scholarly journals The Concept of Dynamic Hosting Capacity for Distributed Energy Resources: Analytics and Practical Considerations

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2576 ◽  
Author(s):  
Tiago Elias Castelo de Oliveira ◽  
Math Bollen ◽  
Paulo Fernando Ribeiro ◽  
Pedro M. S. de Carvalho ◽  
Antônio C. Zambroni ◽  
...  
Keyword(s):  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Low Voltage ◽  
Photovoltaic System ◽  
Communication Tool ◽  
Performance Limits ◽  
Power Performance ◽  
Electrical Distribution Systems ◽  
General Aspects

The hosting capacity approach is presented as a planning, improving, and communication tool for electrical distribution systems operating under specific uncertainties, such as power quality issues, power stabilities, and reliability, among others. In other words, it is an important technique, when renewable sources are present, to answer the amount of power that is possible to supply to the system without trespassing power performance limits. However, the power flow in a distribution system, for instance, can change throughout time due to the penetration of distributed generation, as well as load consumption. Based on the dynamic nature existing in distribution grids nowadays, it is important to highlight that the hosting capacity should not be calculated in a specifically chosen time only, but must be analyzed throughout a period of time. Thus, this paper introduces an extended concept of hosting capacity in relation to an integrated impact of harmonic voltage distortion and voltage rise as a function of time for daily, weekly, monthly, or even yearly periods. This extended concept is named as Dynamic Hosting Capacity (DHC(t)). General aspects of DHC(t) are demonstrated via measured data on a photovoltaic system (PV) connected at a low-voltage (LV) side of a university building.

scholarly journals Voltage Reduction in Medium Voltage Distribution Systems Using Constant Power Factor Control of PV PCS

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5430
Author(s):  
Daisuke Iioka ◽  
Takahiro Fujii ◽  
Toshio Tanaka ◽  
Tsuyoshi Harimoto ◽  
Junpei Motoyama
Keyword(s):  
Power Factor ◽  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Low Voltage ◽  
Voltage Distribution ◽  
Constant Power ◽  
Voltage Rise ◽  
Pv Systems ◽  
Power Factor Control

Reverse power flow from a photovoltaic (PV) system in a distribution system causes a voltage rise. A relative study regarding the reduction in the distribution feeder voltage depending on system conditions and the magnitude of reverse power flow has been conducted. Several methods for mitigating voltage rise have been proposed; however, the influence of these methods on the voltage in the distribution system, where the voltage is reduced due to reverse power flow, remains to be determined. In this study, the effect of constant power factor control in low-voltage PV systems, which are widely used as voltage rise countermeasures in distribution systems, was analyzed under the condition that the distribution line voltage decreases due to reverse power flow. Consequently, the constant power factor control of the low-voltage distribution system was found to adversely reduce voltage in the medium voltage distribution system due to the consumption of lagging reactive power by the PV systems.

scholarly journals Energy Efficiency Study for the Distribution System Using Low Voltage Transformer Under Harmonic Conditions

2021 ◽  
Author(s):  
Bruno M. Laurindo ◽  
Felipe Marins ◽  
Bruno Wanderley França ◽  
Marcio Zamboti Fortes ◽  
Mauricio Aredes
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Low Voltage ◽  
Energy Losses ◽  
Nonlinear Loads ◽  
Voltage Transformer ◽  
Operation Temperature ◽  
Three Phase

In Brazil, technical energy losses in power distribution systems are determined by power flow studies considering medium and low voltage systems, according to ANEEL recommendations, presented in PRODIST Module 7. These technical losses occur due to physical phenomena and are intrinsically associated with the energy distribution process. However, standards currently do not consider energy losses from harmonic components generated by nonlinear loads, which represent almost all the loads present in electrical systems worldwide. Thus, this paper aims to analyze the operation of a low voltage transformer under harmonic current conditions and to evaluate not only the operation temperature of the equipment, but also to verify the energy losses in it. This test is performed on a laboratory platform and the results are experimental using an adjustable three-phase source and a 3kVA three-phase transformer.

scholarly journals A Novel Linear Optimal Power Flow Model for Three-Phase Electrical Distribution Systems

2020 ◽  
Author(s):  
Juan Sebastian Giraldo ◽  
Pedro Pablo Vergara ◽  
Juan Camilo Lopez ◽  
Phuong Nguyen ◽  
Nikolaos Paterakis
Keyword(s):  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Optimal Power Flow ◽  
Flow Model ◽  
Mixed Integer ◽  
Electrical Distribution Systems ◽  
Optimal Power ◽  
Electrical Distribution ◽  
Three Phase

This paper presents a new linear optimal power flow model for three-phase unbalanced electrical distribution systems considering binary variables. The proposed formulation is a mixed-integer linear programming problem, aiming at minimizing the operational costs of the network while guaranteeing operational constraints. Two new linearizations for branch current and nodal voltage magnitudes are introduced. The proposed branch current magnitude linearization provides a discretization of the Euclidean norm through a set of intersecting planes; while the bus voltage magnitude approximation uses a linear combination of the L1 and the L∞ norm. Results were obtained for an unbalanced distribution system, in order to assess the accuracy of the linear formulation when compared to a nonlinear power flow with fixed power injections, showing errors of less than 4\% for currents and 0.005\% for voltages.

scholarly journals A Novel Linear Optimal Power Flow Model for Three-Phase Electrical Distribution Systems

2020 ◽  
Author(s):  
Juan Sebastian Giraldo ◽  
Pedro Pablo Vergara ◽  
Juan Camilo Lopez ◽  
Phuong Nguyen ◽  
Nikolaos Paterakis
Keyword(s):  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Optimal Power Flow ◽  
Flow Model ◽  
Mixed Integer ◽  
Electrical Distribution Systems ◽  
Optimal Power ◽  
Electrical Distribution ◽  
Three Phase

This paper presents a new linear optimal power flow model for three-phase unbalanced electrical distribution systems considering binary variables. The proposed formulation is a mixed-integer linear programming problem, aiming at minimizing the operational costs of the network while guaranteeing operational constraints. Two new linearizations for branch current and nodal voltage magnitudes are introduced. The proposed branch current magnitude linearization provides a discretization of the Euclidean norm through a set of intersecting planes; while the bus voltage magnitude approximation uses a linear combination of the L1 and the L∞ norm. Results were obtained for an unbalanced distribution system, in order to assess the accuracy of the linear formulation when compared to a nonlinear power flow with fixed power injections, showing errors of less than 4\% for currents and 0.005\% for voltages.

scholarly journals A new meta-heuristic pathfinder algorithm for solving optimal allocation of solar photovoltaic system in multi-lateral distribution system for improving resilience

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Varaprasad Janamala
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Voltage Stability ◽  
Optimal Allocation ◽  
Photovoltaic System ◽  
Solar Photovoltaic ◽  
Voltage Profile ◽  
Pv System ◽  
Solar Photovoltaic System ◽  
The Impact

AbstractA new meta-heuristic Pathfinder Algorithm (PFA) is adopted in this paper for optimal allocation and simultaneous integration of a solar photovoltaic system among multi-laterals, called interline-photovoltaic (I-PV) system. At first, the performance of PFA is evaluated by solving the optimal allocation of distribution generation problem in IEEE 33- and 69-bus systems for loss minimization. The obtained results show that the performance of proposed PFA is superior to PSO, TLBO, CSA, and GOA and other approaches cited in literature. The comparison of different performance measures of 50 independent trail runs predominantly shows the effectiveness of PFA and its efficiency for global optima. Subsequently, PFA is implemented for determining the optimal I-PV configuration considering the resilience without compromising the various operational and radiality constraints. Different case studies are simulated and the impact of the I-PV system is analyzed in terms of voltage profile and voltage stability. The proposed optimal I-PV configuration resulted in loss reduction of 77.87% and 98.33% in IEEE 33- and 69-bus systems, respectively. Further, the reduced average voltage deviation index and increased voltage stability index result in an improved voltage profile and enhanced voltage stability margin in radial distribution systems and its suitability for practical applications.

scholarly journals Smart charging for electric vehicles to minimise charging cost

2017 ◽  
Vol 231 (6) ◽  
pp. 526-534 ◽  
Author(s):  
Yue Wang ◽  
David Infield ◽  
Simon Gill
Keyword(s):  
Electric Vehicle ◽  
Electric Vehicles ◽  
Distribution System ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Low Voltage ◽  
Wholesale Price ◽  
Heuristic Method ◽  
Domain Model ◽  
Smart Charging

This paper assumes a smart grid framework where the driving patterns for electric vehicles are known, time variations in electricity prices are communicated to householders, and data on voltage variation throughout the distribution system are available. Based on this information, an aggregator with access to this data can be employed to minimise electric vehicles charging costs to the owner whilst maintaining acceptable distribution system voltages. In this study, electric vehicle charging is assumed to take place only in the home. A single-phase Low Voltage (LV) distribution network is investigated where the local electric vehicles penetration level is assumed to be 100%. Electric vehicle use patterns have been extracted from the UK Time of Use Survey data with a 10-min resolution and the domestic base load is generated from an existing public domain model. Apart from the so-called real time price signal, which is derived from the electricity system wholesale price, the cost of battery degradation is also considered in the optimal scheduling of electric vehicles charging. A simple and effective heuristic method is proposed to minimise the electric vehicles’ charging cost whilst satisfying the requirement of state of charge for the electric vehicles’ battery. A simulation in OpenDSS over a period of 24 h has been implemented, taking care of the network constraints for voltage level at the customer connection points. The optimisation results are compared with those obtained using dynamic optimal power flow.

Optimal Capacitors Placement of Distribution Systems Using 2nd Order Power Loss Sensitivity Analysis and Hierarchical Clustering

2014 ◽  
Vol 986-987 ◽  
pp. 377-382 ◽  
Author(s):  
Hui Min Gao ◽  
Jian Min Zhang ◽  
Chen Xi Wu
Keyword(s):  
Sensitivity Analysis ◽  
Hierarchical Clustering ◽  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Reactive Power ◽  
Digital Simulation ◽  
Second Order ◽  
First Order ◽  
The Impact

Heuristic methods by first order sensitivity analysis are often used to determine location of capacitors of distribution power system. The selected nodes by first order sensitivity analysis often have virtual high by first order sensitivities, which could not obtain the optimal results. This paper presents an effective method to optimally determine the location and capacities of capacitors of distribution systems, based on an innovative approach by the second order sensitivity analysis and hierarchical clustering. The approach determines the location by the second order sensitivity analysis. Comparing with the traditional method, the new method considers the nonlinear factor of power flow equation and the impact of the latter selected compensation nodes on the previously selected compensation location. This method is tested on a 28-bus distribution system. Digital simulation results show that the reactive power optimization plan with the proposed method is more economic while maintaining the same level of effectiveness.

Protection Scheme for DC Microgrid Distribution System

2012 ◽  
Vol 614-615 ◽  
pp. 1661-1665
Author(s):  
Ling Hui Deng ◽  
Zhi Xin Wang ◽  
Jian Min Duan
Keyword(s):  
Distribution System ◽  
Cost Efficiency ◽  
Power Flow ◽  
Low Voltage ◽  
Dc Microgrid ◽  
Protection Scheme ◽  
High Level ◽  
Bidirectional Power Flow ◽  
Efficiency And Reliability ◽  
Laboratory Prototype

The low voltage DC (LVDC) distribution system is a new concept and a promising technology to be used in the future smart distribution system having high level cost-efficiency and reliability. In this paper, a low-voltage (LV) DC microgrid protection system design is proposed. Usually, an LVDC microgrid must be connected to an ac grid through converters with bidirectional power flow and, therefore, a different protection scheme is needed. This paper describes practical protection solutions for the LVDC network and an LVDC system laboratory prototype is being experimentally tested by MATLAB/SIMULINK. The results show that it is possible to use available devices to protect such a system. But other problems may arise which needs further study.

scholarly journals Design and Testing of a Low Voltage Solid-State Circuit Breaker for a DC Distribution System

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 338
Author(s):  
Leslie Tracy ◽  
Praveen Kumar Sekhar
Keyword(s):  
Solid State ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Low Voltage ◽  
Circuit Breaker ◽  
Solid State Circuit ◽  
Dc Distribution ◽  
High Side ◽  
Solid State Circuit Breaker

In this study, a low voltage solid-state circuit breaker (SSCB) was implemented for a DC distribution system using commercially available components. The design process of the high-side static switch was enabled through a voltage bias. Detailed functional testing of the current sensor, high-side switch, thermal ratings, analog to digital conversion (ADC) techniques, and response times of the SSCB was evaluated. The designed SSCB was capable of low-end lighting protection applications and tested at 50 V. A 15 A continuous current rating was obtained, and the minimum response time of the SSCB was nearly 290 times faster than that of conventional AC protection methods. The SSCB was implemented to fill the gap where traditional AC protection schemes have failed. DC distribution systems are capable of extreme faults that can destroy sensitive power electronic equipment. However, continued research and development of the SSCB is helping to revolutionize the power industry and change the current power distribution methods to better utilize clean renewable energy systems.

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