Three-phase Rectifier Circuit Research Articles

Open-circuit fault diagnosis of three-phase PWM rectifier circuits based on transient characteristics and random forest classification

Open-circuit fault diagnosis of three-phase PWM rectifier circuits based on transient characteristics and random forest classification

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.

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.

DPC of Cross-compensated Virtual Flux Double Switch Table

Aiming at the problems of large power ripple, high harmonic components and DC bias on the AC side of the three-phase voltage rectifier Direct Power Control (DPC), as well as the shortcomings of the voltage output of the DC side busbar, the direct power control method of the cross-compensated virtual flux double switch meter has been proposed. The virtual flux can realize the sensorless mode on the input side of the circuit to reduce the high harmonic, even if the first-order low-pass filter is used to replace the integration region, there is still some error. On this basis, the two filters are connected in parallel for virtual flux compensation, and then the voltage vector is selected according to the instantaneous power change, and the sector is re-divided with the voltage as the control vector, and two independent switching state tables are designed. The cross-compensated virtual flux double-switch meter DPC is simulated and compared with the traditional DPC waveform, and the experimental results show that the cross-compensated virtual flux double-switch meter DPC strategy can effectively reduce the proportion of harmonic content, control power fluctuations, improve DC bias, has fast tracking effect, stabilize output voltage, and control active and reactive power flexibly. The three-phase voltage rectifier circuit occupies an important position for the pre-rectifier part of the charging power supply of electric vehicles, and the rectifier circuit that can stabilize the output DC voltage cannot only extend its service life for the charging power supply, but also reduce harmonic pollution.

Research on Harmonic Suppression of High Temperature Boiler Based on Three-phase PWM Rectifier

Traditional boiler temperature control is based on thyristor voltage regulation, and the output AC voltage is controlled by controlling the trigger angle α of thyristor, so that the boiler temperature can be controlled in the pre-set range. However, this way of voltage regulation and temperature control will cause serious harmonic pollution to the power grid, and the output current has high harmonic content and low power factor. At the same time, the traditional three-phase load connection mode generally adopts star connection, and the load is pure resistive silicon carbide. Because of long-term use, the aging of silicon carbide heating rod is different, in fact, it is asymmetric load, three-phase load. The unbalance will cause three-phase unbalance, which will make the voltage of a certain phase exceed the rated working voltage of the heating rod, and greatly reduce the service life of the heating rod. Therefore, in order to improve the efficiency of power supply, reduce harmonic pollution and solve the problem of three-phase unbalance, this paper proposes a three-phase PWM rectifier circuit, which converts AC to DC, and realizes DC voltage regulation and temperature control through PI regulator. In this paper, the feasibility of the scheme is verified by simulation and comparative analysis.

Improved IGBT Dynamic Model and Electro-Thermal-Mechanical Multi-Field Coupling Failure Analysis

Failure of insulated gate bipolar transistors (IGBTs) can make a serious impact on the entire rectification or inverter system. IGBTs are used in different practical applications, causing a large difference in the form of failure of its solder layer. Therefore, it is necessary to study the aging failure law of IGBT solder layer. Firstly, the improved IGBT dynamic model is used to build a three-phase rectifier circuit and correct its circuit power consumption error. Then constructing three-dimensional finite element model of IGBT and analyzing its chip temperature and solder layer stress distribution under electro-thermal-force multiphysics coupling. Finally, the randomly generated solder layer defects are used to investigate the effects of voids, cracks, etc. on solder layer failure, and the aging failure mechanism of the solder layer is obtained. The simulation results show that after the solder layer defect area ratio is higher than 15%, solder layer voids, cracks and shedding have a significant effect on chip junction temperature and solder layer stress. Among them, shedding and cracks have a greater influence on the stress of the solder layer.

A new three-phase rectifier circuit using the partial switching strategy for a high power factor and a harmonic restraint

This paper describes a new three-phase rectifier circuit using the partial switching strategy. A passive method to be composed of a diode rectifier circuit and an active method with the high-freque...

Control Concepts for Hybrid Rectifiers Utilizing a Flying Converter Cell Active Current Injection Unit

A passive three-phase rectifier circuit equipped with a “Flying Converter Cell” (FCC) active current shaping network, based on the third harmonic injection concept, has been introduced recently. This additional/optional circuit allows the upgrade of a standard B6 diode rectifier to a low harmonic input stage with unity power factor. In order to guarantee properly shaped sinusoidal mains input currents, dedicated current and voltage controllers of the active circuitry must be designed carefully. As the active current injection unit consists of an assembly of three individual converter stages, the design procedure of both current and superimposed voltage controllers results in fairly high complexity. It is, therefore, going to be discussed in detail in this work. Based on the analysis of the rectifier system, an appropriate control concept is developed which is implemented using a digital signal processor. It is furthermore shown that the midpoint voltage of the FCC can advantageously be used for balancing of the dc capacitor stage of the cell without deteriorating total harmonic distortion of mains input currents. Measurement results taken from a 10 kW/10 kHz laboratory prototype finally confirm promising characteristics of the total hybrid system.

Didactic platform for teaching of three-phase rectifier circuits in power electronics

With the aim of preventing an Electrical Engineering course from being predominantly theoretical, the didactic materials used in laboratory activities are essential to make the learning process easier and more stimulating for the student. In this context, this paper presents a didactic platform developed for teaching a.c.-d.c. converters in the subject of power electronics at the Federal University of Uberlândia (UFU), Brazil. The proposed platform consists of a three-phase controlled and/or uncontrolled rectifier. The IC TCA785 is used to control thyristor operation. In order to make teaching more dynamical, the didactic platform was designed to have various operating conditions, simulating, for example, breakdown components and mixed use of thyristors and diodes. A prototype of the proposed platform was built, evaluated experimentally in the laboratory and the results are shown in this paper.

Research on Effect of Harmonics to Hysteresis Current Tracking Control Performance

A simulation model was built based on the Simulink module in the Matlab to study the effect of DC power harmonics to hysteresis current control performance. The DC power supply in the hysteresis current control circuit was obtained by a three-phase rectifier circuit, and the harmonics of DC power supply vary with the value of the capacitor which was in parallel to the rectifier circuit output. The result of experiment shows that the harmonics cause the inverter output waveform distortion, even cause hysteresis current control tracking failure.

Current Control of Three-Phase Rectifier Systems Using Three Independent Current Controllers

Three-phase rectifier systems without connection of the neutral wire are characterized by the coupling of the phase input currents. Considering these couplings requires a transformation of the system equations into a static αβ-frame or into the rotating <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -reference frame where instead of the three coupled phase currents two independent current components are controlled. In this paper, it is shown that, despite of the existing cross-couplings, three independent phase current controllers can be used to control the system. Thereto, the cross coupling elements of the system transfer matrix have to fulfill some requirements which are derived using the Gershgorin theorem. The three-phase Δ-switch rectifier circuit is used for analysis and a detailed model of the rectifier system is derived where the cross couplings are visible. The model is subsequently used to evaluate the cross couplings and three independent current controllers are designed. Simulation and experimental results verify the control approach using three independent current controller for three-phase rectifier systems.

A Three-Phase Triple Voltage Rectifier Circuit Using Diode Charge Pump Scheme

A novel three-phase triple-voltage rectifier circuit is presented. The proposed circuit applies the single-phase diode charge pump scheme to the three-phase system and the direct output voltage is about 3 times much than input line-to-line voltage. The validity for the proposed circuit is demonstrated by the simulations and the experiments.

Implementation of HF Current Injection Technique for Three-Phase Converter AC-to-DC

This paper presents the high power factor operation of three-phase AC-to-DC resonant converter. The input three-phase uncontrolled diode bridge rectifier is followed by six pulse modified series parallel resonant converter. The high power factor of three-phase AC source is achieved by injecting high frequency (HF) current from output of the inverter to the input of rectifier. Therefore, HF modulation of AC input voltage of the three-phase line rectifier circuit is achieved. The output voltage of three-phase resonant converter is regulated by using variable frequency mode under 180°-wide gating pulse scheme. Detail analysis and design of HF current injection circuit is given for 3.5 kW output power operating at 300 kHz switching frequency.

A Simple, Passive 24-Pulse AC–DC Converter With Inherent Load Balancing

A new converter topology for a three-phase multipulse rectifier circuit is described. This converter draws almost sinusoidal currents from the ac system with very low harmonic content and typically less than 3% total harmonic distortion. The topology uses only passive components and has a lower component count than other rectifier circuits with similar performance. Two six-pulse rectifier bridges are connected in series, fed by a series connection of transformers, to form a 12-pulse system. An additional low power harmonic injection circuit enhances the performance of the circuit to obtain low harmonic current pollution levels that are comparable with those achieved from a 24-pulse rectifier. The circuit operation is explained and experimental results are presented.

A multilevel-voltage source rectifier with a three-phase diode bridge circuit as a main power circuit

A novel system obtaining very low distorted waveforms of input AC currents of three-phase rectifier circuits are proposed. The proposed rectifier system consists of a three-phase diode bridge circuit as a main power circuit, AC reactors, and an additional circuit which serves as an active filter with low switching frequencies and a forced-commutation circuit for the diodes. This paper describes the operation principle, analysis of the waveforms of input voltage and current, multiple phase-shifted systems, and the experimental results. The proposed system gives excellent input current waveforms and has many advantages over conventional systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Transactions section: Preprint of corresponding pages from the current annual AIEE transactions volume: Pentode ignitrons for electronic power converters

THE history and development of suitable electronic tubes and circuits for high-voltage power-conversion systems is discussed in a companion paper.1 Briefly, the first power unit after laboratory tests consisted of a 40–60-cycle 5,000-kw power converter. The tubes for this unit were of the thyratron∗ type. The nonsynchronous link operated at a direct potential of 30,000 volts and a current of approximately 170 amperes. Power from the 40-cycle system was converted to direct current through 12 phano-tron tubes connected in a cascade arrangement of two three-phase double-way rectifier circuits. The direct current was converted to 60-cycle a-c power through 12 thyratrons connected in a similar arrangement of double-way inverter circuits. Initial operation was remarkably free from any basic trouble. Operation over a period of some five years demonstrated the complete practicability of sealed electronic tubes for this type of service.