Three-phase Bridge Rectifier Research Articles

MoS2 Self-Switching Diode-Based Low Power Single and Three-Phase Bridge Rectifiers

MoS₂ Self-Switching Diode-Based Low Power Single and Three-Phase Bridge Rectifiers

FEA simulation of harmonics generation from 6-pulse rectifier and their impact over rectifier’s transformer

In the present work, the operation of a 6-pulse three-phase rectifier supplying a powerful DC consumer is simulated using the finite element method (FEM). The purpose of the simulations is to research the generation of harmonics from the rectifier circuit and to investigate their influence on the transformer supplying the three-phase bridge rectifier. For this purpose, two co-simulations were made. The first of them is realized with the help of the professional Finite Element Analysis (FEA) software - Ansys Electromagnetic Suite. The voltage-driven model of the rectifier transformer for FEA was built and was used in the Ansys Twin Builder software simulation. The resulting current harmonics from the FFT analysis of the current waves with their amplitudes and phases are input into the primary and secondary windings of the transformer current-driven model in the second electromagnetic-thermal co-simulation in Ansys Workbench to calculate the losses in the transformer. These losses are used in the thermal model to account for transformer heating from higher harmonics.

Performance Prediction of D.C. Motor Fed From Half-Controlled Bridge Rectifier

Controlled rectification is the process of obtaining a controlled output DC voltage from a constant AC voltage. This can be used in the speed control of the DC motor to provide rapid torque control and a quick starting response. In this work, a three-phase half-controlled bridge rectifier has been used. The average output DC voltage varies smoothly by varying the firing angle (α). Different methods of analysis such as state-space and Fourier-series, are used to obtain the performance of the DC motor fed from the bridge-rectifier supply. However, these methods do not deal with the prediction of the discontinuous conduction phenomenon which occurs during the operation of the DC motor with a variation of delay angle. This paper deals with the prediction of performance characteristics during the operation of the DC motor fed by a 3-phase half-controlled bridge rectifier, including the transient as well as steady-state operation with a variation of delay angle as well as application of load torque at starting.

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.

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.

Analysis of Control Strategy of Three-phase Bridge Fully Controlled Rectifier Circuit Based on PID Control

At the present stage of industrial production in China, rectifier circuits still have an important position, and their safe, reliable, and efficient operation is still a necessary issue to be explored in the development of power electronics technology. Therefore, this paper will build an improved three-phase bridge rectifier circuit based on the traditional three-phase bridge fully controlled rectifier circuit, replacing the thyristor with an insulated gate bipolar transistor (IGBT) under the same basic principle, so that it can be more easily controlled by industrial intelligence. The PID controller is introduced to make the output voltage of the rectifier circuit gradually converge to a certain value by continuously correcting the calculation of the trigger angle α and the calculation of the voltage and current values. The simulation results show that the PI-controlled three-phase bridge fully controlled rectifier circuit model established in the paper makes the output of the circuit eventually stabilize under the influence of the closed-loop control, and the simulation results reach the expected value and show strong robust stability. For industrial applications, improving the safety, reliability, efficiency, and flexibility of bridge rectifier circuits is of good reference in practical engineering applications.

A unique method of a PLC controller based performance evaluation of optimization algorithms and power quality methods in a grid-connected hybrid wind-solar system

The electricity demand is growing due to increasing population and fast industrial development . To meet the worldwide energy requirement, the greatest possibilities are the wind-solar energy sources due to excessive accessibility, simplicity in use, and non-polluting in nature . The integration of these resources offers higher advantages, but the quality of the power scheme gets influenced by the different characteristics of wind and solar energy. Thus in the proposed work, an augmented controller and rectifier have been designed to improve the power quality in which the source current gets optimized by using the Hybrid Bat-Dragonfly optimization algorithm. The quality of the optimized power will be enhanced through the Five Legged Power Converter (FLPC) by converting the DC into AC by using a three-phase bridge rectifier without any power loss. The occurrences of harmonics in the current are reduced using a sieve optimized algorithm design.

Разработка источника питания для позиции виброакустической диагностики подшипников локомотивного депо

Purpose: Two possible variants of power sources are considered: controlled three-phase bridge rectifier circuit with a step-down transformer and a pulse converter, getting power from the mains via uncontrolled three-phase bridge rectifier (Larionov circuit) for bringing into rotation with the required frequency of wheel-motor units of electric locomotives and electric trains at the position of indiscriminate diagnosis of bearings. In both cases, it is assumed that power sources receive electro-energy from a depot circuit — 380/220 V, 50 Hz. The comparison of proposed power supply options based on the assessment of energy consumption efficiency is carried out. A capacity coefficient and capacity loss in power supplies are used as measures for energy-consumption efficiency. Methods: Analytical methods are used to determine capacity losses in a transformer, controlled three–phase thyristor rectifier, uncontrolled three-phase diode rectifier, input filter of a pulse converter, IGBT transistor and reverse diode of a pulse converter. Results: Energetical indicators were determined: power losses in a transformer, a controlled three–phase thyristor rectifier, an uncontrolled three-phase diode rectifier, an input filter of a pulse converter, an IGBT transistor and a reverse diode of a pulse converter. Based on the pursued assessment of the energetical indicators of power supply two options, it is concluded on feasibility of transformer-free circuit application in bearings’ position of vibration-acoustic diagnosis. Practical importance: A variant of an energy–efficient power supply for the position of indiscriminate vibroacoustic diagnosis is proposed, which includes an uncontrolled semiconductor rectifier and a pulse converter, accomplished using an IGBT transistor.

Modelling and Analysis of Wind Turbine using Permanent Magnet synchronous generator for Maximum Power Tracking Control

This research uses Matlab/Simulink simulation tools to analyse and simulate the performance of a wind power system powered by a low-speed Permanent Magnet Synchronous Generator (PMSG). A wind turbine (WT), PMSG, maximum power point tracking (MPPT), a three-phase diode bridge rectifier, a dc bus connected to a capacitor, and a PWM voltage source inverter regulated by a current source are all part of the system. With an MPPT control, the optimum coefficient of performance parameter was attained in the WT model as a function of wind velocity. The use of low-speed PMSG, which results in improved efficiency, eliminates the need for a gearbox. The ac output power obtained from PMSG is supplied to a three-phase rectifier bridge, which allows for maximum power extraction by using the boost converter's optimal voltage and current settings. The total system is connected to the electrical utility using a current source PWM inverter for dc/ac conversion.

Power supply for fast-scanning magnet in proton therapy: Design and test

Proton therapy is one of the most effective radiation methods to combat cancer and offers a substantial advantage over conventional photon therapy. Magnetic scanning systems consisting of a magnet and power supply form an integral part of proton therapy and allow the beam position (x, y) to be controlled during spot scanning. Ensuring that the dose is rapidly and precisely distributed within the contour of the tumor requires a high-precision, fast-ramp-speed, and high-stability power supply with accurate control. The present work uses a three-phase bridge rectifier and multiple series-parallel H-bridge converters to propose a prototype power supply for the scanning magnet of a magnetic scanning system. The power supply is controlled using a proportional integral controller using digital signal processing. A prototype of the scanning power supply is developed and tested, and the results demonstrate an output current of ±500A, a ramp speed of ±40 kA/s, and a short- and long-term stability of less than 20 ppm.

An Optimized Single-Stage Isolated Swiss-Type AC/DC Converter Based on Single Full-Bridge With Midpoint-Clamper

The Swiss-type rectifier (SR) uses harmonic injection circuit and two dc–dc converters to help three-phase uncontrolled rectifier bridge to achieve better power factor correction (PFC). By applying the full-bridge topology to the dc structure, both the soft switching and the high-frequency galvanic isolation can be achieved. However, two full-bridge structures are required to realize the PFC principle of SR. That means the current flows through at least four switches and two transformers during the power conduction or freewheeling period. There are improvements in both conduction loss and core utilization. Thus, an optimized single-stage isolated Swiss-type ac/dc converter based on a single full-bridge with midpoint-clamper is proposed. Only one full-bridge structure is used to improve the conduction loss and core utilization. Two bidirectional voltage clampers are used to implement the PFC principle of the SR. The performance of the proposed converter has been verified by experiments. A total of 95.4% efficiency under half rated power and 5% input current THD under rated power have been achieved under a 10-kW 380 Vac input/400 Vdc output prototype with 90 kHz switching frequency.

A new opto-isolator circuit topology for a three-phase alternating current/direct current converter

This paper presents a new design and implementation of the isolation stage between the power and control circuits of a three-phase rectifier controlled by the pulse width modulation technique. The isolation circuit is configured to use an optocoupler for each pulse signal produced by the control circuit, which requires a total of four references (neutral wire) to activate the thyristors of the three-phase bridge rectifier. In addition, the designs of the control and power stages are presented as well as the voltage and current oscillograms obtained at the output of the implemented three-phase converter. The experimental results obtained confirm the correct operation of the proposed configuration. Thus, broadening the discussion about distortions, glitches and enhancement of traditional energy systems. This article illustrates how to build converters in a more cost-effective way, according to the power of the specific load to be energized. The presented computer simulations show the influence of the control circuit’s reference regarding total harmonic distortion. These allow evidence that the non-connection of the neutral wire decreases the waveform distortion in the tension wave.

Open-Circuit Fault Diagnosis and Maintenance in Multi-Pulse Parallel and Series TRU Topologies

Transformer rectifier units (TRUs) are a reliable way for dc generation in several electric applications. These units are formed by multiple three-phase uncontrolled bridge rectifiers connected according to two main topologies (parallel and series), and fed by a phase-shifting transformer, which can have different configurations. Fault diagnosis of the uncontrolled bridge rectifier diodes is one of the most important concerns on the electronic devices, nonetheless, rectifier units are inherently not protected in front of open-circuit (O/C) faults, which cause malfunction and performance deterioration. In order to solve this drawback, the proposed fault diagnosis method is based on the O/C fault signature observed in the dc-link output voltage of TRUs rectifier. It allows detecting the O/C diodes of parallel and series TRUs with different phase-shifting transformer configurations and for the most usual fault scenarios. Moreover, it also helps the prediction of diodes that could be exposed to failure after the fault, which provides corrective maintenance for the TRU development. The proposed method is illustrated from MATLAB numerical simulations of a 12-pulse TRU, and is validated with experimental tests.

Fault Diagnosis Method of Power Electronic Converter Based on Broad Learning

In order to realize the unsupervised extraction and identification of fault features in power electronic circuits, we proposed a fault diagnosis method based on sparse autoencoder (SAE) and broad learning system (BLS). Firstly, the feature is extracted by the sparse autoencoder, and the fault samples and feature vectors are combined as the input of the broad learning system. The broad learning system is trained based on the error precision step update method, and the system is used to the fault type identification. The simulation results of the thyristor fault diagnosis of the three-phase bridge rectifier circuit show that the method is effective and has better performance than other traditional methods.

A Modular Power Converter With Active Front-End System to Mitigate Harmonics in Distribution Networks

Power quality improvement of power electronics systems in many applications such as adjustable speed drive (ASD) is vital due to the high penetration of grid-connected converters in distribution networks. Conventional diode bridge rectifiers are widely utilized in three-phase systems due to their cost-effectiveness, simplicity, and reliability. To improve their harmonic behavior, in this article, a three-phase bridge rectifier with harmonic mitigation function using an electronic inductor is proposed. The proposed system can mitigate current harmonics caused by other conventional rectifiers connected at the same point of common coupling (PCC). Based on the proposed harmonic reduction technique, a combination of three-phase rectifiers can comply with low-order harmonic emission limits according to IEC 61000-3-12 standard. Simulation and practical measurements are performed to validate the proposed method.

Regimes of DC link with gate turn-off thyristors

The analysis has been carried out on the disadvantages of regulating power flows in electric networks and systems using intermediate DC links, which are based on traditional current sourced converters with natural switching thyristors. It has been noted that due to modern advances in the field of power electronics, power static current sourced converters can operate in the modes with leading current, i.e. not consuming, but generating reactive shear power. The possibilities of phase regulation of the converter by the thyristors have been shown, in which the power converter can operate in the modes with the generation of reactive shear power into an alternating current network. The mode of the artificial switching of the valves, in which the converters operate with the leading current, is achieved by opening the thyristors without time delay, and by closing them before the natural moment of their closing. We have carried out the analysis of electromagnetic processes in a static power current sourced converter with fully controlled thyristors according to a three-phase bridge circuit in the rectifier and dependent inverter modes, which can be used to build an intermediate DC link as components of flexible AC transmission systems with the capabilities of four-quadrant control of inter-system power exchange. We have created the conditions under which a three-phase bridge rectifier and a grid-controlled inverter with closing thyristors as a part of a direct current insert will not consume reactive power from the AC network, which is not provided for by the classical theory of their operation. The analytical expressions have been provided that can be used to obtain the basic energy characteristics of a DC insert made on the basis of current sourced converters, which not only does not need an additional resource of reactive power for its functioning, but can itself generate reactive power in an alternating current network. We have obtained analytical expressions for electromagnetic parameters, which can be the basis for further research and design of a prototype DC insert with new properties.

Fault-Tolerant Oriented Hierarchical Control and Configuration of Modular Multilevel Converter for Shipboard MVdc System

Medium-voltage dc (MVdc) distribution system is considered as the promising power architecture of future shipboard power system. Fault-tolerance ability is of great importance for power system on ships. In this paper, zonal dc–dc conversion system based on modular multilevel converter (MMC) and three-phase bridge rectifier are proposed with its hierarchical fault-tolerant scheme. The topology configurations of the front-end MMC with multiwinding medium frequency transformer under normal and postfault circumstances are presented. The reconfiguration scheme and fault-tolerant control strategy are also proposed to ride-through submodule (SM) level fault, phase level fault and bus level fault. Based on the hierarchical fault-tolerant scheme, redundant configuration of the MMC SM is further analyzed with the hierarchical reliability modeling. The effectiveness of the proposed control strategy is verified by the experimental results.

CALCULATION OF CURRENT LOADING OF THREE-PHASE BRIDGE RADIATION IN NON-SUPERMEAL MODES UNDER THE FILTRATION AVAILABILITY

The curves of the rectified voltage of the non-ventilated modes of the three-phase bridge rectifier circuit have in their composition a number of non-canonical higher harmonics, which results in significant pulsations of the load current. Hence the problem of choosing the optimal composition of filters in order to prove the load current pulsation coefficient to allowable values. The analysis of the current state of the problem is carried out by studying the latest publications.
 The analytical expressions and forms of load current curves are obtained based on the results of mathematical modeling of the resonant and inductive filters higher harmonics influence on the outputs and rectifier loads, respectively, on the leads and in the rectifier load cell. The value of the current ripple coefficient in the load cell for the individual cases of the non-ventilated mode of the three-phase bridge rectifier is calculated. The curves of the currents given in this article are valid for those forms of rectified voltage that arises in non-blunt modes of the three-phase bridge rectifier scheme, and can be obtained under the condition of a known composition of higher harmonics of the output voltage of the rectifier. It is shown that the establishment of a resonance filter at the frequency of the largest harmonic significantly reduces the current pulsation coefficient in the load cell.
 In the case of a real resonance filter at the output of the rectifier in the current of the load circuit there will be a harmonic, which will proceed under the action of a voltage drop on the active resistance of the filter. However, its effect will be negligible, since the active resistance of the filters is usually small. The level of harmonic components in the load current will also diminish somewhat as a result of the branching of a certain value of these currents through the branches of the resonant filters.
 The proposed method allows to calculate the current in the recirculation load cell in non-ventilated modes, taking into account a certain composition of resonant parallel and inductive serial filters to achieve the desired level of current pulsations.

Разработка и исследование математических моделей трехфазных мостовых выпрямителей и инверторов

Разработка и исследование математических моделей трехфазных мостовых выпрямителей и инверторов

A Study of a Standalone Renewable Energy System of the Chinese Zhongshan Station in Antarctica

China has built four stations in Antarctica so far, and Zhongshan Station is the largest station among them. Continuous power supply for manned stations mainly relies on fuel. With the gradual increase in energy demand at the station and cost of fuel traffic from China to Zhongshan station in Antarctica, reducing fuel consumption and increasing green energy utilization are urgent problems. This research considers a standalone renewable energy system. The polar environments and renewable energy distribution of area of Zhongshan station are analyzed. The physical model, operation principle, and mathematical modeling of the proposed power system were designed. Low-temperature performance and state of charge (SOC) estimation method of the lead–acid battery were comprehensively tested and evaluated. A temperature control strategy was adopted to prevent the battery from low-temperature loss of the battery capacity. Energy management strategy of the power system was proposed by designing maximum power point tracking (MPPT) control strategies for wind turbine and PV array. The whole power system is broadly composed of a power generator (wind turbine and PV array), an uploading circuit, a three-phase rectifier bridge, an interleaved Buck circuit, a DC/DC conversion circuit, a switch circuit, a power supply circuit, an amplifier, a driver circuit, a voltage and current monitoring, a load, battery units and a control system. A case study in Antarctica was applied and can examine the technical feasibility of the proposed system. The results of the case study reveal that the scheme of standalone renewable energy system can satisfy the power demands of Zhongshan Station in normal operation.