An Enhanced Symmetrical Fault Detection during Power Swing/Angular Instability using Park’s Transformation

2016 ◽  
Vol 2 (1) ◽  
pp. 23 ◽  
Author(s):  
Jeevitha A ◽  
Devi S
Keyword(s):  
Fourier Transform ◽  
Power Systems ◽  
Operating Conditions ◽  
Electrical Machine ◽  
Distance Relay ◽  
Power Swing ◽  
Three Phase ◽  
Wide Range ◽  
Simulation Results ◽  
Line Switching

<p>Power systems are subjected to a wide range of small or large disturbances during operating conditions. Power system disturbances such as line switching, generator disconnection and sudden removal of faults causes oscillations in an electrical machine rotor angles that can result in severe power swings. Depending on the protection controls, the system may remain stable or unstable and it may result in loss of synchronism. In recent years, distance relay finds difficulty between symmetrical fault and power swing which causes undesired tripping of the transmission line is the foremost reason for blackout. This paper proposes a new method Park’s Transformation and Fast Fourier Transform which are used to discriminate between the three phase fault and power swing and also to protect the backup zone of distance relay. This method is verified for normal and abnormal conditions with different load angles and different fault locations in IEEE 6-bus system are simulated in MATLAB/ Simulink. The Simulation results show the capability to avoid unwanted tripping decision of relay quickly and precisely.</p>

scholarly journals An accurate technique for supervising distance relays during power swing

2021 ◽  
Vol 21 (3) ◽  
pp. 1279
Author(s):  
Loai Mohamed Ali El-Sayed ◽  
Doaa Khalil Ibrahim ◽  
Mahmoud Ibrahim Gilany ◽  
Aboul’Fotouh El’Gharably
Keyword(s):  
Power System ◽  
The State ◽  
Distance Relay ◽  
Transient Phenomenon ◽  
Power Swing ◽  
Switching Line ◽  
Power Frequency ◽  
Simulation Results ◽  
Distance Relays ◽  
Line Switching

Power swing is a power system transient phenomenon that arises due to several reasons including line switching, line outage, sudden increment or decrement in load, faults, etc. Unnecessary tripping during power swing and unnecessary blocking for faults occur during power swing result in distance relay maloperation. Several cascaded outages and major worldwide blackouts have occurred due to maloperation of distance relays. This paper proposes a technique for supervising distance relays during power swing. The proposed online technique discriminates real faults and power swing accurately. It relies on constructing a locus diagram for the current and voltage differences (∆I-∆V) between the two ends of the protected line. The locus is estimated at every power frequency cycle to continuously monitor the state of the line by utilizing the synchrophasor measurements at the sending and receiving ends of the line. The proposed technique is tested for two-area, four-machine power system under faults at different locations of zone-1 and zone-2 regions of distance relays, fault resistances, fault inception angles and slip frequencies using MATLAB software. The simulation results proved the superior improvement of distance relay performance for handling power swing blocking and unblocking actions.

scholarly journals Optimized Thermal Efficiency of Rotor and Stator Using CFD

2020 ◽  
Vol 6 (6) ◽  
pp. 29-37
Author(s):  
Md. Shahwaz Hussain ◽  
Sujata Pouranik
Keyword(s):  
Temperature Distribution ◽  
Air Flow ◽  
Operating Conditions ◽  
Electrical Machine ◽  
Total Efficiency ◽  
Transfer Pattern ◽  
Turbulence Effect ◽  
Total Temperature ◽  
Simulation Results ◽  
And Performance

The space between rotor and stator plays a very important role in the design and performance of rotating machinery. The thickness of the gap can vary considerably depending on the size and operating conditions for the different types of rotating machines. Analysis the air velocity and temperature distribution over the air flow gap in stator and motor. Changing the design of rotor to develop turbulence in air flow gap. Compare the velocity and temperature distribution of proposed design with previous studies. The simulation results pinpoint also the periodic heat transfer pattern from the rotor surface and this provides useful information for the prediction of the temperature distribution inside the rotating electrical machine. The simulation results of case-1 show about 117°C temperature inside the rotor machine. Then increase the number of slot inside the rotor machine the total temperature of the rotor machine decreases up to 76°C. Due to low temperature total efficiency of the system increases. And also reduces the loss due to heat. The turbulence effect inside the rotor increase in third case. Due to turbulence effect the air cover large amount of area inside the rotor. So total temperature of the rotor casing decreases. In a system where volume is held constant, there is a direct relationship between Pressure and Temperature. For this case, when the pressure increases then the temperature also increases. When the pressure decreases, then the temperature decreases. So pressure in third case decrease upto1.26Pa and temperature 76 °C.

scholarly journals Flow and Fast Fourier Transform Analyses for Tip Clearance Effect in an Operating Kaplan Turbine

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 264 ◽  
Author(s):  
Hyoung-Ho Kim ◽  
Md Rakibuzzaman ◽  
Kyungwuk Kim ◽  
Sang-Ho Suh
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Tip Clearance Flow ◽  
Kaplan Turbine ◽  
Turbine Performance ◽  
Wide Range ◽  
Clearance Flow ◽  
Fft Analysis

The Kaplan turbine is an axial propeller-type turbine that can simultaneously control guide vanes and runner blades, thus allowing its application in a wide range of operations. Here, turbine tip clearance plays a crucial role in turbine design and operation as high tip clearance flow can lead to a change in the flow pattern, resulting in a loss of efficiency and finally the breakdown of hydro turbines. This research investigates tip clearance flow characteristics and undertakes a transient fast Fourier transform (FFT) analysis of a Kaplan turbine. In this study, the computational fluid dynamics method was used to investigate the Kaplan turbine performance with tip clearance gaps at different operating conditions. Numerical performance was verified with experimental results. In particular, a parametric study was carried out including the different geometrical parameters such as tip clearance between stationary and rotating chambers. In addition, an FFT analysis was performed by monitoring dynamic pressure fluctuation on the rotor. Here, increases in tip clearance were shown to occur with decreases in efficiency owing to unsteady flow. With this study’s focus on analyzing the flow of the tip clearance and its effect on turbine performance as well as hydraulic efficiency, it aims to improve the understanding on the flow field in a Kaplan turbine.

Eigenvalue Assignments in Multimachine Power Systems using Multi-Objective PSO Algorithm

2015 ◽  
Vol 4 (3) ◽  
pp. 33-48 ◽  
Author(s):  
Yosra Welhazi ◽  
Tawfik Guesmi ◽  
Hsan Hadj Abdallah
Keyword(s):  
Power Systems ◽  
Optimal Parameter ◽  
Pso Algorithm ◽  
Operating Conditions ◽  
Performance Indices ◽  
Power System Stabilizers ◽  
Nonlinear Simulation ◽  
Multi Objective ◽  
Electromechanical Modes ◽  
Wide Range

Applying multi-objective particle swarm optimization (MOPSO) algorithm to multi-objective design of multimachine power system stabilizers (PSSs) is presented in this paper. The proposed approach is based on MOPSO algorithm to search for optimal parameter settings of PSS for a wide range of operating conditions. Moreover, a fuzzy set theory is developed to extract the best compromise solution. The stabilizers are selected using MOPSO to shift the lightly damped and undamped electromechanical modes to a prescribed zone in the s-plane. The problem of tuning the stabilizer parameters is converted to an optimization problem with eigenvalue-based multi-objective function. The performance of the proposed approach is investigated for a three-machine nine-bus system under different operating conditions. The effectiveness of the proposed approach in damping the electromechanical modes and enhancing greatly the dynamic stability is confirmed through eigenvalue analysis, nonlinear simulation results and some performance indices over a wide range of loading conditions.

scholarly journals Robust state feedback controller design of STATCOM using chaotic optimization algorithm

2010 ◽  
Vol 7 (2) ◽  
pp. 253-268 ◽  
Author(s):  
Amin Safari ◽  
Hossein Shayeghi ◽  
Ali Heidar
Keyword(s):  
Power Systems ◽  
Optimization Algorithm ◽  
State Feedback ◽  
Controller Design ◽  
Low Frequency ◽  
Operating Conditions ◽  
Feedback Controller ◽  
Static Synchronous Compensator ◽  
State Feedback Controller ◽  
Wide Range

In this paper, a new design technique for the design of robust state feedback controller for static synchronous compensator (STATCOM) using Chaotic Optimization Algorithm (COA) is presented. The design is formulated as an optimization problem which is solved by the COA. Since chaotic planning enjoys reliability, ergodicity and stochastic feature, the proposed technique presents chaos mapping using Lozi map chaotic sequences which increases its convergence rate. To ensure the robustness of the proposed damping controller, the design process takes into account a wide range of operating conditions and system configurations. The simulation results reveal that the proposed controller has an excellent capability in damping power system low frequency oscillations and enhances greatly the dynamic stability of the power systems. Moreover, the system performance analysis under different operating conditions shows that the phase based controller is superior compare to the magnitude based controller.

Yaw Rate Estimation for Vehicle Control Applications

1998 ◽  
Vol 120 (2) ◽  
pp. 267-274 ◽  
Author(s):  
N. Sivashankar ◽  
A. G. Ulsoy
Keyword(s):  
Experimental Validation ◽  
Vehicle Control ◽  
Operating Conditions ◽  
Angle Sensor ◽  
Control Applications ◽  
Rate Estimation ◽  
Yaw Rate ◽  
Wide Range ◽  
Simulation Results ◽  
Instrumented Vehicle

This paper describes a method for vehicle yaw rate estimation using two accelerometers and a steer angle sensor. This yaw rate estimate can be used as an inexpensive alternative to commercial yaw rate sensors in vehicle control applications. The proposed method combines two complementary approaches to yaw rate estimation using accelerometers. This new method is superior to either method used by itself. This paper presents the new approach, supporting analyses, simulation results and experimental validation. The simulation results are based upon both linear and nonlinear vehicle dynamics models and include important effects such as sensor drift and noise, disturbances acting on the vehicle, and model uncertainties. The experimental validation is based on test data from a specially instrumented vehicle driven on a test track. These results indicate that the proposed yaw rate estimation scheme performs well for a wide range of operating conditions and is not difficult to implement.

scholarly journals Two cases studies of Model Predictive Control approach for hybrid Renewable Energy Systems

AIMS Energy ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1241-1259
Author(s):  
Lei Liu ◽  
◽  
Takeyoshi Kato ◽  
Paras Mandal ◽  
Alexey Mikhaylov ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Model Predictive Control ◽  
Power System ◽  
Predictive Control ◽  
Operating Conditions ◽  
Load Frequency Control ◽  
First Case ◽  
Control Scheme ◽  
Wide Range ◽  
Simulation Results

<abstract><p>This work presents a load frequency control scheme in Renewable Energy Sources(RESs) power system by applying Model Predictive Control(MPC). The MPC is designed depending on the first model parameter and then investigate its performance on the second model to confirm its robustness and effectiveness over a wide range of operating conditions. The first model is 100% RESs system with Photovoltaic generation(PV), wind generation(WG), fuel cell, seawater electrolyzer, and storage battery. From the simulation results of the first case, it shows the control scheme is efficiency. And base on the good results of the first case study, to propose a second case using a 10-bus power system of Okinawa island, Japan, to verify the efficiency of proposed MPC control scheme again. In addition, in the second case, there also applied storage devices, demand-response technique and RESs output control to compensate the system frequency balance. Last, there have a detailed results analysis to compare the two cases simulation results, and then to Prospects for future research. All the simulations of this work are performed in Matlab®/Simulink®.</p></abstract>

Development of a Unique, Passive, Microgravity Vortex Separator

2005 ◽  
Author(s):  
M. Ellis ◽  
C. Kurwitz ◽  
F. Best
Keyword(s):  
Waste Water ◽  
Phase Separation ◽  
Power Systems ◽  
Gas Flow ◽  
Full Range ◽  
Operating Conditions ◽  
Microgravity Environment ◽  
Flow Rates ◽  
Wide Range ◽  
Vortex Separator

In the microgravity environment experienced by space vehicles, liquid and gas do not naturally separate as on Earth. This behavior presents a problem for two-phase space systems, such as environment conditioning, waste water processing, and power systems. Furthermore, with recent renewed interest in space nuclear power systems, a microgravity Rankine cycle is attractive for thermal to electric energy conversion and would require a phase separation device. Responding to this need, researchers have conceived various methods of producing phase separation in low gravity environments. These separator types have included wicking, elbow, hydrophobic/hydrophilic, vortex, rotary fan separators, and combinations thereof. Each class of separator achieved acceptable performance for particular applications and most performed in some capacity for the space program. However, increased integration of multiphase systems requires a separator design adaptable to a variety of system operating conditions. To this end, researchers at Texas A&M University (TAMU) have developed a Microgravity Vortex Separator (MVS) capable of handling both a wide range of inlet conditions as well as changes in these conditions with a single, passive design. Currently, rotary separators are recognized as the most versatile microgravity separation technology. However, compared with passive designs, rotary separators suffer from higher power consumption, more complicated mechanical design, and higher maintenance requirements than passive separators. Furthermore, research completed over the past decade has shown the MVS more resistant to inlet flow variations and versatile in application. Most investigations were conducted as part of system integration experiments including, among others, propellant transfer, waste water processing, and fuel cell systems. Testing involved determination of hydrodynamic conditions relating to vortex stability, inlet quality effects, accumulation volume potential, and dynamic volume monitoring. In most cases, a 1.2 liter separator was found to accommodate system flow conditions. This size produced reliable phase separation for liquid flow rates from 1.8 to 9.8 liters per minute, for gas flow rates of 0.5 to 180 standard liters per minute, over the full range of quality, and with fluid inventory changes up to 0.35 liters. Moreover, an acoustic sensor, integrated into the wall of the separation chamber, allows liquid film thickness monitoring with an accuracy of 0.1 inches. Currently, application of the MVS is being extended to cabin air dehumidification and a Rankine power cycle system. Both of these projects will allow further development of the TAMU separator.

Simulation And Analysis of An Intelligent Power System Stabilizer Using Fuzzy Logic

2020 ◽  
Vol 27 (4) ◽  
pp. 70-86
Author(s):  
firas AlDurze ◽  
sura Abdullah
Keyword(s):  
Fuzzy Logic ◽  
Power System ◽  
Synchronous Machine ◽  
Operating Conditions ◽  
Superior Performance ◽  
Power System Stabilizer ◽  
Operation Conditions ◽  
Wide Range ◽  
Simulation Results ◽  
System Stabilizer

The basic aim of the power system stabilizer is to damp the fluctuations that occur on the rotating axis of the synchronous generator that result from noise or disturbance on the power system. This is achieved by producing an appropriate damping torque for these fluctuations across the excitation circuit of the generator and for a wide range of operation conditions. The study describes the types of power system stabilizers and giving an mathematical model of the power system that consists of a synchronous machine connected to the infinite bus though transmission lines. This has been achieved by simulating the electric and mechanical equations of power systems and proposing a methodological approach to design a Fuzzy Logic Power System Stabilize (FPSS) relaying in the design on the (Matlab/Fuzzy logic toolbox).Speed deviation (Δω) and acceleration (∆ώ) of the synchronous machine are chosen as the input signals to the fuzzy controller in order to achieve a good dynamic performance .The complete range for the variation of each of the two controller inputs is represented by a 7×7 decision table, i.e. 49 rules using proportional derivative like fuzzy logic. The power system (SMIB) was tested with the presence and absence of the excitation system, then (CPSS) was added, and then (FPSS).The simulation results of the proposed fuzzy logic on )SMIB( gave a better dynamic response, decreased the settling time and good performance of the stabilizer in damping the fluctuations that arise in the speed of rotation of the generator and its active power in various operating conditions when proposed (FPSS) is compared with conventional PSS. The simulation results proved the superior performance of the proposed (FPSS).

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