scholarly journals Automatic Load Sharing of Distribution Transformers to Reduce Over all Losses in Distribution network

2021 ◽  
Vol 309 ◽  
pp. 01126
Author(s):  
V Ravikumar ◽  
S Ranjith ◽  
T Bhavyasree
Keyword(s):  
Power Factor ◽  
Rapid Growth ◽  
Distribution Network ◽  
Load Sharing ◽  
Voltage Regulation ◽  
Power Demand ◽  
Distribution Transformer ◽  
Distribution Transformers ◽  
Load Conditions

An increase in the development of Industries and rapid growth in the population has led to an increase in the power demand in the distribution network. With these increased needs, the existing distribution transformer have become overloaded conditions. Due to overload on the transformer, the efficiency and power factor drops and also it led to increase in the transformer voltage regulation and windings get overheated. This paper presents a novel topology called transformer auto stop-start that will automatically energise and de-energise, one pair of transformers at a kV/V Distribution network. In this way, the proposed technique reduces overall electric losses. Performance of transformer under different load conditions are illustrated by simulation.

scholarly journals Power factor control of PV generators in local distribution networks using fuzzy logic concept

2018 ◽  
Vol 7 (2.28) ◽  
pp. 362
Author(s):  
Raed A. Shalwala
Keyword(s):  
Fuzzy Logic ◽  
Control System ◽  
Power Factor ◽  
Fuzzy Logic Control ◽  
Reactive Power ◽  
Distribution Network ◽  
Voltage Control ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Logic Control

One of the most important operational requirements for any electrical power network for both distribution and transmission level is voltage control. Many studies have been carried out to improve or develop new voltage control techniques to facilitate safe connection of distributed generation. In Saudi Arabia, due to environmental, economic and development perspectives, a wide integration of photovoltaic (PV) genera-tion in distribution network is expected in the near future. This development in the network may cause voltage regulation problems due to the interaction with the existing conventional control system. In a previous paper, a control system has been described using a fuzzy logic control to set the on-line tap changer for the primary substation. In this paper a new control system is proposed for controlling the power factor of individual PV invertors based on observed correlation between net active and reactive power at each connection. A fuzzy logic control has been designed to alter the power factor for the remote invertors from the secondary substation to keep the feeder voltage within the permissible limits. In order to confirm the validity of the proposed method, simulations are carried out for a realistic distribution network with real data for load and solar radiation. Results showing the performance of the new control method are presented and discussed.  

Cost-optimal as a tool for helping in designing distribution transformer using particle swarm optimization

2019 ◽  
Vol 38 (2) ◽  
pp. 862-877 ◽  
Author(s):  
Mohammad Amin Jarrahi ◽  
Emad Roshandel ◽  
Mehdi Allahbakhshi ◽  
Mohammad Ahmadi
Keyword(s):  
Particle Swarm Optimization ◽  
Design Procedure ◽  
Pso Algorithm ◽  
Voltage Regulation ◽  
Power Losses ◽  
Distribution Transformer ◽  
Swarm Optimization ◽  
Content Type ◽  
Initial Cost ◽  
Distribution Transformers

Purpose This paper aims to achieve an optimal design for distribution transformers considering cost and power losses. Particle swarm optimization (PSO) algorithm is used as an optimization tool for minimizing the objective functions of design procedure which are cost and electrical and iron losses. Design/methodology/approach In this paper, distribution transformer losses are considered as operating costs. Also, transformer construction cost which depends on the amount of iron and copper in the structure is assumed as its initial cost. In addition, some other important constraints such as appropriate ranges of transformer efficiency, voltage regulation, temperature rise, no-load current, and winding fill factor are investigated in the design procedure. The PSO algorithm is applied to find optimum amount of needed copper and iron for a typical distribution transformer. Moreover, transformer impedance considered as a constraint to achieve an acceptable voltage regulation in the design process. Findings It is shown that the proposed design procedure provides a simple and effective approach to estimate the flux and current densities for minimizing the active part cost and active power losses which means reduction in amount of transformer total owning cost (TOC). Originality/value The methodology advances a proposal for reducing distribution transformers costs using PSO algorithm. The approach considers the aforementioned constraints and TOC to minimize the active part cost and maximize the efficiency. It is demonstrated that a designed transformer will not be optimum when the transformer losses over years are not considered in design procedure. Finally, the results prove the effectiveness of the proposed procedure in designing cost-effective distribution transformers from its initial cost until its whole life.

scholarly journals Analysis of Age Transformer Due to Annual Load Growth in 20 kV Distribution Network

2021 ◽  
Vol 1 (1) ◽  
pp. 42
Author(s):  
Indra Roza ◽  
Yussa Ananda ◽  
Lisa Adriana Siregar ◽  
Dharmawati Dharmawati ◽  
Junaidi Junaidi
Keyword(s):  
Customer Service ◽  
Distribution Network ◽  
Peak Load ◽  
Distribution Transformer ◽  
Load Curve ◽  
One Stage ◽  
Annual Peak ◽  
Load Growth ◽  
Distribution Transformers ◽  
Daily Load

Distribution transformer is a component in distributing electricity from distribution substations to consumers. Damage to distribution transformers causes continuity of customer service to be disrupted (power cut or blackout occurs). The length of the PLN electricity network requires a transformer to distribute electricity to serve consumers and how to maintain the transformer. The daily load curve of a peak load for housing, shops and factories / industries varies. Load served 200 kVA distribution transformer cannot serve the load on housing, shops and factories / industry. The method used is the replacement of a distribution transformer with a capacity of one stage greater or the replacement of a distribution transformer with a capacity of two levels larger. The distribution transformer carried out by the research is a capacity of 200 kVA replaced by 250 kVA. The ability of a distribution transformer cannot accommodate a load which will increase as an area is advanced. Observations made by calculating the age of the transformer by assuming the annual load growth (r) = 3% = 0.3. Annual peak load (P) = 1.8 p, u increase in oil temperature at peak load (θo = 96.21 0C; 84.16 0C). The increase in the hottest temperature above the oil cover, the increase in the temperature of the hottest place above the oil (θg = 20 0C; 20 0C). The ratio of the load loss to the nominal load excitation loss (Q = 3; 30). By assuming the values of these methods it can be estimated that the life of a distribution transformer is 20 kV, a capacity of 200 kVA is 18 years.

Unit Template Based Control of PV-DSTATCOM

2020 ◽  
Vol 13 (1) ◽  
pp. 36-42
Author(s):  
Gunjan Varshney ◽  
Durg S. Chauhan ◽  
Madhukar P. Dave ◽  
Nitin
Keyword(s):  
Power Quality ◽  
Power Factor ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Phase Distribution ◽  
Voltage Regulation ◽  
Photovoltaic Array ◽  
Quality Issues ◽  
Static Compensator

Background: In modern electrical power distribution systems, Power Quality has become an important concern due to the escalating use of automatic, microprocessor and microcontroller based end user applications. Methods: In this paper, power quality improvement has done using Photovoltaic based Distribution Static Compensator (PV-DSTATCOM). Complete simulation modelling and control of Photovoltaic based Distribution Static Compensator have been provided in the presented paper. In this configuration, DSTATCOM is fed by solar photovoltaic array and PV module is also helpful to maintain the DC link voltage. The switching of PV-STATCOM is controlled by Unit template based control theory. Results: The performance of PV-DSTATCOM has been evaluated for Unity Power Factor (UPF) and AC Voltage Control (ACVC) modes. Here, for studying the power quality issues three-phase distribution system is considered and results have been verified through simulation based on MATLAB software. Conclusion: Different power quality issues and their improvement are studied and presented here for harmonic reduction, DC voltage regulation and power factor correction.

scholarly journals Configurations, Power Topologies and Applications of Hybrid Distribution Transformers

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1215
Author(s):  
Alvaro Carreno ◽  
Marcelo Perez ◽  
Carlos Baier ◽  
Alex Huang ◽  
Sanjay Rajendran ◽  
...  
Keyword(s):  
Distribution Systems ◽  
Power Converter ◽  
Operating Conditions ◽  
Distribution Transformer ◽  
Nonlinear Loads ◽  
Electric Vehicle Charging ◽  
Distribution Transformers ◽  
Alternative Systems ◽  
Charging Stations ◽  
Hybrid Distribution

Distribution systems are under constant stress due to their highly variable operating conditions, which jeopardize distribution transformers and lines, degrading the end-user service. Due to transformer regulation, variable loads can generate voltage profiles out of the acceptable bands recommended by grid codes, affecting the quality of service. At the same time, nonlinear loads, such as diode bridge rectifiers without power factor correction systems, generate nonlinear currents that affect the distribution transformer operation, reducing its lifetime. Variable loads can be commonly found at domiciliary levels due to the random operation of home appliances, but recently also due to electric vehicle charging stations, where the distribution transformer can cyclically vary between no-load, rated and overrated load. Thus, the distribution transformer can not safely operate under highly-dynamic and stressful conditions, requiring the support of alternative systems. Among the existing solutions, hybrid transformers, which are composed of a conventional transformer and a power converter, are an interesting alternative to cope with several power quality problems. This article is a review of the available literature about hybrid distribution transformers.

scholarly journals Voltage Rise Regulation with a Grid Connected Solar Photovoltaic System

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7510
Author(s):  
Akinyemi Ayodeji Stephen ◽  
Kabeya Musasa ◽  
Innocent Ewean Davidson
Keyword(s):  
Power Quality ◽  
Power Factor ◽  
Reactive Power ◽  
Voltage Regulation ◽  
Photovoltaic System ◽  
Voltage Amplitude ◽  
Phase Voltage ◽  
Unity Power Factor ◽  
Voltage Rise ◽  
Grid Current

Renewable Distributed Generation (RDG), when connected to a Distribution Network (DN), suffers from power quality issues because of the distorted currents drawn from the loads connected to the network over generation of active power injection at the Point of Common Coupling (PCC). This research paper presents the voltage rise regulation strategy at the PCC to enhance power quality and continuous operation of RDG, such as Photovoltaic Arrays (PVAs) connected to a DN. If the PCC voltage is not regulated, the penetration levels of the renewable energy integration to a DN will be limited or may be ultimately disconnected in the case of a voltage rise issue. The network is maintained in both unity power factor and voltage regulation mode, depending on the condition of the voltage fluctuation occurrences at the PCC. The research investigation shows that variation in the consumer’s loads (reduction) causes an increase in the power generated from the PVA, resulting in an increase in the grid current amplitude, reduction in the voltage of the feeder impedance and an increase in the phase voltage amplitude at the PCC. When the system is undergoing unity power factor mode, PCC voltage amplitude tends to rises with the loads. Its phase voltage amplitude rises above an acceptable range with no-loads which are not in agreement, as specified in the IEEE-1547 and Southern Africa grid code prerequisite. Incremental Conduction with Integral Regulator bases (IC + PI) are employed to access and regulate PVA generation, while the unwanted grid current distortions are attenuated from the network using an in-loop second order integral filtering circuit algorithm. Hence, the voltage rise at the PCC is mitigated through the generation of positive reactive power to the grid from the Distribution Static Compensator (DSTATCOM), thereby regulating the phase voltage. The simulation study is carried out in a MATLAB/Simulink environment for PVA performance.

scholarly journals Decentralized Voltage Regulation in Islanded DC Microgrids Based on a Modified Droop Control using Superimposed AC Voltage

2021 ◽  
Author(s):  
Mohammadreza Nabatirad ◽  
Reza Razzaghi ◽  
Behrooz Bahrani
Keyword(s):  
Control System ◽  
Load Sharing ◽  
Voltage Regulation ◽  
Control Technique ◽  
Droop Control ◽  
Dc Microgrids ◽  
Distributed Generator ◽  
Voltage Compensation ◽  
Terminal Voltage ◽  
Unit Output

The conventional droop control is a widely-used technique in load sharing among Distributed Generator (DG) units in islanded DC Microgrids (MGs). This method provides Plug-and-Play (PnP) capability for DG units; however, poor load sharing accuracy and unregulated voltage are two shortcomings of that. This article proposes a novel control system in islanded DC MGs to provide simultaneous regulated voltage and accurate load sharing. The method utilizes a modified droop control technique in a decentralized manner. The proposed control system injects a superimposed AC voltage to the network that carries a frequency proportional to the master DG unit output current. The injected voltage adjusts an added a term to the conventional droop control named as the voltage compensation term in order to cancel voltage changes. This term adjusts terminal voltage of DG units proportional to the frequency of the superimposed AC voltage. The performance of the proposed control system is validated via a set of simulation studies using PLECS, and the experimental results confirm the viability and feasibility of the proposed control system.

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