Power Factor Research Papers - Academia.edu (original) (raw)

This study proposes a simplified super-twisting algorithm (SSTA) control strategy for improving the power quality of grid-connected photovoltaic (PV) power systems. Some quality issues are considered in this study including the power... more

This study proposes a simplified super-twisting algorithm (SSTA) control strategy for improving the power quality of grid-connected photovoltaic (PV) power systems. Some quality issues are considered in this study including the power factor, reducing the total harmonic distortion (THD) of current, compensating the reactive power, and injecting at the same time the energy supplied by the PV system into the grid considering non-linear load. This improvement is achieved by two topologies; controlling both the boost DC–DC converter and the DC–AC inverter that links the PV system to the grid. The DC–DC converter is controlled using proportional-integral (PI) and SSTA to maximize the power generated from the PV panel regardless of its normal and abnormal conditions, while the DC–AC inverter is employed to direct power control strategy with modified space vector modulation using the phase-locked loop (PLL) technique of a three-level neutral-point-clamped (NPC) inverter based on the propose...

A Grid-connected unified power quality conditioner (UPQC) circuit has been controlled through fuzzy sliding mode pulse width modulation using sliding mode control incorporated through the fuzzy controller (FSMPWM) is proposed in this... more

A Grid-connected unified power quality conditioner (UPQC) circuit has been controlled through fuzzy sliding mode pulse width modulation using sliding mode control incorporated through the fuzzy controller (FSMPWM) is proposed in this paper. This FSMPWM control is used to eliminate harmonics and different types of oscillations in the UPQC circuit. Reference values and signals for UPQC was generated based on sliding mode control of UPQC. Shunt and series converters of UPQC are managed by means of proposed control circuits. Gate pulses for these converters were generated from these controls and were useful in reducing chattering related issues. The proposed model was designed and analyzed in SIMULINK tool under different cases of load and voltage unbalance, voltage sag, swell, distortion and phase angle jump. The outcomes of the proposed system are compared with the previous methods and proved to be a better performed & fewer harmonics are observed.

Compared to yesteryear, non-linear loads now proliferate in homes, offices and the industrial environment. Non-linear loads now form a major component of the total loading in the typical electrical network. The Compact Fluorescent Lamp is... more

Compared to yesteryear, non-linear loads now proliferate in homes, offices and the industrial environment. Non-linear loads now form a major component of the total loading in the typical electrical network. The Compact Fluorescent Lamp is but one example of a non-linear load that inherently produces and injects distorted currents into the electrical power network, which could create adverse consequences if appropriate and adequate harmonic mitigation techniques are not employed. CFLs are now a major component of the luminaires market around the world because consideration is being given worldwide to the phasing out of incandescent lamps. However, there are legitimate concerns over the quality of some CFLs. This paper investigates and compares the quality of some major brands of CFLs, in terms of parameters such as harmonic content, power factor, fundamental power factor, nonactive power, and apparent power. The wider implication of these results is ascertained by investigating the e...

To automate a manufacturing system for improved efficiency and quality of its output, a Programmable Logic Controller (PLC) with Internet of Things (IoT) need to be employed. At Company X, the furnaces employed for steel processing are... more

To automate a manufacturing system for improved efficiency and quality of its output, a Programmable Logic Controller (PLC) with Internet of Things (IoT) need to be employed. At Company X, the furnaces employed for steel processing are not connected to PLC-IoT system, thus making the system less effective. This study employs the agent based modeling and simulation for the investigation of the performance of the PLC-IoT system using both quantitative analysis and a simulation model developed from the Any-logic software. A program placed in a computer control system at 20 °C was used to control the levels of the heat in the furnaces that are responsible for further processing of steel pipes. The results obtained indicated that manually operated furnaces run for approximately 5-8 hours while the ones automated with PLC-IoT system run for approximately 3-6 hours respectively. Thus, the integration of PLC-IoT system into the manufacturing system can result in considerable time effectiveness.

This article evaluates energy quality in individual circuits within an industrial electrical system and its impact on common connection point parameters. The research is crucial due to rising challenges in power quality arising from... more

This article evaluates energy quality in individual circuits within an industrial electrical system and its impact on common connection point parameters. The research is crucial due to rising challenges in power quality arising from increased nonlinear electrical loads in industrial processes. The study involves sequential steps, covering the industrial electrical system´s description, power quality parameters analysis, and issue identification. A comprehensive assessment was conducted on a 3,000 kVA, 13.8 kV/460 V point of common coupling (PCC) transformer, and 10 transformers (10 to 250 kVA) supplying individual circuits. Findings indicated load factors below 70% in all transformers and a power factor below 0.9 in eight. Issues like voltage variation, current imbalance, and harmonic distortion were identified in nine transformers supplying individual circuits, while the PCC exhibited no power quality problems. The research emphasizes the importance of including individual circuits in power quality assessments, as compliance with regulatory limits at the PCC may not guarantee the absence of power quality issues in individual circuits, affecting equipment lifespan and increasing energy losses.

The power factor (PF) is an important measurement in an AC electrical system that indicates how much power ‎is utilized to accomplish productive work by a load and how much power is consumed. As a result, it's one of ‎the primary... more

The power factor (PF) is an important measurement in an AC electrical system that indicates how much power ‎is utilized to accomplish productive work by a load and how much power is consumed. As a result, it's one of ‎the primary causes of excessive energy costs and power outages. This paper aims to present a simple, cost-‎effective, and accurate PF metering and monitoring system implemented using an Arduino microcontroller with ‎a novel methodology different from other papers. The proposed method is to design the software code instead ‎of using external components of Zero-Crossing Detectors (Z-CDs) for both voltage (V) and current (I) signals, and ‎instead of using Exclusive-OR (X-OR) gates also. Determining the phase-angle and PF in an efficient manner ‎can be useful in many approaches to electrical systems: 1-for synchronization of parallel connections of ‎alternators; 2-for directional protection systems; 3-for PF correction and load management; and 4-for designing ‎watt/ene...

This paper presents a comprehensive and systematic approach in developing a new switching look-up table for direct power control (DPC) strategy applied to the three-phase grid connected three-level neutral-point clamped (3L-NPC) pulse... more

This paper presents a comprehensive and systematic approach in developing a new switching look-up table for direct power control (DPC) strategy applied to the three-phase grid connected three-level neutral-point clamped (3L-NPC) pulse width modulated (PWM) rectifier. The term of PWM rectifier used in this paper is also known as AC-DC converter. The approach provides detailed information regarding the effects of each multilevel converter space vector to the distribution of input active and reactive power in the converter system. Thus, the most optimal converter space vectors are able to be selected by the switching look-up table, allowing smooth control of the active and reactive powers for each sector. In addition, the proposed DPC utilizes an NPC capacitor balanced strategy to enhance the performance of front-end AC-DC converter during load and supply voltage disturbances. The steady state as well as the dynamic performances of the proposed DPC are presented and analyzed by using M...

This paper presents a proposed technique of virtual-flux direct power control (VF-DPC) as the improvement in control method from the basic of conventional direct power control (DPC) for front-end three-phase pulse width modulated (PWM) in... more

This paper presents a proposed technique of virtual-flux direct power control (VF-DPC) as the improvement in control method from the basic of conventional direct power control (DPC) for front-end three-phase pulse width modulated (PWM) in ac-dc converter. Three sensors in order to measure the three phase input voltage have been eliminated in the proposed method of virtual flux (VF) regarding from the estimation technique. Theoritical principles of VF-DPC are discussed in this paper. The steady-state performance of VF-DPC and conventional DPC are evaluated and presented in this work to estinguish for the excellent performance. It is shown that the VF-DPC exhibits the several advantages, particularly in providing low total harmonic distortion with almost sinusoudal of input current and unity power factor (pf) operation under balanced three phase voltage supply. The simulation results from both methods through Matlab simulation have demonstrated the outstanding performance of the new p...

In a Grid-Connected Photovoltaic System (GCPS), the inverters are applied for integration with the power grid. This integration brings some issues at the connection point. Therefore, grid-tied inverter control performs a vital role in... more

In a Grid-Connected Photovoltaic System (GCPS), the inverters are applied for integration with the power grid. This integration brings some issues at the connection point. Therefore, grid-tied inverter control performs a vital role in feeding the power system with good power quality. This study presents a current-controlled Voltage Source Inverter (VSI) strategy for large-scale GCPS generates 1000 kW rated of power. The methodology and structure of the control system are presented. The power quality issues such as harmonics, voltage fluctuation, voltage unbalance, and power factor are limited at the interfacing point into the required limits as imposed by the standards. This study also discusses the controller design and the simulation results are introduced to show its effectiveness. Furthermore, the values obtained may be used to evaluate the power supply quality of various inverter controllers.

This paper proposes a high step-down ratio AC-DC converter employing a quadratic buck converter with power factor correction. Conventional active power factor correction topologies employ boost-based correction schemes for unity power... more

This paper proposes a high step-down ratio AC-DC converter employing a quadratic buck converter with power factor correction. Conventional active power factor correction topologies employ boost-based correction schemes for unity power factor operation. This will require a steeper step-down ratio and higher switch voltage stress apart from complexity in the control scheme with sensors. The structure of the proposed topology is developed by combining the power factor correction stage with a high step-down stage. The passive input filter is split up into two for the purpose of reducing the thermal heating apart from offering a higher power factor. A single switch operation reduces the complexity of the control scheme. In addition, the number of conducting devices during the current path is also the same as the conventional buck converter due to cascading and hence offers lower conduction losses. The need for the converter to operate at an extremely low duty cycle is reduced due to the ...

Power quality is a crucial aspect of designing a large-scale photovoltaic power plant, particularly regarding harmonics caused by inverter switching. This research aimed to analyze harmonics in a system using electrical transient analyzer... more

Power quality is a crucial aspect of designing a large-scale photovoltaic power plant, particularly regarding harmonics caused by inverter switching. This research aimed to analyze harmonics in a system using electrical transient analyzer program (ETAP) Power Station 20.5.0 to uncover the effect of irradiance on the inverters’ power quality running at 85% and 100% power factors. We analyzed both voltage and current total harmonic distortion (THDi and THDv) from the simulation and compared them with the mathematical model. Moreover, we analyzed the effect of changes in irradiance level on harmonics and reactive power penetration, which influenced power losses in transformers and cables. Inverters at 85% power factor experienced an increase in THDi, whereas those at 100% power factor decreased. Inverters with 85% power factor experienced more frequent switching, causing more prominent distortion. The magnitude of THDv increased proportionally with the rise of irradiance level. Inverte...

This paper explains the experimental study of a distributed energy resource (DER) integrated three-phase, three-wire electrical distribution system (EDS) under power quality (PQ) and optimal active power flow control (OAPFC). In this... more

This paper explains the experimental study of a distributed energy resource (DER) integrated three-phase, three-wire electrical distribution system (EDS) under power quality (PQ) and optimal active power flow control (OAPFC). In this research, a back-to-back connected two-level VSI (BTB-TVSI) based distribution static compensator (DSTATCOM) for unbalanced non-linear load is designed. The aim is to provide better OAPFC in EDS with shunt compensation to maintain a round-the-clock quality power supply for end users. The improved neural network-based adaptive least mean square (ALMS) control algorithms are employed for DSTATCOM. The ALMS control strategy is realized using the SPARTAN-6 field programmable gate array (FPGA) evaluation kit. This research involves the comparative study of a two-level voltage source inverter (VSI) and a BTB-TVSI in terms of their OAPFC capability and robustness in mitigating power quality (PQ) against source current disturbances, low power factor (PF), poor ...

Currently, we are trying to improve electrical energy in the world. In practice, the use of switching devices is increased in the various applications. Non-linearity of loads has adverse effects on energy efficiency, power factor, etc.... more

Currently, we are trying to improve electrical energy in the world. In practice, the use of switching devices is increased in the various applications. Non-linearity of loads has adverse effects on energy efficiency, power factor, etc. This increases the reactive power and oversizes the devices of the electrical installation. Several solutions are therefore proposed. Unlike passive filter, active filters work due to their small size. In this paper, work is done on the Parallel Active Power Filter (SAPF) using nonlinear control based on Lyapunov theory and PQ theory for attenuation of harmonics and reduction of imaginary power in operation of a photovoltaic system. The simulation of the circuits is implemented in MATLAB / SIMULINK. The measurements have been presented with or without SAPF filter. We start the article by modeling the different devices used, then an analysis of the PQ theory is carried out, carrying out simulations, results and interpretations. Finally, we end with a c...

Об'єкт дослідження – енергетичні машини. Мета роботи – вдосконалення методів розрахунку та дослідження енергозберігаючих машин. Методи дослідження - аналіз, обчислювальний експеримент, фізичний експеримент

There are today many techniques for controlling active filters on single-phase networks in order to correct the power factor and limit the harmonics consumed at the source. Almost all of these methods are determined for a perfect... more

There are today many techniques for controlling active filters on single-phase networks in order to correct the power factor and limit the harmonics consumed at the source. Almost all of these methods are determined for a perfect sinusoidal source. The work developed here concerns the taking into account of a perturbed network, that is to say the presence of voltage harmonics at the connection point. The results are validated by experiment on a low power system.

Modern dc power supplies provide power factor correction but the classical two-stage approach, using hard-switched preregulators, has detrimental effects on efficiency and reliability, particularly for high power applications. With some... more

Modern dc power supplies provide power factor correction but the classical two-stage approach, using hard-switched preregulators, has detrimental effects on efficiency and reliability, particularly for high power applications. With some circuit modifications and the addition of a few magnetic components, diodes and capacitors, we have turned a classical boost power factor corrector into a high efficiency soft-switched version. The proposed converter turns on its single switch with zero current and turns it off with zero voltage. In this paper we explain the proposed changes, we study the waveforms and equations and we verify them with an experimental prototype. We also show how the converter can be used for modular single- and three-phase high power applications.

Estudo de Técnicas de Comando de Inversores Multiníveis

Estudo Comparativo dos Inversores VSI e CSI

Brushless motors (polyphased AC induction, synchronous and brushless DC motors) have no alternatives in modern electric drives. They possess highly efficient and very wide range of speeds. The objective of this paper is to represent some... more

Brushless motors (polyphased AC induction, synchronous and brushless DC motors) have no alternatives in modern electric drives. They possess highly efficient and very wide range of speeds. The objective of this paper is to represent some relation between the basic parameters and magnitudes of electrical machines. This allows to be made a comparative analysis and a choice of motor concerning each particular case based not only on catalogue data or price for sale.