Pulse Width Modulation Rectifier Research Articles

Research on Hybrid Rectifier for High Power Electrolytic Hydrogen Production Based on Modular Multilevel Converter

Aiming at the problem that silicon-controlled rectifiers (SCR) and pulse width modulation (PWM) rectifiers cannot balance high power levels, high hydrogen production efficiency, and high grid connected quality in the current research on rectifier power supplies for electrolytic hydrogen production, a new hybrid rectifier topology based on a modular multilevel converter (MMC) is proposed. The hybrid topology integrates a silicon-controlled rectifier (SCR) with an auxiliary power converter, wherein the SCR is designated as the primary power source for electrolytic hydrogen production. The auxiliary converter employs a cascaded modular multilevel converter (MMC) and an input-series-output-parallel (ISOP) phase-shifted full-bridge (PSFB) arrangement. This configuration allows the auxiliary converter to effectively mitigate AC-side harmonics and minimize DC-side ripple, concurrently transmitting a small amount of power. The effectiveness of the hybrid rectifier in achieving low ripple and harmonic distortion outputs was substantiated through hardware-in-the-loop experiments. Notably, the hybrid topology is characterized by its enhanced electric-to-hydrogen conversion efficiency, elevated power density, cost efficiency, and improved grid compatibility.

Design and Implementation of Robust H∞ Control for Improving Disturbance Rejection of Grid-Connected Three-Phase PWM Rectifiers

In response to the high performance requirements of pulse width modulation (PWM) converters in grid-connected power systems, H-Infinity (H∞) control has attracted significant research interest due to its robustness against parameter variations and external disturbances. In this work, an advanced robust H∞ control is proposed for a grid-connected three-phase PWM rectifier. A two-level control strategy is adopted, where cascaded H∞ controllers are designed to simultaneously regulate the DC bus voltage and input currents even under load disturbances and non-ideal grid conditions. As a result, unit power factor, stable DC bus voltage, and sinusoidal input currents with lower harmonics can be accurately achieved. The design methodology and stability of the proposed controller are verified through a comprehensive analysis. Simulation tests and experimental implementation on a dSPACE 1103 board demonstrate that the proposed control scheme can effectively enhance disturbance rejection performance under various operating conditions.

High-Efficient Direct Power Control Scheme Using Predictive Virtual Flux for Three-Phase Active Rectifiers

In recent years, the pulse-width-modulation (PWM) converter has been found to have extensive applications in renewable energy, industrial fields, and others. The high efficiency requirement is crucial to operating a PWM rectifier in various applications, in addition to the fundamental control objectives of sinusoidal grid currents and the correct DC bus voltage. Additionally, in practical application, another issue arises when the grid voltage frequently experiences distortion, leading to a distorted grid current and a significant rise in total harmonic distortion (THD). To resolve these problems, a model predictive virtual flux-based direct power control (MPVFDPC) with improved power loss performance is proposed based on an integrated switching state predetermination strategy. The proposed MPVFDPC for PWM rectifier inherits the merits of both virtual flux control and direct power control, which have fast dynamic performance and the grid current THD is considerably decreased under distorted grid voltage states. The proposed technique aims to minimize switching loss under ideal and distorted grid voltage states by exploiting the discontinuous modulation concept by using a switching state predetermination strategy. The MPVFDPC with switching state predetermination strategy is proven by employing it in experiments as well as simulations in comparison with previous models: predictive direct power control (Conv. MPDPC) and conventional MPVFDPC (Conv. MPVFDPC). The acquired waveforms and quantitative data are employed to prove the effectiveness of the developed algorithm.

The Study of Multi-Terminal DC Systems in an Offshore Wind Environment: A Focus on Cable Ripple Analysis

This paper studies the THD and AC losses on the DC cables of offshore wind farm-based multi-terminal HVDC systems when they extract and deliver power from and to more than one connection point. In the paper, the study of a full system PLECS + Simulink model with two branches, including a wind resource, a wind turbine, a Permanent Magnet Synchronous Generator (PMSG), a Pulse Width Modulation (PWM) rectifier, a Single Active Bridge (SAB) DC–DC converter, an Input Parallel Output Series (IPOS) DC–DC converter, HVDC cables, and a simplified onshore system, is presented. It focuses on the investigation of the output ripple content of multiple DC–DC converters on DC cables under different wind conditions with different voltage and power ratings. The importance of the study is providing a general understanding of the operation of the innovative offshore wind farm-based DC system, as well as the interaction between different DC–DC converters and their influence on cable ripple content under different situations.

Suppression Strategy of Starting Current Impulse in the Front Stage Rectifier of Electric Vehicle WPT System

The three-phase voltage type Pulse Width Modulation (PWM) rectifier is widely used in the front-end power factor of electric vehicle wireless charging systems due to its simple control structure and easy implementation. The system often adopts a double closed-loop PI control method based on voltage and current, which inevitably leads to a significant starting current surge and poses significant risks to the safe operation of the equipment. On the basis of establishing a mathematical model for PWM rectifiers, this article analyzes in detail the causes of starting over-current and designs a starting strategy with a voltage outer proportional and integral separated active current directly given. Simulation experiments show that this method can reduce the starting over-current of PWM rectifiers and the excessive DC voltage surge towards normal operation during the starting process.

Virtual Power Grid Flux-Oriented Vector Control for Three-Phase Voltage-Type PWM Rectifier

More considerable power distortions are produced by the non-reversible diode-bridge rectifiers in the power system’s AC-DC conversion technology. In addition, bridge-rectifiers worsen energy quality and decrease power factor. Three-Phase Pulse Width Modulation (3phase-PWM) rectifiers have seen rapid growth in use due to recent breakthroughs in power device technology. Its benefits include a unity power factor, no harmonic distortion, and pulsating direct currents. An actual power regulation technique based on a novel virtual power grid controller is suggested to cheaply regulate a 3phase-PWM converter with good performance. The study introduces a new sensorless control scheme to improve the 3phase-PWM-performance rectifier. The proposed control technique employs the virtual power grid flux-oriented vector control with a Second-Order Generic Integral with Instantaneous Phase Lock Loop (SOGI-IPLL) to overcome the problems inherent in relying only on low-pass filter estimates. The virtual power grid flux value may then determine the phase difference. The IPLL takes the phase angle as an input and is utilized to construct the power-oriented vector control. The proposed power grid flux-oriented control strategy combines the VFidea with SOGI-IPLL to circumvent the restrictions imposed by relying only on an integrator of low-pass filters (LPF) to provide an estimate. A refined Virtual flux (VF) estimator with direct power control can improve management at a cheaper cost and more efficiently. The modeling findings demonstrate that the DC voltage input and power grid throughput of the 3phase-PWM rectifier can be successfully regulated in both the rectification and inversion states, allowing for the effective functioning of the 3phase-PWM rectifier.

Improved Clamped Z-Source Converter with Optimized Maximum Power Point Tracker for Hybrid Renewable Energy Systems Based Energy Management System

In light of the intermittent and seasonal nature of wind and solar energy, electrical systems are becoming more problematic to operate. The purpose of the work is to establish an energy storage system that helps to minimize such operational challenges, which are essential to improve grid stability and reliability. The tasks solved in the article to achieve the given goal are the following: incorporating an energy management system with the aid of improved converter and optimized maximum power point (MPPT) for (Photovoltaic) PV and PMSG (permanent magnet synchronous generator) based wind system. On comparing with conventional Z-source converters, a novel improved clamped Z-source converter, which is utilized in this work has high efficiency with low THD and it has the capacity to protect electrical circuits against damage caused by short circuits, overcurrent and overvoltage. The Pulse Width Modulation (PWM) rectifier is implemented to convert AC-DC supply obtained from the PMSG wind system. Firefly optimization with an aid of Radial Basis Function Neural Network (RBFNN) technique is employed as an MPPT system for extracting optimal power from photovoltaic system. The excess energy obtained from the hybrid sources are stored in the battery and it is controlled by the recurrent neural network (RNN) with the bidirectional converter. The overall developed system is executed in MATLAB software and the most important outcomes are demonstrated in terms of high efficiency with 91.2%, high tracking efficiency of 98.54% and reduced THD of 2.45% respectively. The significance of results obtained in this research lies in the advancement of renewable energy integration technologies. By overcoming the challenges associated with intermittent energy sources, the developed system contributes to the improvement of grid stability and reliability.

A Multiple-Sensor Fault-Tolerant Control of a Single-Phase Pulse-Width Modulated Rectifier Based on MRAS and GPI Observers

Due to their advantages in ensuring low harmonic distortion and high power factors, single-phase Pulse-Width Modulated (PWM) rectifiers are widely employed in several industrial applications. Generally, the conventional control loop of a single-phase PWM rectifier uses both voltage and current sensors. Hence, in case of sensor fault, the performance and the availability of the converter can be seriously compromised. Therefore, diagnosis approaches and fault-tolerant control (FTC) strategies are mandatory to monitor these systems. Accordingly, this paper introduces a novel multiple-sensor FTC scheme for a single-phase PWM rectifier. The proposed fault diagnosis approach relies on joining several Generalized Proportional Integral (GPI) and Model Reference Adaptive System (MRAS) observers with a residual generation technique to detect and isolate sensor faults in a simple and reliable manner. While conventional sensor FTC methods dedicated to PWM rectifiers can only deal with single faults, the suggested approach guarantees a very good effectiveness level of sensor fault detection, isolation (FDI) and FTC of multiple-sensor fault occurrence scenarios. Consequently, the single-phase PWM rectifier can work with only the survivable single sensor with the guarantee of very good performance as in healthy operation mode. The effectiveness of the proposed sensor FDI approach and its control reconfiguration performance are demonstrated through both extensive simulation and experimental results.

Model Predictive Based Direct Power Control Method Using Switching State Preference for Independent Phase Loss Decrease of Three-Phase Pulsewidth Modulation (PWM) Rectifiers

Model Predictive Based Direct Power Control Method Using Switching State Preference for Independent Phase Loss Decrease of Three-Phase Pulsewidth Modulation (PWM) Rectifiers

Dynamic Performance Improvement of Wound Rotor Synchronous Starter/Generator System Based on PWM Rectifier

This paper proposes an active field current tracking (AFCT) control strategy for pulse width modulation (PWM) rectifier, which can remarkably enhance the system’s dynamic performance of wound rotor synchronous starter/generator (WRSSG) system when the load changes. WRSSG system uses a PWM converter in the aero-engine starting process and can reuse the power circuit as a PWM rectifier for high-voltage direct current (HVDC) power generation, thus simplifying the system structure, volume, and weight. The mathematic model of WRSSG system with PWM rectifier is introduced. Based on the system model, the PI controller of armature current loop is designed. The nonlinear PI controller of excitation voltage loop is also illustrated. A 15kW WRSSG system based on PWM rectifier is implemented. The AFCT control strategy and its high dynamic performance are verified by experiments. The simple system structure and distinguished dynamic performance of PWM rectifier with AFCT control can make the WRSSG system more competitive in aircraft applications.

A High-Accuracy-Light-AI Data-Driven Diagnosis Method for Open-Circuit Faults in Single-Phase PWM Rectifiers

Data-driven solutions like artificial intelligence (AI) are more upright and effectual for fault diagnosis in the power converter system. To decrease computing load and improve the diagnosis speed of the intelligent algorithm, a high-accuracy-light-AI data-driven open-circuit diagnosis method is proposed to diagnose single or multiple IGBT open-circuit faults in the single-phase pulse width modulation (PWM) rectifiers. Firstly, the fault characteristics of three fault scenarios are analyzed to seek the most critical features and provide prior knowledge for developing the intelligent diagnostic algorithm. Then, a fast-learning algorithm named random vector function link network (RVFL) is utilized to extract the mapping knowledge between the well-selected features and fault modes. To balance the testing accuracy and calculation time of the diagnostic algorithm, the RVFL parameters are tuned to decrease the computing burden. After that, a decision-making framework is designed for identifying the faults in real-time. Finally, the effectiveness of the proposed fault diagnosis method is thoroughly verified by extensive experimental tests. A substantial comparison to state-of-the-art techniques shows the proposed scheme’s superiority in diagnostic accuracy, computing time, and diagnosis time.

Reliable current control for single‐phase pulse width modulation rectifiers based on H∞ loop shaping controller

AbstractIn this study, H∞ loop shaping is designed for single‐phase pulse width modulation (PWM) rectifier under current sensor gain faults. Pre‐compensator is used to obtain the desired loop shape at all frequencies and robust stabilization through the normalized coprime factorization. The mathematical model for the rectifier is developed to obtain the nominal plant transfer function, and two algebraic Riccati equations are used to solve the designed controller and obtain the loop shaping controller by combining the designed controller with the weights. ν‐gap metric is adopted to measure the magnitude of the current sensor gain fault that can be stabilized by the controller. The proposed controller is compared with H∞‐mixed sensitivity (H∞‐MS) controller. The robustness capability and dynamic performance is investigated and, hardware‐in‐loop experimental results show excellent balance between robustness and performance in the presence of current sensor gain faults.

Finite-Time Adaptive Fuzzy Control for Three-Phase PWM Rectifiers With Improved Output Performance

For three-phase pulse width modulation (PWM) rectifiers, system uncertainties, such as load disturbances, parametric uncertainties, and grid disturbances, may result in significant DC-link voltage fluctuations, degrade the quality of grid currents, and even lead to system instability. To address this issue, a modified dynamic model of the PWM rectifier with system uncertainties is established, and a finite-time adaptive fuzzy control (FTAFC) method with the dual-loop structure is proposed. In the outer voltage loop, a finite-time adaptive law is used to maintain stable DC-link voltages despite load disturbances. In the inner power loop, an adaptive fuzzy technique is used to estimate and compensate system uncertainties, thus ensuring finite-time power tracking. It is confirmed that all signals of the closed-loop system are finite-time bounded. The experimental and simulation results demonstrate the effectiveness of the proposed method.

Fractional-Order Linear Active Disturbance Rejection Control Strategy for Grid-Side Current of PWM Rectifiers

To further improve the performance of linear extended state observer (LESO), a novel fractional-order linear extended state observer (FOLESO) is proposed in this paper. By incorporating a fractional-order term into the framework of traditional LESO, the design of FOLESO is more flexible and thereby the disturbance estimation error can be further reduced. Based on the proposed FOLESO, a fractional-order linear active disturbance rejection control (FOLADRC) strategy has been designed for grid-side current control of three-phase voltage-type pulse width modulation (PWM) rectifiers. In this way, the harmonic suppression property can be enhanced without sacrificing the tracking performance, and the ideal grid-side current can be achieved. Furthermore, the detailed design process, implementation mode and parameter tuning of FOLADRC are also given in this paper. The theoretical analysis and experimental results show that the proposed method is effective and superior to the traditional PI control or linear active disturbance rejection control (LADRC) strategy.

Disturbance Decoupling for a Single-Phase Pulse Width Modulation Rectifier Based on an Extended H-Infinity Filter

The growing utilization of single-phase pulse width modulation (PWM) rectifiers in various applications has spurred interest in detecting and monitoring faults in these devices. In particular, voltage and current sensors play a crucial role in the control loop of these rectifiers. However, sensor faults can significantly affect the converter’s performance and availability. This paper introduces a novel and efficient method for detecting and decoupling sensor faults in single-phase PWM rectifiers. The proposed method utilizes residual generation and incorporates an extended filter within the rectifier. Unlike conventional filters, the presented fault detection and isolation (FDI) method effectively eliminates the influence of disturbances on the residual signal. This feature helps prevent false alarms in the monitored system, ensuring reliable fault detection. To evaluate the effectiveness of the approach, hardware-in-the-loop and simulation tests were conducted. The results from these tests provide substantial evidence supporting the efficacy of the proposed method. The hardware-in-the-loop experiments involved real-world implementation, validating the practicality and reliability of the approach. Meanwhile, simulation tests allowed for a comprehensive analysis of system behavior and performance under various fault scenarios. The findings demonstrate the rapid and dependable nature of the proposed method for detecting and decoupling sensor faults in single-phase PWM rectifiers. By effectively mitigating the impact of disturbances on the residual signal, false alarms are minimized, ensuring accurate fault detection. The experimental validation highlights the practical applicability and effectiveness of the proposed approach, making it a valuable contribution to fault detection in single-phase PWM rectifiers.

Robust Sensor Fault Detection for a Single-Phase Pulse Width Modulation Rectifier

Maintaining safe and efficient operation in a single-phase pulse width modulation (PWM) rectifier that employs current sensors relies heavily on accurate sensor readings. However, several factors such as environmental conditions, aging, or damage can lead to sensor faults. Therefore, it is imperative to implement robust fault detection methods to ensure reliable system operation. The use of unknown input observer techniques is one such method that involves analyzing the differences between actual and estimated states to detect and identify faults in the system. This paper presents the development of a fault detection method that employs an unknown input observer with high sensitivity to faults and disturbance rejection to achieve robust fault detection. The method involves modeling the system as a state-space model and designing an observer to estimate the system’s state variables based on input and output measurements. The deviations between the actual and estimated states are then analyzed to detect and identify sensor faults, without the need for additional hardware, making it a cost-effective solution. Hardware-in-the-loop tests confirm the effectiveness of the proposed method.

Single-phase energy-fed AC electronic load based on DQ current decoupling

The single-phase pulse width modulation (PWM) converter is the main research object to realize single-phase AC electronic load. To achieve high-quality energy feedback, this paper studies the topology of the PWM rectifier, the mathematical model of DQ current decoupling control, SOGI-PLL phase-locked model analysis, and the energy feedback unit with bipolar SPWM inversion to 50 Hz sinusoidal AC. The scheme is simulated and validated by Matlab/Simulink. The simulated characteristic unit can simulate resistive, inductance, and capacitive loads. The energy feedback unit can verify the stability, high efficiency, and practicability of the scheme with 50 Hz sinusoidal AC feedback.

Virtual Vector-Based Direct Power Control of a Three-Phase Coupled Inductor-Based Bipolar-Output Active Rectifier for More Electric Aircraft

Direct power control (DPC) has gained increasing attention in recent years as a simple and efficient control strategy for pulse width modulation (PWM) rectifiers. In this paper, the idea of DPC is introduced into the three-phase coupled inductor-based bipolar-output active rectifier (TCIBAR) for the first time, and a virtual vector-based direct power control (VVB-DPC) strategy is proposed for TCIBAR to realize the bipolar DC power supply for more electric aircraft (MEA). First, the mathematical model of the TCIBAR is deduced, and the basic principle of the classic DPC strategy is reviewed. On this basis, the limitations of the classic DPC strategy in TCIBAR control are analyzed. Second, a set of virtual vectors are derived to establish a novel virtual-vector switching table. Based on the virtual-vector switching table, the hysteresis power control of TCIBAR can be realized without affecting the DC-side neutral-point potential of TCIBAR. Finally, a neutral-point potential control method based on DPC architecture is studied and integrated into the VVB-DPC strategy to maintain the bipolar DC voltage balance of TCIBAR under unbalanced load conditions. The VVB-DPC strategy is experimentally studied on a TCIBAR prototype, and the experimental results verify the feasibility and effectiveness of the proposed strategy.

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.

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.