Vienna Rectifier Research Articles

Modelling and analysis of vienna rectifier for more electric aircraft applications using wide band-gap materials

This paper presents a comprehensive study on the switching effects of wide bandgap devices and the importance of power electronics in an aircraft application. Silicon (Si), silicon carbide (SiC), and gallium nitride (GaN) are wide bandgap devices that act as a power electronic switch in the AC-DC converter for More Electric Aircraft (MEA) applications. Therefore, it is important to observe their converting efficiency to identify the most suitable wide bandgap device among three devices for AC-DC converters in aircraft applications to provide high efficiency and high-power density. In this study, the characteristics of Si, SIC, and GaN devices are simulated using PSIM software. Also, this paper presents the performance of the Vienna rectifier for aircraft application. The Vienna rectifier using Si, SiC, and GaN devices are simulated using PSIM software for aircraft application. GaN with Vienna rectifier provides better performance than Si and SiC devices for aircraft applications among the three devices. It gives high efficiency, high power density, low input current THD to meet IEEE-519 standard, and high-power factor at mains.

Modified VIENNA Rectifier III to Achieve ZVS in All Transitions: Analysis, Design, and Validation

In this article, analysis and design of a 3.3-kW isolated single-stage three-phase buck-type rectifier for aircraft applications is presented. The operating principle and modulation method of the proposed rectifier are introduced. The advantageous zero-voltage switching (ZVS) feature in all of the switching transitions is analyzed. A comparison with the VIENNA Rectifier III is done, being different both in the phase-leg implementation and the modulation sequence. A detailed rectifier design guideline is discussed and losses estimations are provided aiming at reaching 93.7% overall efficiency, including the EMI (electromagnetic interference) filter. Simulation waveforms are presented. Finally, experimental results obtained with the designed 3.3-kW hardware demonstrator are provided. The results verify achievement of ZVS in all of the switching transitions from full load down to 50% of nominal load, while exhibiting 1.9% THD <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</sub> (total harmonic distortion) and 0.9996 PF (power factor) at nominal power, ultimately showing very good agreement to the simulation results. This article is accompanied by a video demonstrating experimental operation of the proposed rectifier at nominal input voltage, output voltage, and output power.

Model predictive direct power control scheme for Vienna rectifier with constant switching frequency

Model predictive direct power control (MPDPC) has strong robustness and fast dynamic response, so it is widely applied in the control system of grid-connected converter. However, the traditional FCS-MPC bears with variable switching state, which will reduce the current tracking accuracy, accidentally produce current ripple and electromagnetic noise. Here, a double closed-loop control strategy with constant switching frequency based on optimal switching sequence synthesis of model predictive direct power control (MPDPC-CF) in the inner loop and SMC control in the outer loop is proposed for the non-linear system of Vienna rectifier. Firstly, the Vienna rectifier is modelled to obtain the predicted values of input power. Then, the given values of active power and reactive power are obtained through the outer loop. Three adjacent voltage vectors with the lowest cost function in the sector are selected to synthesize the optimal voltage vector, and the pulse time of the corresponding vector is calculated according to the cost function of the voltage vector. To verify the correctness of the theoretical analysis, the Vienna rectifier is taken as the research object, and the comparison with the traditional MPDPC shows that the proposed constant frequency model predictive control has good steadystate and dynamic performance.

Modeling and control strategy analysis of a hydraulic energy-storage wave energy conversion system

Worldwide increasing energy demands promote development of environment-friendly energy sources. As consequences, ocean wave is exploited as an ideal energy source to mitigate greenhouse gas emissions. In this paper, a hydraulic energy-storage wave energy conversion system is constructed, and a mathematical model of main components is built for analysis. Control strategies of generator-side and grid-side are defined for the system, where a Vienna rectifier is applied to converter of generator-side. A two-level space vector plane simplified modulation method for Vienna rectifier is designed for the three-level system and a modulation algorithm is detailed, which has lower complexity compared with traditional three-level space vector pulse width modulation (SVPWM) algorithm. An improved adjusting factor method is proposed to solve the potential imbalance of neutral point caused by uneven charging to the upper and lower capacitors in the three-level structure, which optimizes sector division and inhibits the neutral-point potential offset and fluctuation effectively. Using Matlab/Simulink, the intermittent and continuous power conversion modes of the system under different wave conditions are simulated. The results indicate stable operation of the system, feasible topology scheme, modulation algorithm and control strategy, and effective suppression of AC-side harmonics.

Deadbeat predictive power control for Vienna rectifier under unbalanced power grid condition

Due to the low output distortion and switch voltage stress, Vienna rectifiers have been widely utilized in high-power applications such as communication power supplies, wind power systems and electric vehicle charging piles. However, Vienna rectifiers still have to face tough challenges under unbalanced grid considering the inherit operating range limitation caused by its structure. Consequently, a deadbeat predictive power control (DBP-PC) for the Vienna rectifier under unbalanced grid is proposed. Using the positive and negative sequence double dq decoupling current control strategy, the operating range of the Vienna rectifier under unbalanced grid is analyzed. Furthermore, an improved DBP-PC for Vienna rectifiers under unbalanced grid is proposed. By the improved DBP-PC, the stable operating range can be effectively extended. Finally, the corresponding simulations and experiments are executed to demonstrate the performance of the proposed control strategy.

Research on control strategy of VIENNA rectifier based on electric vehicle DC charging module

Because the VIENNA rectifier has fewer switching devices, a high power factor and no need to set dead zone time, the front rectifier of the DC charging module of ev mostly uses VIENNA circuit. However, the DC charging module has higher requirements on the dynamic response capability and stability of the VIENNA rectifier system. The traditional PI double closed loop control strategy has poor dynamic response capability. For this reason, a hybrid control strategy of PI control for current loop and sliding mode control for voltage loop is used to control the VIENNA rectifier to improve the dynamic response and stability of the system. Finally, through the simulation of the rectifier circuit, and the comparison of the simulation results, it can be proved that the dynamic response ability and stability of the hybrid control strategy is relatively good. Finally, a simulation model of VIENNA rectifier is built, and the hybrid control strategy is proved to have good dynamic performance and stability by comparison.

A compound control strategy of three‐phase Vienna rectifier under unbalanced grid voltage

When traditional finite-set predictive power control is applied to Vienna rectifier, the input current will produce a large number of third harmonics under unbalanced power network, which will seriously affect the normal operation of Vienna rectifier. This paper proposes a compound control strategy for three-phase Vienna rectifier based on grid imbalance. And the new finite control set-model predictive direct power control (N-FCS-MPDPC) is used in the inner current loop. By introducing a redefined reactive power, this method can effectively control the second harmonic of instantaneous active power and the second harmonic of instantaneous reactive power at the same time, and realizes the normal operation of Vienna rectifier under the condition of unbalanced power grid. Linear auto disturbance rejection control (LADRC) is adopted in the outer voltage loop, which overcomes the problem of voltage overshoot and slow dynamic response in PI control. Furthermore, in order to solve the difficulty of grid-side voltage acquisition when the grid is unbalanced, a virtual flux based no-grid voltage sensor is introduced to measure the grid voltage. Simulation, along with experimental results, is presented to show that the proposed control strategy has good robustness and fast tracking performance under the condition of power grid imbalance.

Vienna Rectifier-Fed Squirrel Cage Induction Generator Based Stand-Alone Wind Energy Conversion System

Back-to-back voltage source converters are normally preferred for interfacing squirrel cage induction generators (SCIG) with loads in stand-alone wind power generation applications as they allow for maximum power point tracking. However, the total converter losses tend to be very high, especially near the rated wind speed. Therefore, to reduce the power converter related losses, a Vienna rectifier is utilized as the machine-side converter in this article to interface the SCIG. Owing to the limited reactive power handling capability of the Vienna rectifier, a fixed capacitor bank is also required to provide the excitation VAR for the variable speed SCIG. In this article, a new computational method is proposed to calculate the value of this fixed capacitance based on maximizing the yearly energy output from the wind energy conversion system. A voltage sensorless vector control scheme for the Vienna rectifier-fed SCIG with the reference frame oriented along the machine terminal voltage is also proposed, which adheres to the operating limits of the Vienna rectifier and gives much better dynamic performance under load and wind speed transients compared to similar Vienna rectifier based variable speed constant frequency generating systems reported earlier in the literature.

An efficient soft-switched vienna rectifier topology for EV battery chargers

The requirement of high power rated, efficient and high power density grid connected converters has increased due to their extended use in multiple applications such as battery chargers. The proliferation of electric vehicles (EVs) in the transportation market is essentially associated with the performance and reliability of battery chargers. An efficient, compact and fast battery charger is indispensable in order to provide a way to charge an EV in a short time. In view of this fact, this article proposes a soft-switching three-level T-type vienna rectifier, which can be used as a front-end power stage converter in an on-board EV battery charger. The proposed topology achieves high efficiency and high power density by employing soft-switching strategy, which is achieved by incorporating a simple auxiliary network in the proposed circuit. The reduced component stresses and simple control strategy make it an appealing candidate for EV industries to develop this front-end PFC rectifier as a fast battery charger. The high switching operation with reduced power losses, regulated DC at the output, low-harmonic grid current and power factor correction operation are achieved with the proposed topology. The construction, operating principle and simulation analysis of the proposed converter are discussed in detail. In order to show the stand-point of the proposed scheme, a fair comparison of the proposed soft-switched converter with an existing soft-switched 3-level neutral-point diode-clamped converter is carried out in terms of the number of components and complexity in the PWM signals generation. Additionally, an efficiency comparison of the suggested converter is carried out with some existing well-known rectifier topologies at different power loads. The practical implementation of the proposed power converter scheme is checked by building a laboratory-prototype to perform an experimental analysis.

Computationally Efficient Optimal Switching Sequence Model Predictive Control for Three-Phase Vienna Rectifier Under Balanced and Unbalanced DC Links

Unbalanced dc links usually occur when a Vienna rectifier is used as a charger for series-connected battery packs. The redundant vector preselection optimal switching sequence model predictive control (OSS-MPC) scheme does not require weighting factor tuning and is applicable to unbalanced dc links. However, its use is complicated for switching sequence selections and duty cycle calculations. Therefore, this article proposes a computationally efficient OSS-MPC scheme for three-phase Vienna rectifier operating under balanced and unbalanced dc links. The scheme achieves the same performance as that achieved by the redundant vector preselection OSS-MPC scheme, however, its execution is significantly more efficient. In the proposed method, an unbalanced factor is proposed by considering unbalanced dc links, and a look-up table is derived to describe the equivalence relation among the six feasible switching sequences. Then, duty cycles are calculated for only one switching sequence, and the OSS and its duty cycles are reconstructed based on the predefined table. Unlike the redundant vector preselection OSS-MPC scheme, the enumeration process is eliminated in the proposed method, thus, the computational burden is significantly reduced. Experimental results are provided to validate the effectiveness of the proposed method. This article is accompanied by a PDF demonstrating the look-up tables.

Research and Simulation of Three-phase Vienna Rectifier Based on Feedforward Decoupling Control

This paper takes the three-phase VIENNA rectifier as the research object. Aiming at the problem that its dq-coordinate system model has strong coupling and nonlinear characteristics, which makes the design of the controller system more difficult, a control strategy based on feedforward decoupling control is proposed. First, this paper analyzes the working principle and mathematical model of the rectifier, then introduce the newly proposed control system and controller parameter design, and finally build a simulation model with PESIC software. The simulation results verify the correctness and rationality of the proposed feedforward decoupling control. The proposed control strategy can further reduce the harmonic content of AC side of the rectifier, improve the steady-state performance, and have better dynamic performance when the load power changes.

Direct Power Control Strategy for Three-phase Vienna Rectifier

Firstly, through a detailed analysis of the working principle of the voltage-type Vienna rectifier, the mathematical model of the rectifier power control is established according to the mathematical model of the Vienna rectifier based on the equivalent switch function in the d-q two-phase synchronous rotation coordinate system. Secondly, according to the mathematical model of power control, using the principle of direct power control (DPC), the outer loop of the DC bus voltage PI control of the Vienna rectifier is described in detail, the dual loop structure of the direct power control inner loop and the overall system structure. Finally, the control strategy was verified by Simulink simulation. The results show that the Vienna rectifier based on direct power control has good steady state and dynamic performances, and verify the correctness and feasibility of the control strategy.

A Current Control Method With Extended Bandwidth for Vienna Rectifier Considering Wide Inductance Variation

Wide inductance variation of powder core inductors used in the Vienna rectifier challenges the system stability and limits the bandwidth of the current loop, which leads to more harmonics. In this article, a current control method with extended bandwidth is proposed for a three-phase Vienna rectifier to improve the system stability and reduce harmonics. The averaged model of three-phase Vienna rectifier considering the inductance variation is derived in the natural a-b-c frame. The impact of inductance variation on control system is analyzed. To extend the control bandwidth, the instantaneous inductance is obtained based on a piecewise linearization method and is embedded into a classical current control loop. Since the control method is easy to implement and occupies a little time of digital controller, the sampling frequency can be increased to twice the sampling frequency, which makes the bandwidth further extended. The proposed method keeps a wide and fixed bandwidth of the current loop, which improves the harmonics reduction ability and dynamic performance compared with classical control methods. Finally, the effectiveness of the proposed method is verified by a three-phase Vienna rectifier prototype.

Voltage Oriented Controller Based Vienna Rectifier for Electric Vehicle Charging Stations

Vienna rectifiers have gained popularity in recent years for AC to DC power conversion for many industrial applications such as welding power supplies, data centers, telecommunication power sources, aircraft systems, and electric vehicle charging stations. The advantages of this converter are low total harmonic distortion (THD), high power density, and high efficiency. Due to the inherent current control loop in the voltage-oriented control strategy proposed in this paper, good steady-state performance and fast transient response can be ensured. The proposed voltage-oriented control of the Vienna rectifier with a PI controller (VOC-VR) has been simulated using MATLAB/Simulink. The simulations indicate that the input current THD of the proposed VOC-VR system was below 3.27% for 650V and 90A output, which is less than 5% to satisfy the IEEE-519 standard. Experimental results from a scaled-down prototype showed that the THD remains below 5% for a wide range of input voltage, output voltage, and loading conditions (up to 2 kW). The results prove that the proposed rectifier system can be applied for high power applications such as DC fast-charging stations and welding power sources.

Hybrid Modulation Strategy for the Vienna Rectifier

The Vienna rectifier can produce three voltage levels, however only the connection to the neutral-point is fully controllable using the bidirectional switches. When the neutral-point voltage is not imposed in a phase-leg, the polarity of the pulses generated depends on the diode that is conducting in that phase-leg, which is defined by the current direction. As a result, the voltage pulses generated can go in the opposite direction to what is demanded by the controller, and the current becomes distorted. This can be mitigated by injecting a particular zero sequence so that the reference voltage is clamped to the neutral-point during the intervals, where the current of a phase-leg has the opposite sign than its reference voltage. However, the converter is at risk of entering into overmodulation when operating with high modulation indices. In this article, a hybrid modulation strategy is introduced where a calculated minimal amount of reactive current depending on the operating conditions is injected to avoid overmodulation. The reduction of reactive current required compared to the state-of-the-art solutions is up to 100% in certain operating conditions. With the proposed method, the Vienna rectifier can operate in a wide range of power factors without compromising the quality of the source currents. The concept is verified by simulation and in a 1-kW Vienna rectifier experimental setup.

Hard Switching Characteristics of SiC and GaN Devices for Future Electric Vehicle Charging Stations

Wide bandgap (WBG) semiconductors offer better switching and lower losses, and it is not uncommon to utilize them for high power density, high-efficiency applications. Gallium nitride (GaN) and Silicon carbide (SiC) are the most common WBG materials that are responsible for major switching level changes relative to silicon (Si) devices. This paper explores the contrast of performance between Si, SiC, and GaN devices. The output performance of Si, SiC, and GaN power devices includes efficiency, energy bandgap, thermal conductivity, carrier mobility, saturation speed, power density, switching characteristics, and conduction losses. This article also proposes a Vienna rectifier with GaN materials, which operates as a front-end rectifier on a high-density battery charger targeted at high-performance applications such as electric vehicle charging stations, aircraft applications, and welding power sources. The system would reduce the total harmonics distortion (THD) to less than 5%, and the power factor would be increased to unity to satisfy the IEEE-519 standard.

A Novel Method to Evaluate the Influence of Vienna Rectifier Neutral-Point Voltage Fluctuation on Input Current Quality

The inherent neutral-point (NP) voltage fluctuation of the Vienna rectifier could have side effects on the input current quality. However, such effects have not been thoroughly analyzed in the literature yet. In this article, based on the three-level to two-level space vector modulation transformation, a novel method to evaluate the influence of the NP voltage fluctuation on the input current quality is introduced, which could optimize the NP control parameters. The proposed method superimposes the NP voltage fluctuation on the basis vectors, thereby establishing the correlation between the NP voltage fluctuation and the square root mean square of the input current ripple. The detailed model of the NP oscillation under two-level coordinates is presented. By combining the two-level modulation, NP voltage hysteresis control is adopted to simplify NP voltage control and suppress the NP low-frequency oscillation. The comprehensive influence of the NP compensation coefficient on the input current quality under NP hysteresis control is obtained, and the hysteresis control parameters are optimized by using the proposed evaluation method. The simulation and experimental results verify the correctness and effectiveness of the proposed evaluation method.

Virtual synchronous motor based-control of Vienna rectifier

Vienna rectifiers are widely used because of their advantages of high power-factor, low voltage stress on the power semiconductor switches, high power density, stable output voltage, low current harmonic content, and good economics. And gradually applied to the front stage AC/DC part of the electric vehicle charger. Traditional Vienna rectifier control methods include double closed-loop control, hysteresis current control, and Sliding mode variable structure control strategy, but all strategies usually regulate DC-Voltage and keep the unity power factor. However, if it is used for the interface part of the electric vehicle charger with frequent load switching, it is necessary not only to ensure the stability of the output voltage and low THD of the current, but also to be able to respond to the fluctuation of the voltage and frequency of the power system and improve the inertia and damping at the interface. Thereby, the stability of the power grid is improved to a certain extent, and fast-charging is ensured while being grid-friendly. Therefore, this paper proposes to apply the virtual synchronous motor control to the Vienna rectifier to improve the adaptability of the grid to the large-scale access of electric vehicles. Build the topology of the Vienna rectifier in simlink and the modulation method using SVPWM to build a complete model on the basis of VSM.

Power Quality Improvement in Induction Heating System Using Vienna Rectifier Based on Hysteresis Controller

—Induction heating (IH) technology is increasingly implemented in domestic, industrial as well as medical applications in the modern era. Designing of modern IH system incorporates high frequency (HF) resonant converter that results in the generation of HF harmonics. The HF harmonics has an inherent tendency to back flow toward the supply side and deteriorates the power quality at the grid side. So, in order to mitigate this power quality issue, a single phase Vienna rectifier (1-ø VR) based IH system has been proposed. Hysteresis and pulse density modulation controller is employed in the proposed IH system. The unidirectional nature of VR protects the overall IH system from the HF harmonics. VR also improves the power factor of the input supply along with low total harmonic distortion of input current. The feasibility of the proposed IH system is validated through MATLAB/Simulink environment. Finally, an experimental prototype of 1200 W has been developed and further correlated with the simulation results to verify the uniqueness of the proposed IH system.

A Fast Processing Discontinuous Control Strategy for Vienna Rectifier

In this paper, Vienna rectifier has been inspected as one of the prominent topologies among three-level switched-mode rectifiers. A fast processing discontinuous modulation strategy has been proposed with the aim of improving the rectifier’s performance. The proposed method not only takes advantage of special properties available in three-phase three-level rectifiers, but also reduces the control design complexity and the switching loss. Moreover, neutral point voltage balancing is inherently realized. To achieve these goals, the rectifier is decoupled into two 2-level boost converters in every defined region, leading to simple modulation algorithm and fast processing control strategy. The validity of the proposed technique has been verified via simulation and experimental results conducted on a laboratory prototype.