Three-phase Power Factor Correction Research Articles

Research on Step-Down Aviation Three-Phase Power Factor Correction based on Machine Learning and Optimization Algorithm

Objectives: The study looks at power quality issues, such as phase imbalance, voltage sags, and power factor issues, in aircraft systems. It highlights how immediate power factor correction steps are required to avoid equipment longevity problems and boost system efficiency, which will ultimately improve the performance of the entire aviation system. Methodology: Using a variety of data sources, real-time data gathering, and machine learning approaches, this study focuses on data collecting and real-time monitoring in aviation systems. Predictive modeling, testing methods for data preparation and analysis, and optimization algorithms for capacitor bank size and placement are all included. Considerations for privacy and security are covered. Result: Salp Swarm Optimization and the Dragonfly Algorithm are used in the study to assess the ideal capacitor sizes and positions, which results in better voltage profiles and lower active power losses. Aviation systems benefit from improved power factor correction through the application of integrated machine learning and optimization, which promotes sustainability and energy efficiency. Conclusion: The study demonstrated the significance of power factor correction in aviation by successfully addressing power quality issues in aircraft electrical systems through the use of optimization algorithms for capacitor sizing and location.

A Cryogenically-cooled Three-phase Power Factor Corrector for Advanced Aircraft Power Supply Systems

A Cryogenically-cooled Three-phase Power Factor Corrector for Advanced Aircraft Power Supply Systems

A Three-Phase Single-Stage ac/dc Converter Based on Swiss Rectifier and Three-Level LLC Topology

<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> resonant converter is widely used due to its soft switching, high power density, and high efficiency. To incorporate the merits of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> resonant tank into a three-phase single-stage ac/dc converter, this article proposes a three-phase single-stage ac/dc converter based on Swiss rectifier and three-level <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> topology. It takes advantage of the high-efficiency Swiss rectifier to convert three-phase ac voltages into three variable dc voltages and interface a three-level <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> resonant circuit. With help of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> resonant tank, all the high-frequency three-level switches achieve soft switching. To both regulate the output voltage and achieve three-phase power factor correction, the frequency modulation in combination with the duty cycle control strategy is employed by splitting the resonant current into three parts and then forming three phase sinusoidal currents. The proposed converter's detailed operation principles, steady-state characteristics, and design considerations are given. Finally, a 10 kW experimental prototype with three-phase 220 Vac inputs and 500 Vdc output is built to verify the effectiveness and feasibility of the proposed topology and its control strategy.

Third-Harmonic-Type Modulation Minimizing the DC-Link Energy Storage Requirement of Isolated Phase-Modular Three-Phase PFC Rectifier Systems

A three-phase ac/dc converter with high-frequency isolation can be realized as a monolithic three-phase or as a phase-modular system by combining three single-phase Power Factor Correction (PFC) rectifier modules with individual isolated dc-dc converters. Advantageously, for a phase-modular system the module configuration can be changed depending on the instantaneous input-output voltage ratio (i.e., a star-(Y)- or a delta-(Δ)-arrangement such that wide voltage ranges can be covered without a massive over-dimensioning of the main power components. However, the main disadvantage of a phase-modular converter realization is the fact that the input power of each PFC rectifier module pulsates at twice the mains frequency (which is inherent to single-phase power conversion) such that large dc-link capacitors are required. Recent literature predicts a substantial power pulsation reduction enabled by means of third-(3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> )-harmonic injection modulation which is applicable for the Y-connection (where a common-mode (CM) / zero-sequence (ZS) voltage is injected), and for the Δ-connection of the three single-phase PFC rectifier modules (where a CM / ZS current is injected). This changes the distribution of the power flow in the three-phase system and the power pulsation is shifted to higher frequencies. This paper experimentally verifies and extends the dc-link energy storage requirement reduction of the 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> -harmonic injection modulation concept: In a first step, the derivation of the harmonic injection concept is recapitulated and suitable control methods are discussed for both CM voltage (Y-arrangement) and CM current (Δ-arrangement) injection. Further, an alternative CM voltage injection strategy with simplified reference generation based only on the instantaneous grid voltage measurements is presented and compared to the pure 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> -harmonic injection modulation. Measurement results obtained from a 6 kW prototype reveal a dc-link voltage variation and/or energy buffering reduction by up to 38.6 % enabled by the harmonic injection modulation compared to conventional operation without 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> -harmonic injection modulation.

Design and Analysis of Novel Three-Phase PFC for IM Drives

Induction motor drives (IMDs) can achieve high performance levels comparable to dc motor drives. A major problem in getting high dynamic performance in an IMD is the coupling between the flux and torque producing components of stator current. This is successfully overcome in FOC (Field-Oriented Control) IM, making it to the industry standard control. The performance of an IMD with an improved power quality converter at the front end is presented in this study. In the IMD, boost converter is employed to reduce power quality difficulties at the utility interface. As the boost converter contains only one switch, it results in a low processing time and cost. To ensure sinusoidal supply currents with high PF (Power Factor) and minimal THD (Total Harmonic Distortion), a novel PFC (Power Factor Corrector) control technique is proposed. To enhance the performance of the converter and to lower distortions at the motor side, PI (Proportional Integral) controller is incorporated at the PFC side. Thus it controls the DC bus voltage. The proposed boost converter improves power quality by lowering overall harmonic distortion of AC mains current, improving power factor correction, and regulating dc-link voltage. It is designed, modelled, and simulated in the MATLAB/simulink platform. Using a DSP (Digital Signal Processor), the suggested system’s performance is experimentally validated. The system’s performance is evaluated for speed and load torque, and the power quality indices are determined to meet IEEE-519 standards under all operating conditions. From the obtained results, it is evident that the proposed system mitigates the power quality issues effectively.

Magnetic Components Reduction in a Three-Phase PFC Converter by Using a Reconfigurable LCL Filter

Three-phase power factor correction (PFC) converters are the front-end stage of the power conversion that are required to be connected to the grid with a proper filter to meet international standards. A high-order <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCL</i> filter is a widely used solution to reduce the component size of the filter although it requires six inductors. In this article, a novel reconfigurable <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCL</i> filter that consists of only three inductors is proposed. The principle of the reconfigurable filter is to fully utilize the converter-side inductors by changing their position from the converter side to the grid side and vice versa. The filter is reconfigured by using three low-frequency (LF) bidirectional switches. The ultimate goal of the proposed topology is to reduce the magnetic components by half and achieve comparable grid current quality as the conventional topology. The proposed PFC topology is verified by a 1-kW experimental prototype. All the experimental results agree with the theoretical concepts and prove that the grid current quality of the proposed topology is comparable with the conventional topology.

Parameter design and control of a novel three-phase single-switch power factor correction (PFC) circuit

Three-phase single-switch power factor correction (PFC) circuit has the advantages of simple structure and convenient control, and its current source characteristics is conducive to achieve higher power by parallel interleaving. But theoretical analysis of the circuit was complex and the design theory was not established yet. To solve these problems, a parameters design method based on volt-second balance of the input inductance is proposed. By this method, the key component parameters of a 7.6 kW experimental prototype are designed. At the same time, A constant on-time control method of this circuit based on MATLAB simulation is designed, which can be applied to various converters with constant on-time control. The parameters and control design method of the single-switch PFC circuit are simulated based on the MATLAB. A prototype is built and tested also, the test results verify the correctness of the parameter design theory and constant on-time control simulation method.

An Improved Swiss Rectifier and Its Nonlinear Control for Lower THD

Three-phase power factor correction (PFC) converters capable of step-down voltage are attractive in lower components voltage stress, and optimal design of following dcdc stage, which is an alternative for next-generation datacenter power conversion. An improved three-phase step-down PFC converter (swiss rectifier) based on harmonic-current-injection (HCI) concept is proposed. It improves input current quality by eliminating switching dead zone of HCI network and avoids short circuit fault from hardware level. According to one-cycle control (OCC), a novel nonlinear control strategy (termed as closed-loop OCC) is presented, which reduces the impact of dc inductor current ripple on input current. The principles of the improved swiss rectifier and closed-loop OCC are analyzed in detail, verified by simulation and on an 80 kHz, 300 V/2 kW prototype with digital controller. At rated condition, input current THD &lt; 2%.

Research on Single-Phase and Three-Phase Compatible Isolated On-Board Charger and Control Technology

This paper presents a single-phase and three-phase compatible isolated on-board charger for electric vehicles. The charger is compatible with the single-phase and three-phase AC voltage input and is composed of two-stage circuits. Based on the three-phase six-switch power factor correction (PFC) circuit, by switching on and off, the front stage is transformed into a cascade topology of a totem-pole PFC circuit and boost circuit. The rear stage is a full-bridge LLC resonant converter. In the single-phase or three-phase working mode, the front-stage control strategy is a double closed-loop control. The current inner loop controller is improved for the three-phase six-switch PFC circuit. The PI controller and repetitive controller are connected in parallel to form the current inner loop compound controller, which can effectively reduce the total harmonic distortion of the input current. By using simulation software MATLAB/Simulink, the circuit model was built. The simulation results verify the correctness of the theoretical analysis.

A High-Efficiency High-Power-Density SiC-Based Portable Charger for Electric Vehicles

This paper proposes a portable 11 kW off-board charger for electric vehicles. In the ac/dc stage, a three-phase power factor correction (PFC) in Vienna topology is chosen. The loss and volume of the PFC inductance are calculated over a wide range of parameters and optimized with regard to design, winding, and core material. A three-phase LLC resonant converter operating at 1 MHz is chosen for the galvanically isolated dc/dc stage. A parametrizable loss model of the high-frequency transformer and the resonance inductor is developed to minimize volume, weight, and losses. With the help of an automated algorithm using these loss models, the inductive components are optimized in terms of winding specification, magnetic material, and core geometry, verified by finite element analysis and measurements. For the ac/dc stage, 900 V SiC devices are adopted, and 1200 V SiC devices are used in the primary and secondary sides of the dc/dc stage. A variable dc-link voltage is utilized to adjust the charging profile and to operate the LLC resonant converter at the most efficient point near the series resonance frequency. A mechatronically integrated portable air-cooled off-board charger prototype with 11 kW, three-phase 400 VAC input, and 620–850 VDC output is realized and tested. The prototype demonstrates a power density of 2.3 kW/liter (37.7 W/in³), a peak efficiency of 96%, and 95.8% efficiency over the defined battery voltage range.

A Review of Three Phase AC-DC Power Factor Correction Converters for Electric Vehicle Fast Charging

Electric vehicle charging station for fast DC charging performs AC-DC conversion at off-board. In recent years, three-phase AC-DC power factor correction (PFC) converters are dealt with fast charger. These converters are developed using unidirectional and bidirectional power flow structure. In this study, three-phase AC-DC PFC converter topologies, providing bidirectional power flow, are evaluated in terms of performance. The aim is to present the latest technology of bidirectional multilevel AC-DC PFC converters for EV fast charging. This paper provides a comprehensive and practical review for researchers interested in fast charging infrastructure for electric vehicles.

A novel filter for three-phase power factor correction voltage feedback loop under heavy DC voltage ripple condition

THD and the amplitude balance of three-phase input current are an important index for the performance of three-phase power factor correction (PFC). In general, when the hardware and the load of three-phase PFC are confirmed, the THD and amplitude balance of three-phase input current mainly depend on voltage and current feedback loop of PFC. Firstly, this paper designs the traditional voltage and current feedback loop for three-phase PFC according to traditional small signal theory. Secondly, this paper studies the designing difficulty of large dc voltage ripple for PFC voltage controller and puts forward a new dc voltage ripple filter which can eliminate the ac component of sampling dc bus voltage. Finally, this paper proposes a novel filter with dc voltage ripple frequency adaption function to copy with the frequency variety of the voltage ripple caused by the change of the output inverter frequency. With the help of the proposed algorithm the distortion of three-phase 3 input current reference decreases rapidly, therefore, the low THD and good amplitude balance of three phase input current will be achieved.

Analysis and Design of Interleaved DCM Buck–Boost Derived Three-Phase PFC Converter for MEA

In more-electric aircraft (MEA), the synchronous generators are connected directly to the turbo engine to develop a constant-voltage variable-frequency (CVVF) ac supply bus. In addition, the MEA has adopted a high-voltage dc bus in its power system to cater to the various categories of load used by aircraft. Therefore, this change in power paradigm has created a requirement for ac-dc power factor correction (PFC) converters to convert CVVF ac to constant dc with high power quality in a reliable manner. In this article, a three-phase interleaved buck-boost-derived PFC converter is operated in discontinuous current conduction mode to realize the inherent unity power factor (UPF) operation for MEA wide range of supply frequency. The benefits of the proposed converter are higher power density, efficiency, and reliability. The advantages of the proposed converter are demonstrated by performing an analytical comparison with the single-cell three-phase buck-boost derived PFC converter and presented the relevant results. The experimental results from a 2.0-kW laboratory concept-proof hardware prototype have been provided to confirm the proposed converter UPF operation for a wide range of supply frequencies. A low input power factor of 0.9996 and a minimum current THD of 2.52% are recorded from the developed prototype.

Исследование влияния параметров системы управления на качество входного тока трехфазного корректора мощности

The paper suggests a control system of a three-phase power factor corrector. The study of the control system operation is carried out and the expressions for calculating the permissible values of error amplifier factors are obtained. The influence of the error amplifier parameters on phase current quality is investigated. The dependence of total harmonic distortion input current on a combination of error amplifier parameters is obtained at a given value of power factor. The conditions under which the total harmonic distortion input current has the minimum value are found out. This article is of interest to power electronics engineers, who are aimed at developing a three-phase power factor corrector.

Performance Improvement of Three-Phase Boost Power Factor Correction Rectifier Through Combined Parameters Optimization of Proportional-Integral and Repetitive Controller

This paper performs parameter optimization of proportional-integral (PI) and repetitive controller (RC) with a new objective function by adding two degrees of freedom for a three-phase boost power factor correction (PFC) rectifier. The main objectives are to optimize the multiple control loop parameters for total harmonics distortion (THD) reduction and dynamic performance indices improvement, including overshoot, rise time, and zero steady-state error. The control parameters of the three-phase boost PFC rectifier are optimized through a standard genetic algorithm. After obtaining the optimal PI and RC parameters values, fast Fourier transform and dynamic response analysis were performed using MATLAB. Moreover, separate evaluation functions are used to validate the optimal results in terms of THD reduction and dynamic performance indices improvement. Furthermore, the results are compared with the existing objective functions to show the proposed objective function superiority. Simulation results demonstrated that our proposed objective function outperforms existing objective functions to achieve optimal PI and RC parameters value. Finally, simulation results are validated through experimental results. The experimental setup includes a 5kW three-phase PFC rectifier with DSP TMS320F28335 prototype hardware to verify controller parameter performance.

Three-phase SEPIC PFC for three-phase IM drive under unbalanced and distorted voltage supply

This paper proposes a three-phase power factor correction (PFC) for a three-phase induction motor (IM) drive under normal and abnormal supply voltage conditions. A new technique of PFC based on a positive sequence components method is introduced. The PFC circuit uses a SEPIC converter with a single switch, which needs only one control signal. The PFC control method with the proposed technique provides nearly sinusoidal supply currents maintaining a high power factor under different supply voltage conditions. Furthermore, the PFC method maintains DC bus voltage at the desired value. The regulated DC voltage feeds a four-switch inverter of the three-phase IM drive system. Mathematical analysis of the equivalent circuits based on operation modes of the SEPIC converter is introduced. The performance of the proposed technique is evaluated under ideal and non-ideal supply voltage conditions. The results are analyzed in terms of reduction in the THD of supply currents and improvement of power factor. System validation performed in simulation and experiment has shown the effectiveness of the proposed system under different supply voltage conditions.

Design and Implementation of Four-Switch Current Sensorless Control for Three-Phase PFC Converter

Four-switch current sensorless control for three-phase four-switch converter with power factor correction (PFC) function is presented in this letter. In comparison with conventional multiloop control methods, the proposed control strategy requires sensing of two line voltages and two capacitor voltages only to achieve PFC function. As there is no sensing current, the proposed sensorless control scheme reduces the cost and complexity of design. The performance of the proposed control is validated by its implementation in digital signal processing (DSP) TMS320F28335, and the result shows that the proposed scheme is able to provide comparable PFC performance without sensing current.

An Interleaved Three-Phase PWM Single-Stage Resonant Rectifier With High-Frequency Isolation

This article proposes a novel interleaved three-phase pulsewidth modulation (PWM) single-stage resonant ac–dc converter with high-frequency isolation. The proposed converter comes from an interleaved three-phase power factor correction (PFC) semistage and a three-phase LLC resonant dc–dc semistage. Soft-switching commutation can be achieved on the power switches in this converter including zero-voltage-switching- on on the primary side power switches and zero-current-switching- off on the secondary diodes. The LLC resonant tank in the dc–dc semistage serves as a bandpass filter that attenuates the line-frequency ripple and keeps the switching frequency component passing through the transformer. The high frequency transformer keeps in a small size. Steady-state analysis of the resonant dc–dc semistage for PWM control is proposed to analyze the dc-link voltage stress. Moreover, the dc-link capacitor value can be greatly reduced without affecting the PFC operation. A prototype that converts a wide three-phase input voltage to 300 V dc output voltage is built and tested. The experimental results present an almost unity power factor with a conversion efficiency as high as 96.3% with total harmonic distortion as low as 3.86% at a full-load condition.

Three-Phase Buck–Boost Derived PFC Converter for More Electric Aircraft

In more electric aircraft (MEA), three-phase power factor correction (PFC) rectifiers of several kilowatts are required. In this paper, a three-phase buck–boost derived PFC converter with three switches and with input inductors connected in delta configuration for use in MEA is presented. The proposed converter is operated in a discontinuous conduction mode to achieve PFC at ac input. This avoids the inner current control loop which further eliminates the current sensors. It requires only one output voltage sensor unlike five sensors in conventional PFC converter for its control implementation. This makes the system cost effective, more reliable, and robust. A simple voltage control loop is used to generate the gate signals. The steady state operation of the converter and detailed design calculations are presented. For each power component, the analytical expressions for calculating the average and rms current ratings are derived to facilitate the converter design. The small-signal model of the converter is presented to aid the controller design. The experimental results from a 2 kW laboratory prototype are presented to confirm the operation of the proposed converter. An input power factor of 0.999, an input current total harmonic distortion of as low as 2.76%, and a high conversion efficiency of 96% are achieved from the prototype.

99% Efficient Isolated Three-Phase Matrix-Type DAB Buck–Boost PFC Rectifier

Three-phase power factor correction rectifiers are an essential area of power electronics, supplying a direct current load with tens of kilowatts, or more, from the public three-phase mains and achieving sinusoidal input currents. In many applications, isolation is required between the mains and the load, for example, due to safety reasons or different grounding schemes. This paper describes the modulation, design, and realization of a buck–boost-type, unity-power-factor, isolated matrix-type, dual-active-bridge, three-phase rectifier. It uses a circuit similar to a conventional dual-active-bridge converter, but employs a direct matrix converter to connect the high-frequency transformer's primary winding to the mains. A soft-switching modulation scheme is proposed and comprehensively analyzed, deriving closed-form solutions and numerical optimization problems to calculate switching times that achieve minimal conduction losses. Based on this analysis, the design of an 8-kW 400-V rms three-phase ac to 400-V dc prototype is discussed, striving for the highest possible efficiency. Using 900-V SiC mosfet s and a transformer with an integrated inductor, a power density of ${\text{4}}\; {\text{kW}\cdot \text{dm}^{-3}}$ ( ${\text{66}}\; {\text{W}\cdot \text{in}^{-3}}$ ) is achieved. Measurement results confirm an ultrahigh full-power efficiency of 99.0% at nominal operating conditions and 98.7% at 10% lower input voltage.