Assessment of the Technical and Economic Effect from Using Automatic Voltage Control Devices on 10/0.4 kV Transformers in Power Distribution Networks

Vestnik MEI ◽  
2021 ◽  
pp. 27-36
Author(s):  
Mikhail G. Astashev ◽  
◽  
Artem S. Vanin ◽  
Vladimir M. Korolev ◽  
Dmitriy I. Panfilov ◽  
...  
Keyword(s):  
Power Distribution ◽  
Voltage Control ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Economic Feasibility ◽  
Electrical Network ◽  
Test Model ◽  
Electrical Networks ◽  
Permissible Limits ◽  
Network Load

The article addresses the problem of ensuring permissible voltage levels in distribution electrical networks of various types: distribution networks of large cities, regional distribution electrical networks, and distribution electrical networks containing renewable energy sources. The most typical factors causing the voltage to go beyond the permissible limits specified by the relevant regulatory documents are pointed out. The negative factors conducive to the voltage at the consumer end deviating from the permissible limits, including a long length of network lines, high network load, low controllability of the network, load schedule nonuniformity, and poor observability of the network, are analyzed. The existing principles of voltage control in electrical distribution networks, namely, automatic and seasonal regulation, are studied. A distribution electrical network test model representing a real network fragment is developed. The model operation modes have been verified based on the data of measurements carried out in the original distribution electrical network. The voltage distributions in a medium voltage network during its operation under the conditions of the highest and lowest loads are demonstrated. It is shown, on the test model example, how the network voltage can be controlled by automatically regulating the voltage at the power supply center and selecting a fixed position of the NLTC at 10/0.4 kV transformer substations. It is shown that the use of power transformer OLTCs does not ensure sufficient means for adequately controlling the voltage in networks containing long power lines and featuring highly nonuniform seasonal and daily load schedules. The technical efficiency and economic feasibility of using automatic voltage regulation devices on 10/0.4 kV transformers for local voltage control are analyzed. The economic efficiency of applying automatic voltage regulation devices at 6--10/0.4 kV substations was evaluated in comparison with other means for improving the power distribution network voltage quality by upgrading the 10 kV feeder lines or installing a voltage booster at the inlet to the problematic 10 kV network section. The application field of automatic voltage regulators in the form of semiconductor devices for regulating the transformer output voltage at distribution transformer substations is shown.

scholarly journals On the Efficiency in Electrical Networks with AC and DC Operation Technologies: A Comparative Study at the Distribution Stage

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1352 ◽  
Author(s):  
Oscar Danilo Montoya ◽  
Federico Martin Serra ◽  
Cristian Hernan De Angelo
Keyword(s):  
Power Distribution ◽  
Urban Areas ◽  
Optimal Power Flow ◽  
Low Voltage ◽  
Mathematical Formulation ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Numerical Results ◽  
Energy Losses ◽  
Electrical Networks

This research deals with the efficiency comparison between AC and DC distribution networks that can provide electricity to rural and urban areas from the point of view of grid energy losses and greenhouse gas emissions impact. Configurations for medium- and low-voltage networks are analyzed via optimal power flow analysis by adding voltage regulation and devices capabilities sources in the mathematical formulation. Renewable energy resources such as wind and photovoltaic are considered using typical daily generation curves. Batteries are formulated with a linear representation taking into account operative bounds suggested by manufacturers. Numerical results in two electrical networks with 0.24 kV and 12.66 kV (with radial and meshed configurations) are performed with constant power loads at all the nodes. These simulations confirm that power distribution with DC technology is more efficient regarding energy losses, voltage profiles and greenhouse emissions than its AC counterpart. All the numerical results are tested in the General Algebraic Modeling System widely known as GAMS.

A Model of Voltage Distribution and Change of Current in the Network Containing Unaccounted Electricity Consumption

Vestnik MEI ◽  
2021 ◽  
pp. 91-99
Author(s):  
Ivan M. Kazymov ◽  
◽  
Boris S. Kompaneets ◽  
Keyword(s):  
Graphical Representation ◽  
Low Voltage ◽  
Electricity Consumption ◽  
Distribution Networks ◽  
Electrical Network ◽  
Electrical Networks ◽  
Voltage Distribution ◽  
Electrical Grids ◽  
Proposed Model ◽  
Nominal Voltage

The aim of the study is control of commercial losses in electrical grids, especially in low voltage grids, which is one of the priority lines of activities conducted by electric network companies. The complexity of solving this problem is stemming from the difficulty of exactly locating the commercial loss occurrence place under the conditions of extensively branched low and medium voltage electrical networks. Various methods are currently used to determine the commercial loss occurrence places. However, no effective methods have been created for determining the fact and place of unaccounted electricity consumption in networks under the conditions of performing remote analysis of networks based on the data from modern electricity meters used in the automated fiscal electricity metering system. These difficulties can be overcome by developing a model of voltage distribution and change of current in distribution networks of the 0.4--35 kV nominal voltage levels. A model of voltage distribution and changes of current for a network containing unaccounted electricity consumption is proposed. The effectiveness of using the proposed model has been theoretically substantiated; its applicability limits are defined, and the accuracy of the obtained results is estimated. Graphical representation of the proposed model, which is one of the electrical network digital imaging forms, can be used to analyze electrical networks for revealing if there is unaccounted electricity consumption in them. By using the proposed model of voltage distribution and change of current in the network, it is possible to represent the electrical network as a set of electrical parameters to analyze electrical networks for the presence of commercial losses.

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.  

scholarly journals Structure of many-level adaptive automatic voltage regulation system

2020 ◽  
Vol 178 ◽  
pp. 01068
Author(s):  
I.O. Golikov ◽  
A.V. Vinogradov ◽  
V.E. Bolshev ◽  
A.V. Vinogradova ◽  
M. Jasinski ◽  
...  
Keyword(s):  
Voltage Regulation ◽  
Electrical Network ◽  
Regulation System ◽  
Processing Unit ◽  
Electrical Networks ◽  
Structural Diagram ◽  
Voltage Level ◽  
Voltage Change ◽  
Tap Changer ◽  
Load Tap Changer

This article describes the features of voltage regulation in electrical networks of 35, 110, 220 kV. The structural diagram of the 35/10/0.4 kV network is presented. The paper also describes the adaptive automatic voltage regulation system which allows regulating the voltage taking into account the actual voltage values at the consumers’ inputs. The structural diagram of the adaptive automatic voltage regulation system in the 0.4 kV electrical network using a boost transformer as an additional means of voltage regulation is given. The system is based on voltage sensors installed in different parts of an eletcrical network sending information on voltage values to to the processing unit which generates a signal for voltage regulating supplied to the executive device and the working body whuch, in turn, change the on-load tap-changer position of a transformer. The paper justifies the need for the enhancement of the adaptive automatic voltage regulation system for different voltage classes wich allows controlling a voltage change at different power supply system levels and regulating voltage level in accordance with this change. For this problem the multi-level adaptive automatic voltage regulation systemis proposed. The system allows regulating the voltage not only in the 0.4 kV network but also in networks of higher voltage classes. The proposed system can be integrated into the structure of intelligent electrical networks.

Decentralised-distributed hybrid voltage regulation of power distribution networks based on power inverters

2019 ◽  
Vol 13 (3) ◽  
pp. 444-451 ◽  
Author(s):  
Yu Wang ◽  
Yan Xu ◽  
Yi Tang ◽  
Mazheruddin Hussain Syed ◽  
Efren Guillo-Sansano ◽  
...  
Keyword(s):  
Power Distribution ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Power Distribution Networks ◽  
Power Inverters

scholarly journals High Frequency Solid State Transformer Design Considerations for Power Systems Applications

2021 ◽  
Vol 2 (5) ◽  
Author(s):  
Raton Kumar Nondy ◽  
Md. Abul Bashar ◽  
Prema Nondy ◽  
M. Hazrat Ali
Keyword(s):  
Power Quality ◽  
Power Factor ◽  
Power Distribution ◽  
High Frequency ◽  
Low Voltage ◽  
Voltage Drop ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Power Converter ◽  
Voltage Sag

The conventional power frequency (50 or 60 Hz) transformers are economical, highly reliable and quite efficient but they suffer with certain drawbacks like sensitive to harmonics, voltage drop under load, no protection from system disruptions and overloads, poor performance under dc offset load unbalances and no scope to improve power factor. These transformers with copper wound wires on iron cores are unable to respond to control signals as power generations become distributed and intermittent. So, the need of electronic based regulated power supply with software based remote intelligence has become essential. Also, to easily connect the new energy sources to the grid and to improve the power quality by harmonic filtering, voltage sag correction and highly dynamic control of the power flow, a new type of transformer based on power electronics, known as SST has been introduced. The SST realizes voltage transformation, galvanic isolation, power quality improvements such as instantaneous voltage regulation, voltage sag compensation and power factor correction. It is a collection of high-powered semiconductor components, high frequency power transformer and control circuitry which is used to provide a high level of flexible control to power distribution networks. The SST is a high frequency switched Power Electronic Devices (PEDs) based transformer with high controllability that enables flexible connectivity between existing medium voltage power distribution network, low voltage AC residential system and envisioned DC residential system. In this paper a systematic constructional detail of a SST with a power rating of 2 kVA, operating frequency of 20 kHz and voltage rating of 600/60 V as a scaled-down prototype used for power converter topologies is presented. The design is simple and it avoids the difficulty of choosing massive amounts of empirical parameters.

scholarly journals Voltage regulation in LV distribution networks with PV generation and battery storage

2021 ◽  
Vol 72 (6) ◽  
pp. 356-365
Author(s):  
Jordan Radosavljević
Keyword(s):  
Low Voltage ◽  
Voltage Control ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Local Load ◽  
Battery Storage ◽  
Second Stage ◽  
High Penetration ◽  
Optimal Coordination ◽  
Pv Generation

Abstract High penetration of photovoltaic (PV) generation in low voltage (LV) distribution networks can leads some power quality problems. One of the most important issues in this regard is the impermissible voltage deviation in periods with a large imbalance between PV generation and local load consumption. Accordingly, many authors deal with this issue. This work investigates voltage regulation for LV distribution networks equipped with the hybrid distribution transformer (HDT), and with high penetration of PV units. A two-stage algorithm for voltage regulation is proposed. In the first stage, a local (distributed) voltage control is performed by minimizing the injection power of the PV-battery storage system (BS)-local load entity at the common bus. In the second stage, optimal coordination is performed between the HDT and the local voltage control. In fact, the second stage is an optimal voltage regulation problem. The aim is to minimize the voltage deviations at load buses by optimal settings the voltage support of the HDT. A PSO algorithm is used to solve this optimization problem. the proposed approach is implemented in MATLAB software and evaluated on the IEEE european LV test feeder.

scholarly journals Electric Vehicle–Grid Integration with Voltage Regulation in Radial Distribution Networks

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1802 ◽  
Author(s):  
Chong Cao ◽  
Zhouquan Wu ◽  
Bo Chen
Keyword(s):  
Electric Vehicle ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Grid Integration ◽  
Distribution Grid ◽  
Voltage Compensation ◽  
Control Schemes ◽  
Grid Level

In this paper, a vehicle–grid integration (VGI) control strategy for radial power distribution networks is presented. The control schemes are designed at both microgrid level and distribution level. At the VGI microgrid level, the available power capacity for electric vehicle (EV) charging is optimally allocated for charging electric vehicles to meet charging requirements. At the distribution grid level, a distributed voltage compensation algorithm is designed to recover voltage violation when it happens at a distribution node. The voltage compensation is achieved through a negotiation between the grid-level agent and VGI microgrid agents using the alternating direction method of multipliers. In each negotiation round, individual agents pursue their own objectives. The computation can be carried out in parallel for each agent. The presented VGI control schemes are simulated and verified in a modified IEEE 37 bus distribution system. The simulation results are presented to show the effectiveness of the VGI control algorithms and the effect of algorithm parameters on the convergence of agent negotiation.

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