An investigated reactive power measurements-based fault-identification scheme for teed transmission lines

Measurement ◽  
2019 ◽  
Vol 136 ◽  
pp. 185-200 ◽  
Author(s):  
Mohamed I. Zaki ◽  
Ragab A. El-Sehiemy ◽  
Ghada M. Amer ◽  
Fathy M. Abo El Enin
Keyword(s):  
Transmission Lines ◽  
Reactive Power ◽  
Fault Identification ◽  
Identification Scheme ◽  
Power Measurements

Sensitive/stable complementary fault identification scheme for overhead transmission lines

2019 ◽  
Vol 13 (15) ◽  
pp. 3252-3263 ◽  
Author(s):  
Mohamed I. Zaki ◽  
Ragab A. El Sehiemy ◽  
Ghada M. Amer ◽  
Fathy M. Abo El Enin
Keyword(s):  
Transmission Lines ◽  
Fault Identification ◽  
Identification Scheme ◽  
Overhead Transmission Lines

scholarly journals Efficient fault identification scheme of compensated transmission grid based on correlated reactive power measurements and discrete wavelet transform

2021 ◽  
Vol 72 (4) ◽  
pp. 217-228
Author(s):  
Mohamed I. Zaki ◽  
Ragab A. El-Sehiemy ◽  
Ghada M. Amer
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Reactive Power ◽  
Short Circuit ◽  
Measuring System ◽  
Fault Identification ◽  
Discrete Wavelet ◽  
Identification Scheme ◽  
Transmission Grid ◽  
Wide Range

Abstract The early fault identification in high-voltage power systems is a substantial aspect not only to minimize equipment failure but also to increase both the reliability and stability in power system. Subsequently, the aim of this paper is to propose the adaptive fault-identification scheme based on multi-resolution analysis technique. The proposed method is dependent on monitoring both voltages and currents from single-ended measuring system. The correlation among the reactive power computation and discrete wavelet transform is used to generate the significant criteria which are used to discriminate between short-circuit currents and energizing heavy loads behaviour. Different transmission network configurations are investigated to assess the dependability, security, and reliability of fault identification relay as well. The correlative protection scheme attains the accurate results under healthy disturbances, and therefore it is superior to other conventional approaches. In addition, a selective study is applied to different mother wavelets to find the best one. The response of the proposed scheme to the compensated transmission line is also verified at a wide range of compensation levels with faults before and after compensated bank. Simulation tests have been handled via ATP-EMTP to investigate the proper practicability and adaptability of the fault-identication relay.

scholarly journals Multisensor Fault Identification Scheme Based on Decentralized Sliding Mode Observers Applied to Reconfigurable Manipulators

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Bo Zhao ◽  
Yuanchun Li
Keyword(s):  
Sliding Mode ◽  
Sliding Mode Observer ◽  
Fault Identification ◽  
Stable Theory ◽  
Sensor Fault ◽  
Identification Scheme ◽  
Neural Network Controller ◽  
Network Controller ◽  
Sliding Mode Observers ◽  
Reconfigurable Manipulators

This paper concerns with a fault identification scheme in a class of nonlinear interconnected systems. The decentralized sliding mode observer is recruited for the investigation of position sensor fault or velocity sensor fault. First, a decentralized neural network controller is proposed for the system under fault-free state. The diffeomorphism theory is utilized to construct a nonlinear transformation for subsystem structure. A simple filter is implemented to convert the sensor fault into pseudo-actuator fault scenario. The decentralized sliding mode observer is then presented for multisensor fault identification of reconfigurable manipulators based on Lyapunov stable theory. Finally, two 2-DOF reconfigurable manipulators with different configurations are employed to verify the effectiveness of the proposed scheme in numerical simulation. The results demonstrate that one joint’s fault does not affect other joints and the sensor fault can be identified precisely by the proposed decentralized sliding mode observer.

Optimization of Restoration Paths of Power System after Blackout

2013 ◽  
Vol 347-350 ◽  
pp. 1467-1472
Author(s):  
Wen Wei Huang ◽  
Gang Yao ◽  
Xiao Yan Qiu ◽  
Nian Liu ◽  
Guang Tang Chen
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Reactive Power ◽  
Minimum Spanning Tree ◽  
Operation Time ◽  
Combinatorial Problem ◽  
Weather Conditions ◽  
Recovery Process ◽  
Point Of View ◽  
Improved Genetic Algorithm

Optimization of restoration paths of power system after blackout is a multi-stage, multi-target, multi-variable combinatorial problem in the power system restoration. This paper presents a reasonable model and effectually method. The proposed model is considered as a typical partial minimum spanning tree problem from the mathematical point of view which considering all kinds of constraints. Improved data envelopment analysis (DEA) was used to get the weight which considering line charging reactive power, weather conditions, operation time and betweenness of transmission lines. The improved genetic algorithm method is employed to solve this problem. Finally, an example is given which proves the strategy of the line restoration can effectively handle the uncertainty of the system recovery process, to guarantee the system successfully restored after the catastrophic accidents.

scholarly journals STUDY ON EFFECT OF UPFC DEVICE IN ELECTRICAL TRANSMISSION SYSTEM: POWER FLOW ASSESSMENT

2013 ◽  
pp. 70-74
Author(s):  
CH. CHENGAIAH ◽  
R.V.S. SATYANARAYANA ◽  
G.V. MARUTHESWAR MARUTHESWAR
Keyword(s):  
Transmission Lines ◽  
Power Flow ◽  
Reactive Power ◽  
Power Transmission ◽  
Stability Limit ◽  
Transmission System ◽  
Real Time Control ◽  
Electrical Transmission ◽  
Transmission Systems ◽  
Time Control

The power transfer capability of electric transmission lines are usually limited by large signals ability. Economic factors such as the high cost of long lines and revenue from the delivery of additional power gives strong intensive to explore all economically and technically feasible means of raising the stability limit. On the other hand, the development of effective ways to use transmission systems at their maximum thermal capability. Fast progression in the field of power electronics has already started to influence the power industry. This is one direct out come of the concept of FACTS aspects, which has become feasible due to the improvement realized in power electronic devices in principle the FACTS devices should provide fast control of active and reactive power through a transmission line. The UPFC is a member of the FACTS family with very attractive features. This device can independently control many parameters. This device offers an alternative mean to mitigate transmission system oscillations. It is an important question is the selection of the input signals and the adopted control strategy for this device in order to damp power oscillations in an effective and robust manner. The UPFC parameters can be controlled in order to achieve the maximal desire effect in solving first swing stability problem. This problem appears for bulky power transmission systems with long transmission lines. In this paper a MATLAB Simulink Model is considered with UPFC device to evaluate the performance of Electrical Transmission System of 22 kV and 33kV lines. In the simulation study, the UPFC facilitates the real time control and dynamic compensation of AC transmission system. The dynamic simulation is carried out in conjunction with the N-R power flow solution sequence. The updated voltages at each N-R iterative step are interpreted as dynamic variables. The relevant variables are input to the UPFC controllers.

Researches on Reactive Compensation for Long-Distance and Highcapacity Hybrid Submarine Cable Lines

2012 ◽  
Vol 433-440 ◽  
pp. 2406-2410
Author(s):  
Dong Mei Sun ◽  
Jun Wen
Keyword(s):  
High Voltage ◽  
Transmission Lines ◽  
Reactive Power ◽  
High Capacity ◽  
Reactive Power Compensation ◽  
Submarine Cable ◽  
Long Distance ◽  
Power Frequency ◽  
Electro Magnetic ◽  
Cable Lines

In order to balance reactive power, reduce line losses, prevent excessive power frequency and switching over-voltage and adjust and control the line voltage etc. The long-distance and high voltage transmission lines are needed reactive power compensation. High voltage overhead transmission lines and high voltage submarine cable (including mixed-submarine) transmission lines are different, for example, the capacitance in the submarine cable lines is larger than in the conventional overhead lines. Therefore, the reactive power compensation on the EHV transmission lines which contains submarine cable lines is focus on the compensation of submarine cable lines. The reactive power compensation in 500 kV AC submarine cable interconnection project for Hainan power grid and Guangdong power grid[1], which is the first 500 kV long-distance and high-capacity sea trails interconnection project in China and which is just completed soon, is researched by Electro-Magnetic Transient Program——PSCAD/EMTDC (Power System Computer Aided Design/ Electro Magnetic Transient in DC System in this paper). The simulation results verifies that the role of shunt reactor which could absorb charging power and suppress the power frequency overvoltage for the long-distance and high-capacity hybrid submarine cable lines. The conclusions can offer references to suppress power frequency overvoltage and the reactive power compensation in extra high voltage transmission lines which is the mixed mode of overhead transmission lines and submarine cables.

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