Decrease Power Loss Research Articles

Enhancement of Voltage Profile in the Distribution system by Reconfiguring with DG placement using Equilibrium Optimizer

As the load steadily rises in a distribution system (DS), electrical power generation is improved. Inserting Distributed Generation (DG) unit in a DS has benefits such as enhancement in voltage profile and decreased power losses. In combination with optimal size, these advantages can be obtained to inject DG in the optimal location. Reconfiguration is another framework for optimizing the voltage profile and reduction of energy loss. Furthermore, reconfiguring the distribution network and installing the DG would ultimately improve system efficiency, which is undoubtedly challenging task. In this paper, equilibrium optimizer (EO) is explored to find out how to reconfigure the distribution network and how best DG can be positioned. For the IEEE-33 bus. Reliability Analysis is also done. The suggested method is implemented in MATLAB R2020A platform software. Outcomes of the suggested Technique based on the EO is compared with the existing techniques. There is Substantial improvement in voltage profile in addition to the decline in loss of power and reliability indexes (EENS, SAIFI, and SAIDI) for different cases of System with DG placement and System.

Low-Voltage GaN FETs in Motor Control Application; Issues and Advantages: A Review

The efficiency and power density improvement of power switching converters play a crucial role in energy conversion. In the field of motor control, this requires an increase in the converter switching frequency together with a reduction in the switching legs’ dead time. This target turns out to be complex when using pure silicon switch technologies. Gallium Nitride (GaN) devices have appeared in the switching device arena in recent years and feature much more favorable static and dynamic characteristics compared to pure silicon devices. In the field of motion control, there is a growing use of GaN devices, especially in low voltage applications. This paper provides guidelines for designers on the optimal use of GaN FETs in motor control applications, identifying the advantages and discussing the main issues. In this work, primarily an experimental evaluation of GaN FETs in a low voltage electrical drive is carried out. The experimental investigation is obtained through two different experimental boards to highlight the switching legs’ behavior in several operative conditions and different implementations. In this evaluative approach, the main GaN FETs’ technological aspects and issues are recalled and consequently linked to motion control requirements. The device’s fast switching transients combined with reduced direct resistance contribute to decreased power losses. Thus, in GaN FETs, a high switching frequency with a strong decrease in dead time is achievable. The reduced dead time impact on power loss management and improvement of output waveforms quality is analyzed and discussed in this paper. Furthermore, input filter capacitor design matters correlated with increasing switching frequency are pointed out. Finally, the voltage transients slope effect (dv/dt) is considered and correlated with low voltage motor drives requirements.

A Novel Analytical Approach for Optimal Placement and Sizing of Distributed Generations in Radial Electrical Energy Distribution Systems

Considering the strong influence of distributed generation (DG) in electric distribution systems and its impact on network voltage losses and stability, a new challenge has appeared for such systems. In this study, a novel analytical algorithm is proposed to distinguish the optimal location and size of DGs in radial distribution networks based on a new combined index (CI) to reduce active power losses and improve system voltage profiles. To obtain the CI, active power losses and voltage stability indexes were used in the proposed approach. The CI index with sensitivity analysis was effective in decreasing power losses and improving voltage stability. Optimal DG size was determined based on a search algorithm to reduce active power losses. The considered scheme was examined through IEEE 12-bus and 33-bus radial distribution test systems (RDTS), and the obtained results were compared and validated in comparison with other available methods. The results and analysis verified the effectiveness of the proposed algorithm in reducing power losses and improving the distribution system voltage profiles by determining the appropriate location and optimal DG size. In IEEE 12 and 33 bus networks, the minimum voltage increased from 0.9434 p.u and 0.9039 p.u to 0.9907 p.u and 0.9402 p.u, respectively. Additionally, the annual cost of energy losses decreased by 78.23% and 64.37%, respectively.

The Reconfiguration of Network at 20 kV Distribution System Nagan Raya Substation with the Addition of the Krueng Isep Hydroelectric Power Plant

Switching substations are usually supplied from one express feeder which can cause a low level of reliability due to disruption or outage on the express feeder. Also, the lack of power supply at the ends of the network causes voltage drops. One way to solve this problem is to reconfigure the network. In this study, testing was carried out on a distribution system in the Nagan Raya Regency, namely the distribution system of PT. PLN (Persero) ULP Jeuram originally had a radial system. Furthermore, the distribution system was reconfigured with the Krueng Isep hydroelectric power plant which was included in the PLN ULP Jeuram grid so that the system that was originally radial became a loop configuration. The method used in analyzing the network reconfiguration process is to use the ETAP 12.6 application. As a result, after reconfiguring the network the voltage increased from 19.2 kV to 20.7 kV, the highest increase was at the Beutong Substation which reached 1.5 kV and decreased power losses in the network with a total of 188.2 kW and 263.1 kVAR. Furthermore, before the network reconfiguration, ULP Jeuram SAIFI value was 22.25 times/customers and SAIDI values 1337.74 minutes/ customers. However, after reconfiguring the network, ULP Jeuram SAIFI value fell to 15.39 times/customers and SAIDI to 945.6 minutes/customers, resulting in an increase in system reliability by 70.69%. Keyword: Reconfiguration of network, distribution system, hydroelectric power plant, SAIDI, SAIFI

Straty mocy i sprawnosc transformatorow

Energy efficiency of transformers has been defined in the paper. The continuous progress noted in technology of electrical steel used for transformer laminations results in decreased lossiness and increase of flux density saturation in the core. Therefore, conditions are established for decreasing core weight and, to a lesser degree, decreasing winding weight as well. The examples of idle and load power losses have been provided for distribution transformers manufactured in 1960s and for those manufactured now. The European Commission [8] and European Standards have ruled that further decrease in power losses and increase in efficiency of newly-installed transformers must come into effect by 1st July, 2021.

Multi-Type FACTS Controllers for Power System Compensation: A Case Study of the Nigerian 48-Bus, 330 kV System

Flexible alternating current transmission system (FACTS) devices have provided proficient answers to power system instabilities faced in the systems operations today with very little infrastructural investment fund. This paper investigates the effects of the installation of the combination of two kinds of FACTS controllers; static VAR compensator (SVC) and thyristor controlled series compensator (TCSC) compared with the installation of SVC or TCSC alone in the system. Voltage magnitude profile, active and reactive power losses of the three scenarios were achieved in the Nigerian 48-bus power system network using power system analysis toolbox (PSAT) in MATLAB environment. Simulation results obtained without and with FACTS devices optimally placed using voltage stability sensitivity factor (VSSF), revealed that the percentage decrease of the net real and reactive power losses of the combined SVC and TCSC was the highest at 31.917% whereas that of the standalone SVC and TCSC stood at 19.769% and 30.863% respectively. This shows that in addition to their capabilities to maintain acceptable voltage profile, the combination of SVC and TCSC has better compensating effect as they mitigate against power losses which was observed in their high percentage decrease in power losses compared to the standalone FACTS devices.
 Keywords: FACTS, optimum location, PSAT, SVC, TCSC, VSSF

Optimum Topology of Power Distribution Networks Using Sunflower Optimizer for Loss Reduction.(Dept.E)

The network reconfiguration can aid in loss reduction in distribution systems. A neoteric optimization method, Sunflower Optimizer (SFO), is suggested for addressing the reconfiguration of power distribution networks case. The main problem is to determine the network's optimal topology, which satisfies the objective function by considering the problem constraints. The fitness function is formulated to achieve the maximum percentage of active power loss decrease. To obtain the load flow solution, an efficient approach is applied called Backward/forward sweep. Besides, an improved graph theory is developed to address the configuration variations problem. The suggested optimization approach is executed on three power distribution networks: IEEE 33, 69, and 119 bus networks. The efficiency of the suggested SFO is verified by evaluating its operational characteristics. The obtained test results show that the percentage of active power loss reduction is maximized to 31%, 56%, and 33% for the IEEE 33, 69, and 119 bus networks, respectively. Finally, the introduced SFO approach's superiority is also confirmed by measuring its outcomes with other approaches..

Adaptive scheme protecting renewable‐dominated micro‐grids against usual topology‐change events

Miscoordination and faulty operation are the two main protection challenges of renewable Distributed Generations (DGs) in Distribution Networks (DNs) and Micro-Grids (MGs). Although various approaches have already been presented in the literature, none of them has proposed a solution for simultaneous impact of DN/MG reconfigurations and DGs’ protection challenges. Topology-change being a usual method in decreasing power loss or voltage deviations, it would be preferable to have an online adaptive scheme considering all protection challenges together. Hence, the ordinary overcurrent relays using the IEC 61850 protocol capabilities are utilized in an algorithm capable of definitely assigning which relays are responsible for the on-going fault and which ones are not. That is, the algorithm is applied on a peer-mode multi-agent system (MAS) structure. First, the relay agents are classified into radial and loop Virtual Local Area Networks (VLANs). When a relay detects the fault, the MAS will find the responsible VLAN and instantly isolate other VLANs, including their agents. Next, the main and backup relays using the proposed communication map are assigned within the responsible VLAN. Last, a suitable protection algorithm is applied on the selected relays, according to direction of fault current.

Features of the dynamics of walking machines and robots with cycle type of movers and controlled dissipation in the foot joint

The expediency of introducing an additional damping device (analog of a shock absorber) into the cyclic walking mechanism of a mobile robot, which provides a dissipative connection of a ski-shaped foot with a support link, is discussed. The influence of the damper on the dynamics of the feet changing and the dynamics of the meeting of the foot with an obstacle is considered. It is shown that dissipation in the hinge of the foot leads to a decrease in the intensity of shock processes when changing feet and when meeting an obstacle, provides a decrease in power losses for vertical vibrations of the body, and also expands the propulsion unit’s capabilities for self-adaptation to an unorganized surface.

WITHDRAWN: Optimal deployment of UPFC based on critical bus ranking using an effective PSO algorithm

This paper presents critical bus ranking based on load approach for optimal deployment of UPFC device in grid network. An effective PSO is programmed for optimal deployment of UPFC based on proposed critical bus ranking to enhance voltage stability of system. The deployment of UPFC at critical bus location can increase the stability of system by decreasing power loss of the grid system. Further the fuel cost can be minimized improving economic criteria. IEEE 14-bus network is programmed in MATLAB and results shows efficacy of proposed method .

Data-driven system identification and optimal control of an active rotor-bearing system

Both diagnostics and control in any piece of rotating machinery is getting more and more attention as computational powers allow storage of big data sets, and we are able to perform approximation, feature extraction and classification of big data. Such transfer from traditional diagnostics and control to machine learning and decision making also makes new ways of system identification based on artificial neural network architectures more attractive as they are more flexible in representing non-linear dynamics. Data-driven linear system identification or non-linear system identification based on artificial neural networks when coupled with optimal control obtained using either traditional or machine learning approaches result in a powerful tool for rotor-bearing system modeling and control that allows using identified model for predictive analysis as well. In the present paper such approach is presented for a rotor system on two journal fluid-film bearings, one of the bearings is equipped with a set of two actuators for feeding pressure control that allows adjustments of rotor position in the bearing. Such adjustments are aimed at decreasing power loss due to friction, so the system is more energy efficient. The presented approach of system identification and modeling can be applied to any similar rotor system.

Chaotic darwinian particle swarm optimization for real-time hierarchical congestion management of power system integrated with renewable energy sources

The increasing penetration of renewable energy sources that have intermittent outputs challenge the Independent System Operator while managing transmission congestion. A new Real-Time Hierarchical Congestion Management (RHCM) technique is proposed that reschedules generators in two stages based on Available Congestion Clearing Time (ACCT) of the transmission lines in presence of renewable energy sources. Chaotic Darwinian Particle Swarm Optimization (CDPSO) is used for determining the optimal schedules of demand response loads and reschedules of conventional generators to mitigate congestion. The solar and wind energy sources are modelled using Rayleigh and Beta probability density functions; Latin Hyper cube sampling is adopted for sampling. IEEE 39 bus system is simulated for cases of overloads and contingencies and RHCM using CDPSO is tested to ensure the security of the system. The benefit of RHCM incorporating demand response is presented in terms of reduced congestion relieving costs and decreased power loss.

Adaptive Switch Matrix for PV Module Connections to Avoid Permanent Cross-Tied Link in PV Array System Under Non-Uniform Irradiations

In this paper, the significance of cross-tied link between the solar photovoltaic (PV) modules in an array during partial shading conditions (PSCs) is introduced. In order to conduct a detailed analysis, twenty numbers of 20W PV modules ( 4×5) are arranged in a series-parallel (SP) configuration. The change in the pre-arranged SP configured PV array is implemented using a cross-link matrix switch between parallels based on shadow patterns. The switch matrix based modified PV array configuration is called Adaptive-cross-tied (A-CT) configuration. An embedded system based adaptive switch matrix (ASM) controller is developed to control the cross-linking connections between the PV modules under the PSCs to improve global maximum power. In addition, a performance analysis is carried out and compared all PV modules arranged in conventional SP and A-CT configurations. Moreover, realistic shadow test cases are under consideration to characterize current-voltage (I-V) and power-voltage (P-V) characteristics. The output power of the PV array decreases as well as the P-V curves show multiple power maxima points., such as the local maximum power point (LMPP) and the global maximum power point (GMPP). LMPP and GMPP locations, mismatch loss (ML), enhanced fill factor (FF), decreased power loss (PL) and performance ratio (PR) are indicators of performance during experimental and MATLAB/Simulink studies.

Influence of the Proposal of a Photovoltaic System on Electrical Losses

For the year 2017, renewable energy in the world through photovoltaic systems constitutes around 21% of the total energy generated through renewable sources. In this work, the impact represented by the proposal of a photovoltaic system connected to the grid in terms of reducing losses was analyzed. In the study, the calculation tools PVSyst and DIgSILENT PowerFactory were used to determine the power generation of the photovoltaic installation. Using the Radial 7.7 tool, the power losses were determined. The energy losses of the line were determined using empirical equations developed in the literature discussed. The commissioning of the installation represents a saving of 397 MWh/year. The impact that the installation represents on the grid is represented by a decrease in electrical energy losses and not in the decrease in power losses.

ANALISIS RUGI – RUGI DAYA DAN JATUH TEGANGAN UNTUK REKONFIGURASI PENYULANG RWO 05 DAN RWO 07 GARDU INDUK RAWALO MENGGUNAKAN ETAP 12.6 DAN MATLAB R2018a

The need for electrical energy which always rises causes an increase in the loading of each feeder in Rawalo Substation. PT. PLN (Persero) UP3 Purwokerto strives to carry out a reconfiguration on RWO 05 and RWO 07 feeder in order to decrease the load in RWO 05 feeder so that the electrical energy distributed to the consumers can be optimized. The distribution of electrical energy cannot be separated from the loss of power in the system which causes the disappearance of numbers of power in the electrical energy distribution process, starting from the main substation to the consumers. Therefore, there has to be an analysis done about power loss and voltage drop which occurs in the distribution networks by configuring one out of four switches in a normally open condition that connects RWO 05 and RWO 07, not only in an existing condition but also after the reconfiguration being done. Based on the result of the analysis, the power loss occurred in an existing condition which is in switch 2 holds the amount of 0,137 MW and 0,436 MVAR or equal to 2,18 % with the amount of 6,58% voltage drop, while the power loss occurred in a reconfiguration condition which is in switch 4 holds the amount of 0,116 MW and 0,385 MVAR or equal to 1,84 % with the amount of 6,13% voltage drop. The result of the loss obtained from both conditions concludes that there is a decrease in power loss with the amount of 0,33 %, whereas the voltage drop occurred decreases by 0,45%.

Power losses reduction of power transmission network using optimal location of low-level generation

Due to the growth of demand for electric power, electric power loss reduction takes great attention for the power utility. In this paper, a low-level generation or Distributed Generation (DG) has been used for transmission power losses reduction. Karbala city transmission network (which is the case study) has been represented by using MATLAB m-file to study the load flow and the power loss for it. The paper proposed the Particle Swarm Optimization (PSO) technique in order to find the optimal number and allocation of DG with the objective to decrease power losses as possible. The results show the effect of the optimal allocation of DG on power loss reduction.

Комплексная система регулирования мощности установки поперечной емкостной компенсации в системе с распределенной нагрузкой

The complex system of power control of transverse capacitive compensation device (CD) allows to increase the railroad traffic capacity and decrease power losses in the electrical traction network. The necessity of power control introduction to increase the traffic capacity is caused by the increased value of the traction current which is referred to the sectioning post and when the first harmonic traction current is higher than the current of the devices the additional section of capacitor battery is switched on. The suggested system can be implemented into CD where capacitor battery with reactor is connected through the filter on the third harmonic. It can also be used in other controlled CD, for example, in a static generator of reactive power.

Effect of spin–orbit coupling on the hot-electron energy relaxation in nanowires

The energy relaxation of hot electrons is proposed based on the spin–orbit (SO) interaction of both Rashba and Dresselhaus types with the effect of hot phonons. A continuum theory of optical phonons in nanowires taking into account the influence of confinement is used to study the hot-electron energy relaxation. The energy relaxation due to both confined (CO) and interface (IO) optical phonon emission on nanowire radius, electrical field strength, parameters of SO couplings and electron temperature is calculated. For considered values of the nanowire radius as well as other system parameters, scattering by IO phonons prevails over scattering by CO phonons. The presence of an electric field leads to the decrease of power loss in transitions between states with the same spin quantum numbers. With the increase of the electric field strength, the influence of the Dresselhaus SO interaction on the energy relaxation rate decreases. The effect of SO interaction does not change the previously obtained increasing dependence of power loss on electron temperature. The sensitivity of energy relaxation to the electric field also through the Rashba parameter allows controlling the rate of energy by electric field.

Determining the size and location of variable speed wind turbines for reducing power losses and improving voltage profile

Due to the voltage level and current of feeders in distribution systems, power loss is high in such networks. With the proliferation of distributed generations, it has become more important to determine their location and rating. These goals can be obtained according to different purposes such as improving the voltage profile. Unlike fixed speed wind turbines, the variable speed type can produce or absorb the reactive power. Hence, this paper specifies the placement and sizing of variable speed wind turbines based on a multi-objective function and according to the reactive power management. In the first step, the variable speed wind turbine is modeled by using the practical curve and Levenberg–Marquardt algorithm and then, the objective functions are optimized simultaneously to achieve the locations and sizes. Also, the impact of wind speed uncertainty on the functions is evaluated. To validate the results, a comparison between variable speed and fixed speed wind turbines is also presented. The proposed model is implemented on an IEEE 33-bus standard test system and the results show a significant (42%) decrease in power loss by adding variable speed wind turbines. However, the investment cost is also increased. Moreover, with considering the uncertainty, power loss and investment cost are increased by about 8% and 15%, respectively. However, the robustness of the system is enhanced against the wind speed fluctuations.

Low Friction Clutch Using Planetary Gears and Cams Mechanisms (Part I: Idea and Preliminary Design)

Research progress in the automotive industry sector is highly motivated by scarcity and rapid depletion of the fossil fuels. Hence, designing automotive components that could support decreasing power losses is critical to efficient use of fuel. Clutches are basic elements in automotive industries for controlling motion transmission. Furthermore, of power related to the spin loss phenomenon in clutches significantly affects the motion transmission efficiency. Therefore, automotive industry developers are looking forward to develop advanced clutches that yield to low losses associated with quick response. The friction in clutches' disks is a main source of power losses. Also, the friction affects the clutches life time which causes sudden troubles. This paper presents a conceptual design of low friction clutch using permanent magnet cylinders, planetary gears and cams mechanisms for reducing of power in order to improve system efficiency. This clutch uses the magnetic forces effect of magnetic cylinders instead of the direct contact effect of the regular clutch's friction disks. Also, this clutch is provided with cams mechanism for assuring that motion is completely stopped. Moreover, planetary gears of this clutch decrease rotation speed and increase torque as an initial reduction gear box. Finally, a prototype of this clutch is presented for testing the conceptual design validity.