scholarly journals Proposed Fuzzy Logic System for Voltage Regulation and Power Factor Improvement in Power Systems with High Infiltration of Distributed Generation

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4241 ◽  
Author(s):  
Ndamulelo Tshivhase ◽  
Ali N. Hasan ◽  
Thokozani Shongwe
Keyword(s):  
Power Generation ◽  
Control System ◽  
Power Systems ◽  
Power System ◽  
Power Factor ◽  
Reactive Power ◽  
Renewable Energy Sources ◽  
Voltage Regulation ◽  
Active Power ◽  
Distributed Generators

Recently, the awareness of the severe consequences of greenhouse gases on the environment has escalated. This has encouraged the world to reduce the usage of fossil fuels for power generation and increase the use of cleaner sources, such as solar energy and wind energy. However, the conventional power system itself was designed as a passive power system, in which power generation is centralised, and power flows from substations towards the loads. Decentralised renewable energy sources, also called distributed generators, were introduced to create an active power system in which power generation can occur anywhere in the power system. Decentralised power generation creates challenges for the conventional power system, such as voltage fluctuations, high voltage magnitudes, reverse power flow, and low power factor. In this paper, an adaptive control system that coordinates different distributed generators for voltage regulation and power factor correction is introduced and designed. The control system will decrease the total reactive power that flows in the transmission network through a reactive power exchange between distributed generators. Therefore, power factor will improve, power system losses will reduce, and the total apparent power on lines will reduce, giving more room to active power to flow. The results obtained showed that the control system is effective in regulating voltage and improving the power factor when multiple distributed generators are connected.

Microgrids Emergency Control and Protection

2013 ◽  
Vol 2 (1) ◽  
pp. 78-100 ◽  
Author(s):  
Hassan Bevrani ◽  
Mehrdad Gholami ◽  
Neda Hajimohammadi
Keyword(s):  
Power Systems ◽  
Large Scale ◽  
Reactive Power ◽  
Renewable Energy Sources ◽  
Voltage Regulation ◽  
System Stability ◽  
Stable Operation ◽  
Energy Storage Devices ◽  
Control Plan ◽  
Emergency Control

Economical harvesting of electrical energy on a large scale considering the environmental issues is a challenge. As a solution, Microgrids (MGs) promise to facilitate the widely penetration of renewable energy sources (RESs) and energy storage devices into the power systems, reduce system losses and greenhouse gas emissions, and increase the reliability of the electricity supply to the customers. Although the concept of MG is already established, the control strategies and energy management systems for MGs which cover power interchange, system stability, frequency and voltage regulation, active and reactive power control, islanding detection, grid synchronization, following contingencies and emergency conditions are still under development. Like a conventional power system, a Micro-grid (MG) needs emergency control and protection schemes to have secure and stable operation. Since MG can operate in both grid-connected and islanded mode, in addition to the control loops and protection schemes, extra issues must be considered. Transition between two operation modes requires an extra control plan to eliminate and stabilize transients due to mode changing. This paper presents an overview of the key issues and new challenges on emergency control and protection plans in the MG systems. The most important emergency control and protection schemes such as load shedding methods that have been presented over the past years are summarized.

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 A Survey on Smart Grid-Connected Photovoltaic Power Systems and Its Issues

IJOSTHE ◽  
2017 ◽  
Vol 4 (3) ◽  
pp. 6 ◽  
Author(s):  
Sarika Gautami ◽  
Rajeev Tiwari
Keyword(s):  
Power Generation ◽  
Power Systems ◽  
Power System ◽  
Distribution System ◽  
Operation Mode ◽  
Harmonic Distortion ◽  
Voltage Regulation ◽  
Pv System ◽  
Local Conditions ◽  
Photovoltaic Power

Photovoltaic power generation refers to the use of solar photovoltaic cells to the solar radiation can be directly transformed into electricity generation. Distributed photovoltaic power generation, refers to the construction in the vicinity of the user's location, the operation mode to the user side of spontaneous self-occupied mainly, the excess power on the Internet, and in the distribution system to balance the characteristics of the photovoltaic power generation facilities. Distributed photovoltaic power generation follow the principle of local conditions, clean and efficient, decentralized layout, the principle of the nearest use, and make full use of local solar energy resources, alternative and reduce fossil energy consumption. This paper aims to investigate and emphasize the importance of the grid-connected PV system. The investigation was conducted to critically review the literature on expected potential problems associated with issues of PV based grid system. The main purpose of this paper is to discuss the basic understanding of photovoltaic (PV) based distributed generation power system and how these power flows will influence the performance and stability of a power system. Some of the PV grid integration issues such as voltage regulation, voltage sags, harmonic distortion, etc are also discussed and possible solutions are also mentioned.

scholarly journals Secondary voltage regulation based on average voltage control

TecnoLógicas ◽  
2018 ◽  
Vol 21 (42) ◽  
pp. 63-78
Author(s):  
Edwin H. Lopera-Mazo ◽  
Jairo Espinosa
Keyword(s):  
Control System ◽  
Power Systems ◽  
Reactive Power ◽  
Voltage Control ◽  
Voltage Regulation ◽  
Voltage Profile ◽  
Real Power ◽  
Power Resources ◽  
Control Actions ◽  
Secondary Voltage

This paper compares a conventional Secondary Voltage Regulation (SVR) scheme based on pilot nodes with a proposed SVR that takes into account average voltages of control zones. Voltage control significance for the operation of power systems has promoted several strategies in order to deal with this problem. However, the Hierarchical Voltage Control System (HVCS) is the only scheme effectively implemented with some relevant applications into real power systems.The HVCS divides the voltage control problem into three recognized stages. Among them, the SVR is responsible for managing reactive power resources to improve network voltage profile. Conventional SVR is based on dividing the system into some electrically distant zones and controlling the voltage levels of some specific nodes in the system named pilot nodes, whose voltage levels are accepted as appropriate indicators of network voltage profile.The SVR approach proposed in this work does not only consider the voltage on pilot nodes, but it also takes the average voltages of the defined zones to carry out their respective control actions. Additionally, this innovative approach allows to integrate more reactive power resources into each zone according to some previously defined participation factors.The comparison between these strategies shows that the proposed SVR achieves a better allocation of reactive power in the system than conventional SVR, and it is able to keep the desired voltage profile, which has been expressed in terms of network average voltage.

scholarly journals Development of an Intelligent Voltage Control System for Bulk Power Systems

2021 ◽  
Vol 11 (19) ◽  
pp. 9233
Author(s):  
Heungjae Lee ◽  
Wonkun Yu ◽  
Junghyun Oh ◽  
Hyungsuk Kim ◽  
Jinyoung Kim
Keyword(s):  
Control System ◽  
Expert System ◽  
Power Systems ◽  
Power System ◽  
Performance Index ◽  
Reactive Power ◽  
Voltage Control ◽  
Searching Strategy ◽  
Space Modeling ◽  
Bulk Power

As modern power systems become large and complicated, an automated voltage and reactive power control system is required in most developed countries due to the remarkable recent progress in computer networks and information technology. To date, voltage control has depended on human operators in the Korean power system. Accordingly, this paper proposes a universal intelligent voltage control system for bulk power systems based on sensitivity analysis and a main expert system. A detailed state space modeling technique is discussed, and an effective performance index is proposed to accelerate the searching performance of the expert system. As the searching strategy is an important factor for the speed of the expert system, the least-first search algorithm is applied using this performance index. The proposed system has been applied to the Korean power system, showing promising results.

scholarly journals A Systematic PVQV-Curves Approach for Investigating the Impact of Solar Photovoltaic-Generator in Power System Using PowerWorld Simulator

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2662 ◽  
Author(s):  
Abdullahi Oboh Muhammed ◽  
Muhyaddin Rawa
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Power Factor ◽  
Reactive Power ◽  
Power Grid ◽  
Percentage Change ◽  
Droop Control ◽  
Solar Photovoltaic ◽  
The Impact

With the recent growing interest in renewable energy integrated power systems across the globe for the various economic and environmental benefits, it is also significant to consider their influence on voltage stability in power systems. Therefore, this paper reports the static voltage stability impact of solar photovoltaic generation on power networks using PowerWorld simulator power-voltage (P–V)- and voltage-reactive power (V–Q)-curves to investigate the renewable energy generator model performance suitability. The impact of varying power factor control and static voltage droop control of a photovoltaic plant on the maximum generated power, threshold voltage profile and reactive power marginal loading has been examined. Besides, the concept of percentage change in voltage-power sensitivity has been systematically utilized to determine the optimal location for the solar photovoltaic generator on the power grid and the feasible penetrations have been defined for selected system buses. From the simulation results it can be concluded that in a steady-state analysis of the grid integrated power system the effects of power factor (pf) control and voltage droop control should be considered by power grid engineers for effective system operation and, equally, the application of percentage change in voltage-power sensitivity should be extended to real networks to determine the best positions for multiple installations of renewable energy resources.

Model of Power Factor Charge for Photovoltaic Generation System Based on its Contribution to Power Systems

2015 ◽  
Vol 781 ◽  
pp. 262-266
Author(s):  
Marut Hemsuree ◽  
Chanan Thiranan ◽  
Surachai Chaitusaney
Keyword(s):  
Power Systems ◽  
Power Factor ◽  
Reactive Power ◽  
Voltage Regulation ◽  
Generation System ◽  
Photovoltaic Generation ◽  
Small Power ◽  
Acceptable Range ◽  
Charge Model ◽  
Proposed Model

This paper proposes a power factor charge model, which considers the operation of photovoltaic generation system (PVGS). The proposed model is aimed to encourage Very Small Power Producer (VSPP) to have contribution, by its operation, to voltage regulation in the connecting power system. The proposed model allows PVGS has to either consume or supply reactive power for maintaining system voltages to be within an acceptable range. In the financial part, consuming or supplying reactive power may cause the power factor charge to be increased while the opportunity for generating active power (PVGS income) to be reduced. The proposed model is tested in impact of PVGS to utility grid, and the results show that PVGS can have contribution to grid support.

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