Maximum Power Loss Research Articles

Enhancing power system loadability using IPFC device

In today’s scenario, there is a need for efficient transmission of power from power plants to consumers end. To meet such a need, a recently evolved FACTS technology is used. In this paper, IPFC device is used to enhance loadability of transmission line. An improved gravitational search algorithm is proposed to increase the maximum transfer capability using this device. In the proposed algorithm, the velocity of each agent is improved. If the agents’ velocity is at maximum, only then the optimum solution is obtained. Here all the solutions are contributing to select the best solution through mass determination of each agent. Maximum power loss of the system is used as a fitness function in IGSA algorithm. Proposed algorithm is implemented on MATLAB platform using IEEE 57 bus test system. Performance of IGSA is compared with gravitational search algorithm (GSA).

Optimal location and sizing of Unified Power Flow Controller (UPFC) to improve dynamic stability: A hybrid technique

In this paper a hybrid technique based optimal location and sizing of UPFC to improve the dynamic stability is proposed. Here, the maximum power loss bus is identified at the most favorable location for fixing the UPFC, because the generator outage affects the power flow constraints such as power loss, voltage, real and reactive power flow. The optimum location has been determined using the Artificial Bees Colony (ABC) algorithm. Depending on the violated power flow quantities the Gravitational Search Algorithm (GSA) optimizes the required quantity of the UPFC to recover the initial operating condition. Then the proposed work is implemented in the MATLAB/simulink platform and the performance is evaluated by using the comparison, at different techniques like ABC and GSA. The comparison results demonstrate the superiority of the proposed approach and confirm its potential to solve the problem.

Optimal location and sizing of DSTATCOM in distribution systems by immune algorithm

In this paper, optimal location and sizing of DSTATCOM for the sake of power loss reduction, and improvement of current and voltage profile in distribution networks are investigated. An effective biologically inspired algorithm (Immune Algorithm) is used to search the best location and determine the size of DSTATCOM. By keeping voltage and current profile improvements in mind, minimum cost of installation of DSTATCOM and maximum power loss reduction are integrated into an objective function through appropriate weighting factors. Comparative results are obtained on two standard distribution systems (IEEE 33-bus and IEEE 69-bus) with encouraging optimization as far as location and size of DSTATCOM and objective function minimization are concerned.

Principle Optimal Placement and Sizing of Single Distributed Generation for Power Loss Reduction using Particle Swarm Optimization

This study presents a methodology using Particle Swarm Optimization (PSO) for the placement of single Distributed Generation (DG) in the radial distribution systems to reduce the power loss. The single DG placement is used to find the optimal DG location and sizing which is corresponded to the maximum power loss reduction. The proposed method is tested on the 26-bus radial power distribution system which modified from the Provincial Electricity Authority system in Thailand. The load flow analysis on distribution system used forward-backward sweep methodology. The simulation results show that PSO can obtain the maximum power loss reductions. The total consumption power is 8.49 MW and 5.97 MVAR and total power loss is 11.68 kW and 26.08 kVAR. This study can be verify that the PSO method can solve the best placement and sizing on the real system.

Performance of FeCoB based thin-film microwave noise suppressor applied to the electromagnetic interference design in the GHz frequency range

To develop high performance microwave noise suppressor, the microwave noise suppressors based on a microstrip line using FeCoB based magnetic thin film are presented, whose microwave noise suppression effects have been investigated. It was found that suitable low argon pressure is beneficial to the improvement of microwave noise suppression. In addition, the microwave noise suppression properties of microwave noise suppressor could be tuned by controlling the geometric dimension of FeCoB based magnetic thin film and SiO2 dielectric layer, resulted from the ferromagnetic resonance loss and eddy current loss. The maximum power loss ratio (Ploss/Pin) of thin-film microwave noise suppressor (the length, width, and thickness of FeCoNiB thin film are 25 mm, 10 mm, and 250 nm, respectively) achieves 0.75 at 3.4 GHz. These results show that the presented film noise suppressors have potential for the electromagnetic interference design in the GHz frequency range.

Smart Personal Sensor Network Control for Energy Saving in DC Grid Powered LED Lighting System

Emerging smart grid technologies aim to renovate traditional power grid by integrating intelligent devices and their communications for monitoring and automation of the power grid to enable efficient demand-side energy management. In this paper, energy management in smart dc building grid powered dc electrical appliances like lighting is investigated, in particular energy savings from proposed personal lighting management strategy. Unlike conventional fluorescent lamps powered mainly by ac grid, LED luminaires are dc in nature, thus results in significant power conversion losses, if operate on traditional ac powered system, are analyzed with proposed dc distribution building grid for LED lighting. This paper continues to explore the use of smart wireless sensors for personal control of the dc grid powered networked LED lighting. Experimental results show that the proposed smart LED lighting system with an energy saving mechanism incorporated is able to achieve similar lighting performance as the conventional lighting condition, while at the same time, able to attain about 44% energy saving as compared to the original ac fluorescent system. For a low voltage dc grid being implemented, the maximum power loss and voltage drop of the developed dc distribution building grid are 2.25% and 3% respectively.

RF noise suppressor using FeCoNiB soft magnetic thin films on the microstrip line

A radio-frequency noise suppressor based on a microstrip line using FeCoNiB magnetic thin film is presented, whose noise suppression effects have been investigated. The FeCoNiB thin films with excellent soft magnetic properties and high-frequency characteristics were synthesized by the RF magnetron sputtering. It is found that the intensity and frequency of RF transmission signal attenuation can be adjusted by controlling the geometric dimension of the soft magnetic FeCoNiB thin film and SiO2 dielectric layer, owing to the L–C resonance, eddy current loss and FMR loss. Appropriate nickel content in FeCoNiB magnetic thin film is propitious to RF noise suppression characteristics. The maximum power loss of RF noise suppressor achieves 0.87 with the nickel content is 0.09. It indicates that the mentioned FeCoNiB thin film RF noise suppressors have great potential for the application of electromagnetic interference in the gigahertz range.

Optimal Placement and Sizing of Distributed Generation for Power Loss Reduction Using Particle Swarm Optimization

This paper presents a new methodology using particle swarm optimization (PSO) for the placement of distributed generation (DG) in the radial distribution systems to reduce the power loss. Single DG placement is used to find the optimal DG location and its size which corresponding to the maximum loss reduction. The proposed method is tested on the 26-bus radial distribution system which modified from the Provincial Electricity Authority (PEA) distribution system. The total power is 8.49 MW and 5.97 MVAR and the power loss is 11.68kW and 26.08 kVAR. The load flow analysis on distribution use forward-backward sweep methodology. The simulation results show that PSO can obtain the maximum power loss reductions.

Robust and Powerful Tests for Rare Variants Using Fisher's Method to Combine Evidence of Association From Two or More Complementary Tests

Many association tests have been proposed for rare variants, but the choice of a powerful test is uncertain when there is limited information on the underlying genetic model. Proposed methods use either linear statistics, which are powerful when most variants are causal and have the same direction of effect, or quadratic statistics, which are more powerful in other scenarios. To achieve robustness, it is natural to combine the evidence of association from two or more complementary tests. To this end, we consider the minimum-p and Fisher's methods of combining P-values from linear and quadratic statistics. Extensive simulation studies show that both methods are robust across models with varying proportions of causal, deleterious, and protective rare variants, allele frequencies, and effect sizes. When the majority (>75%) of the causal effects are in the same direction (deleterious or protective), Fisher's method consistently outperforms the minimum-p and the individual linear and quadratic tests, as well as the optimal sequence kernel association test, SKAT-O. When the individual test has moderate power, Fisher's test has improved power for 90% of the ~5000 models considered, with >20% relative efficiency gain for 40% of the models. The maximum absolute power loss is 8% for the remaining 10% of the models. An application to the GAW17 quantitative trait Q2 data based on sequence data of the 1000 Genomes Project shows that, compared with linear and quadratic tests, Fisher's test has comparable power for all 13 functional genes and provides the best power for more than half of them.

Optimal location and capacity of multi-distributed generation for loss reduction and voltage profile improvement using imperialist competitive algorithm

This paper proposes an Imperialist Competitive Algorithm (ICA) for optimal multiple distributed generations (DGs) placement and sizing in a distribution system. The objective is to minimize the total real power losses and improve the voltage profile within real and reactive power generation and voltage limits. Three types of DG are considered and the ICA is used to find the better sizes and locations of DGs for maximum real power losses reduction and voltage improvement for given number of DG units in each type. Both integer and continuous variables are considered in ICA, integer variable for locations and continues variable for sizes. The total real power losses and voltage profile evaluation are based on a power flow method for radial distribution system with the representation of DGs. The proposed method has been demonstrated on 33 bus radial distribution system. The efficiency of the ICA in reducing the total power losses and improving voltage is validated by comparing the obtained results with Particle Swarm Optimization (PSO) algorithm.

An Analytical Approach to Maximum Power Tracking and Loss Minimization of a Doubly Fed Induction Generator Considering Core Loss

To get maximum output power from a doubly fed induction generator (DFIG), it is essential to extract maximum mechanical power from the wind turbine and to minimize generator losses. The goal of maximum power tracking and minimum loss is usually achieved through vector control of rotor current. In other words, the d-axis and q-axis rotor currents I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dr</sub> and I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">qr</sub> must be properly controlled as wind speed changes with time. In this paper, an analytical approach is developed to determine proper rotor current commands I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dr</sub> * and I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">qr</sub> * which give maximum mechanical power and minimum loss based on the measured generator speed. The proposed analytical approach is more efficient than the exhaustive search approach proposed in a previous study and is, therefore, more suitable for real-time performance improvements. In addition, core loss component, which was usually neglected in previous studies, is included in the DFIG model in order to have more accurate results. The effectiveness of the derived analytical formulas is demonstrated by an example.

Heuristic Approach for Distribution Systems Feeder Reconfiguration to Line Maximum Loadability

This paper presents a heuristic approach for optimal feeder reconfiguration of radial distribution systems (RDS). Optimal feeder reconfiguration involves the selection of the best set of branches to be opened by considering the all tie switches, such that the resulting RDS has the desired performance. Amongst the several performance criteria considered for optimal feeder reconfiguration, line maximizing loadability is an important one. In this paper an algorithm is proposed based on simple heuristic rules and identified an effective switch status configuration of distribution system for maximizing the line maximum loadability of the system. The line maximum loadability, power loss and voltage profile calculation of the best switching combination are found by load flow solution. Compared to other published articles, the proposed method reduces the switching combinations searched and gives the optimum solution in few number of load flow runs. To demonstrate the validity of the proposed algorithm, computer simulations are carried out on 33-bus system and the performance of the proposed method compared with the other existing methods.

Multiobjective Optimization for Optimal Placement and Size of DG using Shuffled Frog Leaping Algorithm

There has been a great interest in integration of distributed generation (DG) units at distribution level in the recent years. DGs can provide cost-effective, environmental friendly, higher power quality and more reliable energy solutions than conventional generation. For maximum power loss reduction, proper sizing and position of distributed generators are ardently necessary. This paper presents a simple method for optimizing cost and optimal placement of generators. A simple vector based load flow technique is implemented on 38 bus distribution systems. This paper presents a new methodology using a new population based meta heuristic approach namely Shuffled frog leaping algorithm for the placement of Distributed Generators (DG) in the radial distribution systems to reduce the real power losses and cost of the DG. The paper also focuses on optimization of weighting factor, which balances the cost and the loss factors and helps to build up desired objectives with maximum potential benefit. The proposed method has outperformed the other methods in terms of the quality of solution and computational efficiency.

Effect of maximal sprints performed with ball on anaerobic power and performance of footballers

The effect of sprints performed with a ball on the anaerobic power and performance was examined after RAST (Running-Based Anaerobic Sprint Test) that measures the anaerobic power was applied to...

Electro-Optic Tuneable of Direct Current Voltage in Ring Resonator

In this paper, a new design of the electro-optical tuning voltage in buried fiber ring resonator (BFRR) system is proposed. The crystals of LiNbO3, (Ba, Sr)TiO3, K(Ta, Nb)O3 and KH2PO4 are used as electro-optic core materials. The applied voltage can generate different refractive index deformation when used different electro-optic crystals. Different electro-optic crystals produce distinct maximum power loss within BFRR. The power loss in an electro-optic crystal can be controlled by tuning the applied voltage. The K(Ta, Nb)O3 crystal produce maximum power loss with lower voltage compared to other crystals.

Coordinated Tuning of a Group of Static Var Compensators Using Multi-Objective Genetic Algorithm

&#x0D; &#x0D; &#x0D; The optimal coordinated tuning of a group of Static Var Compensators (SVC), in steady state, allows the Power Electric Systems (PES) to operate close to their overload limits, maintaining the voltage stability in several operating conditions. The mentioned tuning problem was considered as a Multi- objective Optimization Problem (MOP) with three objectives to optimize: the financial investment for acquiring the set of compensators, the maximum voltage deviation and total active power loss. The Genetic Algorithm (GA), which belongs to the group of Evolutionary Algorithms, was utilized and adapted for MOP, obtaining a Multi-Objective GA (MOGA). The parameters to be adjusted in each compensator are: the reference voltage and the minimum and maximum reactive power injected to the system. In this work, the number of compensators and their locations were calculated using the Q-V sensitivity curve, from the Load Flow algorithm, based on Newton–Raphson method. The proposed coordinated tuning method will be validated considering an example of PES, where was located and tuned a specific set of compensators. Time simulations were made for dynamic performing the steady state coordinated tuning.&#x0D; &#x0D; &#x0D;

Effect of Rotor Excitation Voltage on Steady-State Stability and Maximum Output Power of a Doubly Fed Induction Generator

The effect of rotor excitation voltage on steady-state stability and output power of a doubly fed induction generator (DFIG) is investigated. Wind turbine mechanical torque-speed characteristics, as well as generator electromagnetic torque-speed characteristics, are considered in the derivation of the steady-state stability region for the magnitude and phase angle of the rotor excitation voltage. To evaluate the maximum output power of a DFIG, detailed expressions for stator power, rotor power, stator loss, rotor loss, and electrical power are derived as functions of the generator speed and the magnitude and phase angle of the rotor excitation voltage. The effect of stator resistance on the magnitude and phase angle of the resultant optimal rotor excitation voltage, which gives maximum output power and minimum loss, is examined. Experimental results are given to demonstrate the effectiveness of the theoretical analysis.

Fault-Tolerant Torque Control of BLDC Motors

Fault tolerance is critical for servomotors used in high-risk applications, such as aerospace, robots, and military. These motors should be capable of continued functional operation, even if insulation failure or open-circuit of a winding occur. This paper presents a fault-tolerant (FT) torque controller for brushless dc (BLdc) motors that can maintain accurate torque production with minimum power dissipation, even if one of its phases fails. The distinct feature of the FT controller is that it is applicable to BLdc motors with any back-electromotive-force waveform. First, an observer estimates the phase voltages from a model based on Fourier coefficients of the motor waveform. The faulty phases are detected from the covariance of the estimation error. Subsequently, the phase currents of the remaining phases are optimally reshaped so that the motor accurately generates torque as requested while minimizing power loss subject to maximum current limitation of the current amplifiers. Experimental results illustrate the capability of the FT controller to achieve ripple-free torque performance during a phase failure at the expenses of increasing the mean and maximum power loss by 28% and 68% and decreasing the maximum motor torque by 49%.

Topologies of multiterminal HVDC-VSC transmission for large offshore wind farms

AbstractTopologies of multiterminal HVDC-VSC transmission systems for large offshore wind farms are investigated. System requirements for multiterminal HVDC are described, particularly the maximum power loss allowed in the event of a fault. Alternative control schemes and HVDC circuit topologies are reviewed, including the need for HVDC circuit breakers. Various topologies are analyzed and compared according to a number of criteria: number and capacity of HVDC circuits, number of HVDC circuit breakers, maximum power loss, flexibility, redundancy, lines utilization, need for offshore switching platforms and fast communications.

IMPROVEMENT IN DATA TRANSMISSION EFFICIENCY IN COMMUNICATION SYSTEMS USING SCATTERING COMPENSATION TECHNIQUES

The primary requirement for maximum power transfer and minimum power loss is matched impedance in a transmission system. However, static design variations in system such as parasitics and dynamic variations such as changes in transmission frequency will result in re∞ections. A redesign or reconflguration of complex systems is neither easy nor cost efiective. A noble technique for compensating re∞ections in a communication system is presented here. The proposed methodology adapts the system to change without any modiflcation to the system physical conflguration. In this methodology compensation signals are added by I/O drivers with programmable phase delay and drive strength adjustments to cancel re∞ections. The concept application is demonstrated for a narrow bandwidth antenna system. An operating frequency ofi the antenna frequency results in a degraded received message eye. Using the proposed technique, without modifying the antenna, re∞ections were compensated and a signiflcantly improved data eye was produced, as measured by the enhancement of critical performance parameters. The architecture of an expanded driver to implement the concept is outlined here. An algorithm and ∞ow chart to dynamically identify and compensate for re∞ections are also presented.