Power Quality Control Research Articles

Power quality control through automated demand side management in microgrid equipped with battery energy storage for protection

Apparently, battery energy storage (BES), intelligent protection and power quality are considered as independent issues. These three factors can be interlinked effectively for control of microgrid through automated demand side management (ADSM). In this context, the proposed approach may change the conventional way for microgrid operation and control giving priority to the power quality issues considering protection and BES systems. The control algorithm is implemented through fuzzy inference system based power quality monitoring index and ADSM. As a part of intelligent protection, logic table for circuit breaker (CB) coordination has been developed without/with backup for relay devices to provide ADSM. The model has been simulated using Matlab-software and validated experimentally using OPAL-RT OP4510 real-time simulator through the assessment of power quality-related parameters such as voltage, frequency, total harmonic distortion and power factor. The results are found satisfactory showing the feasibility of the proposed microgrid model.

Development of a model of automatic regulation of reactive power compensation for the oil and gas industry

Reactive power has a significant impact on the parameters of the power supply system in the oil and gas industry; as a result, there is a decrease in the quality of the electric network. The relevance of the study is justified by the tasks of improving the quality of electricity in the load nodes consisting of asynchronous motors, one of which is the reactive power compensation, including the calculation and automatic regulation of compensating devices. The aim of the article is to design and research a reactive power compensation control system to improve the quality of electricity. The article proposes a solution to the actual problem of reactive power compensation based on the proposed power quality control algorithm. The system of automatic control of reactive power compensation developed in the Matlab and Simulink software package allows us to generate parameters according to current measurements and adjust the voltage when the load operation mode changes. The use of MOSFET transistors in the control system made it possible to create the necessary compensation currents with a low content of higher harmonics that create distortions in the supply voltage and ensure high speed of the reactive power compensation unit operation.

Power quality improvement of wind energy conversion system with unified power quality controller: A hybrid control model

The real problems in diminution of power quality (PQ) occur due to the rapid growth of nonlinear load are leading to a sudden decrease of source voltage for a few seconds. All these problems can be compensated by unified power quality controller (UPQC). The proposed research is based on designing a wind energy conversion system (WECS) fed to the dc-link capacitor of UPQC so as to maintain proper voltage across it and operate the UPQC for PQ improvement. The proposed research utilizes two techniques for enhancing the performance of UPQC known as integrated ant lion optimizer (IALO)-adaptive neuro fuzzy inference system (ANFIS), called IALO-ANFIS. Here, induction motor is considered as non-linear load. ALO searching behavior is enhanced by crossover and mutation. Initially, the objective function parameters are defined, that is, voltage, real, grid parameters, load parameters, real and reactive power and current. Based on these parameters, the control pulse is produced for series and shunt active power filter (APF). IALO is used to identify the optimal solutions and creates the training dataset. In light of the accomplished dataset, ANFIS predicts the best control signals of UPQC. During load variation conditions, the proposed strategy minimized the power loss and voltage instability issue individually. Subsequently, the power quality of the system is enhanced. In order to evaluate the effectiveness of the proposed method, three different cases are considered. The performance of the proposed technique is validated through MATLAB/Simulink and compared with existing techniques such as genetic algorithm and ALO.

Power Quality Control Method of Distributed Generation Based on Improved PI and Repetitive Control

In view of the similar structure between the distributed generation (DG) inverter and the active power filter (APF), it is of great significance to develop the DG inverters with harmonic suppression functions. The accurate tracking and rapid response to the phase and amplitude of the harmonic components is the guarantee of the effective use of the DG inverter to suppress the harmonic. In this paper, a harmonic suppression control method of DG inverter based on improved PI and repetitive control is proposed. This method can make the DG inverter output the active power of the fundamental wave by using the PI controller, and output the high precision harmonic current compensation by the repetitive controller. While considering the existence of a periodic delay in the repetitive controller, the feedforward control of harmonic components is added to speed up the dynamic response of harmonic suppression. Finally, the simulation results show that, compared with the traditional harmonic suppression method, the proposed control strategy can ensure the steady-state accuracy and dynamic response speed of the active output and harmonic suppression of the DG inverter while reducing the computational complexity.

Power Quality Improvement of Isolated Power System Network using UPQC

The Unified Power Quality Controller (UPQC) is the Custom Power device designed for improving the power quality of the electrical network. In this paper, we proposed UPQC design for an isolated power system network to attend both voltage and current distortion by using Unit Vector template algorithm and Instantaneous Reactive Power theory. Also UPQC is designed for the hybrid generation with Hysteresis control algorithm. The power quality improvement of the power system network is the main aim . The performance analysis is done by comparing its Total Harmonic Distortion (THD). Based on its THD the quality of the power at the “Point of common coupling (PCC)”with and without compensator is quantified in this paper. Keywords : About four key words or phrases in alphabetical order, separated by commas.

IoT Based Wireless Sensor Network for Power Quality Control in Smart Grid

The IoT based Power management system requires data from the feeder in the grid. Sufficient power supply with demand is a significant challenge for several countries around the world. RaPID growing demand for power supply requires power quality enhancement to get higher reliability in the smart grid. This smart power system sensor equipped that measures grid power capacity and update to the organization on a consistent schedule. Energy supplies to the specific region indicated by power install capacity in the grid; use a global system for mobile communications (GSM) messaging service to notify customers of power generation and power supply time. The IoT based wireless Sensor network (WSN) is a revolutionary system for smart monitoring. In this article propose a system demonstrate for the progress and implementation of WSN-based communication systems for smart monitoring and automated control in the electric grid. This work allows for the improvement of grid sharing for maintaining power quality. The dynamic controller has controlled the event of Power quality problem and voltage rise. Appropriate systems and controllers have been demonstrated and analyzed for control performance of a monitoring system in the smart grid.

Mitigation techniques of power quality issues from materials

Developing the utilization of nonlinear industrial and commercial loads, for example, power converters and variable speed engine drives, causes high harmonic distortion of the distribution networks in specific industrial motors, air conditioning, and mechanical systems. The main objective of this study is to have a detailed review of power quality problems and to suggest possible solutions to them through the passive harmonic mitigation technique and DSTATCOM method. A comprehensive analysis of power quality in power systems, along with the criteria that outline these issues, as well as the DC systems yet done as renewable sources area unit. Power quality control methods and possible solutions for intricately power quality problems researched for the unit area capability systems. Briefly, in an extremely single job, a complete overview of the overall problems with power quality is given. The techniques derived from social network analysis have adopted to conduct the research. Due to the increased sensitivity of the equipment and devices used by the consumers, the power quality of property energy is impaired and they want careful observance and evaluation for mitigation functions. Power efficiency is another important challenge that needs to be satisfied simultaneously with the power quality check throughout the transmission and distribution lines. Considering the expense and ecological concerns have slowed the process of building new power plants and transmission lines in the present modem industrial scenario.

Investigation and Feasibility Evaluation of Using Nanogrid Technology Integrated Into Road Lighting System

Currently, light-emitting diode (LED) technologies and solar power production are in popular use. This paper proposes the concept of improving conventional road lighting systems using LED technologies and solar energy applications, known as a “nanogrid road lighting system.” The power quality of a nanogrid road lighting system is analyzed in stand-alone and grid-connected operations using an experimental setup. In addition, the IEC 61000-3-2 (2018) Class C standard and power quality control regulations for grid connections are also discussed. The energy storage installed for individual and central systems are analyzed. Moreover, economic comparisons of three kinds of road lighting systems, namely grid-powered high-pressure sodium, LED solar stand-alone, and nanogrid systems, are compared in terms of their individual discounted payback period (DPP), net present value (NPV), and internal rate of return (IRR). The results show that in stand-alone mode, the system can effectively charge its batteries with the maximum power point tracking (MPPT) control and discharge power to supply the road lighting system. In the grid connection mode, the electrical energy produced from the solar power system can be supplied to the electrical grid at all ranges of solar irradiance levels with the MPPT control. However, a high total current harmonic distortion (THDi) flows into the electrical grid when solar irradiance levels are low. Solar road lighting systems installed in a central system have a low initial investment cost, resulting in better economic performance (in terms of DPP, IRR, and NPV). For this reason, using nanogrid road lighting systems shows satisfactory feasibility in terms of power quality and economic performance.

Optimal Operation of Multi-Converter-UPQC for Power Quality Improvement in Distribution

In this paper the power compensation for power system during faults in distribution line is described. The proposed system is designed by using the series and shunt APF based hysteresis control scheme to compensate harmonic distortion and control the system stability. Moreover, the system can be compensated the current as well as voltage simultaneously by using Unified Power Quality Controller (UPQC). Voltage Source Inverters (VSI) are connected in both the series and shunt. The main feeder is used to injecting power to these inverters using transformer and VSI compensate the imperfection line such as sag, interruption, swell, voltage unbalance. DC link voltage of the system is maintained at series and shunt operation. The proposed system is verified successfully and tested using MATLAB/Simulink.

Quasi-Two-Stage Multifunctional Photovoltaic Inverter With Power Quality Control and Enhanced Conversion Efficiency

A novel quasi-two-stage multifunctional inverter (QMFI) for photovoltaic (PV) applications is proposed in this article. With the help of the quasi-two-stage architecture, part of active power can be directly transferred from PV arrays to the grid or load within a single power conversion stage and hence improve the efficiency. In addition to active power transfer, both the realization of maximum power point tracking (MPPT) and compensation of nonactive current (i.e., reactive, harmonic, or unbalanced current) of the QMFI are considered. A mathematical model of the QMFI is presented to guide the control parameter design. Meanwhile, an analysis model based on the rotating frame is proposed to derive the space vector pulsewidth modulation strategy of the QMFI, and also, offer straightforward insight into the influence of nonactive current compensation on quasi-two-stage active power flow. Compared with traditional solutions, the QMFI can realize active power delivery with higher efficiency and also keep functions of achieving MPPT and enhancing power quality. The feasibility and effectiveness of the proposed solution are verified with a 3-kVA prototype.

Connecting the Home Grid to the Public Grid: Field Demonstration of Virtual Synchronous Machines

Power systems are going through a paradigm shift. More and more distributed energy resources (DERs) and loads are being connected to power systems, mostly through power electronic converters. These power electronic converters can be controlled as virtual synchronous machines (VSMs), leading to a unified interface for grid integration. As a result, all active players in a power system can take part in the regulation of system frequency and voltage in a synchronized and democratized (SYNDEM) manner, significantly simplifying system operation and improving grid stability, reliability, resiliency, security, and sustainability. This article presents a pilot smart home grid at the Llano River Field Station, Texas Tech University Center at Junction, that is built according to the SYNDEM grid architecture. The home grid consists of five DER units, including four 3-kW solar units and one 3-kW wind unit with built-in battery storage in each unit, and one energy bridge for grid connection. The energy bridge has two VSMs connected back-to-back with a common dc bus. All the units are equipped with a self-synchronized universal droop controller (SUDC) with many advanced functions, i.e., black-start, grid-forming, self-synchronization without a phase-locked-loop (PLL), voltage and frequency regulation, power sharing, and power quality control. The home grid can work with or without the public grid, with seamless mode change between grid-tied operation and islanded operation. All the functions are achieved without using a communication network; hence, potential cyberattacks can be avoided. Field operation results of the home grid are presented to demonstrate the autonomous operation of the system.

Low-voltage power supply system based on three-phase to two-phase and integrated power quality control method

The two-input single-phase transformer is widely used in the 10kV power distribution system. However, this power supply mode has the disadvantage of the 10kV side three-phase unbalance problem. In response to this problem, the paper proposes a new 220V single-phase low-voltage power supply system based on a three-input single-phase transformer. The power supply system consists of a three-phase transformer and a two-phase transformer and a phase-to-phase power controller. The three-phase to two-phase transformer is used to realize two low-voltage single-phase power supply, and the phase-to-phase power controller is used to realize the negative sequence and harmonic control of the low voltage side. This power supply mode is suitable for large-capacity low-voltage power supply systems with single-phase load intensive. The paper analyzes the transformation theory and control strategy of the power supply mode. Finally, the superiority and effectiveness of the proposed technical scheme and control strategy are verified by simulation analysis.

Research on power quality control of grid-connected microgrid based on distributed generation

ABSTRACT With the development of distributed generation and Microgrid technology, the structure and load of microgrid system will become more and more complex, and the probability of power quality problems such as harmonics, voltage fluctuation and flicker will be higher and higher. In this paper, the problem is studied. According to the development rule of international flexible transmission, a power quality control method based on active power filter is proposed. The simulation results show that the advanced correction in this paper is feasible, and it effectively improves the power quality of grid-connected microgrid.

Electric power quality control in electro-technical complexes of oil processing plant

The paper deals with electric power quality research, in the load buses of the electrical networks of oil processing plant (“Production Association “Kirishinefteorgsintez”, LLC). Measurements were carried out under conditions of operating equipment at the distribution substations of the enterprise and at the division boundary of inventory responsibility with the power-supply system at the points of power transmission from the power-supply system to the industrial consumer. Assessment of the allowed contribution to the deterioration of electric power quality showed that at the increase in the rated capacity of drives based on frequency converters over 12% of the total installed capacity of electricity receivers of oil processing plant, the maximum allowed voltage waveform distortion coefficient values at the points of power transmission will be exceeded. To implement normalizing the electromagnetic environment and lowering non-sinusoidality of voltage, proposed is a system of measures, that allows controlling electric power quality indicators within the limits, stipulated by regulatory documents, resulting to reducing the risk of penalties by the power-supply authority and large scale undersupply of products under conditions of continuous technological cycle.

The Research on Key Technologies of Power Quality Comprehensive Control in Complex Distribution Network

As new types of power sources and loads such as distributed photovoltaic and electric vehicle charging facilities are connected to the distribution network, the distribution network has become more variable and complex, and the simple distribution network has evolved into a complex distribution network. The access of new elements, especially the application of power electronic devices, has a great impact on the power quality of the distribution network. The technical framework of power quality comprehensive management of complex distribution network is proposed, and the corresponding technical route is put forward from three aspects: the influence of power electronic equipment application on power quality of distribution network, power electronic equipment modeling of distribution network, flexible monitoring of power quality and rapid control.

Disturbing Load Classification Based on the Grey Relational Analysis Method and Load Performance Index

This paper proposes an approach based on grey relational analysis to analyze and classify potentially disturbing loads taking into account the power factor, unbalance, harmonics and reactive power. By computer simulations, a set of loads with different characteristics were analyzed through various load performance indexes. Using the grey relational analysis applied to load performance indexes, such disturbances can be quantified; to carry out the load assessment; to help adopt energy billing policies; to support power quality control, grid management, as well as to provide information to the electric utility about analyses and decision making regarding the preventive maintenance of the grid for improved reliability and efficiency. Finally, the method was applied in practice to evaluate real disturbing loads in various industries with power quality problems.

Multifunction Transformer With Adjustable Magnetic Stage Based on Nanocomposite Semihard Magnets

In order to improve the efficiency, reliability of power supply, and to give overall consideration to the power transformation and power quality control, a brand-new multifunction transformer with intrinsic adjustable magnetic state is put forward based on semihard magnets NdFeB in this paper. First, according to the formation mechanism of dc bias and the regulation means of inductance value, the peculiar core structure of a single-phase transformer is designed so as to realize the flux adjustment of transformer core under different magnetic states. Second, taking advantage of the magnetic conductive and excitation characteristics of NdFeB, the magnetic state conversion of electromagnet core between several kinds of working conditions can be achieved, such as voltage transformation, adjustable inductance, and dc bias compensation. Finally, two 10 kVA transformers with adjustable magnetic state are manufactured. The experiments of dc bias compensation and inductance regulation are carried out, which validates the feasibility and correctness of the design scheme.

Supply Voltage and Grid Current Harmonics Compensation Using Multi-Port Interfacing Converter Integrated Into Two-AC-Bus Grid

A modified multi-port converter topology is proposed for active power quality control of two-ac-bus grid while maintaining a flexible integration of distributed dc energy sources. In this system, the lower converter cells work in voltage controlled mode to supply power to autonomous local critical loads with reduced harmonic distortions. At the same time, the upper converter cells working in current controlled mode are placed in between the main grid and the lower cells, to block the harmonic current from the local nonlinear loads to pollute the higher voltage grid current. In this proposed system, the upper and lower power cells harmonic control are well decoupled with minimal interferences. This features reduced computational load as there is no need to use any harmonic components extractions in the whole compensation process. In addition, the proposed harmonic compensation method has no interference with the interphase power flow control through zero sequence voltage injection. It has been examined that the proposed power quality control method works well in various conditions including that with large grid impedance and dc rail voltage variations.

A Review on Wind Turbine and Wind Generator Used in WECS

The applications of wind energy develop much rapidly than the other renewable resources such as solar, geothermal and so on in the 21st century. It becomes the third core energy resource following non-conventional fuels as oil and chemical. Electrical energy generated by wind power plants is the best ever developing and most promising renewable energy source. The wind is a clean, free and limitless energy source. Wind Energy Generation Systems (WECS) are confront with increasing demands for power quality and harmonic distortion control. With the advance in power electronics technology, the fast growth of variable speed WECS is now witness. However, the power quality still remains an important issue to be addressed thoroughly by researchers. This paper presents a comparative study on grid connected WECS having two different Wind Turbine Generator Systems (WTGS) using DFIG and PMSG.

Integration of Large Scale PV-Based Generation into Power Systems: A Survey

This paper reports a general overview of current research on analysis and control of the power grid with grid scale PV-based power generations as well as of various consequences of grid scale integration of PV generation units into the power systems. Moreover, the history of PV renewable growth, deregulation of power system and issues related to grid-connected PV systems considering its contribution to various responsibilities like frequency control, virtual inertia capabilities and voltage regulation are discussed. Moreover, various outcomes of the high-penetrated grid with PV power plants such as power quality, active and reactive power control, protection, balancing and reliability under various loading conditions are reviewed and discussed.