simulation that shunt reactor at PV node and inverter controlling can solve the voltage violation problem.

Improving the Performance of Long Distance Tuned AC Transmission Systems

2019 ◽  
Vol 8 (2S8) ◽  
pp. 1133-1135
Keyword(s):  
Power Flow ◽  
Reactive Power ◽  
Voltage Profile ◽  
Long Distance ◽  
Transmission Systems ◽  
Long Distance Transmission ◽  
Reactive Power Flow ◽  
Shunt Compensation ◽  
Ac Transmission ◽  
Economic Constraints

The line series reactance and shunt susceptance can be tuned by adopting series and shunt compensation. Practical, size and economic constraints will lead to limitations in location of the compensating elements at optimal points along the line. While planning long-distance transmission, it is necessary to determine not only the average degrees of compensation required, but also ensure the stable and uniform voltage profile with minimal reactive power flow.

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