Industrial Distribution Systems Research Articles

Voltage support in industrial distribution systems in presence of induction generator-based wind turbines and large motors

Industrial loads are usually composed of large induction motors (IM). These motors present a critical behavior under some circumstances, e.g. during starting and faults in the system. Currently, induction generator-based wind turbines are also connected to distribution systems. Essentially, these generators present the same behavior of large IM and, when directly connected to the system, their interaction can increase voltage sag levels or even lead the system to a voltage collapse. These generators, however, are usually provided with specific controls or power electronic-based equipment to comply with the voltage ride-through capability required by the grid codes. These resources, however, can be used to minimize the impact of large motors in the grid or even minimize their impact on voltage sags caused by faults in the system. In this context, this paper has the objective of analyzing the impact of different technologies used in induction generator-based wind turbines during disturbances in distribution systems in the presence of large IM. The analysis aims to clarify the potential benefit of wind turbine allocation at the demand side of an industrial power distribution system. Based on the results, an adapted control scheme, considering the control strategies currently available, is proposed for the grid side converter of the doubly fed induction generators to improve power quality.

Decision Area of Distributed Generation Investment as Deferral Option in Industrial Distribution System Using Real Option Valuation

Distribution system planning (DSP) aims to ensure, that the electricity distribution can satisfy the demand in an optimum way. It has to provide the necessary economical, reliable, and secure electricity to consumer. Network solutions of DSP are the solutions that need adding and/or replacing some network asset. Traditional response is a large investment that creates large capacity. Therefore there may be unused capacity for period years. Thus, there is excess system capacity after the investment is made. In other hand, the alternative responses frequently install distributed generation in very small size. Original plan can be deferred by installing distributed generation. Investment using distributed generation is an option to defer the larger investment in distribution planning. Utility can use this option to face the uncertainty in demand projection. This paper proposes model for determining decision area of distributed generation investment as deferral option in industrial distribution system planning. It uses real option valuation to define the boundary by using the critical value. This study depicts the decision area by 'discount rate'- 'electricity price on transmission' and 'discount rate' -'delaying time' boundary.

Water management in Egypt for facing the future challenges

The current water shortage in Egypt is 13.5 Billion cubic meter per year (BCM/yr) and is expected to continuously increase. Currently, this water shortage is compensated by drainage reuse which consequently deteriorates the water quality. Therefore, this research was commenced with the objective of assessing different scenarios for 2025 using the Water Evaluation and Planning (WEAP) model and by implementing different water sufficiency measures. Field data were assembled and analyzed, and different planning alternatives were proposed and tested in order to design three future scenarios. The findings indicated that water shortage in 2025 would be 26 BCM/yr in case of continuation of current policies. Planning alternatives were proposed to the irrigation canals, land irrigation timing, aquatic weeds in waterways and sugarcane areas in old agricultural lands. Other measures were suggested to pumping rates of deep groundwater, sprinkler and drip irrigation systems in new agricultural lands. Further measures were also suggested to automatic daily surveying for distribution leak and managing the pressure effectively in the domestic and industrial water distribution systems. Finally, extra measures for water supply were proposed including raising the permitted withdrawal limit from deep groundwater and the Nubian aquifer and developing the desalination resource. The proposed planning alternatives would completely eliminate the water shortage in 2025.

A modular, partitioned, discrete element framework for industrial grain distribution systems with rotating machinery

A modular discrete element framework is presented for large-scale simulations of industrial grain-handling systems. Our framework enables us to simulate a markedly larger number of particles than previous studies, thereby allowing for efficient and more realistic process simulations. This is achieved by partitioning the particle dynamics into distinct regimes based on their contact interactions, and integrating them using different time-steps, while exchanging phase-space data between them. The framework is illustrated using numerical experiments based on fertilizer spreader applications. The model predictions show very good qualitative and quantitative agreement with available experimental data. Valuable insights are developed regarding the role of lift vs drag forces on the particle trajectories in-flight, and on the role of geometric discretization errors for surface meshing in governing the emergent behavior of a system of particles.

The Impact of Distributed Generators Placements on the Reliability of Typical Industrial Power Distribution System

Electrical Distribution systems that are radially configured with one utility power source are inherently exposed to higher rates of outages and interruptions, due to failures of system components, including: transformers, breakers and switching devices. In addition, fault conditions can also be caused by weather, animals or human error. Historically in Saudi Arabia, many industrial and residential distribution networks suffered from these problems. Large-size, growing demand and cost — with the time requirements for enhancement projects — results in distributed generation (DG) — as online or backup —playing a key role in the residential, commercial and industrial sectors of the power system. In this paper, the value of DG — installed as an online power source for typical industrial distribution network in Saudi Arabia — is quantified by reliability indices that include System Average Interruption Duration Index (SAIDI), Customer Average Interruption Duration Index (CAIDI) and Energy Not Supplied (ENS). The study outcomes will provide power system engineers with the reliability benefits of DG penetration and an approach to assessing its installations, based on different factors such as size and location.

Development of an improved H-bridge cascaded static synchronous compensator in power system.

This paper presents a new configuration of H-bridge cascaded static synchronous compensator (STATCOM) based on auto disturbance rejection control and modulation wave shifting control intended for installation in industrial and utility power distribution systems. It proposes an improved controller that devotes itself not only to satisfying the requirement of dynamic reactive power compensation but also to achieving the balance of DC capacitor voltage. The new configuration is prominent in having no restriction on the number of power module. Simulation results show the proposed controller exhibits better performance in terms of response time and transient stability compared with the proportion integration controller. Two actual H-bridge cascaded STATCOMs are constructed at 10 kV, 2 MVA and 380 V, 6.5 kVA, respectively, and a series of verifications test are executed in 380 V, 6.5 kVA STATCOM experimental system. The experiment results further prove that H-bridge cascaded STATCOM with the proposed controller has excellent dynamic performance and strong robustness.

MITIGATION OF POWER QUALITY PROBLEM DUE TO STARTING OF INDUCTION MOTOR

Power quality problems such as voltage sag which is to be generate effect on industrial distribution system. In this paper analyses the application of custom power devices using dynamic voltage restorer for mitigation of power quality problems voltage sag due to starting of three phase induction motor.contol strategies for DVR is based on dqo transformation feed forward control techniques. DVR to have less THD In distribution system. the propose control scheme simulation results carried out by MATLAB Simulink. The result shows that although period of voltage sag and rating of the load changes even then voltage sags are totally compensated.

Increase of Voltage Quality in Industrial Distribution Systems

Increase of Voltage Quality in Industrial Distribution Systems

Hydraulic analysis of design alternatives to improve an industrial water distribution system

A CCTV inspection method has been widely used to assess sewer condition and performance, but Korea lacks a proper decision support system for prioritizing sewer repair and rehabilitation (R&R). The objective of this paper is to introduce the results that we have developed in the Sewer Condition Assessment and Rehabilitation Decision-making (SCARD) Program using MS-EXCEL. The SCARD-Program is based on a standardized defect score for sewer structural and hydraulic assessment. Priorities are ranked based on risk scores, which are calculated by multiplying the sewer severity scores by the environmental impacts. This program is composed of three parts, which are decision-making for sewer condition and performance assessment, decision-making for sewer R&R priority assessment, and decision-making for optimal budget allocation. The SCARD-Program is useful for decision-makers, as it enables them to assess the sewer condition and to prioritize sewer R&R within the limited annual budget. In the future, this program logic will applied to the GIS-based sewer asset management system in local governments.

Closed Loop Non Linear Control of Shunt Hybrid Power Filter for Harmonics Mitigation in Industrial Distribution System

In recent years, the amount of non-linear loads has been increasing considerably since there are improvements in power electronic equipment (such as adjustable speed drives or converter ac-dc, ac-ac, dc-ac and dc-dc) in industrial sectors which cause deterioration of the quality of the electric power supply through distortion of supply voltage and supply current. This has led to improvement of many stringent needs regarding generation of harmonic current, which are found in IEEE519 and IEC61000 standards. This paper proposes a non-linear function based closed loop control strategy (without load current extraction) for three-phase Shunt Active Power Line Conditioner and LC passive filter to compensate harmonics, power factor improvement and enhance the dynamic performance of Shunt Hybrid Power Filter (SHPF). By using a PI controller the DC bus voltage of the Shunt Active Power Filter is maintained constant. Results obtained from simulation shows the performance of expected hybrid filter in transient and steady state operation .This indicates that the controller is able to compensate even under severe load current imbalances. DOI: http://dx.doi.org/10.11591/ijpeds.v5i2.6181

Harmonics Analysis of Power Electronics Loads

linear customer loads are now being dominated by sensitive and sophisticated non-linear customer loads with the growth in the power electronics and control system industries. This have a catastrophic impact on a power system and equipment: increasing harmonics pollution. In this paper the modelling of power electronics loads used in domestic and small scale industrial distribution systems are discussed. Various domestic loads such as computer, fluorescent lamp, CFL lamp and small scale industry loads such as adjustable speed drive, arc welder and lift are modelled in PSCAD/EMTDC and then the harmonic analysis of these models are performed KeywordsQuality, Harmonics, Total Harmonic Distortion (THD), Current harmonics, industrial system, Power Elactronics Load.

A %THD analysis of industrial power distribution systems with active power filter-case studies

Increasing use of variable speed drives in industry causes harmonic proliferation in industrial power distribution supply system. Harmonic currents generated by the variable speed drives interact with power system impedance to give rise to harmonic voltage distortion. Thus it is essential to analyze, evaluate and introduce appropriate mitigation techniques for harmonic reduction in the power system networks. In this paper, %THD harmonic load flow analysis for different industrial power system networks in the presence of harmonic loads has been carried out using DIgSILENT software. From the %THD harmonic profile of different feeders and buses of the power distribution system, it is observed that there is more %THD present at certain feeders and buses where nonlinear loads are connected. In order to reduce the %THD within the allowable limits as per IEEE standards, both passive and active filters are designed and installed in the power system networks. Simulation results are presented to validate the proposed scheme. From the results, it is observed that the reduction of %THD is more in power system networks at various buses and feeders with active power filter compared to passive filter.

An optimal investment planning framework for multiple distributed generation units in industrial distribution systems

This paper presents new analytical expressions to efficiently capture the optimal power factor of each Distributed Generation (DG) unit for reducing energy losses and enhancing voltage stability over a given planning horizon. These expressions are based on the derivation of a multi-objective index (IMO), which is formulated as a combination of active and reactive power loss indices. The decision for the optimal location, size and number of DG units is then obtained through a benefit–cost analysis. Here, the total benefit includes energy sales and additional benefits, namely energy loss reduction, network upgrade deferral and emission reduction. The total cost is a sum of capital, operation and maintenance costs. The methodology was applied to a 69-bus industrial distribution system. The results showed that the additional benefits are imperative. Inclusion of these in the analysis would yield faster DG investment recovery.

Voltage Sag Characterization in a Distribution Systems: A Case Study

Voltage sags caused by the short-circuit faults in transmission and distribution lines have become one of the most important power quality problems facing industrial customers and utilities. Voltage sags are normally described by characteristics of both magnitude and duration, but phaseangle jump should be taken into account in identifying sag phenomena and finding their solutions. In this paper, voltage sags due to power system faults such as single phase-to-ground, phase-tophase, and two-phase-to-ground faults are characterized by using symmetrical component analysis and their effect on the magnitude variation and phase-angle jumps for each phase are examined. A simple and practical method is proposed for voltage sag detection, by calculating RMS voltage over a window of one-half cycle. The industrial distribution system at Bajaj hospital is taken as a case study. Simulation studies have been performed by using MATLAB/SIMULINK and the results are presented at various magnitudes, duration and phase-angle jumps.

DG Placements Impact on the Reliability of Typical Industrial Distribution System In Saudi Arabia

Electrical Distribution systems that are usually radially configured with one utility power source are inherently exposed to higher rates of outages and interruptions due to the fact that failures of system components including transformers, breakers and switching devices along with fault conditions caused by different conditions are not preventable but rather improvable. Historically at Saudi Arabia (SA), many industrial and residential distribution networks suffered from the problems incurred by the utility grid connection including equipment failure, low power quality or human, animal and weather conditions. The fact that the large‐size, the growing demand and the cost with the time requirements for enhancements projects have made distributed generation (DG) in all its application, namely, online or backup to play a key role in the residential, commercial and industrial sectors of the power system. In this paper, the value of DG installed as an online power source of typical industrial distribution network at SA (Abqaiq) is quantified by reliability indices that include SAIDI, CAIDI and ENS. The study outcomes will provide power system engineers with the sense of the reliability benefits of DGs penetration and an approach to assess its installations based on different factors such as the size and location.

PSO-Based PI Controller for Shunt APF in Distribution Network of Multi Harmonic Sources

PI controller tuning with the assumption of linear PWM model leads to unsatisfactory results under varying operating conditions. Optimal tuning of PI gains is required to get the best response of PI controllers. This paper presents a new method for harmonic suppression using particle swarm optimization (PSO) based PI controller (PSOPI) to estimate an efficient shunt active power filter (SAPF). The proposed filter is tested on a 13 bus industrial distribution system. The study system with the 18 study cases are simulated through MATLAB Simulink with different loading condition and single and multi harmonic sources. The results of applying the PIPSO controller are compared with those out of a double proportional controller (DPC). The obtained results ensure the effectiveness of the proposed filter and its superiority in reducing harmonics.

Energy‐water efficiency and U.S. industrial steam

S team systems are a ubiquitous element in nearly every type of manufacturing plant. In the United States, steam systems are the single largest consumer of energy in the industrial sector, where they account for 37% of annual onsite energy use. Steam use is particularly prominent in the chemicals, paper, petroleum refining, and food and beverage industries, where it is used in a wide range of processes, including reforming, distillation, concentration, cooking, and drying. Together, these four industries comprise nearly 90% of U.S. industrial steam demand, with chemicals manufacturing (30%) and paper manufacturing (30%) holding the largest shares. At the national level, industrial steam systems account for around 6% of U.S. total primary energy use, or 5,900 trillion British thermal units (TBtu). As such, much attention has been paid to steam system energy efficiency improvements as part of corporate, utility, and government energy and air pollution initiatives. Key incentives include local utility rebates, tax incentives, and lowor no-cost steam system energy efficiency audits. Steam system energy efficiency not only makes sense from an environmental perspective, but also from an economic perspective. As of 2006, U.S. manufacturers spent $21 billion on externally purchased boiler fuels. The actual price tag of industrial steam is likely much higher; nearly one-half of U.S. boiler fuels are self-generated within plants in the form of waste gas, black liquor, wood wastes, and other byproducts. These byproduct fuels are not free, as they are generated from purchased materials and typically require further processing for efficient combustion. Reducing demand for boiler fuels can, therefore, help reduce operating costs and improve profit margins. While clearly justified, the historical focus on reducing energy use has overlooked an increasingly compelling benefit of steam system efficiency: namely, reduced water use. Compared to the many public and private incentives for industrial energy efficiency, there are surprisingly few external incentives for industrial water efficiency. One key barrier to such incentives is the lack of credible data on industrial water use, which, unlike data on energy use, are not compiled at the manufacturing industry or process level in regular national surveys. This dearth of data contributes to a general lack of awareness of the sources and scale of industrial water use within the engineering and policy communities, which limits broader attention to water efficiency beyond the plant floor. Another barrier to steam system water efficiency is that the cost of boiler water—and the associated chemicals required for its treatment—typically only represents a small fraction of boiler operating costs, which are dominated by the costs of fuel. However, as we discuss in this Perspective, U.S. industrial steam systems consume copious amount of water. It follows that steam systems are worth a closer look as a manufacturing water efficiency target. Several current trends suggest that water efficiency will play an increasingly prominent role in the financial and sustainability plans of U.S. manufacturers. Recent water stress due to droughts and rising water infrastructure costs have led to increased public water rates around the country. These conditions may worsen with a changing climate. An increasing number of manufacturers are reporting water use as an important environmental indicator in annual corporate sustainability reports, which raises both public awareness of and accountability for water efficiency. Many manufacturers are also being asked by their corporate customers for environmental “footprint” data as part of large-scale sustainable Correspondence concerning this article should be addressed to E. Masanet at eric.masanet@northwestern.edu; M.E. Walker at mwalker9@hawk.iit.edu.

Robust control strategy for PV system integration in distribution systems

This paper proposes a decentralized control strategy for higher penetration of photovoltaic (PV) units without violating system operating constraints. A systematic procedure is developed and a robust controller is designed to ensure both dynamic voltage and transient stability for a specific PV integration level. The change in the model due to the volatile nature of PV generations is considered as an uncertain term in the design algorithm. Simultaneous output-feedback linear quadratic controllers are designed for PV generators. This designed control scheme is robust with respect to intermittency and enhances the integration level in a sub-transmission and distributed system. The effectiveness of the proposed controller is verified on a 43-bus industrial meshed distribution system under large disturbances. It is found that the designed control scheme enhances stability and increases the renewable integration levels.

Optimal planning of passive harmonic filters using hybrid differential evolution considering variation of system parameters

SUMMARY This paper presents an optimal planning of passive harmonic filter using the hybrid differential evolution method considering variation of system impedance, harmonic current sources and filter tuning points. The proposed method minimizes an objective composed of the total harmonic distortion of current and voltage, selects different filters topologies, and determines their optimal parameters and tuned points under a constant cost. The harmonic currents and voltages in a power system are expressed as probabilistic models which are obtained using the statistical simulation method. Monte-Carlo simulation is employed to verify the accuracy of the obtained probabilistic models. The method proposed is applied to solve the harmonic problems in a practical chemical plant, and the results show that the proposed method is effective for passive filter planning in industrial distribution systems. Copyright © 2012 John Wiley & Sons, Ltd.

Optimal (short-term) pump schedule detection for water distribution systems by neutral evolutionary search

The application of neutrality is a straightforward tool to preserve population diversity since it allows the genotype (on the represented search space) to be changed without affecting the corresponding fitness. To implement neutrality the literature suggests representational redundancy (more to one correspondence in genotype–phenotype mapping) although using it as a source of neutrality researchers uniformly reported better or worse results. Instead of applying representational redundancy here the utilization of pseudo redundancy as the source of neutrality is proposed, that is, neutrality is achieved by simple objective-fitness transformation while pseudo redundancy (as another redundancy interpretation) denotes more to one correspondence between objective-fitness domains by objective-fitness mapping. The contribution of this work is specified by the dynamic generational gap model introduced for evolutionary algorithms which appears when elitist strategy is used under neutrality by pseudo redundancy. This paper investigates the influence of dynamic generational gap model on the performance of a micro-genetic algorithm framework applied to achieve least cost water pump control policy for an industrial size water network distribution system. The presented constrained mixed-integer optimization problem is originated from the regional water network of the city of Sopron (60,000 citizens) located in Hungary. Here, the goal is to obtain intra-day pump schedule which minimizes the cost required for operation while satisfies the system constraints (water reservoir level limitations, pump flow and delivery regulations, pump energy consumption limitations) and fulfills the water requirement by the users.