scholarly journals Solutions to Increase PV Hosting Capacity and Provision of Services from Flexible Energy Resources

2020 ◽  
Vol 10 (15) ◽  
pp. 5146
Author(s):  
Hannu Laaksonen ◽  
Chethan Parthasarathy ◽  
Hossein Hafezi ◽  
Miadreza Shafie-khah ◽  
Hosna Khajeh ◽  
...  
Keyword(s):  
Adaptive Control ◽  
Smart Grids ◽  
Reactive Power ◽  
Distribution Network ◽  
Energy Resources ◽  
Related Services ◽  
Control Functions ◽  
Provision Of Services ◽  
Network Operation ◽  
Technical Services

Future smart grids will be more dynamic with many variabilities related to generation, inertia, and topology changes. Therefore, more flexibility in form of several active and reactive power related technical services from different distributed energy resources (DER) will be needed for local (distribution network) and whole system (transmission network) needs. However, traditional distribution network operation and control principles are limiting the Photovoltaic (PV) hosting capacity of LV networks and the DER capability to provide system-wide technical services in certain situations. New active and adaptive control principles are needed in order to overcome these limitations. This paper studies and proposes solutions for adaptive settings and management schemes to increase PV hosting capacity and improve provision of frequency support related services by flexible energy resources. The studies show that unwanted interactions between different DER units and their control functions can be avoided with the proposed adaptive control methods. Simultaneously, also better distribution network PV hosting capacity and flexibility services provision from DER units even during very low load situations can be achieved.

scholarly journals Solar photovoltaic-based microgrid hosting capacity evaluation in electrical energy distribution network with voltage quality analysis

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Arvind Sharma ◽  
Mohan Kolhe ◽  
Alkistis Kontou ◽  
Dimitrios Lagos ◽  
Panos Kotsampopoulos
Keyword(s):  
Reactive Power ◽  
Distribution Network ◽  
Electrical Energy ◽  
Droop Control ◽  
Solar Photovoltaic ◽  
Voltage Profile ◽  
Power Conditioning ◽  
Network Operation ◽  
Hardware In Loop ◽  
Pv Penetration

Abstract In this paper, solar photovoltaic hosting capacity within the electrical distribution network is estimated for different buses, and the impacts of high PV penetration are evaluated using power hardware-in-loop testing methods. It is observed that the considered operational constraints (i.e. voltage and loadings) and their operational limits have a significant impact on the hosting capacity results. However, with increasing photovoltaic penetration, some of the network buses reach maximum hosting capacity, which affects the network operation (e.g. bus voltages, line loading). The results show that even distributing the maximum hosting capacity among different buses can increase the bus voltage rise to 9%. To maintain the network bus voltages within acceptable limits, reactive power voltage-based droop control is implemented in the photovoltaic conditioning devices to test the dynamics of the network operation. The results show that implementation of the droop control technique can reduce the maximum voltage rise from 9% to 4% in the considered case. This paper also presents the impact of forming a mesh type network (i.e. from radial network) on the voltage profile during PV penetration, and a comparative analysis of the operational performance of a mesh type and radial type electrical network is performed. It is observed that the cumulative effect of forming a mesh type network along with a droop control strategy can further improve the voltage profile and contribute to increase photovoltaic penetration. The results are verified using an experimental setup of digital real-time simulator and power hardware-in-loop test methods. The results from this work will be useful for estimating the appropriate photovoltaic hosting capacity within a distribution network and implementation of a droop control strategy in power conditioning devices to maintain the network operational parameters within the specified limits. Highlights Voltage and line loading constraints’ combination can reduce PV hosting capacity by 50% as compared to only voltage as a constraint. Implementation of reactive power versus voltage droop control in PV power conditioning device can reduce voltage variation from 9% to 4%. In a PV integrated electrical energy network, line loading can be reduced by 20% if the network is configured from radial to mesh type.

scholarly journals Photovoltaic Power Converter Management in Unbalanced Low Voltage Networks with Ancillary Services Support

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 972 ◽  
Author(s):  
Fermín Barrero-González ◽  
Victor Pires ◽  
José Sousa ◽  
João Martins ◽  
María Milanés-Montero ◽  
...  
Keyword(s):  
Power Flow ◽  
Reactive Power ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Distribution Network ◽  
Power Converter ◽  
Maximum Energy ◽  
Practical Implementation ◽  
Network Operation ◽  
The Impact

The proliferation of residential photovoltaic (PV) prosumers leads to detrimental impacts on the low-voltage (LV) distribution network operation such as reverse power flow, voltage fluctuations and voltage imbalances. This is due to the fact that the strategies for the PV inverters are usually designed to obtain the maximum energy from the panels. The most recent approach to these issues involves new inverter-based solutions. This paper proposes a novel comprehensive control strategy for the power electronic converters associated with PV installations to improve the operational performance of a four-wire LV distribution network. The objectives are to try to balance the currents demanded by consumers and to compensate the reactive power demanded by them at the expense of the remaining converters’ capacity. The strategy is implemented in each consumer installation, constituting a decentralized or distributed control and allowing its practical implementation based on local measurements. The algorithms were tested, in a yearly simulation horizon, on a typical Portuguese LV network to verify the impact of the high integration of the renewable energy sources in the network and the effectiveness and applicability of the proposed approach.

The Design and Implementation of an Integrated Distribution Automation Scheme

2012 ◽  
Vol 241-244 ◽  
pp. 1942-1946
Author(s):  
Zhi Hong Liu ◽  
Jian Wei Zhang ◽  
Xiang Zhao ◽  
Fang Yang
Keyword(s):  
Power Supply ◽  
Reactive Power ◽  
Distribution Network ◽  
Distribution Automation ◽  
Automation System ◽  
Network Operation ◽  
On Line ◽  
Network Fault ◽  
Compensation Function

According to the statistic of the distribution network operation, distribution network fault is generally located on line branch, rather than the main line. In view of the structure and characteristics of the current distribution automation system, combining the distribution network reformation and construction practice, this paper puts a comprehensive distribution automation solution that the branch line is equipped with distribution automation terminal which integrates protection and reactive power compensation function. It can achieve the rapid isolation of the distribution network failures and the power supply reliability, and dynamically improve the quality of power supply.

scholarly journals Utilization of Active Distribution Network Elements for Optimization of a Distribution Network Operation

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3494
Author(s):  
Nevena Srećković ◽  
Miran Rošer ◽  
Gorazd Štumberger
Keyword(s):  
Reactive Power ◽  
Distribution Network ◽  
Optimization Procedure ◽  
Electric Power System ◽  
Time Interval ◽  
Power Losses ◽  
Medium Voltage ◽  
Active Elements ◽  
Network Operation ◽  
Network Operations

Electricity Distributions Networks (DNs) are changing from a once passive to an active electric power system element. This change, driven by several European Commission Directives and Regulations in the energy sector prompts the proliferated integration of new network elements, which can actively participate in network operations if adequately utilized. This paper addresses the possibility of using these active DN elements for optimization of a time-discrete network operation in terms of minimization of power losses while ensuring other operational constraints (i.e., voltage profiles and line currents). The active elements considered within the proposed optimization procedure are distributed generation units, capable of reactive power provision; remotely controlled switches for changing the network configuration; and an on-load tap changer-equipped substation, supplying the network. The proposed procedure was tested on a model of an actual medium voltage DN. The results showed that simultaneous consideration of these active elements could reduce power losses at a considered point of operation while keeping the voltage profiles within the permitted interval. Furthermore, by performing a series of consecutive optimization procedures at a given time interval, an optimization of network operations for extended periods (e.g., days, months, or years) could also be achieved.

scholarly journals Optimal Placement of Capacitor to Enhance the Efficiency of the Distribution Network

2019 ◽  
Vol 8 (9) ◽  
pp. 2877-2881 ◽  
Keyword(s):  
Reactive Power ◽  
Distribution Network ◽  
Flow Analysis ◽  
Distribution Networks ◽  
Load Flow ◽  
Optimal Placement ◽  
Load Flow Analysis ◽  
Network Operation ◽  
Overall Performance ◽  
Shunt Capacitor

In this paper optimal placement of capacitor is carried out by using exhaustive load flow analysis for minimization of the power loss at different loading conditions. The shunt capacitor mainly used for reactive power compensation to maintain the good p.f in the network to improve the overall performance of the distribution networks. The obtained results are satisfactory interms of improvement in the efficiency of the distribution network operation.

Dysphagia Services in Schools: Applying Special Education Requirements to a Health Service

2009 ◽  
Vol 18 (3) ◽  
pp. 86-90 ◽  
Author(s):  
Lissa Power-deFur
Keyword(s):  
Special Education ◽  
Health Service ◽  
Due Process ◽  
Due Process Hearings ◽  
Related Services ◽  
Eligibility Determination ◽  
Legal Provisions ◽  
Provision Of Services ◽  
Related Service ◽  
Specially Designed Instruction

Abstract School speech-language pathologists and districts frequently need guidance regarding how the legal provisions of special education affect the needs of children with dysphagia. This article reviews key principles of special education that guide eligibility determination and provision of services to all children. In the eligibility process, the school team would determine if the child's disability has an adverse effect on his/her education program and if the child needed special education (specially designed instruction) and related services. Dysphagia services would be considered a related service, a health service needed for the child to benefit from specially designed instruction. The article concludes with recommendations for practice that stem from a review of due process hearings and court cases for children with disabilities that include swallowing.

scholarly journals Distribution system power quality compensation using a HSeAPF based on SRF and SMC features

2021 ◽  
Author(s):  
Akram Qashou ◽  
Sufian Yousef ◽  
Abdallah A. Smadi ◽  
Amani A. AlOmari
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Reactive Power ◽  
Sliding Mode ◽  
Distribution Network ◽  
Harmonic Distortion ◽  
Phase Locked Loop ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Non Linear

AbstractThe purpose of this paper is to describe the design of a Hybrid Series Active Power Filter (HSeAPF) system to improve the quality of power on three-phase power distribution grids. The system controls are comprise of Pulse Width Modulation (PWM) based on the Synchronous Reference Frame (SRF) theory, and supported by Phase Locked Loop (PLL) for generating the switching pulses to control a Voltage Source Converter (VSC). The DC link voltage is controlled by Non-Linear Sliding Mode Control (SMC) for faster response and to ensure that it is maintained at a constant value. When this voltage is compared with Proportional Integral (PI), then the improvements made can be shown. The function of HSeAPF control is to eliminate voltage fluctuations, voltage swell/sag, and prevent voltage/current harmonics are produced by both non-linear loads and small inverters connected to the distribution network. A digital Phase Locked Loop that generates frequencies and an oscillating phase-locked output signal controls the voltage. The results from the simulation indicate that the HSeAPF can effectively suppress the dynamic and harmonic reactive power compensation system. Also, the distribution network has a low Total Harmonic Distortion (< 5%), demonstrating that the designed system is efficient, which is an essential requirement when it comes to the IEEE-519 and IEC 61,000–3-6 standards.

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