Single-phase Full-bridge Rectifier Research Articles

A 24-Pulse Rectifier With a Passive Auxiliary Current Injection Circuit at DC Side

In this article, a simple series-connected 24-pulse rectifier with a passive auxiliary current injection circuit (ACIC) is proposed. The proposed rectifier consists of a 12-pulse rectifier and an ACIC. The ACIC includes a circulation current forming circuit, an auxiliary single-phase transformer (AST), and an auxiliary single-phase full-bridge rectifier (ASFR). The ASFR extracts alternating square-wave current from the dc side and injects it into the outputs of three-phase rectifier bridges to increase the output state of these bridges. The operating mode of the proposed rectifier is analyzed, and the functional relationship between the input current and turns ratio of AST is established. The AST turns ratio that minimizes the input line current total harmonic distortion (THD) is derived. The voltage and current rating of AST are calculated, and the design method of capacitors C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> and C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> in ACIC is given. Under the optimal turns ratio, the ACIC extends the 12- to a 24-pulse rectifier. The resulting 24-pulse rectifier draws near-sinusoidal input currents with less than 5% THD. The AST in ACIC has a very low kilovolt-ampere rating (1.96% <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</sub> ), and the current ratings of ASFR are small. The theoretical analyzes are provided and experimentally verified using a 1.7 kW experimental prototype.

Comparison of Models of Single-Phase Diode Bridge Rectifiers for Their Use in Harmonic Studies with Many Devices

Harmonic modeling of low-voltage networks with many devices requires simple but accurate models. This paper investigates the advantages and drawbacks of such models to predict the current harmonics created by single-phase full-bridge rectifiers. An overview is given of the methods, limiting the focus to harmonic analysis. The error of each method, compared to an accurate numerical simulation model, is quantified in frequency and time domain considering realistic input scenarios, including background voltage distortion and different system impedances. The results of the comparison are used to discuss the applicability of the models depending on the harmonic studies scale and the required level of detail. It is concluded that all models have their applicability, but also limitations. From the simplest and fastest model, which does not require a numerical solution, to the more accurate one that allows discontinuous conduction mode to be included, the trade-off involves accuracy and computational complexity.

A Simple Two-Stage AC-AC Circuit Topology Employed as High-Frequency Controller for Domestic Induction Heating System

The induction heating process at a domestic level is getting attention nowadays as this power converting topology ensures clean, reliable, flexible, and fast operation. The low input frequency is converted to required regulated high output frequency with indirect and direct power converting approaches. The circuit and control complexity and high conversion losses associated with indirect power converting approaches lower their uses for domestic induction systems. The direct ac-ac power conversion approach is one of the viable solutions for low and medium power level loads, especially for domestic induction heating loads. The circuit complexity, cost, and conversion losses of the direct power converting systems depend on the number of the controlled switching devices as each controlled switch requires one gate driving circuit and one isolated dc supply. Simplified pulse width modulation (PWM) switching control also lower their control effort. Therefore, in this article, a simplified direct ac-ac power converting approach is introduced for a high-frequency domestic induction heating system. Here, the regulation of the high output frequency is achieved by simply cascading the single-phase full-bridge rectifier with a full-bridge inverter with a simple control strategy. The characteristics of the developed topology are validated through simulation results of the Simulink-based platform and practical results of the developed practical setup.

Implementation of a Fault-Tolerant AC/DC Converter for Permanent Magnet Synchronous Motor Drive Systems

Fault tolerant drive systems have played an increasing role for electric vehicles in order to improve reliability, availability, and to reduce maintenance. For safety reason, a fault-tolerant drive system, which includes some redundant devices and a traditional motor drive system, has been developed. This fault-tolerant system executes real-time fault detection, diagnosis, isolation, and control to make the fault-tolerant drive system operate normally even though some faults have happened. In this paper, an AC/DC converter faults, which includes a single-phase full-bridge rectifier diode fault, a three-phase full-bridge rectifier diode fault, and a DC-link capacitor fault are investigated. The fault-tolerant processes include fault detection, diagnosis, isolation, and control to improve the reliability of the drive system and reduce the disturbances during faulty interval. A digital signal processor, manufactured by Texas Instruments, type TMS320F2808, is used as a control center to achieve the fault tolerant processes. Experimental results validate theoretical analysis to demonstrate the correctness and feasibility of the proposed methods. The proposed method can be easily implemented in industrial products due to its simplicity.

A Simple 36-Pulse Diode Rectifier With Hybrid Pulse Multiplication Interphase Reactor at DC Side

A simple and robust 36-pulse diode rectifier which consists of a conventional 12-pulse rectifier and a hybrid pulse multiplication interphase reactor (HPM-IPR) is proposed in this article. The HPM-IPR includes a modified interphase reactor (M-IPR), an auxiliary single-phase full-bridge rectifier (ASFBR), and an auxiliary single-phase full-wave rectifier (ASFWR). The ASFBR is connected in series with the load to modulate the output current of the rectifier bridges directly. The ASFWR is connected in parallel to shape the output current of the rectifier bridges indirectly. The conjoint modulation of ASFWR and ASFBR significantly increases the number of output current states of the rectifier bridge, which in turn extends the conventional 12-pulse operation to 36-pulse operation. The proposed 36-pulse diode rectifier draws near the sinusoidal input line currents with THD less than 5%. The kVA ratings of ASFBR and ASFWR are only 1.1% and 1.8% of the output power of the proposed rectifier, respectively, which indicates that the proposed method is suitable for high-power industrial applications. Since only one ASFWR and one ASFBR are adequate, the proposed scheme is low cost, highly reliable, and simple. The detailed analysis is presented, and some experimental results are provided to verify the proposed method.

A Harmonic Frequency Domain Modeling Method for Single-Phase Full Bridge Rectifiers

The increase in power electronic (PE) devices has caused a wide penetration of Switch Mode Power Supply (SMPS)-based loads, which include single-phase full bridge rectifiers. Therefore, potential problems on power quality may also increase. Thus, the modeling and harmonic analysis of SMPSs are useful to assess the contribution on current distortion and the impact of several of these loads connected on a low-voltage network. However, an assessment of multiple loads considering the interactions between them and the equivalent system impedance together with the voltage distortion and the harmonic phase angle dispersion represents a challenge on harmonic modeling. This paper proposes the use of a SMPS Time Domain Model (TDM) to compute synthetic signals which are used to fit a Frequency Domain Model (FDM) that allows the estimation of the harmonic current distortion with lower computation cost than a Time Domain simulation. Moreover, this paper proposes a probability approach to compute this FDM rather than a regular deterministic approach. The proposed approach is based on the signals that more likely to be present over a time and to comply with the limits proposed by distortion standards or possible phase angle operation points. The FDMs results from the proposed and regular approaches are compared with respect to the TDM through the magnitude relative error and phase angle absolute error on MATLAB platform. The study reveals that despite the approaches have the same computational cost, the proposed approach is more effective than the regular approach for computing accurate FDMs for an SMPS.

Harmonic damping characteristics of single-phase full-bridge rectifier based loads

With the rapid development of power electronic technology, many linear single-phase loads in low voltage systems are replaced by those equipped with a single-phase diode rectifier. Therefore, most of single-phase loads become harmonic producers due to their nonlinear characteristics. The nonlinear loads may have different damping characteristics at harmonic frequencies, which would bring potential power quality problems. This paper studies the harmonic damping characteristics of such nonlinear loads. The harmonic damping index is defined to quantify the damping effect of nonlinear loads at harmonic frequencies by analyzing the harmonic model. Then, the harmonic damping index at different harmonic frequencies is compared through simulations and experiments. The results show that the nonlinear load has a constant damping effect at the fundamental frequency, but stronger damping at harmonic frequencies. The harmonic damping of such nonlinear loads varies with the harmonic phase angle of supply voltage, and becomes stronger with the increase of the harmonic order. It implies that this type of nonlinear loads may be beneficial to the suppression of harmonic resonance.

Simulation and Analysis of Full Wave Bridge Rectifier Connected to DC/DC Buck Converter Feeding DC Motor

In present day situation, the analysis of drive circuits for DC motors are advancing and recent innovative technologies make the system more cheaper and market friendly. The adjustable speed drive system is utilized for speed control purpose of DC motor. In this paper, open loop analysis and output response is studied for a Single phase full bridge rectifier connected to a DC motor feeding from a DC/DC Buck converter. The voltage regulator between two networks make the load voltage adjustable. The Matlab simulation software is used to analyze the system performance and its characteristics under various factors. The performance parameters such as ripple factor, motor and rectifier efficiency, voltage and current THD, and form factors of the system for various firing angles are compared and analyzed. Moreover it is observed that the system output voltage remains constant eventhough there is load and field disturbance in motor. Besides, if the firing angle increases form factor, ripple factor increases whereas the motor efficiency and rectifier efficiency decreases. The main aim of the paper is to prove that the developed model must transmit power with high efficiency and low ripple compared to existing models. The results presented in this paper match with the experimental results.

On the Practical Design of a Two-Terminal Active Capacitor

A two-terminal active capacitor concept has been proposed recently based on an active power electronic circuit with a voltage control method and self-power scheme. It retains the convenience of use as a passive capacitor with two power terminals only without any additional required connections and has the potential to either increase power density or reduce design cost depending on the applications. Based on the previously proof-of-concept study, this paper addresses the design constraints, impedance modeling, and start-up solutions of two-terminal active capacitors. A design method for functionality, efficiency, lifetime, and cost-constraint applications is applied to size the active components and passive elements. A voltage feedforward control scheme is implemented to improve its dynamic response. Two start-up solutions are proposed to overcome the issues brought by the self-power scheme. A case study of an active capacitor for the dc link of a single-phase full-bridge rectifier is presented to demonstrate the theoretical analyses.

Effect of Single-Phasing on Multipulse Rectifier With Active Interphase Reactor

When one of the input terminals of multipulse rectifier (MPR) is open, MPR operates under single-phasing. This paper analyzes the effect of single-phasing on MPR with active interphase reactor (AIPR). The output voltages of phase shift transformer and the voltage across the secondary winding are calculated under single-phasing. Compared with the voltages under normal operation, the amplitude of ouput voltages are not equal to each other under single-phasing, and phase difference of arbitrary two phases are not equal to 120°. The MPR with AIPR is equivalent to two single-phase full-bridge rectifiers operating in parallel. Zero-phase difference of output voltages of the two bridge rectifiers leads to no harmonic power being absorbed by the AIPR. Some simulation and experiment are carried out to validate the theoretical analysis.

Design and Simulation of Energy Efficient Fixed Frequency Pulse Controlled Power Converter for Induction Melting Application

This paper discusses the design and simulation of pulse width modulated based circuit for induction melting application. This high frequency inverter topology have the practical advantages of energy saving, clean environment, high output power due to low switching losses, less electromagnetic noise and low total harmonic distortion. This two stage power converter has single phase full bridge rectifier, DC filter, zero voltage switching pulse width modulation controlled high frequency inverter. In this work, the steady state operation and control strategy of pulse width modulated high frequency inverter is analyzed. In order to achieve energy efficiency switching losses are reduced by operating the inverter above resonance frequency. Input side supply harmonics is also reduced using EMI filter. The simulation of the designed high frequency power supply is carried out at a frequency of 20 kHz using MATLAB simulink tool. Simulation results proof the energy saving due to reduction in switching losses of the presented control strategy and reduction in harmonic distortion of the presented power supply for induction heating load.

A Fault-Tolerant Parallel Structure of Single-Phase Full-Bridge Rectifiers for a Wound-Field Doubly Salient Generator

The fault-tolerance design is widely adopted for high-reliability applications. In this paper, a parallel structure of single-phase full-bridge rectifiers (FBRs) (PS-SPFBR) is proposed for a wound-field doubly salient generator. The analysis shows the potential fault-tolerance capability of the PS-SPFBR over the common three-phase FBR. The normal no-load and loading operations are discussed, and the fault-tolerance ability is analyzed. A doubly salient generator prototype is built and tested; the machine is also modeled and simulated with the finite element method. The results obtained from simulation are in good agreement with that from the experiments under both normal no-load and loading operations. The impacts of a single-phase open-circuit fault have been discussed, and the fault-tolerance ability has been demonstrated.

The Effects of Harmonic Components on Transformer Losses of Sinusoidal Source Supplying Non-Linear Loads

An important consideration when evaluating the impact of harmonics is their effect on power system component and loads. Transformers are major components in power systems. The increased losses due to harmonic distortion can cause excessive losses and hence abnormal temperature rise. The measurement of iron losses and copper losses of single-phase transformers is important in particular for transformers feeding nonlinear loads. In computing of transformer losses, it is assumed that source voltage is sinusoidal and load impedance is linear. This study presents the effects of harmonic distortion of load current and voltage on single-phase transformer losses utilizing the on-line measurements (monitoring) method of the primary side. The transformer is loaded with an SCR speed controller that consists of a single-phase full-bridge rectifier, SCR and a resistant load to generate various total harmonic current and voltage distortions (THDi and THDv) conditions.