Types Of Distributed Generation Research Articles

Harmonic Based Strategy for Location and Sizing of Distributed Generation Insertion (Dept.E)

Technical advances and institutional changes in the electric power industry have resulted in a constantly increasing penetration of distributed generation (DG) integrated with distribution networks. For the connection of new DG installations to the networks a variety of factors have to be taken into account, including technical requirements imposed by utilities to ensure that the DG doesn't adversely affect the operation and power quality of the networks. The use of power electronics at the front end of many DG types poses harmonic control requirements for their insertion into the grid. The attention is focused on the harmonic emissions. This paper introduces a harmonic based strategy for the best location and size of DG sources integrated with distribution network. Also, this paper introduces a new index called unified harmonic index (UHI) that is based on the values of voltage harmonic distortion, current harmonic distortion, and hosting capacity. The procedure is used to rank the available locations of DG and then examined optimum capacities of DGs in the ranked sites based on both the UHI and harmonic limit consideration in IEEE-519. The strategy is applied to an actual Egyptian feeder to indicate the best location and size of DG connected to the feeder as a preliminary study for the distribution network in Egypt for the near future as planned to allow the DG to be inserted.

Optimal integration of multi-type DG in RDS based on novel voltage stability index with future load growth

In this article, a novel voltage stability index is proposed for the optimal placement and an analytical as well as particle swarm optimization method is implemented for optimal sizing of different types of distributed generation (DG) in a radial distribution system. The three types of DG considered are Type I, Type II and Type IV model. The methods account for changes in long-term system load profile in the planning phase to enhance power system performance. The load model chosen is composite. The optimal power factor and the cost of the DG are also considered. The efficiency of the proposed technique is tested and validated on IEEE 33-bus and 69-bus systems. The significant savings in annual energy loss, reduction in system power losses with upgraded voltage profile is observed for Type IV DG at optimal PF over other types. The results attained are further compared to other analytical and nature-inspired methods to exemplify the dominance of the proposed methodology. The statistical analysis has also been carried out for both bus systems without and with considering all types of DG.

Mitigation of Line Losses in Distribution System using Optimized Placement of Distributed Generation

Line losses are the most significant challenge faced by Pakistan's energy department. 6.5% of the country's GDP, a large figure of $1.8 billion is lost every year due to line losses in power generation, transmission, distribution and consumption. In distribution systems, researchers are attracted by the penetration of distributed generation (DG) nowadays. The performance of a distribution network is affected by the significant role of number, capacity and situation of DG units. This study will focus on the distributed generation of a centralized national grid and provide an algorithmic model that implements Improved Particle Swarm Optimization to reduce the system power loss and improve the voltage profiles via optimization of the locations and sizes of multip1le DG(s). The overall sensitive feature was determined and utilized efficiently to reduce research space for the algorithm. In the case of IEEE 33Bus test system, 10% of candidate buses are selected as possible DG situations. The IPSO methodology produced severe loss reduction and improve the voltage profiles in all the three types of DGs considered using the IEEE 33-Bus system. The percentage decrease in active power losses was reduced 68.10492%, 66.91669% and 58.89211% for DG type -1, DG type-2 and DG type-3 respectively. At the same time, reactive power losses were reduced 53.095%, 53.0922% and 50.4145% for DG type -1, DG type-2 and DG type-3 respectively.

Optimal allocation of inverter connected DGs: An objective function to minimize deterioration of transient stability of power system

While renewable energy resources have provided more flexibility in operation of power system, it may threaten the security of the power system during transient phenomena. Previous investigation on the power system with high penetration of inverter based connected (IBC) distributed generations (DG) reveal that this type of DG has negative influence on the transient stability margin of the power system (Seungchan et al., 2018). An optimization framework is proposed in this paper, in which the negative effects of IBC type of DGs on the transient stability margin of the power system is minimized. More specifically, this paper proposes a new objective function (OF) to distribute the IBC type of DGs that have minimum deterioration of transient stability margin. To such aim, an improved index based on the kinetic energy is introduced which considers IBC type of DGs based on virtual synchronous generator concept. To calculate index, equal area criterion (EAC) and sensitivity analysis are respectively used for extracted critical kinetic energy (CKE) and consequently to take into account the effect of fault trajectory. The IBC type of DGs in this investigation includes photovoltaic and electrical vehicles. The proposed framework is applied on the IEEE 14-bus and 30-bus test system and further discussed during several contingencies and fault conditions.

Distributed generation planning from the investor's viewpoint considering pool-based electricity markets

Independent investors can install distributed generations (DGs) in power networks as long as they follow the systems’ rules and frameworks. Logically, they try to maximize their profits, and network owners/operators usually cannot directly control their decisions regarding the DG location and size. However, there are inherent interactions between their decisions and the systems’ technical and economic characteristics. In this paper, a new approach is presented for optimal DG placement and sizing from the standpoint of independent investors, with specific consideration given to interactions with pool-based electricity markets. The proposed approach is founded on the innovative combination of the meta-heuristic optimization model and the reinforcement learning-based market simulation strategy. This approach is implemented using the particle swarm optimization algorithm and the Q-learning technique, and it is comprehensively examined in the IEEE 30-bus system with consideration for different pricing rules and DG types. The results confirm that there are significant interdependencies between the optimal decision of DG investors and the strategic bidding behavior of market players. Also, they indicate that the proposed approach is useful for independent investors in identifying the most valuable DG location and size as well as for the systems’ policy-makers in investigating the long-term effects of specific rules.

A novel multi-objective modified symbiotic organisms search algorithm for optimal allocation of distributed generation in radial distribution system

This article presents a novel optimization technique to allocate distributed generation (DG) units optimally in radial distribution system (RDS). Three renewable type DG units (such as wind turbine, solar photovoltaic and biomass system) have been integrated in the RDS. In this regard, an optimization problem is formulated considering multiple technical and economic objectives of the DG planning. A new metaheuristic, namely multi-objective modified symbiotic organisms search (MOMSOS), is proposed to solve this optimal DG allocation problem. A chaos-based cross-over operator is introduced in the parasitism phase of the proposed MOMSOS to enhance diversity in the population. The proposed MOMSOS is equipped with hierarchical non-dominated sorting technique which is superior to the existing fast non-dominated sorting strategy in terms of computational complexity. An adaptive penalty function is utilized for constraint handling. The proposed algorithm is tested on some CEC 2009 benchmark test problems to ensure its global optimization capability. Furthermore, performance of the proposed MOMSOS is validated on 69-node RDS and the obtained results are compared with other well-established multi-objective optimization algorithms.

Protection Coordination of Radial Distribution Networks Connected with Distributed Generation Considering Auto-reclosing Schemes by Resistive Superconducting Fault Current Limiters

AbstractRadial distribution networks are normally protected against fault currents by fuses and reclosers. This protection is coordinated in a way that reclosers clear temporary faults before the melting of fuses and fuses melt to clear permanent faults. Distribution networks, which are recently connected with distributed generations (DGs), incur a variety of issues that are certainly worthy of closer considerations. One of these issues is the operation of protection devices. Recloser-fuse coordination may be lost when DGs are integrated with distribution networks due to the effect of current flowing from DGs during fault period and the breaking of the radiality nature of these networks. The impact of DGs on recloser-fuse coordination depends on penetration level, location, and type of DG. Recloser-fuse coordination of radial distribution networks connected with DGs can be kept by connecting resistive superconducting fault current limiter (R-SFCL) in series with the DG to limit the fault current contribution of DG during the fault period. However, when considering the auto-reclosing scheme of the recloser, recloser-fuse coordination may be lost even if R-SFCL is connected. This paper shows the effectiveness of R-SFCL to restore recloser-fuse coordination without considering auto-reclosing scheme. It also proposes solution methods based on three different configurations of R-SFCL to maintain recloser-fuse coordination when auto-reclosing scheme is considered. Simulation results illustrate the effectiveness of the proposed configurations of R-SFCL to keep recloser-fuse coordination. All simulations are performed using MATLAB/Simulink package.

Effect of optimal Multi-DG siting and sizing in transmission system using hybrid optimization technique for voltage control

<span>The advancement of Distributed Generation (DG) technologies have caused great impact to power system operation. Inappropriate installation of DGs may lead to over-compensation or under-compensation situation. Thus, a reliable optimization is urgent to avoid any unwanted effect. This paper analyses the installation impact of different types-multi-DGs determined using a pre-developed hybrid optimization technique termed as Immunized-Brainstorm-Evolutionary Programming (IBSEP). It is imperative to study the effect of multi-DGs installation such that a relevant utility can make a correct decision, whether its installation is worth or vice versa. Rigorous study has been conducted in terms of identifying the optimal location and sizing, installed on transmission system for voltage control involving different DG types. Comprehensive results are embedded in this paper to demonstrate the effect of multi-DGs installation in transmission system which in turns beneficial to the utility.</span>

Interconnected microgrids frequency response model: An inertia-based approach

Preserving the frequency stability of new important blocks in smart grids such as interconnected microgrids, is a serious challenge. Inertia can act as a significant stability/performance index for frequency regulation in the power grids. Renewable energy sources have low inertia and mostly need a special control mechanism to emulate an inertia and inject to the system. In this work, a frequency response model is introduced for AC interconnected microgrids based on the inertia concept. The absence of a suitable model for study on frequency and tie-line power control in the interconnected microgrids, limits research activities in this field. A clear classification has not been done considering the inherent dynamic behavior of all distributed generators types, which may help researchers to introduce more simple strategies to provide better dynamic performance. This paper addresses a new approach for study on inertia-based simple frequency response model for interconnected microgrids. The outcome can be useful for frequency and tie-line power control analysis and synthesis in interconnected microgrids.

Optimal integration of different types of DGs in radial distribution system by using Harris hawk optimization algorithm

The probable availability of renewable power sources is unexceptionable, and the government of India is setting high goals for the use of renewable energy. Renewable distributed generation (DG) red...

Optimal Distributed Generation Allocation and Sizing Using Genetic and Ant Colony Algorithms

Distributed generators (DG) which installed into distribution network to face the increasing of load demand. DG can used to enhance power generation systems and improve distribution network efficiency. However, the distributed generators units’ implementation at not convenient position and sizing can lead to negative impacts such as a growing in power losses and invasion of system constraints. Because the rising of demand in energy. The appropriate placement and sizing of DG’s units is a credible solution to much problems in distribution system, for example power loss reduction and voltage regulation. The allocation of distributed generators into the distribution network can significantly impact in the transmission and distribution systems. Therefore, a method, which can identify an optimum DG location and size, is necessary. In this paper, Genetic Algorithm (GA) and Ant colony Algorithm (ACO) optimization techniques are proposed to find optimal sizing and location for distributed generation in electrical networks. The objective function of the work relies upon a linearized model to compute the active power losses as a function of power supplied from the generators. This strategy based on a strong coupling between active power and power flow taking into consideration the voltage angles. With the end goal to exhibit the adequacy of the proposed method, the proposed strategy is applied on IEEE 57-bus standard systems. Different maximum penetration level capacity of DG units and various possible places of DG units among several types of DG (active, reactive or active and reactive power) are considered. Results show that the optimization tools employing GA and ACO are effective in reducing active power losses by finding the optimal placement and sizing of DG units

A Proposed Passive Islanding Detection Approach for Improving Protection Systems

Nowadays, distributed generation (DG) is commonly used in networks. In spite of the numerous benefits of DG units in these networks, several challenges are introduced such as unintentional islanding, reverse power flow, protection concerns, etc. In this paper, a new passive islanding detection approach is proposed depends on the production of voltage sequence components at every relay location not only at the DG point of common coupling. The proposed approach uses only one threshold value for all relays in the distribution network. The performance of the proposed approach is not influenced by changes in type, capacity or location of DG. The proposed approach is evaluated under different transient conditions such as capacitor switching, load switching and DG switching. Also, the performance of the suggested islanding approach has been compared with most prevalent islanding detection techniques. The performance of the proposed algorithm is stable during balanced and unbalanced conditions. Moreover, detecting the islanding case at all relays provides the ability to improve the protective relays performance by updating the protection setting for all relays based on local measurement only without the need for fault current limiters (FCLs) or a communication network. The proposed approach is evaluated using the Canadian distribution system embedded with DG units in MATLAB/Simulink simulation. The achieved results demonstrate that the proposed approach is robust during all non-islanding events. Also, it succeeds to detect islanding condition with high confidence without non detection zone (NDZ).

Renewable Energy Performance of the Green Buildings: Key-Enabler on Useful Consumption Yield

Malaysia's Eleventh Plan started to encourage green building developments and green industries to stimulate green growth. Eventually, the Malaysian government had launched a new commitment to accelerate the green and efficient energy sector and revised the quota of Renewable Energy (RE) towards higher capacity for electricity generation. These scenarios had highlighted the latest commitment of the Malaysian government to implement both green building development and concurrently, streamline the additional quota for RE generation. Due to this, the evolution of the requirement of RE-based Distributed Generation (DG) in the green building development for higher installed-capacity was expected to occur in ensuring the government key achievement becomes more visible. This study focuses on measuring the expanded-capacity performance of the Solar Photovoltaic (PV)-type DG unit (PV-DG) through the Green Building Rating System (GBRS), particularly on the useful energy consumption yield for load and total line loss minimization. Previous work has conducted a MATLAB simulation on a PV-DG capacity expansion guided by the Net Energy Metering (NEM) specification considering the total line loss minimization as the main objective function. These results are being adopted to obtain the ratio of useful energy consumption from the generated PV-DG through the selected distribution network. Consequently, the Performance Ratio (PR) - as the internationally recognized formulation for a complete PV-DG system - is proposed to be revolutionized towards extended version, considering the specific total line losses minimization, via the formed of the proposed ratio.

Hybrid Artificial Immune System-firefly Algorithm Technique for Optimal DG Capacity and Operational Strategy in Distribution System

This paper presents a study on hybrid optimization technique for optimal distributed generation (DG) capacity and operational strategy in distribution system. In this study, hybrid method namely Artificial Immune System-Firefly Algorithm (AISFA) is developed to determine the optimal size of the schemes respectively in the distribution system. The Firefly Algorithm (FA) which is a type of meta-heuristic algorithm is inspired by the blinking or flashing behaviour of fireflies that is embedded into Artificial Immune System (AIS) algorithm. The aim of this study is to develop the AISFA algorithm in order to improve the voltage profile and minimize losses of distribution system between the different operational strategy and types of DG. The types of DG include DG type 1, DG type 2, and DG type 3. The proposed technique was verified on IEEE 69-bus test system and the program was developed using the MATLAB programming software. The results showed a significant loss reduction in the line losses and voltage profile improvement has been obtained for optimal DG capacity and operational strategy in distribution system. From the simulation, the results were recorded in terms of the total losses and minimum voltage for the system. The results of the optimisation process of DG are utilized for the assistance of power system operators and planners. The power system planner can adopt the suitable sizes and locations from the obtained result for the planning of utility in term of economic and geographical consideration.

Optimal distributed generation in green building assessment towards line loss reduction for Malaysian public hospital

This paper presents an optimization approach for criteria setting of Renewable Distributed Generation (DG) in the Green Building Rating System (GBRS). In this study, the total line loss reduction is analyzed and set as the main objective function in the optimization process which then a reassessment of existing criteria setting for renewable energy (RE) is proposed towards lower loss outcome. Solar photovoltaic (PV)-type DG unit (PV-DG) is identified as the type of DG used in this paper. The proposed PV-DG optimization will improve the sustainable energy performance of the green building by total line losses reduction within accepted lower losses region using Artificial bee colony (ABC) algorithm. The distribution network uses bus and line data setup from selected one of each three levels of Malaysian public hospital. MATLAB simulation result shows that the PV-DG expanding capacity towards optimal scale and location provides a better outcome in minimizing total line losses within an appropriate voltage profile as compared to the current setting of PV-DG imposed in selected GBRS. Thus, reassessment of RE parameter setting and the proposed five rankings with new PV-DG setting for public hospital provides technical justification and give the best option to the green building developer for more effective RE integration.

Multiple distributed generations placement and sizing based on voltage stabilityindex and power loss minimization

This paper proposes a rapid analytical method to determine the locations and sizes of multiple distributed generations (DGs) inside a distribution network. DGs locations are chosen with the aim of enhancing voltage stability and their sizes are picked so as to minimize system power losses. To evaluate the effect of the DG's nature on the system's performance, the proposed DG allocation method is tested for all DG types and the impact of the combination of different types of DGs is equally investigated, which offers a guide to designing an optimal hybrid network.

Optimal DG Deployment Based on Technical and Economic Considerations with Daily Load Variation

The concept of distributed generation (DG) has been developed as a hopeful solution to meet the demand increase in distribution systems. The optimal DG deployment in the distribution system can improve the technical benefits. This study presents a framework to find the optimum location and size for different types of DG units to enhance the voltage stability index (VSI), improve the voltage regulation and reduce the daily energy losses. The emission effect and cost function (environment and economic benefits) are augmented in the multi-objective function. Combinations of DG types are introduced to obtain the best benefits from each one. The daily load variations and dynamic output of each DG type are considered in the problem formulation. The genetic algorithm (GA) technique is used to find the optimal allocation for different cases. The typical IEEE 33-bus system is utilized to evaluate the proposed framework.

Effect of Optimal Multi-DG Siting and Sizing in Transmission System using Hybrid Optimization Technique for Loss Control

The advancement of Distributed Generation (DG) technologies have caused great impact to power system operation. The installation of DG has been expanded in both the transmission and distribution systems. Improper planning of DGs installation may lead to over-compensation or under-compensation. Thus, a reliable optimization is urgent to alleviate any undesirable event. This paper analyses the impact of multi-DGs installation utilizing a pre-developed hybrid optimization technique termed as Immunized-Brainstorm-Evolutionary Programming (IBSEP). It is imperative to study the effect of multi-DGs installation such that a relevant utility can make a correct decision, whether its installation is worth or vice versa. Rigorous study has been conducted in terms of identifying the optimal location and sizing, installed on transmission system for loss control involving different DG types. Comprehensive results embedded in this paper show that more optimal DGs of a particular type are superior to the other in controlling transmission system loss.

Photovoltaic Expansion-Limit through a Net Energy Metering Scheme for Selected Malaysian Public Hospitals

This paper presents an optimization approach in determining the expansion-limit of Renewable Distributed Generation (DG) capacity through a Net Energy Metering (NEM) scheme specifically for selected Malaysian public hospitals. In this study, the total line loss reduction was analyzed and set as the main objective function in the optimization process where an acceptance region for DG extensiveness was proposed via the lower total line loss outcome value. Solar photovoltaic (PV)-type DG unit (PV-DG) was identified as the type of DG used in this paper. Artificial Bee Colony (ABC) algorithm was chosen to alleviate such PV-DG optimization. The distribution network uses a bus and line data setup from the three selected Malaysian public hospitals prior to three different levels, i.e., National, State, and District level hospitals. MATLAB simulation result showed the PV-DG expansion capacity towards bigger scale and location bounded by the U-trajectory shape theory which resulted in a contradiction between NEM current maximum capacity requirement and actual PV-DG expansion-limit. These limitations were also found to be different among three different level hospitals, and the expansion-limit was tailored by their own distribution network parameters. Thus, this paper provides technical justification and gives the best option to the renewable energy (RE) developer for more effective PV-DG integration through the utilization of a NEM scheme. The importance of the study is portrayed in-depth towards achieving a more sensible and accurate way of estimating the outcome. This will encourage developers, building owners, and users in participating towards achieving potential benefits both in monetary and power system reliability improvement, specifically for Malaysian public hospital applications.

Optimal Integration of Distributed Generation in Primary Distribution System and its Economics

The paper analyses four types of DG (distributed generators) for their optimal placement in primary distribution system. They are sited and sized optimally to obtain maximum loss reduction. The ultimate objective of the adopted work in this paper is to identify the size and location of distributed generators for their placement in primary distribution network and to justify the economics of these placements. To serve the purpose, an analytical method is used in this paper for determination of sizes and sites for four DG types. The analytical method is considered suitable for the analysis purpose in proposed work. The paper presented a comprehensive analysis for four types of DGs for their placement in primary distribution system. The type 1 DG is capable of delivering real power only whereas type 3 DG is capable of providing real as well as reactive power to the distribution network. Out of other two types, type 2 can deliver only the reactive power whereas type 4 supplies active power but at the same time it consumes reactive power. The paper compares the economic feasibility of placement of four DG types in primary distribution system.