Input Power Factor Research Articles

Modulation Strategy with Minimum Switching Losses for Three-Phase Non-Isolated AC–DC Matrix Converters

This paper presents an analysis of the operational characteristics of three-phase AC–DC matrix converters, which operate as rectifiers but possess a range of additional capabilities. These include the ability to reverse the power flow, control the input power factor, and generate a multilevel output voltage. The analysis yields a modulation strategy that minimizes switching losses. The proposed modulation strategy is compared with seven well-known space vector modulation strategies in terms of efficiency and distortion of input and output current. The performance is experimentally validated.

Advanced Venturini control for PMSM with modular multilevel matrix converter

This paper provides a comprehensive analysis of control strategies for modular multilevel matrix converters (MMMC) utilizing advanced second-order sliding mode control (ASOSMC) within the context of permanent magnet synchronous motor (PMSM) applications. The research introduces a novel control framework based on the Venturini method, which, when integrated with ASOSMC, achieves a unity input power factor while generating sinusoidal phase current waveforms with markedly reduced harmonic distortion. These advancements not only enhance overall system performance but also significantly improve power quality, addressing critical requirements in contemporary electrical engineering. Additionally, the study conducts a rigorous comparative analysis between classical Proportional Integral (PI) control and ASOSMC, elucidating the substantial limitations of PI control in nonlinear environments where dynamic adaptability is paramount. In contrast, ASOSMC demonstrates superior capability in managing disturbances and nonlinearities, thereby offering enhanced reliability and efficiency for MMMC systems. The findings illustrate that ASOSMC not only addresses the challenges posed by traditional control techniques but also contributes to the development of more robust control methodologies within power electronics. By establishing a clear superiority of ASOSMC over conventional methods, this research paves the way for future innovations in control strategies specifically tailored for high-performance applications that require resilience under varying operational conditions. Ultimately, this work underscores the necessity of integrating advanced control techniques to optimize the operational capabilities of modular multilevel converters, facilitating the creation of sophisticated solutions that meet the evolving demands of electrical systems and power quality enhancement in diverse applications. The implications of these findings are significant, offering foundational insights for both theoretical exploration and practical implementation in the field.

Direct Torque Control Space Vector Modulation for Induction Motor Driven by Matrix Converter

This study proposes enhancing induction motor (IM) drive systems by developing a DTC-MC with SVPWM integration to reduce ripple. DTC-MC is effective for precise torque control in AC drives, offering high control accuracy by isolating stator flux and torque. The method excels in sensor-less speed control, maintaining unity input power factor at low speeds, and constant switching frequency for rapid torque adjustments. Combining DTC-MC with SVPWM improves simplicity, dynamic behavior, and torque response. The DTC-SVM approach further refines the torque response by correcting flux and torque discrepancies. MATLAB/SIMULINK simulations validated the approach, showing a robust dynamic response and significantly reduced motor torque ripple and control of speed.

Three-Phase Single-Stage AC-DC Converter Using Series–Series Compensation Circuit in Inductive-Power-Transfer-Based Small Wind Power Generation System

In this paper, a three-phase single-stage AC-DC converter for an IPT-based small wind power generation system (WPGS) with an S-S compensation circuit is proposed. It applies a three-phase single-stage AC-DC converter to improve the input power factor (PF), efficiency, and reliability in small WPGSs. Also, inductive power transfer (IPT) was applied to compensate for brush wear in the nacelle of small and medium-sized wind turbines while ensuring electrical safety. In conditions of the three-phase Permanent Magnet Synchronous Generator (PMSG) voltage (80~260 Vrms) for the wind turbine and the load (150~1000 W), it was verified that the desired output voltage below 3% can be controlled through the fixed link voltage (VLink) control without wireless communication. A 1 kW prototype was built and tested to demonstrate its applicability to the rotation of small and medium-sized wind turbine nacelles instead of brushes and slip rings.

Design of adaptive speed controllers for matrix‐converter‐based interior permanent magnet synchronous motor drive systems

AbstractInterior permanent magnet synchronous motors (IPMSMs) which are driven by matrix converters have many advantages, including one‐stage power conversion, high efficiency, bidirectional power transfer, near unity input power factor, and low input current harmonics. However, the virtual DC‐link voltages of matrix‐converters vary from 0.866 to and the current commutations of matrix‐converters create serious three‐phase stator harmonic currents as well. Moreover, matrix‐converter‐based IPMSM drive systems, in general, have very large external loads, which require advanced control methods. To solve these problems, two adaptive controllers, including a model reference adaptive controller and a self‐tuning controller, are investigated in this article for matrix‐converter PMSM drive systems. From the experimental results, the proposed two adaptive speed controllers provide excellent dynamic responses, which are superior to PI speed controllers, including faster transient responses, better tracking abilities, and greater robustness. As a result, this proposed matrix‐converter‐based IPMSM drive system is very suitable in industrial applications.

Active power compensation circuit for resonance mitigation and harmonic reduction in microgrid system

The nature and behavior of capacitors, transformers, inductors, active compensators, and non-linear loads can produce power resonance. Unfortunately, the presence of a resonance phenomenon can have a negative impact on system stability and lead to catastrophic power system failures. Therefore, even when using modern or conventional techniques to enhance total harmonic distortion (THD) or improve input power factor (IPF), it is necessary to avoid resonance. An active power compensation circuit (APCC) is proposed and designed to function with two categories of linear/non-linear loads. The APCC has been implemented and regulated using an adjusted pulse width modulation technique. The aim of the suggested APCC is to minimize AC side distortions, improve the IPF, and mitigate harmonics resonance at the same time. The simulation results demonstrate that the proposed APCC investigates the aim function of this study by absorbing harmonics, correcting IPF, and eliminating resonance problems under both transient and steady-state operating conditions. The supply voltage and current THD values for the first power circuit type are reduced by 96.7 % and 96.3 %, respectively, at α=30°. Meanwhile, for the second power circuit, the THD is reduced by 91.92 % and 90.4 %. Also, the IPF changed for the first and second power circuits from 0.72 and 0.86 to almost unity. These results demonstrated the effective performance of the APCC circuit and controller in reducing power harmonics, eliminating power resonance, and modifying power factors.

Power factor preregulation in power supplies using modified single stage non-isolated interleaved Sepic converter with minimal part count

This paper pontificates on design and realization of low-cost single phase single stage modified interleaved Sepic (MILS) converter for power supplies. On contrary to the classical Sepic power converters, the introduced active power factor correction (APFC) converter involves simple idea of paralleling that enables low input and output ripples with minimal device count. The interleaving conceptualization also lessens current stresses and static losses. Also, this modified power processing converter reveals natural power factor correction (PFC) and zero current switching (ZCS) features by discontinuous conduction mode (DCM) operation. Furthermore, the practical corroboration of the proposed converter is built and tested for 250 W hardware model to affirm benefits with 92 % efficiency and their relevant outcomes are reported in this scope. Finally, the power quality (PQ) attributes like, input power factor (PF), total harmonic distortion (THD) over input current under stable and transient cases are disclosed to prove bettered PQ limits at the AC mains as prescribed by various IEEE-519 and IEC 61,000–3-2 standards.

Switched capacitor and coupled inductor based high power factor charger for E-2/E-3 wheelers

This paper introduces a modified Zeta converter topology designed specifically for charging low voltage electric vehicles (LVEVs), enhancing performance for electric two (E-2) and electric three (E-3) wheelers. Unlike traditional Zeta converter, which offers buck-boost gain, an AC-DC converter in this study, utilizes a switched capacitor configuration to efficiently step-down voltage in a single phase, bridging the gap between the AC grid and low potential battery assemblies. This design incorporates a coupled inductor structure and operates in discontinuous inductor current mode (DICM), reducing the size of magnetic components and overall dimensions of converter and power factor correction (PFC) rectifier. DICM operation provides intrinsic PFC and minimizes switching losses, ensuring exceptional grid-side performance with unity power factor and minimal input current harmonic distortions, while maintaining an optimal battery charging profile. The meticulously developed hardware prototype, rated at 450 W, features precise component selection and carefully designed modes of operation. Performance analysis reveals a converter peak efficiency of 94.7 %, total harmonics distortion (THD) in input current at 2.7 % under rated conditions, and near unity power factor with zero phase displacement between input voltage and current.

3-level inverter based compensator for power quality enhancement using proposed Trianguzoidal PWM technique

In today’s scenario, the integration of a grid-connected load system with a hybrid energy system (HES) is encouraged to improve the reliability of the system. With the stunning rise in nonlinear loads in HES over the last two decades, the power quality (PQ) of the system has emerged as a paramount concern in contemporary times. The power quality problems include the injection of harmonics in the source current, low input power factor, poor voltage regulation, the burden of reactive power, etc. So, to mitigate these power quality problems in a single-phase distribution system, a 3-level Cascade H-bridge (CHB) inverter-based shunt active power filter (SAPF) is employed alongside a proposed Trianguzoidal pulse width modulation (TRZ PWM) strategy. The single-phase distribution system with SAPF is simulated in fixed and dynamic load conditions to check the system’s efficacy. The proposed PWM techniques for SAPF are compared with conventional PWM techniques, i.e., level shift, phase shift, and hybrid PWM techniques. Results indicate satisfactory performance of the proposed PWM techniques, exhibiting low harmonic distortion in source current, well within IEEE 519 limits, and high active filtering efficiency (AFE) compared to conventional PWM methods. Furthermore, this paper provides detailed comparisons of conventional and proposed PWM techniques in the context of active & reactive power supplied or delivered by load, source, and compensator, input power factor, harmonics in source or grid current, AFE, and individual harmonic components concerning fundamental component of source current.

A new topology of non-isolated AC-DC quadratic boost converter with enhanced power traits

A novel AC-DC quadratic boost converter (QBC) topology is presented in this paper which can provide higher power factor (PF), lower total harmonic distortion (THD) and higher voltage when compared to a conventional AC-DC boost convertero This is achieved by using additional switched capacitor and switched inductor in the power processing stage. The presented converter is analyzed theoretically, and a voltage gain equation is derived. A simulation model is created to evaluate the converter performance under various duty cycles, switching frequency, and changing output load. The input PF, THD, and voltage gain of the simulated model were compared with conventional converter to determine the validity of the suggested converter circuit. The results show that the efficiency, PF, THD and voltage gain value reaches approximately 97.9%, 0.98, 16.14, and 2.83 respectively at a duty cycle of 50% with fixed output load of 100 Ω. A dual loop voltage and current controller is also arrayed with the proposed circuit which allows further enhancement in PF (0.997) and THD (7.45%). This converter can be a suitable option for systems where isolation is not necessary but high PF, high voltage gain and low THD are required.

Empirical Investigation of a Single-phase Input Switched AC-DC Boost Converter with Improved Power Quality

The Boost converter topology is most widely used for power factor correction (PFC) converters. The conventional passive Boost PFC converter inherently suffers from the lack of controllability and non-ideal characteristics of the diode-bridge rectifier. Replacing diodes with active switch(es) offers viable solutions but increases the circuit complexity. Addressing this trade-off, a novel design of a single–phase input switched AC to DC Boost converter has been presented in this article. The active switch of the Boost DC converter is shifted to the input side of the full-bridge diode rectifier which provides more control on the input current without increasing much of the circuit complexity. Two Boost inductors and two output split capacitors are used for providing higher step-up operation compared to the conventional. The converter has been simulated both in open-loop and closed-loop conditions using the PSIM software. The simulation results show that the proposed converter provides good dynamic response and can maintain a constant stable output voltage during sudden load change. Furthermore, to evaluate the experimental performance of the suggested converter, a prototype converter has been developed. A scaled-down experiment has been performed which shows that the converter can achieve up to 85.2 % efficiency and an input power factor of 0.9.

A Novel Series 24-Pulse Rectifier Operating in Low Harmonic State Based on Auxiliary Passive Injection at DC Side

To reduce the current harmonics on the input side of a multi-pulse rectifier, this paper proposes a low harmonic current source series multi-pulse rectifier based on an auxiliary passive injection circuit at the DC side. The rectifier only needs to add an auxiliary passive injection circuit on the DC side of the series 12-pulse rectifier, which can change its AC input voltage from 12-step waves to 24-step waves. We analyzed the working mode of the rectifier, optimized the optimal turn ratio of the injection transformer from the perspective of minimizing the total harmonic distortion (THD) value of the input voltage on the AC side, and analyzed the diode open circuit fault in the auxiliary passive injection circuit. Test verification shows that, after using the passive harmonic injection circuit, the THD value of the input voltage of the AC side of the rectifier is reduced from 14.03% to 4.86%. The THD value of the input current is reduced from 5.30% to 2.16%. The input power factor has been increased from 98.86% to 99.83%, and the power quality has been improved.

Design Recommendations Considering Charging Pads’ Self-Inductance Variation With LCC–S and LCC–LCC Compensation Based IPT Chargers in Low Clearance EVs

Inductive Power Transfer (IPT) based Electric Vehicle (EV) charging systems practically experience self-inductance variation in charging pads with air-gap, especially for low ground-clearances. Conventional design model ignores these variations, resulting in poor sizing and performance. This paper presents a comprehensive theoretical modelling and evaluation of system’s performance considering self-inductance variation for LCC-Series (LCC-S) and LCC-LCC type compensation. The work begins by examining various types of charging-pads with similar design-specifications, and finds circular-pad to exhibit least self-inductance variation. Subsequently, through extensive theoretical analysis, several contour-plots are derived, depicting variation of output voltage/current, output power, input Volt-Ampere (VA), input power-factor, and VA of compensation elements with various load and coupling-coefficient, for both the conventional and proposed models systematically. It is shown that proposed model provides accurate design recommendations over conventional model on various critical parameters, including optimal load, charging-time, dc-link voltage, maximum gain of secondary-side dc-dc converter, and VA ratings of the input and compensation elements. For example, proposed model predicts that a 7% increase in self-inductance with LCC-S type compensation (designed for 5kW) leads to 36.4% reduction in maximum output power, requiring compensatory increases in dc-bus voltage by 25.3% and input VA rating by 34.47%. The proposed model is validated experimentally.

Alternative Performance Indices-Based Control Technique for a Unity Power Factor Three-Phase Rectifier

The implementation of a unity power factor (UPF) three-phase rectifier has the potential to enhance the power factor (PF). However, the PF and total harmonic distortion (THD) experience degradation in low-output regions due to the utilization of a “critical input inductor” under rated load conditions. In this study, an analysis of the operation principle of a UPF three-phase rectifier is conducted and a reference compensation current technique based on alternative performance indices is proposed. The optimal control algorithm is utilized to calculate the single harmonic phase delay of each phase and determine the compensator gain, taking into account factors such as the single harmonic distortion limit, THD limit, PF, and active power consumption. The output of the current compensator serves as the desired current source, which in turn drives the bidirectional switches. The simulation and experimental results demonstrate that the proposed control technique can significantly mitigate power supply current distortion, and the input power factor has been effectively improved within a wider load range.

Optimization of Single-phase PWM Rectifier Performance by Using the Genetic Algorithm

This paper is dealing with single phase PWM rectifier parameter optimization. A control loop has been designed to attain a suitable output DC voltage with minimum ripple, input current with minimum harmonic and maximum input power factor. In this paper these parameters have been optimized by using Genetic algorithm. To verify the effectiveness of proposed optimization, different simulations have been done. By using MATLAB simulink the simulation results prove that the proposed system working good.

Minimisation of AC Grid Side Input Power Factor Angle for Three-phase AC to Three-phase AC Matrix Converter under Varying Load

Abstract Minimisation of AC grid side input power factor angle for a ‘matrix converter (MC)’ improves the efficiency of the grid. Input volt-ampere requirement is minimum if the current drawn by the ‘MC’ is sinusoidal and input displacement power factor (IDPF) is unity. A MC is inherently capable of maintaining a unity displacement power factor (UDPF) angle at its input terminals. However, the input currents drawn from the grid are not sinusoidal. The high-frequency ripples are suppressed by input current filters (ICFs).These filters additionally introduce a leading phase angle for the current which varies with the loading. This phase lead can be compensated by adjusting the angle between the input current space vector and the input voltage space vector of the MC. The computation of this adjustment angle depends on the estimation of power losses in the switching devices. A simple method is proposed in this paper to estimate the switching losses without measuring device voltages and currents using the perturbation technique. The perturbation logic depends on input current, instantaneous active and reactive power computed at regular intervals of time. The proposed method effectively minimises the IDPF angle very close to zero. The experimental results are included for validation,

Grid power control of direct matrix converter fed three-phase induction generator

The direct matrix converter (DMC) and the modulation technique were presented in this paper, moreover the power of the grid is controlled. Due to its high flexibility and low computation demands, the DMC's most widely used modulation technique is space vector modulation. The double-side modulation is used in this paper instead of the single-side modulation because less harmonics at the input and output side can be obtained, however this would increase slightly the number of branch-switch-overs (BSO) for each switching period. In addition to being able to create input and output sinusoidal currents with various frequencies, it would adjust the input power factor. Along with that, the simple power control loop would regulate the grid power and then generate controlled three-phase reference signals for pulses generation accordingly. Results from the simulations show that the topology is appropriate for machine drive applications.

Design and Development of an Efficient, High Power Factor, Low-Cost, RGB LED System for Tuneable Lighting Application

Branded smart red (R) – green (G) – blue (B) light emitting diode (LED) products commercially available in developing countries are too costly to afford for most of the population, especially for household applications. Locally manufactured cheaper alternatives of such products suffer from poor power factor and reduced circuit efficiency. To address these technical issues, a smart RGB LED system is presented here which offers high input power factor, good circuit efficiency, and at the same time lower fabrication cost and user-friendly control interface. The unique features of the proposed system are the front-end AC/DC converter is a constant-voltage, multiple-output flyback converter that mitigates the need of multiple drivers and inductors. The second is that the same converter is operated in discontinuous conduction mode to achieve a high input power factor. The third is that for dimming and colour tuning, pulse width modulation (PWM) control of the MOSFET switches is accomplished by an Arduino Mega 2560 microcontroller instead of other costlier and more sophisticated options. And the fourth is that the microcontroller gets its command signal from a smartphone or computer through an HC‑05 Bluetooth module. Through laboratory testing, it is confirmed that the LED system offers close-to-unity input power factor (0.928–0.985) and high efficiency of (88.14–95.46) % for a wide range of colour and luminous intensity. A comparative study reveals that the developed system is a better option than the earlier reported prototypes of multicolour LED systems in terms of the bill of material, economy, power factor, and efficiency.

A non-inverting single-switch buck-boost converter based LED driver

<span lang="EN-US">This paper focuses on a single-switch buck-boost (SSBB) converter for light emitting diode (LED) lighting applications. The proposed LED driver with power factor correction (PFC) shows enhanced performance in terms of input power factor, efficiency and reduced voltage stress across the switch. The presented LED driver is operated in discontinuous conduction mode (DCM). The input PFC is carried out using average current mode control (ACMC) and the controller is optimized using artificial bee colony (ABC) algorithm. A hardware prototype of 50W LED driver with ACMC for PFC is implemented using a programmable interface circuit (PIC) microcontroller. The experimental results are presented and the performance is compared with a conventional buck boost LED driver. The proposed SSBB LED driver achieves an input power factor of 0.96 with an efficiency of 98%.</span>

Parametric study on the flight envelope of a radio-frequency ion thruster based atmosphere-breathing electric propulsion system

The atmosphere-breathing electric propulsion (ABEP) system utilizes atmospheric species as propellants to generate thrust for drag compensation of a satellite in very-low-Earth-orbit (VLEO). A parametric approach is used to assess the impact of different parameters on the flight envelope of a sample VLEO satellite with an ABEP system based on a radio-frequency ion thruster (RIT). The considered parameters include capture efficiency, maximum input power, solar activity, and atomic oxygen recombination factor. The NRLMSIS 2.0 atmosphere model is used to determine the flow conditions at VLEO, at a target altitude of 150–300 km with high, moderate, and low solar activity levels. DSMC method is employed to calculate the drag of the sample satellite with the ABEP system. The 0-D model of the RIT discharge chamber is used to predict the thrust of the RIT-based ABEP system. The flight envelope of a sample RIT-based ABEP system shows that drag can be compensated at altitudes between 196 km and 248 km. Increasing capture efficiency and maximum input power expands the feasible range for drag compensation to higher and lower altitudes, respectively. Also, the flight envelope shifts to higher altitudes with increasing solar activity levels. However, the atomic oxygen recombination factor of the intake device has minimal effects on the flight envelope.