Active Power Loss Reduction Research Articles

Active Power Loss Reduction by Particle Swarm Optimization Algorithm

Active Power Loss Reduction by Particle Swarm Optimization Algorithm

Повышение надежности электроснабжения металлургических агрегатов за счет схемотехнических решений

The electrical equipment of modern metallurgical units - electric arc furnaces, section and sheet mills of hot and cold rolling, has undergone a number of significant changes over the past decades. This resulted in an increase in the unit power of transformers and converters, the massive introduction of microprocessor control systems, and the complication of internal plant power supply schemes with significant own generation of electric energy. Consequently, the electric drives of continuous production, primarily rolling mills, have become more sensitive to voltage dips and interruptions in power supply. The aim of this work is to increase the reliability of power supply to metallurgical units using the rational choice of the configuration of 110 kV networks based on the analysis of various circuitry solutions. The consequences of emergency situations are usually assessed based on two indicators – short-circuit current and residual voltages of responsible consumers. It has been proved that the most radical way to reduce the first indicator and increase the second is to convert a 110 kV complex closed circuit into independent circuits with a simple configuration. This provides for a significant reduction in short-circuit currents, a reduction in the number of emergency situations, as well as a reduction in active power losses in 110 kV networks. The total annual effect of the implementation of the proposed activities exceeds 40 million rubles.

Assessment of the Impact of the Rigidity of Nodes on the Operating Reliability of EPSs

The operating reliability of electrical power systems is mostly based on the topology and parameters of the schemes considered in this article. The preliminary (before the calculation of operating conditions) analysis of the rigidity or sensitivity of nodes, based on the matrix of node conductivity, allows for evaluating and increasing the controllability of conditions by voltages and limiting short-circuit currents, making the reduction of active power losses in the grid more efficient. A conclusion was made regarding the consistent effects of changes in the node rigidity on increasing the EPS operating reliability.

Distributed generation integration optimization using fuzzy logic controller

Distributed generators (DGs) are connected near load centers and integrated to grid for optimum power system operations. The challenging task for integration of DGs is the proper size and location, due to random character of generation and energy consumption. The objective of the research is to provide the proper size and location of DGs to optimize the voltage profile and reduction in active and reactive power losses. Optimization of distributed generators is performed through fuzzy logic controllers at Ramchandrapura 33/11 kV, 69 bus radial distribution substation, Kota, India. Fuzzy logic controller provides possible solution on selection of distributed generators on the basis of voltage profile of the bus and the impedance of the branch connected DGs at consumer’s end. Forward or backward sweep methodology is used to optimize the load flow analysis for calculation of real and reactive power losses and voltage profile with and without implementation of distributed generators. Proposed approach provides a possible solution for efficient integration of DGs.

ACTIVE POWER LOSS REDUCTION AND IMPROVEMENT OF STATIC VOLTAGE STABILITY MARGIN INDEX BY WATERWAY ALGORITHM

In this paper, the Waterway Algorithm (WA) is used for Active Power Loss Reduction and improvement of Static Voltage Stability Margin Index. The design of the Waterway Algorithm (WA) is imitated from nature and the whole waterway process which involves the flow of streams and rivers into the sea in the natural world. The proposed Waterway Algorithm (WA) algorithm has been tested on standard IEEE 30 bus test system and simulation results show clearly about the superior performance of the proposed algorithm in reducing the real power loss and upgrading the Static Voltage Stability Margin Index.

Charging Coordination of Plug-In Electric Vehicle for Congestion Management in Distribution System

Abstract In modern electricity market, high penetration of Plug-In Electric Vehicle (PEV) creates a huge burden on distribution system operator (DSO). This high penetration creates a gap between demand-supply which further leads to the congestion in distribution lines. Power flow in a grid connected PEV is bidirectional i. e. it can work either in Grid to Vehicle (G2V) or Vehicle to grid (V2G) mode depending upon the grid constraints and owners demand. This paper proposes a charging coordination strategy of PEVs to alleviate congestion in distribution lines. Firstly, Active Power Flow Sensitivity Factors (PFSFs) are calculated to predict the branch flows or congestion status due to the uncoordinated charging of PEVs. Secondly, a coordination strategy of PEVs charging-discharging is made using different heuristic based algorithms in order to mitigate congestion in radial distribution system. The result of proposed work also shows the reduction in total active power loss while maintaining the electricity grid constraints. The present work is simulated and analyzed on IEEE 10 bus radial distribution system integrated with residential systems. Several case studies are analyzed to demonstrate the heftiness of the proposed work.

Novel approach to reconfiguration power loss reduction problem by simulated annealing technique

Summary The network reconfiguration is done by changing the status of the switches, mainly for 2 reasons: an active power loss reduction and load balancing attracting the attention of distribution engineers for quite a long period of time. In this article, solving method for the active power loss reduction is given. Searching for the relevant radial configurations is done by a simulated annealing technique. To aid the search, a program for checking the connectivity of the power system, with imposed radiality constraint, is enhanced by a new approximate power flow method. The applied power flow program is very efficient and fast but can be used only as an indication for the loss estimation because of the insufficient method accuracy. At the end of the algorithm, it is necessary to run an efficient power flow program to determine the real situation concerning loss reduction. A numerical example for Baran and Wu network is analyzed. The developed method converges to the global optimum given in a numerical example. The time duration of the used method is of an hour order and does not depend on the fast manipulation of incoming data files. This advantage makes the method interesting in the planning stage as well as the application in real time. Main contribution of this paper is a novel approach that exploits mostly the following mechanisms: network connectivity checking matrix, Lavorato et al criterion for imposing radiality constraint, and efficient power flow algorithm combined with precise power flow for exact loss calculation.

Determination of optimal transformation ratios of power system transformers in conditions of incomplete information regarding the values of diagnostic parameters

On the base of damage rate analysis of power transformers and methods of EES modes control, the necessity of using the results of on-line diagnostics of LTC transformers not only for determination s of the expediency of further operation or equipment repair but also for calculation of optimal transformation coefficients (with account of the suggested RRCT) for their application in the process of modes control has been proved. The mathematical model of RRCT is developed to by applying the methods of neural-fuzzy modeling, this model, taking into account both current and retrospective values of diagnostic parameters enables to study the impact of diagnostic parameters of RRCT and determine its current value, which is necessary for automatic and automated reliable and optimal control of EES modes. The improved method of determination of optimal control actions, realized by the LTC transformers by means of comparative analysis of the results of calculation of EES modes with quasi-resistances of the circuit branches, enables to select the transformer and calculate transformation ratios that provide minimal losses of active power, minimal amount of LTC switching. The error of RRCT determination by means of the developed mathematical fuzzy model as compared with the training sample of the model and the opinion of independent experts does not exceed the error of the devices, measuring diagnostic parameters. Such results are explained by complex usage of probability theory methods, neuro-fuzzy modeling and modern software Matlab. Such peculiarity of the suggested method of determining optimal control actions by LTC transformers, as the account of RRCT, in the process of EES mode control provides such advantages as reduction of the damage rate of the equipment, reduction of active power losses in EES. The peculiarities of the method of determining optimal control actions by LTC transformers, with the account of their technical state, open up the prospects of development and introduction of modern microprocessor-based systems of optimal automatic control of LTC transformers in EES. Usage of quasi-resistors of circuit branches, which, unlike the transformers, used for calculation of nominal resistances of the lines, take into account the state of the transformers and possible losses of utility companies due to the possible damages, enables to calculate the EES mode in case of transformers transformation ratio change and by means of comparison of calculated power losses, select the most efficient transformer. Further progress of the given research includes the development of mathematical models of other kinds of high voltage equipment involved in the process of ESS modes control, damage of which is possible.

Reconfiguration of Smart Distribution Network in the Presence of Renewable DG’s Using GWO Algorithm

In this paper, the optimal reconfiguration of smart distribution system is performed with the aim of active power loss reduction and voltage stability improvement. The distribution network is considered equipped with wind turbines and solar cells as Renewable DG’s (RDG’s). Because of the presence of smart metering devices, the network state is known accurately at any moment. Based on the network conditions (the amount of load and generation of RDG’s), the optimal configuration of the network is obtained. The optimization problem is solved using a recently introduced method known as Grey Wolf Optimizer (GWO). The proposed approach is applied on 69-bus radial test system and the results of the GWO are compared to those of Particle Swarm Optimization (PSO), and Genetic Algorithm (GA). The results show the effectiveness of the proposed approach and the selected optimization method.

Distribution STATCOM with optimal phase angle injection model for reactive power compensation of radial distribution networks

AbstractIn this paper, a distribution static compensator (DSTATCOM) model based on optimal angle injection is devised and used in reactive power compensation of radial distribution systems. In the proposed DSTATCOM model, the rating of the DSTATCOM is determined with the injection of optimal phase angle of the voltage at the location, in which a DSTATCOM is placed. The proposed DSTATCOM model is suitably incorporated in the forward‐backward sweep load flow algorithm. The optimal location and rating for DSTATCOM are determined by minimizing the active power loss of a distribution network. Differential evolution algorithm is used as the solution strategy. The 69‐bus radial distribution system is used in the case study. The results show that the proposed approach is more efficient in active power loss reduction as compared with some of the previously published approaches.

Power Loss Analysis for Wind Power Grid Integration Based on Weibull Distribution

The growth of electrical demand increases the need of renewable energy sources, such as wind energy, to meet that need. Electrical power losses are an important factor when wind farm location and size are selected. The capitalized cost of constant power losses during the life of a wind farm will continue to high levels. During the operation period, a method to determine if the losses meet the requirements of the design is significantly needed. This article presents a Simulink simulation of wind farm integration into the grid; the aim is to achieve a better understanding of wind variation impact on grid losses. The real power losses are set as a function of the annual variation, considering a Weibull distribution. An analytical method has been used to select the size and placement of a wind farm, taking into account active power loss reduction. It proposes a fast linear model estimation to find the optimal capacity of a wind farm based on DC power flow and graph theory. The results show that the analytical approach is capable of predicting the optimal size and location of wind turbines. Furthermore, it revealed that the annual variation of wind speed could have a strong effect on real power loss calculations. In addition to helping to improve utility efficiency, the proposed method can develop specific designs to speeding up integration of wind farms into grids.

Optimal Reconfiguration of Power Distribution Systems Based on Symbiotic Organism Search Algorithm

This paper presents a reconfiguration of electric power distribution network based on the symbiotic organism search algorithm (SOS). The goal here is to come out with an optimal reconfiguration of a power distribution network that minimises the active power losses for a good power flow. This method is applied to IEEE 33 bus and the results show a significant reduction of active power losses. The execution time for this algorithm is found to be smaller compared to other metaheuristic algorithms.

A Comparative Analysis of Performance Evaluation of SVC and TCSC for Transmission Loss Reduction on Nigerian 330 kV Grid System Using Self- Adaptive Firefly Algorithm

Flexible alternating current transmission systems (FACTS) devices are emerging technologies that serve as a means of providing reactive power support to mitigate issues of active power loss and voltage instability on existing power grid. The optimal placement, locations and sizes of these devices influence its performance on the grid. This paper presents a comparative analysis of performance evaluation of SVC and TCSC for transmission loss reduction on Nigerian 330kV grid system using self- adaptive firefly algorithm. The results of the analysis showed that with the system reinforced with SVC, the total system loss reduced from 98.21MW to 92.44MW which is about 5.88% reduction. The reduction in active power loss with the optimal location of TCSCs is 94.259MW which amount to 4.02% reduction. An appreciable voltage enhancement occurred at Ayede, New Haven, Onitsha and Kano due to the system reinforcement with SVCs and TCSCs. In all, SVC gives better result than TCSC in term of active power reduction and voltage profile enhancement.

Optimal Reactive Power Dispatch with Static VAR Compensator Using Harmony Search Algorithms

One of the major optimization problems in power systems is the optimal reactive power dispatch (ORPD) problem. ORPD plays an important role for secure and reliable operation of power systems. The main purpose of ORPD is to find the settings of control variables such as voltage rating of generators, reactive power injection of VAr compensators and tap ratios of the tap setting transformers in order to minimize the total active power losses of the network while satisfying a given set of constraints. The whole ORPD problem is considered as a non-linear multi-modal optimization problem with a combination of discrete and continuous variables. Along with the conventional control variables in ORPD the optimal location and the Var settings of SVC are included in the optimization problem for additional active power loss reduction. In this paper, two versions of harmony search algorithms namely basic Harmony Search Algorithm (HSA) and Improved Harmony Search algorithm (IHSA) are applied to solve conventional ORPD, as well as ORPD with the FACTS device Static Var Compensator (SVC), to minimize the total active power loss of the power system. The harmony search algorithms for ORPD, as well as ORPD considering SVC are implemented on IEEE 14 and 57 bus systems. Comparison of simulation results reveals the effectiveness of harmony search algorithms over other well established population based optimization techniques.

Analytical Approach for Optimal Allocation of Distributed Generators to Minimize Losses

In this paper the integration of Distributed Generation (DG) in radial distribution system is investigated by computing the optimal site and size of DG to be placed. An analytical expression based on equivalent current injection has been derived by utilizing topological structure of radial distribution system to find optimal size of DG to minimize losses. In the presented formulation, the optimal DG placement is obtained without repeatedly computing the load flow. The proposed formulation can be used to find the optimal size of all types of DGs namely Type-I, Type-II, Type-III and Type-IV DGs. The investigations are carried out on IEEE 33-bus and 69-bus radial distribution systems. The optimal DG placement results into reduction in active and reactive power losses and improvement in voltage profile of the buses.

ENERGY SAVING DURING OPERATION OF EQUIPMENT WITH NON-CONTROLLED ELECTRIC DRIVE IN LOCOMOTIVE DEPOT

Purpose. To conduct research of electric motors in order to obtain the results that will assess the degree of energy saving due to electric loss reduction in the equipment with non-controlled electric drive. Methodology. The paper proposes an engineering method for determination of active power losses in the motors of the equipment with non-controlled electric drive in locomotive depot during load changes on the motor shaft. It is necessary to analyse the reduction of active power losses in the motor and the power supply network when an under-loaded motor is replaced with a motor having less power. Findings. After the calculations performed by the authors, it was found that for electric motors, in case of reducing the load factor from to active loss reduction after the motor replacement for the less powerful one ranges from 0.58 kW to 2.865 kW. Also, the calculations were carried out on the example of electric motors with a lower synchronous speed, the effect of under-loaded motor replacement increases in terms of active power loss reduction. The greatest effect is achieved when the load factor is . Originality. For the first time the paper outlines the issues of energy saving efficiency for the equipment with non-controlled electric drive in locomotive depot by replacing the under-loaded motors with the less powerful ones. As long as there is a significant amount of the considered electric drives, it may cause severe losses, taking into account the peculiarities of their operation. Practical value. The obtained research results allow us to solve the problem of replacement of under-loaded motors in locomotive depot equipment with the motors having less power as efficiently as possible in terms of reducing electric losses. For instance 90-kW motor of a washing machine can be replaced with 75-kW motor when the load factor is , this can significantly reduce the performance losses. This method can be applied not only in locomotive depot but also for all equipment with non-controlled electric drives that operates in under-load mode.

Congestion management of deregulated power systems by optimal setting of Interline Power Flow Controller using Gravitational Search algorithm

In a deregulated electricity market it may at times become difficult to dispatch all the required power that is scheduled to flow due to congestion in transmission lines. An Interline Power Flow Controller (IPFC) can be used to reduce the system loss and power flow in the heavily loaded line, improve stability and loadability of the system. This paper proposes a Disparity Line Utilization Factor for the optimal placement and Gravitational Search algorithm based optimal tuning of IPFC to control the congestion in transmission lines. DLUF ranks the transmission lines in terms of relative line congestion. The IPFC is accordingly placed in the most congested and the least congested line connected to the same bus. Optimal sizing of IPFC is carried using Gravitational Search algorithm. A multi-objective function has been chosen for tuning the parameters of the IPFC. The proposed method is implemented on an IEEE-30 bus test system. Graphical representations have been included in the paper showing reduction in LUF of the transmission lines after the placement of an IPFC. A reduction in active power and reactive power loss of the system by about 6% is observed after an optimally tuned IPFC has been included in the power system. The effectiveness of the proposed tuning method has also been shown in the paper through the reduction in the values of the objective functions.

The impact of distributed power sources to the best of flow in electrical networks

Intensive implementing distributed generation sources from alternative energy sources leads to a situation where one feeder can connect several different types of distributed energy sources, including solar power plant and small hydropower plant. The system consists of distributed generation small-capacity power plants scattered throughout the energy system. They supply electricity to consumers in the near and in the case of excess energy can transfer its network centralized power. This paper discusses the reduction of active power losses in the local electrical systems that operate different types dispersed energy sources. The main goal is to develop a methodology for determining the point of power flow section the local electrical system of dispersed generation sources and develop a method for choosing the optimal place network disconnection criterion of active power losses. The article shows the computer model regime for local electricity system that allows to determined the place point of power flow section and calculated the power loss at section schemes in the respective nodes. The choice of multi sections is difficult optimization problems. It is proved that in the use of multiple distributed sources of energy in the local electrical system for optimum energy losses point of power flow section (several possible points of power flow section) is selected at the lower junction voltage. Regulation of power generated by small hydroelectric power plant affects the change point of power flow section local electric networks and reduces the active power losses in the local electrical system

Optimal Placement of Distributed Generators in Radial Distribution System for Reducing the Effect of Islanding

The present trend of increasing the penetration levels of Distributed Generator (DG) in the distribution network has made the issue of Islanding crucial for the reliable operation of the network. The islanding, if not detected early may lead to the collapse of the system as it can drive the distribution system to the cascaded failure. In this paper, an extensive study of the effect of DG placement and sizing is performed by dividing the system into different zones to obtain a reduced effect of islanding. The siting and sizing of DG is carried out to improve the overall voltage profile or/and reduction in active power loss using two stage Genetic Algorithm (GA). In the first stage a basic knockout selection is considered and the best population is taken for next stage, where roulette selection for crossover and mutation is performed for optimal placement and sizing of DGs. The effect of the islanding, due to load variations is reduced by optimal siting and sizing of DG. The effectiveness of the proposed scheme is tested on the IEEE 33 and 69 radial bus systems and the results obtained are promising.

OPTIMAL LOCATION OF DISTRIBUTED GENERATION ON THE NIGERIAN POWER SYSTEM

The optimal sizing and location of distributed generators (DG) remain crucial factors in their application for active power loss minimization as well as voltage profile improvement. This paper describes an analytical method for the optimal sizing and placement of DG in the Nigerian power network for active power loss minimization. The effectiveness of the proposed method showed a 6.2% reduction in active power losses on the 33kV Nigerian network (i.e. from 92.7MW to 87.0MW). The results showed an improvement in the voltage profile of that six load buses whose voltages were outside the statutory limit of 0.95 pu≤ V i ≤ 1.05pu.