Three-phase Rectifier Research Articles

Development and Performance Evaluation of Integrated Hybrid Power Module for Three-Phase Servo Motor Applications.

This study aims to develop a 30 kHz/12 kW silicon carbide (SiC)/Si integrated hybrid power module (iHPM) for variable frequency drive applications, particularly industrial servo motor control, and, additionally, to theoretically and experimentally assess its dynamic characteristics and efficiency during operation. This iHPM integrates a brake circuit, a three-phase Si rectifier, and a three-phase SiC inverter within a single package to achieve a minimal current path. A space-vector pulse width modulation (SVPWM) scheme is used to control the inverter power switches. In order to reduce parasitic inductance and power loss, an inductance cancellation design is implemented in the Si rectifier and SiC inverter. The switching transients and their parasitic effects during a three-phase operation are assessed through an electromagnetic-circuit co-simulation model, by which the power loss and efficiency of the iHPM are estimated. The modeled parasitic inductance of the inverter is validated through inductance measurement, and the effectiveness of the simulated results in terms of switching transients and efficiency is verified using the experimental results of the double pulse test and open-loop inverter operation, respectively. In addition, the power loss and efficiency of the SiC MOSFET inverter are experimentally compared against those of a commercial Si IGBT inverter.

Fault-Tolerant Self-Tuning Control for Three-Phase Three-Level T-Type Rectifier

This paper proposes a sensorless self-tuning control algorithm for a three-phase T-type rectifier. The proposed sensorless algorithm consists of three layers including an observer, which estimates grid voltages or currents based on the Kalman filter algorithm (KFA), an online estimator, which estimates the state-space matrix parameters, and a linear quadratic tracker (LQT), which is the main controller in this study. On the other hand, the performance of the LQT depends on the gains that need to be adjusted according to the system parameters, which is a challenge. To overcome this problem, a self-tuning method based on recursive least square algorithm (RLSA) is also proposed to tune the gains of LQT online. An experimental prototype is established, and the results, including the steady-state and dynamic performances, are carried out and presented to validate the effectiveness of the proposed controller.

An Integrated Three-Phase AC–DC Wireless-Power-Transfer Converter With Active Power Factor Correction Using Three Transmitter Coils

Three-phase AC-DC converters are more commonly used for high-power applications compared to single-phase converters. For high-power wireless power transfer (WPT) applications, such as wireless electric vehicle chargers, usually a two-stage topology is applied, which consists of a three-phase AC-DC rectifier with power factor correction and a DC-DC converter for WPT. Recently, there are several studies on three-phase single-stage WPT solutions being proposed to reduce power conversion stages, and furtherly increase overall efficiency and reduce system cost. In this paper, an integrated three-phase AC-DC WPT converter topology with active power factor correction is proposed. The count of power semiconductor devices is significantly reduced compared to state-of-the-art three-phase single-stage topologies. Moreover, three transmitter coils are used to enhance the system power capacity. Topology description, operation analysis, control method, power loss analysis, and reference design guideline of the proposed topology are presented in detail. Finally, a laboratory prototype is built and evaluated. The functionalities, performances, and advantages are demonstrated by the corresponding experimental results.

Three-phase Voltage Imbalance Protection System

Voltage imbalance condition often causes issues in the operation of three-phase electrical equipment. It results in overheating, improper operation, or performance-related issues. The system proposed here was developed to protect the three-phase rectifier used in a DC Machines lab with 30kW capacity from the voltage imbalance. It was developed as a simple and low-cost system that can effectively satisfy the intention. It continuously compares the supply voltage levels using voltage sensors and stops the power supply if there is a significant difference in the phase voltage levels. It will display the phase voltage levels in the liquid crystal display and also will give an alert using the buzzer. This system was successfully implemented and tested and can be used to protect other three-phase equipment as well.

Parallel Distributed Compensation for Three-Phase pulse width modulation converter

In applications such as industrial drive systems and power supply systems, the use of a three-phase voltage-source Rectifier pulse width modulation converter is becoming increasingly common. Examples of these types of applications include: Power Factor Corrections and the reduction of harmonics. The critical control requirements of an application involving a three-phase voltage-source Rectifier pulse width modulation converter are to achieve a unity power factor and to regulate the dc voltage. The unity power factor guarantees the highest possible efficiency, while the dc voltage regulation guarantees that the converter will operate as desired. In this study, a novel control method for stabilizing a Rectifier-Inverter pulse width modulation converter is designed and simulated to reach higher levels of stability while also improving dynamic performances. In the first step, the nonlinear equation system of the converter is transformed into a polytopic form. This is done with the help of the sector nonlinearity transformation. After that, a Takagi-Sugeno fuzzy controller that uses the parallel distributed compensation operating concept is applied. The design of the control system takes into account practical control requirements, such as a fast voltage tracking strategy and line-currents regulation. In order to obtain the controller gain, a series of linear matrix inequalities must be resolved. Simulations performed using Matlab/Simulink make it abundantly evident that the proposed method possesses excellent performance in terms of both voltage tracking control and unity power factor regulation.

Optimization Design of Voltage Stabilization Based on Three-Phase Rectification, APF and PWM Technology and Its Application in Grid-connected Transmission

Aiming at the problems of voltage fluctuation and harmonics in photovoltaic grid connection, the improvement of a three-phase rectifier circuit is proposed, and the results are verified by MATLAB simulation. At the same time, this paper also puts forward the application of a three-phase four-wire three-level parallel APF structure and Three-term rectifier PWM rectification technology. By compensating harmonic current generated by APF and controlling the switching state of the inverter by PWM, the bidirectional flow of electric energy can be realized, and the harm of harmonic and voltage fluctuation of photovoltaic grid connection can be solved.

DIODE EXCITERS OF A BRUSHLESS MEDIUM POWER SYNCHRONOUS GENERATOR

The aim of the work is a comparative analysis of the parameters of the diode exciter of a brushless synchronous generator of medium power on the number of pole pairs of an auxiliary electric machine, the development of recommendations for choosing the number of pole pairs of an auxiliary electric machine and the design of the exciter.
 An improvement of the automated method of electromagnetic calculation of the exciter of a brushless synchronous machine has been carried out. The diode exciters of a brushless synchronous generator with a power of 250 kW with the number of pole pairs p = 2 based on a three-phase bridge rectifier and an auxiliary electric machine of a synchronous type with different numbers of pole pairs are compared. At the first stage, a preliminary electromagnetic calculation of the auxiliary electric machine is performed, taking into account the initial value of the relative magnitude of the resulting electromotive force, the allowable values ​​of inductions in all sections of the magnetic circuit in in forced mode, the length of the magnetic circuit and the rotor winding support are determined. According to the results of the calculation of the rectifier model in the quasi-steel mode of operation, the relative value of the resulting electromotive force of the auxiliary electric machine is specified. 
 At the first stage, a preliminary electromagnetic calculation of the auxiliary electric machine is performed, taking into account the initial value of the relative magnitude of the resulting electromotive force, the allowable values ​​of inductions in all sections of the magnetic circuit in in forced mode, the length of the magnetic circuit and the rotor winding support are determined. According to the results of the calculation of the rectifier model in the quasi-steel mode of operation, the relative value of the resulting electromotive force of the auxiliary electric machine is specified pB = 4.

Designing a Multi-Output Power Supply for Multi-Electrode Arc Welding

Multi-output power converters using different architectures can have significant efficiency advantages. This paper proposes a multi-output welding power supply that is based on the middle DC converter distributed architecture. This machine includes two converter groups, and each group comprises a three-phase rectifier unit, a full-bridge converter unit, a HF (high frequency) transformer, a rectifier unit, and a chopper converter unit. Among these units, the three-phase rectifier unit, full-bridge converter unit, HF transformer, and rectifier unit convert three-phase AC voltage into a low voltage, and the chopper converter unit converts the low voltage into the required current. The welding power supply can output four DC and two AC currents. This paper also analyzes the stability of the welding power supply. Finally, a prototype is designed and verified through experiments, and the maximum output of the prototype is 300 A. The experimental results show that the converter can output different DC and AC currents according to the requirement, the multiple outputs are independent of the others, and the output phase and value are independently adjustable. After verification, the proposed multi-output welding power supply can output steady current according to the requirement.

Switching Loss Reduction Method for Instantaneous Reactive Power Compensator in Three-Phase Rectifier System

This article discusses a switching loss reduction method for an instantaneous reactive power compensator (IRPC) of a rectifier system that consists of a three-phase synchronous rectifier and a buck converter. The compensator generates a compensating current to suppress the instantaneous reactive power produced by the rectifier, resulting in a sinusoidal three-phase grid current. Zero-voltage switching (ZVS) and discontinuous pulsewidth modulation are used to reduce the switching power loss caused by the high peak of the compensating current in the compensator. A new dead-time compensation method is developed based on switching current estimation to reduce the harmonic distortion of the grid current. A 4.5-kW experimental setup was used to verify the effectiveness of the proposed methods. These methods are found to improve the grid current with a total harmonic distortion (THD) of around 3% and a peak efficiency of 99.2%.

Применение изделий полупроводниковой электроники в экстремальных условиях

A study of the thermal properties of materials used in semiconductor electronics has been carried out. The dependence of the thermal resistance of GaAs diodes on the temperature increase of the product body is determined. They are determined taking into account the design solutions of the housing design of the REA, which can protect components from extreme, difficult conditions, but they increase the weight and complexity of the system. Materials such as SiC, GaAs, GaN, diamond that can withstand extreme conditions may have advantages that go far beyond their electronic characteristics. An example of the application of GaAs-based diode modules of p-i-n diodes developed by JSC "VZPP-S" is given - a three-phase bridge rectifier made according to the Larionov scheme for an electric generator with a power of up to 2750 watts. A methodology for conducting reliability tests has been developed. Short-term tests for the reliability of diode modules at extreme housing temperatures were carried out. The results of the calculation of the thermal resistance of the junction-housing are presented. To simplify the calculation of the thermal resistance of the junction-housing of the developed module, we will make the following assumptions: the materials used in the design of the module diodes have isotropic thermal conductivity; heat exchange in the internal parts of the structure is carried out only by thermal conductivity; there are no contact resistances between the layers; the power dissipated by the terminals of the diode crystals is negligible compared with the power discharged through the lower base into the heat sink; the side surfaces of the thermal model are insulated; each layer of the same material is homogeneous and has a thermal conductivity coefficient determined by the average temperature of the layer; the influence of the thermal effect of neighboring crystals of the module is not taken into account. The algorithm of stationary thermal regime (method of equivalents) of Appendix N OST 11 0944-96 is chosen as the basis of calculation.

Wind SRG-Based Bipolar DC Microgrid with Grid-Connected and Plug-In Energy Supporting Functions

Although a switched reluctance generator (SRG) is not the mainstream wind generator, it possesses the application potential and is worth developing for its many structural merits and high developed power ability. This paper presents a wind SRG-based bipolar DC microgrid having grid-connected and plug-in energy supporting functions. First, a surface-mounted permanent magnet synchronous motor (SPMSM)-driven wind turbine emulator (WTE) is established. Next, the wind SRG with an asymmetric bridge converter is developed. Good generating characteristics are obtained through proper designs of power circuit, commutation mechanism, external excitation source, voltage and current controllers. Third, a DC/DC boost interface converter and a bipolar voltage balancer are constructed to establish the 500 V microgrid bipolar DC-bus. To preserve the microgrid power supplying quality, a battery energy storage system (BESS) with bidirectional DC/DC interface converter is equipped. A dump load leg is added across the bus to limit the DC-bus voltage under energy surplus condition. In load side, a three-phase bidirectional load inverter is developed, which can be operated as a single-phase three-wire (1P3W) inverter or a three-phase three-wire (3P3W) inverter. Good sinusoidal voltage waveform and regulation characteristics are obtained using the proportional-resonant (PR) control. The microgrid to load and microgrid to grid operations are conductible. Finally, to further improve the powering reliability of microgrid, a three-phase T-type Vienna switch-mode rectifier (SMR) based plug-in energy supporting scheme is developed. When the microgrid energy shortage occurs, the possible harvested energy can be used to supply the microgrid.

Prescribed Performance Control-Based Semi-Active Vibration Controller for Seat Suspension Equipped with an Electromagnetic Damper

Seat suspension plays a vital role in improving riding comfort and protecting drivers’ health. This paper develops semi-active seat suspension that equips a controllable electromagnetic damper (EMD) and proposes a prescribed performance control-based semi-active vibration controller with experimental validation. The semi-active EMD mainly consists of a permanent magnet synchronous motor, a ball screw, a three-phase rectifier, and a controllable external resistor, which can vary its damping from 90 to 800 N·s/m by tuning the controllable external resistor in real-time. The EMD is applied to seat suspension, and a semi-active controller is proposed for the EMD seat suspension. In order to control the seat suspension vibration, a prescribed performance method is applied to obtain a desired control force and then a force-tracking strategy is designed to make the EMD track the desired control force. Finally, the semi-active seat suspension with the proposed controller is tested in experiments with different vibration conditions. The semi-active seat suspension performs excellently for the bump, sine wave and random vibration. The root mean square (RMS) acceleration, the frequency-weighted RMS acceleration and the acceleration’s fourth power vibration dose value were reduced by 17.5%, 39.9%, and 25.4%, respectively, in the random vibration, compared with a passive system.

Sliding mode approach for control and observation of a three phase AC-DC pulse-width modulation rectifier

Introduction. For AC-DC conversion systems, the electrical systems typically use thyristor or diode bridge rectifiers, which have relatively poor performance. Nowadays, three-phase pulse-width modulation rectifiers are widely applied in various applications for their well-known intrinsic benefits, such as adjustable DC link voltage, unity power factor, bidirectional power flow and very low total harmonic distortion. Purpose. The objective of this work is to achieve better stability and dynamic performance using sliding mode strategy for control and observation. Methods. For that purpose, first a sliding mode controller is introduced on the DC-link side to ensure a fast and accurate response of the output load voltage. Then, the sliding mode approach is employed to control the quadrature and direct components of power to maintain the input power factor at unity. Finally, this approach is used to design two observers for grid voltage estimation and online variation of load resistance. To overcome the problem associated with the use of the classical low-pass filter, an adaptive compensation algorithm is used to compensate the attenuation of the amplitude and phase delay of the observed grid voltages. This algorithm is based on the use of the two low-pass filters in cascade and ensures the minimization of chattering. Results. Comparative studies have been carried out between sliding mode control method for controlling the three-phase AC-DC pulse-width modulation rectifier and other conventional techniques. The validation by simulation and the tests carried out gave very satisfactory results and proved the effectiveness and feasibility of the sliding mode for both control and observation of three phase pulse-width modulation rectifier.

Mitigation of Total Harmonic Distortion and Power Factor Improvement Based PVSTATCOM

The increasing use of power-electronics equipment has led to various power quality problems, including current wave distortion . Also, renewable energies (solar and wind energy ) are increasingly used to supply part of the electrical load,especially Photovoltaic (PV). The use of PV-STATCOM achieves many benefits, among them mitigating the distortion of the current wave , improving the power factor , compensatingthe active and reactive power , and improving the system 's stability. This paper deals with mitigating current wave distortion and improving power factors together. This paper designs a STATCOM Modular Multilevel Converter (MMC) controller with combines reactive power compensation and harmonicsmitigation for linear load and proposed a simulated six pulse three-phase rectifier as nonlinear load. The pulses gate of theswitches of the sub -modular converter has been obtained by using a proportional -integral (PI) current controller with d-q references. The time-domain-based reference method for the reference current extraction is adopted. MMCSTATCOM were simulated with proposed nonlinear model loads in MATLAB . The simulation result showed that the developed MMCSTATCOM minimizes the total harmonic distortion below the standards recommended by the IEEE.

Advanced Control of Three-Phase PWM Rectifier Using Interval Type-2 Fuzzy Neural Network Optimized by Modified Golden Sine Algorithm

Three-phase Pulse-Width Modulated (PWM) rectifiers used between the power grid and the load in applications requiring DC voltage have features such as high efficiency, high power factor, and low harmonics. This paper proposes a hybrid control approach to improve the dynamic performance of three-phase PWM rectifiers under different operating conditions. Operating conditions are considered as step response, internal disturbance, and regenerative operation. First, Interval Type-2 Fuzzy Neural Network (IT2FNN) is designed and then antecedent and consequent parameters of IT2FNN are optimized with Modified Golden Sine Algorithm (GoldSA-II). The dynamic performance of the hybrid controller, named GoldSA-II-IT2FNN, is analyzed for all operating conditions in Matlab/Simulink environment. The simulation studies are realized to evaluate the performance of the proposed controller. In the simulations, settling times of proposed controller are observed as 27.2 ms, and 10.8 ms for step response, respectively. Moreover, recovery times are calculated as being 12 ms to 5.5 ms for internal disturbance, and 7.2 ms to 19 ms for regenerative operation, respectively. The obtained results demonstrate that the proposed controller not only provides better dynamic performance but also improves the stability of PWM rectifier.

A Novel Graphical Approach for the Fast Estimation of Filter Capacitor Value and the Output Performance of Various Uncontrolled Rectifier

This paper proposes a novel approach for low-power applications for the fast estimation of filter capacitor value and the output performance parameters such as average, and Root Mean Square (RMS) values for the voltage and current considering single-phase full-wave, three-phase half-wave and three-phase full-wave rectifier circuits. For this aim, the novel equations in this work are derived for the average output voltage and rms ripple voltage separately for each of the above-mentioned three rectifier types. Then % ripple factors for each rectifier type are calculated using newly derived equations and plotted versus the newly introduced Normalized Time Constant (NTC). Besides, considering the peak supply voltage as the base voltage, the Per Unit (p.u.) output average voltage and rms ripple voltage for each of the rectifier circuits are computed and plotted versus NTC. These graphs will be normalized graphs since the output values of these graphs have turned into independent of both supply voltage amplitude and supply frequency. Normalized graphs are set up only once for each type of the rectifier circuit. Then, and for a pre-selected ripple factor value, the corresponding NTC value is obtained by straightforward reading from the graphs set up between the % ripple factor and NTC. Once the NTC value has been acquired, using the formula of NTC leads to finding the capacitor value required for the pre-selected ripple factor with one simple step calculation. Furthermore, the p.u. values of the average output voltage and rms ripple voltage values that correspond to the same NTC value are obtained by reading them from the set-up graphs directly. Finally, the efficiency of the proposed method is demonstrated through design examples for each type of rectifier circuit. The three design examples highlight how the output performance values can be obtained easily, accurately and swiftly. Furthermore, the viability of the graphical approach is verified by the experimental results which demonstrate the suitability of the derived equations in the proposed method.

Reconstructed Phase Voltages Based Power Following Control for Three-Phase Buck Rectifier Under Unbalanced Phase Voltages and Wide AC Input Frequency

In wide ac input frequency applications, such as more electric aircraft, ac input frequency of the three-phase buck rectifier varies in the range of 360–800 Hz. In this article, a reconstructed phase voltages based power following control for the three-phase buck rectifier under unbalanced input phase voltages in wide ac input frequency application is proposed. The input phase voltages are reconstructed to get more balanced modulation signals compared with the input phase voltages. The input currents are controlled to be in proportion to the reconstructed phase voltages to mitigate the imbalance of the input currents. The control strategy is simple and easy to be realized in digital. The analysis and design of the proposed control strategy and digital implementation are illustrated. An experimental prototype with 1.5 kW is built. The experimental results show that the sinusoidal input currents can be obtained when input phase voltages are unbalanced in wide ac input frequency application.

A New Low Switching Frequency Control of Regenerative CHB Drive With Low-Voltage Ride-Through Capability

In conventional medium-voltage high-power cascaded H-bridge (CHB) drive, a three-phase rectifier is adopted in each power cell to provide isolated dc-bus voltage for the output H-bridge. This limits the application of the conventional CHB drive, where regeneration capability is desired. The regenerative CHB drive can be made possible by replacing the diode rectifier with a three-phase IGBT-based active-front-end (AFE) rectifier in each power cell. However, due to thermal constraints in the high-power medium-voltage drives, the first challenge of the regenerative CHB drive is to deal with the extra switching losses introduced by the IGBT devices. Another challenge of the grid-tied regenerative CHB drive is to handle the low-voltage sags in the power grid without triggering unnecessary downtime in transients. In this article, a novel low-switching frequency control strategy is proposed for the AFEs in the regenerative CHB drive with low-voltage ride-through (LVRT) capability. The main harmonic contents generated by the AFEs with the proposed control strategy can be eliminated by the existing phase-shifting transformer in the CHB drives. This allows meeting with IEEE STD 519-2014 requirement with a 60 Hz switching frequency to minimize the extra introduced switching losses in steady state. Moreover, LVRT capability is integrated into the proposed control scheme with reduced current sensor count. Accompanied with videos, the experiments on a seven-level regenerative CHB drive are implemented to validate the feasibility of the proposed control scheme, which can be extended to regenerative CHB drives with any voltage levels.

Design of high-performance triboelectric-piezoelectric hybridized mechanical energy harvester inspired by three-phase asynchronous generator

Hybridized nanogenerators harvesting ambient mechanical energy via multiple energy conversion mechanisms is attractive for the development of next-generation energy sources. However, existing devices are still restricted in device size, structure complexity, power circuit and energy utilization scheme. Herein, inspired by the principle of three-phase asynchronous generator, we designed a triboelectric-piezoelectric hybridized mechanical energy harvester (HMEH) that tightly combines triboelectric and piezoelectric components in all-in-one package. Through the strategy of three-phase full-wave rectifier and integration of triboelectric/piezoelectric components with similar impedance to optimize the power extraction, one HMEH device can deliver remarkable outputs of 810 V and 0.65 mA at excitation frequency of 0.5 Hz, and even up to 1.10 mA at 4.0 Hz. The device also can endure 40,000 contact-separation cycles stability tests with no device failure and little outputs decay, demonstrating its excellent durability and reliability. The power density of this HMEH device approaches a high value of 1.02 mW cm−2 among similar contact-separation mode HNGs reported to date. Scalable performance of ∼4 mA can be obtained through the 2 × 2 HMEH arrays, supplying power for a smart band in sensing of heart rate and transmitting data wirelessly. The continuous charging of supercapacitor and lithium battery through HMEH arrays are demonstrated, providing extended energy utilization schemes for pulse-power and constant-power types electronics. This work can provide new insights in designing high-performance hybridized mechanical energy harvester and facilitate the development of power-generating technologies in further real-life applications, such as smart road infrastructures, wearable electronics and large-scale blue energy.

Орта мектеп физикасын оқытуда оқушыларды айнымалы токтың негізгі сипаттамаларымен таныстыру

The article provides a theoretical analysis of various types of alternating current. These types of alternating current are used in industry, lighting networks, electrical and radio engineering, and also in computer networks. The following characteristics of alternating current are investigated: instantaneous, amplitude, average and effective (effective) values of current and voltage. The parameters of the average and effective (effective) values of sinusoidal, periodic, rectified, three-phase and pulsating current are studied. Various types of AC rectifiers, a phase-pulse regulator and a three-phase rectifier were considered as examples. Calculations were carried out to find the average and effective (effective) values of alternating currents and voltages generated using these devices and equipment. The principles of operation of magnetoelectric, electrodynamic and thermal measuring devices are analyzed.