scholarly journals Novel Approach to Collect and Process Power Quality Data in Medium-Voltage Distribution Grids

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 460
Author(s):  
Sergei Kryltcov ◽  
Aleksei Makhovikov ◽  
Mariia Korobitcyna
Keyword(s):  
Power Quality ◽  
Reactive Power ◽  
Quality Data ◽  
Processing Plant ◽  
Grid Node ◽  
Voltage Distribution ◽  
Nonlinear Load ◽  
Medium Voltage ◽  
Harmonic Components ◽  
Distribution Grids

The paper is devoted to the development of the structure of a fast and flexible data collecting system based on the proposed approach to measure power quality indicators in three-phase medium-voltage distribution grids with an example of a Mikhailovsky mining and processing plant. The approach utilizes the properties of a space vector, obtained from grid currents and voltages with disturbed waveform, to allow faster extraction of the harmonic components compared to traditional approaches, based on the direct Fourier-transform applied to a line or phase values. During the study, the concept of a universal measurement device was introduced, which allows fast estimation of the following values at the grid node: magnitudes and phases of voltage and current harmonic components, active and reactive power of harmonics and fundamental components, positive and negative instantaneous powers. The structure of interconnected measurement and control units for the considered grid node with simultaneous operation of two active variable frequency drives with active rectifiers was proposed in accordance with a concept of the Internet of things. The benefits of the proposed solution are shown by the example of the model of the grid node with two operating draglines and nonlinear load, which was developed in MATLAB/Simulink software. The proposed approach was utilized to produce distributed references for control systems of grid inverters to compensate nonlinear currents, which allowed to significantly improve THDi of the grid node input power.

scholarly journals Stochastic Optimization of PQ Powers at the Interface between Distribution and Transmission Grids

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4057
Author(s):  
Jérôme Buire ◽  
Frédéric Colas ◽  
Jean-Yves Dieulot ◽  
Xavier Guillaud
Keyword(s):  
Reactive Power ◽  
Daily Basis ◽  
Control Effort ◽  
Control Laws ◽  
Medium Voltage ◽  
Distributed Generators ◽  
Real Size ◽  
Grid Codes ◽  
Distribution Grids ◽  
Hourly Basis

This paper addresses the volt-var control of distribution grids embedding many distributed generators (DGs). Specifically, it focuses on the compliance of powers to specified PQ diagrams at the high voltage/medium voltage (HV/MV) interface while the voltages remain well controlled. This is achieved using a two-stage optimization corresponding to two different classes of actuators. The tap position of capacitor banks is selected on a daily basis, given a stochastic model of the input powers prediction, which allows infrequent actuation and increases the device lifespan. In a second stage, a confidence level optimization problem allows to tune on an hourly basis the parameters of the DGs reactive power affine control laws. Results on a real-size grid show that the combined tuning of these actuators allows the ability to comply with European grid codes while the control effort remains reasonable.

Research and Application of SVC Technology in Grid

2014 ◽  
Vol 543-547 ◽  
pp. 878-883
Author(s):  
Jun Dong ◽  
Jian Guo Xu ◽  
Hao Zhang ◽  
Yu Jie Pei ◽  
Xian Feng Li
Keyword(s):  
Power Systems ◽  
Power Quality ◽  
Distribution System ◽  
Power Flow ◽  
Reactive Power ◽  
Control Strategies ◽  
Load Capacity ◽  
Flow Distribution ◽  
Nonlinear Load ◽  
The Impact

The cause serious deterioration in power quality problems for the growing impact and nonlinear load capacity, introduced SVC device in the role of modern power systems and applications. According to the lack of adequate regional dynamic reactive power regulation means to cause voltage fluctuations, harmonics exceeded the actual situation, through analysis and simulation of the existing 66kV grid power quality conditions, refers to the necessity of application of SVC, the compensation capacity for SVC, filter capacitor system parameters and control strategies were designed, the results show improved 220kV SVC reactive power flow distribution system, reducing the system once or twice a net loss, reducing the impact and harmonic interference voltage caused by nonlinear loads, system security, economic operation of great significance.

scholarly journals Heuristic Methodology for Planning AC Rural Medium-Voltage Distribution Grids

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5141
Author(s):  
Oscar Danilo Montoya ◽  
Federico Martin Serra ◽  
Cristian Hernan De Angelo ◽  
Harold R. Chamorro ◽  
Lazaro Alvarado-Barrios
Keyword(s):  
Power Flow ◽  
Minimum Spanning Tree ◽  
Search Algorithm ◽  
Flow Simulation ◽  
Mixed Integer ◽  
Voltage Distribution ◽  
Medium Voltage ◽  
Planning Project ◽  
Distribution Grids ◽  
Selection Of

The optimal expansion of AC medium-voltage distribution grids for rural applications is addressed in this study from a heuristic perspective. The optimal routes of a distribution feeder are selected by applying the concept of a minimum spanning tree by limiting the number of branches that are connected to a substation (mixed-integer linear programming formulation). In order to choose the caliber of the conductors for the selected feeder routes, the maximum expected current that is absorbed by the loads is calculated, thereby defining the minimum thermal bound of the conductor caliber. With the topology and the initial selection of the conductors, a tabu search algorithm (TSA) is implemented to refine the solution with the help of a three-phase power flow simulation in MATLAB for three different load conditions, i.e., maximum, medium, and minimum consumption with values of 100%, 60%, and 30%, respectively. This helps in calculating the annual costs of the energy losses that will be summed with the investment cost in conductors for determining the final costs of the planning project. Numerical simulations in two test feeders comprising 9 and 25 nodes with one substation show the effectiveness of the proposed methodology regarding the final grid planning cost; in addition, the heuristic selection of the calibers using the minimum expected current absorbed by the loads provides at least 70% of the calibers that are contained in the final solution of the problem. This demonstrates the importance of using adequate starting points to potentiate metaheuristic optimizers such as the TSA.

scholarly journals A Unique Control Strategy and Power Management in Wind/Solar Renewable Energy Power System to Improve the Power Quality of Grid System

2021 ◽  
pp. 52-60
Author(s):  
Khashiya Parveen ◽  
Prof. Shravan Vishwakarma
Keyword(s):  
Wind Turbine ◽  
Power Quality ◽  
Power Plants ◽  
Large Scale ◽  
Reactive Power ◽  
Hybrid Energy ◽  
Enhancement Method ◽  
Photo Voltaic ◽  
Compensation Device ◽  
Harmonic Components

Hybrid energy generation which includes both wind and solar energy has grown exponentially in latest years, and this will continue. Power quality problems such as voltage-swells, voltage-sags, harmonic components, power factor, and inadequate voltage control are caused by intermittent various exposures and the incorporation of wind-turbine and Photo-voltaic power generating systems with the grid. A Static Compensator (STATCOM) is employed to enhance power-quality. The power quality enhancement method for grid-connected wind-turbine and photo voltaic power plants employing STATCOM is introduced in this paper.  The framework of the proposed methodology describes in order to improve the transient voltage stability of the large-scale wind / solar hybrid system, the STATCOM reactive power compensation device is connected to the grid.   The compensator is offered to further improve output parameters such as voltage THD, current THD and active power.

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