scholarly journals Control Configurations for Reactive Power Compensation at the Secondary Side of the Low Voltage Substation by Using Hybrid Transformer

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 620
Author(s):  
Mohammed Radi ◽  
Mohamed Darwish ◽  
Gareth Taylor ◽  
Ioana Pisica
Keyword(s):  
Reactive Power ◽  
Low Voltage ◽  
Circuit Simulation ◽  
Piecewise Linear ◽  
Distribution Networks ◽  
Electrical Circuit ◽  
Distribution Transformer ◽  
Voltage Level ◽  
Transmission Grid ◽  
New Device

The high penetration of new device technologies, such as Electric Vehicles (EV), and Distributed Generation (DG) in Distribution Networks (DNs) has risen new consumption requirements. In this context, it becomes crucial to implement a flexible, functional and fast responsive management of the voltage level and Reactive Power (RP) in the DN. The latest improvements in the Solid State Switches (SSS) field demonstrate they can be used as a Power Electronic (PE) converter. In particular, they have been shown to be capable of operating synchronously with transformers, making the Hybrid Distribution Transformer (HT) concept a potential and cost-effective solution to various DN control issues. In this paper, a HT-based approach consisting of augmenting the conventional Low Voltage (LV) transformer with a fractionally rated PE converter for regulating and controlling the RP in the last mile of the DN is proposed. In this way, it is expected to meet the demand of the future DN from an efficiency, controllability and volume perspective. The proposed approach is implemented using a back-to-back converter. In addition, a power transfer control topology is used to implement the proposed control of the RP injection that controls the voltage level at the Direct Current (DC) link. The proposed approach has been demonstrated in different load scenarios using the Piecewise Linear Electrical Circuit Simulation (PLECS) tool. The simulation results show that the proposed approach can compensate the loads with their need from RP instead of feeding them from the transmission grid at the primary side of the Distribution Transformer (DT). In this way, the proposed approach is able to decrease the transferred amount of RP in the transmission lines.

scholarly journals Using Energy Storage Inverters of Prosumer Installations for Voltage Control in Low-Voltage Distribution Networks

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1121
Author(s):  
Rozmysław Mieński ◽  
Przemysław Urbanek ◽  
Irena Wasiak
Keyword(s):  
Energy Storage ◽  
Control Strategy ◽  
Reactive Power ◽  
Low Voltage ◽  
Storage System ◽  
Distribution Networks ◽  
Energy Storage System ◽  
Voltage Regulation ◽  
Active Power ◽  
Total Power

The paper includes the analysis of the operation of low-voltage prosumer installation consisting of receivers and electricity sources and equipped with a 3-phase energy storage system. The aim of the storage application is the management of active power within the installation to decrease the total power exchanged with the supplying network and thus reduce energy costs borne by the prosumer. A solution for the effective implementation of the storage system is presented. Apart from the active power management performed according to the prosumer’s needs, the storage inverter provides the ancillary service of voltage regulation in the network according to the requirements of the network operator. A control strategy involving algorithms for voltage regulation without prejudice to the prosumer’s interest is described in the paper. Reactive power is used first as a control signal and if the required voltage effect cannot be reached, then the active power in the controlled phase is additionally changed and the Energy Storage System (ESS) loading is redistributed in phases in such a way that the total active power set by the prosumer program remains unchanged. The efficiency of the control strategy was tested by means of a simulation model in the PSCAD/EMTDC program. The results of the simulations are presented.

Research on the Reactive Power Optimization

2013 ◽  
Vol 385-386 ◽  
pp. 991-994
Author(s):  
Yan Yan Wang ◽  
Yan Song Li
Keyword(s):  
Power System ◽  
Reactive Power ◽  
Power Optimization ◽  
Low Voltage ◽  
Pso Algorithm ◽  
Reactive Power Optimization ◽  
Voltage Level ◽  
Line Network ◽  
Improved Pso

The power system is facing line losses, low voltage level and some other issues, this article begin with the point of the reactive power optimization, and through with the improved PSO algorithm, we find a way to reduce the line network loss.

Research on Reactive Power and Voltage Optimization of Regional Distribution Network

2011 ◽  
Vol 58-60 ◽  
pp. 474-479
Author(s):  
Yu Du
Keyword(s):  
Reactive Power ◽  
Regional Distribution ◽  
Distribution Networks ◽  
Radiation Characteristic ◽  
Reactive Power Optimization ◽  
Voltage Level ◽  
Medium Voltage ◽  
Regulation Effect ◽  
Practical Operation ◽  
Transformer Taps

The high-medium voltage level distribution networks have their own characters. Because of the radiation characteristic of the network, this paper looks on the network as the combination of some small optimization unit. The paper simplifies the resolution of the reactive power optimization by the way of alternatively solving the adjusting transformer taps and switching capacity banks. At the same time, considering the practical operation request, the paper evaluates the regulation effect and improves the practicability of the software.

VOLTAGE LEVEL CONTROL IN WEAK DISTRIBUTION NETWORKS WITH DG BY USING HYBRID REACTIVE POWER COMPENSATIONS

2016 ◽  
Vol 78 (5-9) ◽  
Author(s):  
Piyadanai Pachanapan
Keyword(s):  
Rural Areas ◽  
Reactive Power ◽  
Voltage Control ◽  
Cost Effective ◽  
Distribution Networks ◽  
Test System ◽  
Level Control ◽  
Voltage Level ◽  
Capacitor Banks ◽  
Dynamic Voltage

The hybrid reactive power compensations, using capacitor banks and distribution static compensator (DSTATCOM) in the coordinated manner, are introduced to enhance voltage level control performances in weak distribution networks with the increasing of distributed generation (DG), such as in the rural areas. While the conventional compensation using capacitor banks gives the poor dynamic voltage control, these hybrid compensations are the cost effective solution which can deal with both under-and over-voltage changes, either short- or long duration voltage variations. The dynamic voltage control performances are demonstrated under various operating scenarios using the test system implemented in DIgSILENTPowerFactory. The simulation results showed that this approach can improve voltage controllability in weak distribution networks with DG effectively.  

scholarly journals Advanced voltage control method for improving the voltage quality of low-voltage distribution networks with photovoltaic penetrations

2021 ◽  
Vol 4 (S2) ◽  
Author(s):  
Marika Nakamura ◽  
Shinya Yoshizawa ◽  
Hideo Ishii ◽  
Yasuhiro Hayashi
Keyword(s):  
Reactive Power ◽  
Control Method ◽  
Low Voltage ◽  
Distribution Network ◽  
Distribution Networks ◽  
Voltage Distribution ◽  
Power Conditioning ◽  
Pv Systems ◽  
Measurement Period ◽  
Voltage Violation

AbstractAs the number of photovoltaic (PV) power generators connected to the distribution grid increases, applications of on-load tap changers (OLTCs), power conditioning systems, and static reactive power compensators are being considered to mitigate the problem of voltage violation in low voltage distribution systems. The reactive power control by power conditioning systems and static reactive power compensators can mitigate steep voltage fluctuations. However, it creates losses in generation opportunities. On the other hand, OLTCs are installed at the bases of distribution lines and can collectively manage the entire system. However, the conventional voltage control method, i.e., the line drop compensation (LDC) method, is not designed for the case in which a large number of PV systems are installed in the distribution network, which results in voltage violations above the limit of the acceptable range. This study proposes a method to determine the optimal LDC control parameters of the voltage regulator, considering the power factor of PV systems to minimize the magnitude of voltage violations based on the voltage profile analysis of low-voltage (LV) distribution networks. Specifically, during a measurement period of several days, the voltages at some LV consumers and pole transformers were measured, and the optimal parameters were determined by analyzing the collected data. The effectiveness of the proposed method was verified through a numerical simulation study using the actual distribution system model under several scenarios of PV penetration rates. Additionally, the difference in the effectiveness of voltage violation reduction was verified in the case where all the LV consumer’s consumer voltage data measured per minute were used as well as in the case where only the maximum and minimum values of the data within the measurement period were used. The results reveal that the proposed method, which operates within the parameters determined by the voltage analysis of the LV distribution network, is superior to the conventional method. Furthermore, it was found that even if only the maximum and minimum values of the measurement data were used, an effective voltage violation reduction could be expected.

scholarly journals A Practical Approach to Optimising Distribution Transformer Tap Settings

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4889
Author(s):  
Joshua Paoli ◽  
Bernd Brinkmann ◽  
Michael Negnevitsky
Keyword(s):  
Low Voltage ◽  
Computation Time ◽  
Distribution Networks ◽  
Distribution Transformer ◽  
Average Case ◽  
Embedded Generation ◽  
Distribution Transformers ◽  
Real Distribution ◽  
Loading Case ◽  
Optimal Set

This paper proposes a method of determining the optimal tap settings for no-load distribution transformers with tap-changing capabilities that is practical to apply in real distribution networks. The risk of low voltage distribution networks violating voltage constraints is impacted by the increasing uptake of distributed energy resources and embedded generation. Some of this risk can be alleviated by suitably setting no-load transformer tap settings, however, modifying these taps requires customer outages and must be infrequent. Hence, loading over the entire year must be considered to account for seasonal variations when setting these taps optimally. These settings are determined using evolution strategy optimisation based on an average loading case. Monte Carlo simulations are used to calculate the probability that the terminal voltages on the distribution transformer secondary terminals violate the network voltage limits when the optimal set of taps for the average case is applied over a whole year. This algorithm was tested on several cases of a real distribution feeder of varying complexity, and produces a sufficiently-optimal set of taps without significant computation time.

scholarly journals Review of Voltage and Reactive Power Control Algorithms in Electrical Distribution Networks

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 58 ◽  
Author(s):  
Daiva Stanelyte ◽  
Virginijus Radziukynas
Keyword(s):  
Smart Grids ◽  
Reactive Power ◽  
Low Voltage ◽  
Distribution Networks ◽  
Power Grids ◽  
Renewable Energy Resources ◽  
Distribution Grid ◽  
Harmonic Compensation ◽  
Distributed Power Generation ◽  
Control Devices

The traditional unidirectional, passive distribution power grids are rapidly developing into bidirectional, interactive, multi-coordinated smart grids that cover distributed power generation along with advanced information communications and electronic power technologies. To better integrate the use of renewable energy resources into the grid, to improve the voltage stability of distribution grids, to improve the grid protection and to reduce harmonics, one needs to select and control devices with adjustable reactive power (capacitor batteries, transformers, and reactors) and provide certain solutions so that the photovoltaic (PV) converters maintain due to voltage. Conventional compensation methods are no longer appropriate, thus developing measures are necessary that would ensure local reactive and harmonic compensation in case an energy quality problem happens in the low voltage distribution grid. Compared to the centralized methods, artificial intelligence (heuristic) methods are able to distribute computing and communication tasks among control devices.

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