Impacts of UHV on Short Circuit Currents in China's Central 500kV Grid and Its Countermeasures

2014 ◽  
Vol 960-961 ◽  
pp. 891-895
Author(s):  
Xu Zheng ◽  
Jiang Hong Wang ◽  
Mei Li ◽  
Shuang Zhao ◽  
Bu Han Zhang ◽  
...  
Keyword(s):  
Power System ◽  
High Voltage ◽  
Sharp Increase ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Central China ◽  
Fault Current ◽  
Access Scheme ◽  
Short Circuit Currents ◽  
Lower Voltage

Ultra-high voltage (UHV) projects are making power system growing lager and resulting in sharp increase of short circuit currents in some area especially in the vicinity of UHV access points. The paper presented the damage of short circuit current increases and common methods to limit fault current. Taking the construction and development of UHV grid in a province of central China as background, the over short circuit currents in 500kV Grid within UHV were showed and several countermeasures including choosing proper UHV access scheme, implementing UHV substation lower voltage bus partition running, installing reactors, optimizing power grid network based on UHV connection point were proposed and then verified by PSASP simulation. The results show those measures are useful to reduce the short circuit current to a reasonable level.

First Superconducting Fault Current Limiter in Russian Power Grid

2021 ◽  
Vol 4 (4) ◽  
pp. 4-16
Author(s):  
Michael E. MOZAH ◽  
◽  
Sergey V. SAMOYLENKOV ◽  
Andrey P. VAVILOV ◽  
Evgeny P. PROKHOROV ◽  
...  
Keyword(s):  
Power System ◽  
High Voltage ◽  
Short Circuit ◽  
Relay Protection ◽  
Short Circuit Current ◽  
Fault Current ◽  
Fault Current Limiter ◽  
Superconducting Fault Current Limiter ◽  
Current Limiter ◽  
Technical Solutions

Superconducting fault current limiter (SFCL) is an innovative method for reducing the level of short-circuit currents in high-voltage electrical networks. This reduces the number of points of separation of the electrical network in conditions of short-circuit current limitation and thereby increases the network capacity and reliability of power supply to consumers. At the same time, the development of such devices poses new challenges for power engineers related to the integration of this equipment into the existing power system. The article discusses the process of implementation and pilot operation of the SFCT 220 kV pilot project (produced by CJSC “SuperOx”) at the 220/20 kV “Mnevniki” high-voltage substation in Moscow. The project required an extensive set of scientific studies and tests to confirm the characteristics of new devices and the possibility of their use in Russian power systems, the use of digital modeling technologies to test the operability of relay protection devices, as well as the development of new methodological documents for calculating the short-circuit current and relay protection parameters. As a result of the work, SFCT was switched on at the 220/20 kV “Mnevniki” substation at the end of 2019. The subsequent operation of the SFCT in 2019-2020 fully confirmed the declared characteristics of the device and the correctness of the selected technical solutions. The article is devoted to the features of the process of integrating a new device into the existing power system, the main technical solutions, the results of testing and operation of the device, as well as possible prospects for the development of SFCT technology.

scholarly journals Frequency and time fault diagnosis methods of power transformers

2018 ◽  
Vol 18 (4) ◽  
pp. 162-167 ◽  
Author(s):  
Miroslav Gutten ◽  
Daniel Korenciak ◽  
Matej Kucera ◽  
Richard Janura ◽  
Adam Glowacz ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
High Voltage ◽  
Impact Test ◽  
Power Transformer ◽  
Short Circuit ◽  
Small Deformation ◽  
Short Circuit Current ◽  
Diagnostic Methods ◽  
Response Analysis ◽  
Short Circuit Currents

Abstract The authors describe experimental and theoretical analyses of faults of power transformer winding. Faults were caused by mechanical effect of short-circuit currents. Measurements of transformer were carried out in high-voltage laboratory. Frequency and time diagnostic methods (method SFRA - Sweep Frequency Response Analysis, impact test) were used for the analyses. Coils of transformer windings were diagnosed by means of the SFRA method and the time impact test. The analyzed methods had a significant sensitivity to a relatively small deformation of coil. In the analysis a new technique for analyzing the effects of short-circuit currents is introduced. This technique is developed for high-voltage transformers (different types of power). The proposed analyses show that it is necessary to analyze the value of short-circuit current. Short-circuit current represents a danger for the operation of the power transformer. The proposed approach can be used for other types of transformers. Moreover, the presented techniques have a potential application for fault diagnosis of electrical equipment such as: transformers and electrical machines.

Modeling Analysis of Impedance Characteristics of Saturated Core Superconducting Fault Current Limiter

2013 ◽  
Vol 389 ◽  
pp. 1089-1095
Author(s):  
Jun Zhen Peng ◽  
Kun Nan Cao ◽  
Da Da Wang ◽  
Meng Song ◽  
Nan Nan Hu ◽  
...  
Keyword(s):  
High Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Fault Current ◽  
Fault Current Limiter ◽  
Element Analysis ◽  
Superconducting Fault Current Limiter ◽  
Saturation Properties ◽  
Modeling Analysis ◽  
Current Limiter

As one of the most applicable to high-voltage network superconducting fault current limiterSCFCL(saturated core superconducting fault current limiter) ,which use of core saturation properties can be achieved the current-limiting function without delay ,will be the most widely applied in the future,By analyzing the working principle of SCFCL,this paper use of PSCAD and finite element analysis software Ansoft to build the 500kV\/3150A grade SCFCL model and accurate calculation coil self-inductance and mutual inductance, the harmonic of each size and analyzed its Impedance characteristic on the different external parameters,The results show that SCFCL has a excellent performance for high voltage power network short-circuit current limitation, and provides important reference for design.

scholarly journals Modeling of transformer type fault current limiter in 22kv distribution power system at Ho Chi Minh City

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Đoàn Tự Do ◽  
Lê Bửu Toàn ◽  
Lê Thị Tịnh Minh
Keyword(s):  
Power System ◽  
Distribution System ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Fault Current ◽  
Fault Current Limiter ◽  
Technical Problems ◽  
High Impedance ◽  
Transformer Type ◽  
Current Limiter

Nowadays, with consecutive development of the power system, not only the scale of the grid is expanded but also many technical problems exist. One of the most important problems is the exceeding short circuit current in the power grid, this value exceeds out of the regulation’s range as well as breaking capacity of the protection devices. In this paper, a fault current limiter (FCL) device is introduced as a solution; it works as a high impedance in short circuit cases and low impedance in normally case. This paper simulates the fault current limiter transformer type in MATLAB/SIMULINK, the effect of FCLT’s parameters to short circuit reduction is given in the results. Application of FCLT in reality network also is presented with markable results of short circuit reduction in Ho Chi Minh Power Corporation‘s distribution system.

scholarly journals Fault Assessment and Mitigation of the 132kV Transmission Line in Nigeria using Improved Resonant Fault Current Limiting (RFCL) Protection Scheme

2018 ◽  
Vol 3 (10) ◽  
pp. 38-44
Author(s):  
D. C. Idoniboyeobu ◽  
S. L. Braide ◽  
Wigwe Elsie Chioma
Keyword(s):  
Power System ◽  
Transmission Line ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Resonant Circuit ◽  
Fault Current ◽  
Protection Scheme ◽  
Current Limiting ◽  
Simulation Results ◽  
The Impact

This research work proposed an improved Resonant Fault Current Limiting (RFCL) protection scheme to reduce the impact of three-phase short-circuit faults in a power system sub-transmission network. The model used an interpolator-extrapolator technique based on a Resonant Fault Current Limiter (RFCL) for automating the procedure of predicting the required reactor value that must be in resonant circuit to limit the short-circuit current values to permissible values. Using the developed model, short-circuit fault simulations on the three phases of the transmission line (Phase A-C) were performed in the MATLAB-SIMULINK environment. Simulation results were obtained by varying the resonant inductance (reactor) parameter of the RFCL circuit for each of the phases to obtain permissible short-circuit current levels and the values used to program a functional interpolator-extrapolator in MATLAB; the resonant values were typically set to values of inductance equal to 0.001H, 0.01H and from 0.1H to 0.5H in steps of 0.1H. Simulation results revealed the presence of very high short-circuit current levels at low values of the resonant inductor. From the results of simulations, there are indications that the RFCL approach is indeed very vital in the reduction of the short circuit current values during the fault and can safeguard the circuit breaker mechanism in the examined power system sub-transmission system. In addition, lower fault clearing times can be obtained at higher values of inductances; however, the clearance times start to converge at inductance values of 0.1H and above.

scholarly journals Comparative Analysis of High-Voltage Power Line Models for Determining Short-Circuit Currents in Towers Earthing Systems

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4729
Author(s):  
Rafał Tarko ◽  
Jakub Gajdzica ◽  
Wiesław Nowak ◽  
Waldemar Szpyra
Keyword(s):  
High Voltage ◽  
Current Distribution ◽  
Single Phase ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Power Line ◽  
Power Lines ◽  
Distribution Analysis ◽  
Short Circuits ◽  
Short Circuit Currents

The article deals with the problems of single-phase short-circuit current distribution in overhead power lines. Short-circuit disturbances cause many negative phenomena in power networks. Since experimental studies of short-circuits in real networks are practically impossible to perform, these effects can be evaluated only theoretically, based on short-circuit current calculations with the use of appropriate mathematical models. Although short-circuit modeling is considered to be one of the simplest power system calculations, the exact mathematical description of the phenomena occurring at short-circuits is complex. Simplified normative methods are often used for short-circuit current calculations; however, this does not give ground for a thorough analysis of short-circuit current distribution in power lines. The distributions are analyzed using power line models with different degrees of complexity in line with the assumptions made for a given model. The paper presents the problem of current distribution analysis in high-voltage overhead lines for single-phase faults to the tower structures. Simulation studies were conducted on the models developed for the calculation of short-circuit currents in the high-voltage power line earthing. The objective of the analysis was to assess the validity of simplification assumptions followed by practical recommendations on the applicability of the models.

A Type of Depth Fault Current Limiter Based on Fast Switch and its Experimental Research

2014 ◽  
Vol 521 ◽  
pp. 213-216
Author(s):  
Li Jun Qin ◽  
Xiao Teng Wu
Keyword(s):  
Power System ◽  
Energy Loss ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Short Circuit Current ◽  
Current Level ◽  
Fault Current ◽  
Fault Current Limiter ◽  
Fault Currents ◽  
Current Limiter

Along with the expansion of power system, the rapid growth of load in power system and large capacity generators continuously going into operation, the increasing of short-circuit current level cause a serious threat to the security of the power system. The contradiction between high fault currents and limited circuit breaker interrupting capacity is prominent, in order to limit high short-circuit current, reduce the energy loss of traditional fault current limiter, and improve the limiting depth, this paper presents an new fault current limiter (FCL), and analysis its ability of limiting short current.

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