Exact pi-model of UPFC-inserted transmission lines in power flow studies

2002 ◽  
Vol 22 (12) ◽  
pp. 54-56 ◽  
Author(s):  
M.I. Alomoush
Keyword(s):  
Transmission Lines ◽  
Power Flow

A phasor-distance based faulty phase detection and fault classification technique for parallel transmission lines

2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Nishant Kothari ◽  
Bhavesh R. Bhalja ◽  
Vivek Pandya ◽  
Pushkar Tripathi ◽  
Soumitri Jena
Keyword(s):  
Transmission Lines ◽  
Power Flow ◽  
Detection Algorithm ◽  
Current Transformer ◽  
Operating Conditions ◽  
Fault Classification ◽  
Phase Detection ◽  
Parallel Transmission ◽  
Classification Technique ◽  
Computational Requirement

AbstractThis paper presents a phasor-distance based faulty phase detection and fault classification technique for parallel transmission lines. Detection and classification of faulty phase(s) have been carried out by deriving indices from the change in phasor values of current with a distance of one cycle. The derived indices have zero values during normal operating conditions whereas the index corresponding to the faulty phase exceeds the pre-defined threshold in case of occurrence of a fault. A separate ground detection algorithm has been utilized for the identification of involvement of ground in a faulty situation. The performance of the proposed technique has been evaluated for intra-circuit, inter-circuit and simultaneous faults with wide variations in system and fault conditions. The suggested technique has been evaluated for over 23,000 diversified simulated fault cases as well as 14 recorded real fault events. The performance of the proposed technique remains consistent under Current Transformer (CT) saturation as well as different amount and direction of power flow. Moreover, suitability to different power system network has also been studied. Also, faults having fault current less than pre-fault conditions have been detected accurately. The results obtained suggest that it is able to detect faulty phases as well as classify faults within quarter-cycle from the inception of fault with impeccable accuracy. Besides, as modern digital relays have been already equipped with phasor computation facility, phasor-based technique can be easily incorporated with relative ease. At last, a comparative evaluation suggests its superiority in terms of fault classification accuracy, fault detection time, diversify fault scenarios and computational requirement among other existing techniques.

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.

scholarly journals Co-Optimized Analysis and Design of Electric and Natural Gas Infrastructures

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 2012 ◽  
Author(s):  
Santiago Lemos-Cano ◽  
James McCalley
Keyword(s):  
Natural Gas ◽  
Transmission Lines ◽  
Power Flow ◽  
Planning Process ◽  
The United States ◽  
Integrated System ◽  
Mixed Integer ◽  
Eastern Region ◽  
Analysis And Design ◽  
Expansion Planning

This paper proposes and implements a long-term deterministic capacity expansion model for the co-optimization of electric and natural gas infrastructures. It determines the required investments in generation units, transmission lines and pipelines for meeting future demands, while representing electricity and natural gas flows using DC Power Flow and Weymouth equations, respectively. A Mixed Integer Nonlinear Programming (MINLP) problem is developed, from which a linearized version is derived. A 26 node integrated gas-electric system for the Eastern Region of the United States is used to demonstrate the model’s capabilities. Results show that the model provides an accurate operational representation of the integrated system, and, therefore, enhances the expansion planning process.

Optimal Transmission Switching Problem Utilizing an Enhanced Multi-Phase Seeker Optimization Algorithm

2016 ◽  
Vol 24 ◽  
pp. 85-102 ◽  
Author(s):  
Ragab A. El-Sehiemy ◽  
Mohammed Badeaa Shafiq ◽  
Ahmed M. Azmy
Keyword(s):  
Transmission Lines ◽  
Optimization Algorithm ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Cost Savings ◽  
Production Costs ◽  
Voltage Deviation ◽  
Multi Phase ◽  
The Cost ◽  
Seeker Optimization Algorithm

This paper proposes a procedure based on a multi-phase seeker optimization algorithm (MSOA) for optimizing the commitment of transmission system. The under consideration problem is formulated with the aid of AC-based security constrained optimal power flow (SC-OPF) considering system constraints. The target is to detect transmission lines commitment schedule that reduces system production costs and enables sufficient reserve levels from both generation and transmission. The methodology is illustrated through several computational tests on IEEE 57 and IEEE 118 bus test systems to confirm the previous objectives. It is proven that numerical results based on the use the AC model demonstrate that the calculation time is short enough and the cost savings are reasonably better than DC power flow model. In addition, all transmission lines are preserved within their permissible boundaries and the voltage deviation is maintained at the least levels.

Synchrophasors-Assisted IPII-Based Intelligent Relaying for Transmission Lines Including UPFC

2015 ◽  
Vol 16 (1) ◽  
pp. 47-57 ◽  
Author(s):  
Manas Kumar Jena ◽  
S. R. Samantaray
Keyword(s):  
Data Mining ◽  
Decision Tree ◽  
Transmission Lines ◽  
Power Flow ◽  
Unified Power Flow Controller ◽  
Phasor Measurements ◽  
Real Time Digital Simulator ◽  
Mining Model ◽  
Power Flow Controller ◽  
Instantaneous Voltage

Abstract This paper proposes a synchrophasors-assisted intelligent relaying scheme for transmission lines compensated by Unified Power Flow Controller (UPFC). The algorithm uses a new relaying signal termed as imaginary part of integrated impedance (IPII). The synchronized phasor measurements at both ends of the transmission line are used to extract voltage and current phasors from instantaneous voltage and current signals. The voltage and current phasors are utilized to derive IPII of each phase. Further, IPII of each phase is used as input to a data-mining model termed as decision tree (DT) which provides the final relaying decision. The proposed algorithm is validated on real-time digital simulator (RTDS) platform, and the results obtained indicate that the proposed scheme is both dependable and secure in protecting transmission system compensated by UPFC.

Relation of Damping to Power Flow on Transmission lines

2009 ◽  
Author(s):  
Xuezhi Liu ◽  
Dichen Liu ◽  
Qingfen Liao ◽  
Yong Huang ◽  
Xiaojie Pan
Keyword(s):  
Transmission Lines ◽  
Power Flow
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