Line Loss Reduction Research Articles

Optimization of Electrical 3 phase power Distribution loss to rural areas in Uttrakhand State - A case study

This paper presents the technique of reducing distribution system losses of Kotuli village in Almora district of Uttrakhand state. The field survey was done to know about the condition of feeder and distribution system. The village distribution feeder generally supplies load to household lighting and agricultural loads. Strict observations were done and Recommendation for overall loss reduction techniques that leads to further improvement of overall efficiency of the system. After observation in the village it was found there is uneven distribution system was set up and due to this there distribution line losses were found to be very high and just by changing the distribution transformer position nearer to load center and replace the same with energy efficient transformer there was huge distribution line loss reduction and even the payback for the same is less than 4 years. In doing so the power theft chances will also reduce, as the high voltage line will directly be supplied nearer to load center this is known as the High voltage distribution system(HVDS). As the distribution line losses will reduce the demand for power from the utility will also get reduced thereby reducing the loading on 10MVA ,33/11KV distribution transformer that can share the power to other  village loads. In the proposed system there will be two single-phase transformers in place with 3 phase transformer that can also avoid overloading on 1 particular transformer as in future the load will going to increase as the population will increase and due  to the new upcoming technology, most of the process will be done by electrical energy.

New Metrics for Evaluating Technical Benefits and Risks of DGs Increasing Penetration

Increasing penetration of distributed generation (DG), may be interesting from several points of view, but it raises important challenges about distribution system operation and planning practices. To optimal allocation of DG, which play an important role in construction of microgrids, the benefits and risks should be qualified and quantified. This paper introduces several probabilistic indices to evaluate the potential operational effects of increasing penetration of renewable DG units such as wind power and photovoltaic on rural distribution network with the aid of evaluating technical benefits and risks tradeoffs. A probabilistic generation-load model is suggested to calculate these indices which combine a large number of possible operating conditions of renewable DG units with their probabilities. Temporal and annual indices of voltage profile and line flow-related attributes such as interest voltage rise, risky voltage rise, risky voltage down, line loss reduction, line loss increment, and line overload flow are introduced using probability and expected values of their occurrence. Also, to measure the overall interests and risks of installing DG, composite indices are presented. The implementation of the proposed framework in a 4-bus and IEEE 33-bus radial distribution systems shows the effectiveness of the benefits and risks assessment technique with the proposed metrics.

Security-constrained line loss minimization in distribution systems with high penetration of renewable energy using UPFC

Focused on the challenges raised by the large-scale integration of renewable energy resources and the urgent goal of energy saving, a novel control scheme for the unified power flow controller (UPFC) series converter is proposed to achieve line loss reduction and security enhancement in distribution systems with a high penetration of renewable energy. Firstly, the line loss minimum conditions of a general distribution system with loop configurations are deduced. Secondly, security constraints including the permissible voltage range, the line loading limits and the UPFC ratings are considered. System security enhancement with the least increase in line loss is tackled by solving a much reduced optimal power flow (OPF) problem. The computational task of the OPF problem is reduced by deducing the security-constrained line loss minimum conditions and removing the equality constraints. Thirdly, a hybrid control scheme is proposed. Line loss minimization is achieved through a dynamic controller, while an OPF calculator is integrated to generate corrective action for the dynamic controller when the security constraints are violated. The validity of the proposed control strategies is verified in a modified IEEE 33 bus test system.

Optimal allocation of static VAR compensator by a hybrid algorithm

Flexible AC transmission system (FACTS) devices are gaining popularity in electrical transmission networks for the last few years due to their ability to improve a system’s performance without restructuring or expanding the existing network. But, placing the FACTS device at any arbitrary location in the network may not be optimally beneficial. Also, judging the optimally beneficial location of these devices becomes necessary prior to investment owing to their high expense of installation and maintenance. In this paper, a novel hybrid algorithm combining Cuckoo Search Algorithm (CSA) and Chemical Reaction Optimization (CRO) is proposed to solve the problem of optimally allocating a static VAR compensator (SVC) for the standard IEEE 14-bus, 30-bus and 57-bus transmission systems under heavily loaded condition. The optimal allocation of SVC is done by considering technical aspects like voltage stability, power generation minimization and line loss reduction and also by considering commercial facets like savings on annual cost of power generation and return-on-investment (ROI) time period for the expenditure incurred on the SVC. The ROI calculation is a novel addition to the problem formulation which adds a practical outlook to the feasibility of investment. Thus, a holistic approach is followed for determining the optimal location of the SVC in the power network and the results validate the superior performance of the proposed algorithm.

Energy management using volt/var control of end-use appliances without affecting their performances and lives

Globally, environmental concerns have become the main motive behind energy management to save energy. The compelling rise in security threats due to gradual depletion of conventional energy sources, carbon emissions, global warming, and hikes in global energy prices has increased the global need for energy saving. In this paper, a simple but cost-effective method for energy management through energy saving has been proposed. The proposed method shows that the consumption level of the voltage regulated loads (constant impedance types) can be reduced by a significant amount by reducing input voltage across them while keeping the lowest customer utilization voltage consistent. The reduction in the consumption level also ensures significant reduction in line losses through reduced line flows. The network capacity release due to reduced line flows is also indicative, which prevents investment deferral required for further expansion in network capacity to meet the growing demand. The proposed method is not only beneficial to consumer savings through reduced demand but also enhances appliances' lives, as their operation is at low voltage which again does not affect their performances. On the other hand, although a utility loses revenue due to reduced energy usage among consumers, it is being benefitted indirectly. Indirect benefits include network capacity release, avoided prices for power-purchase during supply-demand gap, net loss reduction including transformers and distribution lines, potential incentives from regulators, fuel preservation, emission reduction, etc. The proposed method is tested on an IEEE 33-bus system, and the results show that an energy saving of 5.91% per year can be achieved.

A novel and fast single-phase three-wire power flow solution for a modern home premises wiring systems

Single-phase 2-wire (1φ2w) and single-phase 3-wire (1φ3w) circuit layouts are commonly adopted in premises wiring systems. Compared with 1φ2w circuits, the arrangements of 1φ3w circuits have some advantages such as reduced voltage drop, reduced line loss, and fewer conductors. Currently, more detailed power flow solutions of premises wiring systems are required because they can be used in more applications, such as power loss analysis, conservation voltage regulation (CVR), load balancing, and network reconfiguration especially in the design and operation of modern home energy management systems (HEMSs). This paper presents a novel approach to solve the power flow problem of a 1φ3w premises wiring system. The proposed approach is based on the loop frame of reference rather than the conventional approach, which is normally based on the bus frame of reference. Because the proposed approach is mainly based on graph theory, feeders and branch circuits of a premises wiring system are represented in a more detailed fashion than in previous corresponding mathematical models. In addition, the proposed approach provides an efficient and simple way to help engineers build a performance equation and full-scale system model of a premises wiring system. The simulation results of the proposed approach are verified through the OpenDSS software package and field testing. The proposed approach and implementation technique are of value to engineers and technicians in the design and operation of premises wiring system for dwelling units or smart buildings and may be implemented in HEMSs.

Reactive power deployment and cost benefit analysis in DNO operated distribution electricity markets with D-STATCOM

The aim of this paper is to analyze unbalanced radial distribution systems (UBRDS) with the distribution static compensator (D-STATCOM). The main objectives of this paper are D-STATCOM allocation in UBRDS with an objective of providing reactive power support to enhance voltage profile and reduce line losses of the distribution network, determination of optimal D-STATCOM rating subjected to minimization of total cost, and impact of D-STATCOM placement on improving power factor and savings in cost of energy loss. The analysis is conducted on a large industrial load model with light, medium and high loading scenarios. Further, the impact of load growth is also considered for better planning of the power distribution system. The results are obtained on standard 25-bus UBRDS to check the feasibility of the proposed methodology.

Derivative load voltage and particle swarm optimization to determine optimum sizing and placement of shunt capacitor in improving line losses

The purpose of this research is to study optimal size and placement of shunt capacitor in order to minimize line loss. Derivative load bus voltage was calculated to determine the sensitive load buses which further being optimum with the placement of shunt capacitor. Particle swarm optimization (PSO) was demonstrated on the IEEE 14 bus power system to find optimum size of shunt capacitor in reducing line loss. The objective function was applied to determine the proper placement of capacitor and get satisfied solutions towards constraints. The simulation was run over Matlab under two scenarios namely base case and increasing 100% load. Derivative load bus voltage was simulated to determine the most sensitive load bus. PSO was carried out to determine the optimum sizing of shunt capacitor at the most sensitive bus. The results have been determined that the most sensitive bus was bus number 14 for the base case and increasing 100% load. The optimum sizing was 8.17 Mvar for the base case and 23.98 Mvar for increasing load about 100%. Line losses were able to reduce approximately 0.98% for the base case and increasing 100% load reduced about 3.16%. The proposed method was also proven as a better result compared with harmony search algorithm (HSA) method. HSA method recorded loss reduction ratio about 0.44% for the base case and 2.67% when the load was increased by 100% while PSO calculated loss reduction ratio about 1.12% and 4.02% for the base case and increasing 100% load respectively. The result of this study will support the previous study and it is concluded that PSO was successfully able to solve some engineering problems as well as to find a solution in determining shunt capacitor sizing on the power system simply and accurately compared with other evolutionary optimization methods.

Integration of renewable distributed generators into the distribution system: a review

Recent advances in renewable energy technologies and changes in the electric utility infrastructures have increased the interest of the power utilities in utilisation of distributed generation (DG) resources to generate electricity. The recent trends in the development and utilisation of DG resources for power generation application are subject to the deregulation of the electric power sector and technical constraints to extend distribution and transmission networks to some areas. The electric power system planners, regulators and the policy makers have derived many benefits from integration of DG units into the distribution networks. These benefits depend on the characteristics of DG units such as photovoltaic (PV), wind system and reciprocating engines, characteristics of the loads, local renewable resources and network configuration. This study comprehensively reviews various research works on the technical, environmental and economic benefits of renewable DG integration such as line-loss reduction, reliability improvement, economic benefits and environmental pollution optimisation. These benefits can be optimised if all the renewable DG units are optimally sized, located and configured. This study also reviews the current status of renewable DG technologies based on different characteristics and the operational issues of integration of renewable DG into the electric power systems.

Optimal Reconfiguration-Based Dynamic Tariff for Congestion Management and Line Loss Reduction in Distribution Networks

This paper presents an optimal reconfiguration-based dynamic tariff (DT) method for congestion management and line loss reduction in distribution networks with high penetration of electric vehicles. In the proposed DT concept, feeder reconfiguration (FR) is employed through mixed integer programming when calculating the DT, leading to minimized energy cost and reduced DT as compared with the DT concept without FR. This paper further demonstrates that the line losses can be taken into account during the calculation of DT. As a result, the line loss reduction can be realized in a decentralized manner through the DT framework. Three case studies were conducted to validate the optimal reconfiguration-based DT method for congestion management and line loss reduction in distribution networks.

Energy efficiency in developing countries: Roles for sector regulators

In addition to implementing Renewable Energy (RE) initiatives, sector regulators also have roles to play in promoting Energy Efficiency since EE can be expanded via utility actions (incentivized and monitored by the regulator) and actions by other agencies. The former include reduced line losses, improvements in load patterns and system reliability, decision-relevant customer billing information, energy audits, and smart grids. The adequacy and cost-effectiveness of utility programs clearly fall under regulatory oversight. Other agencies set appliance standards and provide government financial support. The sector regulator must then factor in the interdependencies among EE programs when determining the cost-effectiveness of utility-based programs. EE promotes energy conservation, so such programs impact utility revenues and costs (directly through changes in consumption and production patterns and in program costs). These impacts mean that the energy sector regulator can promote or block some EE initiatives carried out by the electric utilities.

MF-APSO-Based Multiobjective Optimization for PV System Reactive Power Regulation

This paper proposes a reactive power-regulation strategy for a distribution system connected with high-penetration photovoltaic (PV) generation. The PV reactive power regulation is formulated as a multiobjective optimization problem to relieve the overvoltage caused by high PV penetration and to minimize total line loss. With integrated power-flow analysis, a new mutation fuzzy adaptive particle swarm optimization (MF-APSO) algorithm is proposed to solve the multiobjective optimization problem. The proposed reactive power-regulation strategy and MF-APSO algorithm are, respectively, compared with conventional methods for overvoltage mitigation and total line-loss reduction, as well as with the referenced optimization algorithms for the problems of concern. Numerical results verify that the proposed multiobjective optimization method can more effectively mitigate the overvoltage issue and greatly reduce the total line loss as compared to other methods. Utilization of high-penetration PV systems can thus be further enhanced with reduced power curtailment owing to the added functions of voltage regulation and line-loss minimization.

Strategic Energy Management (SEM) in a micro grid with modern grid interactive electric vehicle

In this paper, strategic energy management in a micro grid is proposed incorporating two types of storage elements viz. unitised regenerative fuel cell (URFC) and electric vehicle (EV). Rather than a simple approach of optimizing micro grid operation to minimize line loss in the micro grid, this paper deals with multi objective optimization to minimize line loss, operational cost and maximize the value of stored energy of URFC and EV simultaneously. Apart from URFC, two operation strategies are proposed for EV enabling V2G operation to reduce overall system cost of operation. To address the complexity, non-linearity and multi dimensionality of the objective function, particle swarm optimization-a heuristic approach based solution methodology along with forward and back sweep algorithm based load flow solution technique is developed. Combined with particle swarm optimization (PSO), forward and backward sweep algorithm resolves the complexity and multi dimensionality of the load flow analysis and optimizes the operational cost of micro grid. The simulation results are presented and discussed which are promising with regard to reduction in line loss as well as cost of operation. Scheduling strategy of the micro grid with both URFC and EV enabling V2G operation presents a promising approach to minimize line loss and cost of operation.

Loss Reduction on Adoption of High Voltage LT Less Distribution

In India there is a need to improve the quality of the electricity distribution process which has increased varying from year to year. In distribution networks, the limiting factor to load carrying capacity is generally the voltage reduction. High voltage distribution system (HVDS) is one of the steps to reduce line losses in electrical distribution network. It helps to reduce the length of low tension (LT) lines and makes the power available close to the users. The high voltage power distribution system reduces the probability of power theft by hooking HVDS suggests an increase in installation of small capacity single-phase transformers in the network which again save considerable energy. This paper is compared to existing conventional low tension distribution network with HVDS. The paper gives a clear picture of reduction in distribution losses with adoption of HVDS system. Losses Reduction of 11 kV Feeder in Nuniya (India) with adoption of HVDS have been worked out/ quantified and benefits thereby in generating capacity have discussed.

Unbalanced Active Distribution Analysis with Renewable Distributed Energy Resources

This paper presents unbalanced active distribution system analysis with renewable distributed Energy Resources (DER). The renewable DER models have been considered are photovoltaic (PV) and Wind Turbine generation (WTG). The three-phase distribution load flow on the basis of the symmetrical components have been used in the analysis. The unbalanced active distribution system has been analized using IEEE 13 node feeder and IEEE 8500 node feeder with renewable DER units. The variation of wind speed (m/s) for WTG, solar radiation (W/m²) and temperature (°C) for PV have been simulated. The simulation results show that the proposed DER model can be used to analysis renewable DER impacts in unbalanced distribution system. The integration of renewable DER units into an existing distribution network can improve the voltage profile and reduce total system losses. The simulation results show that DERs size and location are important factors to improve voltage profile and line loss reduction.

Positioning of PV panels for reduction in line losses and mismatch losses in PV array

Partial shading decreases the power output of PV arrays due to mismatch losses. These losses are dependent on the shading pattern and the relative positions of shaded modules in the array. Various static and dynamic reconfiguration techniques have earlier been proposed to mitigate these losses. In an earlier proposed static reconfiguration technique, the power generation is enhanced by altering the physical location of the PV panels using a random Sudoku configuration without modifying the TCT (Total-Cross-Tied) based electrical connections. However, this arrangement faces drawbacks due to ineffective dispersion of shade and significant increase in wiring required. In this work, an optimal Sudoku arrangement to overcome these drawbacks is formulated. Further analysis indicate that the global peak of the optimal Sudoku based PV array occurs as the right most peak in the curve for most shading conditions, thus evidently obviating the need for complex MPPT (Maximum-Power-Point-Tracking) algorithms. The proposed configuration is compared with various other existing reconfiguration schemes in terms of power output and the comparison is presented. In addition, a general formulation is proposed to expand this pattern to any generic array. A strategy is also proposed to make such an interconnection practicable for very large size PV arrays.

Rotating Machine Based DG Islanding Detection Analysis Using Wavelet Transform

The increased use of distributed generation in the power system due to increased load demand has brought about many benefits to the power grids. This is due to the concerns about whether the technology in use currently in power generation and distribution, is sufficient to cover the future increasing demand with the limited supply. In response to this problem of increased load demand, efforts have been made to decentralize this infrastructure through the use of distributed generators. The benefits of using distributed generation include; improved reliability and increased efficiency in power supply, avoidance of transmission and distribution capacity upgrades, improved power quality and reduced line losses, minimize peak load demand, reduce voltage flicker, eliminate the need of having high spinning reserve among others. Despite these advantages, un-intentional islanding remains a big challenge and has to be addressed in integration of Distributed Generation to the power system. Unlike inverter based distributed generators, rotating machine based generators with fast response governors and AVRs are highly capable of sustaining an island. Therefore, anti-islanding protection for these generators is a more challenging problem in comparison with the inverter-based DG. This paper analyses the use of wavelet transform in islanding detection for rotating based distributed generators.

Research and Analysis of Reliability of Power Grid SVG Master Circuit in Rural Areas

Problems such as low voltage and big line loss have long existing in the power grid in rural areas of China. In recent years, some province and cities have improved voltage and reduced line loss by installing SVG at substations in rural power grids, and the effect is remarkable.With great compensation capacity and a good variety of modes of compensation, SVG is sure to replace old reactive compensation devices in rural power grid in future, which requires evaluation and analysis of SVG reliability so as to guarantee safety and stability of the power grid. However, now no research or analysis has been made in China on SVG reliability in rural power grids, which affects wide promotion of SVG in rural power grids.Under the background of Liaoning Power Grid 10kV/±5Mvar Chain SVG, this paper analyzes the reliability of k/n (G) system model of SVG master circuit structure, improving the accuracy of system reliability estimation. The estimation matches the operation outcome, thus providing data basis for the feasibility of SVG’s wide application in rural power grid in future.

A new approach based on the experimental design method for the improvement of the operational efficiency in Medium Voltage distribution networks

Abstract This paper presents a new approach for the improvement of the operation in Medium Voltage (MV) networks. The developed methodology is based on an innovative use of the experimental design method, the aim of which being the reduction of the total line losses while ensuring the best voltage profile possible along the feeders of the grid. Practically, it consists in the optimal positioning, sizing and real-time use of the different devices and processes that can currently be employed by the Distribution System Operators (DSOs) to operate efficiently and securely the network: the on-load tap changer (OLTC) of transformer, the reactive power compensation devices, the curtailment of distributed generation (DG) and the load-shedding. This work is divided into two complementary studies. Firstly, a planning procedure is implemented. This stage includes a screening process of the optimal positioning of the network regulation devices followed by a sizing procedure of those devices that takes technical as well as economic constraints into account. Secondly, an optimization process of the values of these parameters is implemented in order to be used in the context of a real-time management of distribution systems. The effectiveness of the proposed approach is then tested on a 28-bus radial MV network with several DG units. The simulations are carried out under various load and generation profiles over an extensive period of time and the evaluation criteria of the methodology are the costs related to the line losses and the probabilities of voltage violation.

Importance of Voltage Reduction and Optimal Voltage Setting During Reactive Power Compensation

After reactive power compensation, voltage-dependent loads, such as constant impedance and constant current loads, consume more power because of the increase in node voltage; therefore, customers pay more for their electricity while utilities experience savings from line-loss reduction. Here, a voltage-reduction strategy plays an important role in reducing total energy consumption during reactive power compensation. In this paper, we have presented a rationale for the necessity of reducing voltage during reactive power compensation and determined the optimal voltage setting at the substation regulator. We have also analyzed the joint effects of ambient temperature, price, size, and phase kVAr of the capacitor on line loss and load demand using a 2 4 factorial design.