Pulse Width Modulation Control Strategy Research Articles

부트스트랩 회로를 적용한 3-레벨 NPC 인버터의 저속 운전을 위한 PWM 스위칭 전략

This paper proposes the pulse width modulation (PWM) control strategy for low-speed operation in the three-level neutral-point-clamped (NPC) inverters based on the bootstrap gate drive circuit. As a purpose of the cost reduction, several papers have paid attention to the bootstrap circuit applied to the three-level NPC inverter. However, the bootstrap gate driver IC cannot generate the gate signal to the IGBT for low-speed operation, because the bootstrap capacitor voltage decreases under the threshold level. For low-speed operation, the dipolar and partial-dipolar modulations can be the effective solution. However, these modulations have drawbacks in terms of the switching loss and THD. Therefore, this paper proposes the PWM control strategy to operate the inverter at low-speed and to minimize the switching loss and harmonics. The experimental results are presented to verify the validity on the proposed method.

Fuzzy PWM based on Genetic Algorithm for battery charging

This paper investigates the use of fuzzy logic control together with Genetic Algorithm (GA) to tune corresponding membership functions in a pulse width modulation voltage (PWM)-based converter for battery charging. For quick charging purposes, a current-charging mode is built on the charging battery series with small impedance resistance. Once the rechargeable battery voltage reaches the preset output voltage value during the current-charging mode, constant voltage-charging mode should take to do the battery charging. No matter what you use a voltage/current mode for battery charging, the PWM converter with tuning duty cycle is necessary to obtain various output voltages to charge battery. The proposed pulse width modulation (PWM) control strategy based on fuzzy logic systems is applied to charge batteries for buck converter. A simulation is proposed to illustrate the efficiency of the design proposed in this paper.

High Power Density Series Resonant Inverter Using an Auxiliary Switched Capacitor Cell for Induction Heating Applications

This paper proposes a unique topology of voltage-fed high-frequency series load resonant inverter with a lossless snubber capacitor and an auxiliary switched cell for induction heating appliances. The main objective of this paper is to demonstrate how high power density can be achieved by including a switched capacitor cell with the capacitor-clamped half-bridge zero voltage switching high-frequency inverter circuit using the PWM control scheme. The operation principle of the proposed inverter circuit is based upon an asymmetrical duty cycle pulsewidth modulated (PWM) control scheme. The operating performances of high-frequency ac regulation and power conversion efficiency characteristics are shown through experiments with their soft-switching operating ranges.

A Novel Reduced Switching Loss Bidirectional AC/DC Converter PWM Strategy With Feedforward Control for Grid-Tied Microgrid Systems

This paper presents a novel simplified pulse width modulation (PWM) strategy for the bidirectional ac/dc single-phase converter in a microgrid system. Then, the operation mechanism of the novel simplified PWM is clearly explained. The number of switchings of the proposed simplified PWM strategy is one-fourth that of the conventional unipolar PWM and bipolar PWM. Based on the novel simplified PWM strategy, a feasible feedforward control scheme is developed to achieve better rectifier mode and inverter mode performance compared with the conventional dual-loop control scheme. The proposed simplified PWM strategy with the proposed feedforward control scheme has lower total harmonic distortion than the bipolar PWM and higher efficiency than both unipolar and bipolar PWMs. Furthermore, the proposed simplified PWM operated in the inverter mode also has larger available fundamental output voltage VAB than both the unipolar and bipolar PWMs. A prototype system is constructed and the control scheme is implemented using FPGA Spartan-3E XC3S250E. Both simulation and experimental results verify the validity of the proposed PWM strategy and control scheme.

Boost-Derived Hybrid Converter With Simultaneous DC and AC Outputs

This paper proposes a family of hybrid converter topologies which can supply simultaneous dc and ac loads from a single dc input. These topologies are realized by replacing the controlled switch of single-switch boost converters with a voltage-source-inverter bridge network. The resulting hybrid converters require lesser number of switches to provide dc and ac outputs with an increased reliability, resulting from its inherent shoot-through protection in the inverter stage. Such multioutput converters with better power processing density and reliability can be well suited for systems with simultaneous dc and ac loads, e.g., nanogrids in residential applications. The proposed converter, studied in this paper, is called boost-derived hybrid converter (BDHC) as it is obtained from the conventional boost topology. The steady-state behavior of the BDHC has been studied in this paper, and it is compared with conventional designs. A suitable pulse width modulation (PWM) control strategy, based upon unipolar sine-PWM, is described. A DSP-based feedback controller is designed to regulate the dc as well as ac outputs. A 600-W laboratory prototype is used to validate the operation of the converter. The proposed converter is able to supply dc and ac loads at 100 V and 110 V (rms), respectively, from a 48-V dc input. The performance of the converter is demonstrated with inductive and nonlinear loads. The converter exhibits superior cross-regulation properties to dynamic load-change events. The proposed concept has been extended to quadratic boost converters to achieve higher gains.

Analysis, design and implementation of isolated bidirectional converter with winding‐cross‐coupled inductors for high step‐up and high step‐down conversion system

In this study, a zero voltage switching (ZVS) isolated bidirectional DC/DC converter is proposed for high step-up and high step-down conversion systems. In the low voltage side, an interleaved Buck and Boost converter is employed to reduce the current ripple and improve the power level. In the high voltage side, a modified three-level structure is adopted to bring each power switch sustain half of the high bus voltage, which makes the low voltage rated MOSFETs available for the performance improvement. Two coupled inductors are interleaved in the low voltage side and in series in the high voltage side, which can not only serve as the filter inductors for the current ripple cancellation, but also as the transformer for isolation, which is named as winding-cross-coupled inductors. As a result, the magnetic size can be reduced to enhance the power density. ZVS operation is ensured from light load to full load conditions by the advanced pulse width modulation plus phase shift control strategy. The voltage regulation and transferred power are decoupled for easy design and implementation. Finally, a 1.5 kW 48 V/800 V prototype is built to verify the effectiveness of the proposed converter.

Design of Automobile Gear Fatigue Test System Based on Servo Control

A kind of decoupling mathematical model of Permanent Magnet Synchronous Motor (PMSM) in two-phase rotated coordinate is established. According to the Space Vector Pulse Width Modulation (SVPWM) control strategy and optimum parameters scheme, the three closed-loop servo control system for Automobile Gear Fatigue Test (AGFT) is designed. Rapid and accurate positioning must meet the requirement of testing gear fatigue system. Simulation results show it can achieve the goal of linearization control and the scheme mentioned is feasible and effective.

Improved Pulse Regulation Control Technique for Switching DC–DC Converters Operating in DCM

Improved pulse regulation (IPR) control, a novel control technique for switching dc-dc converters, is proposed and studied in this paper. According to the output voltage and load current of the switching dc-dc converter, IPR control technique achieves output voltage regulation by generating control pulse train made up of some preset control pulses with different duty ratios. IPR control needs only comparators, triggers, and some simple logic devices, without error amplifier and the corresponding compensation circuit of pulse width modulation control scheme, thus IPR control scheme is easy to realize, benefits with excellent transient performance and stability. The principle and operation of IPR control scheme are introduced and illustrated with buck converter operating in discontinuous conduction mode as an example. Simulation and experimental results are presented to show that IPR-controlled converter has much lower output voltage ripple and more accurate output voltage regulation than PR converter.

Mathematical Modelling of PV Module With multilevel 3-Ø inverter using SPWM technique for Grid application

This paper presents a simple step-by-step procedure for the simulation of photovoltaic modules with Matlab/ Simulink as well as Grid connected system for considering Three phase multistring inverter with sinusoidal pulse width modulation control scheme. The single -diode equivalent circuit is employed in order to Investigate I-V and P-V characteristics of a solar module. This paper focuses on a Matlab/SIMULINK model of a photovoltaic cell and Grid connected system, considering three phase multistring inverter with SPWM control scheme to reduce harmonics in primary side and same was applied to grid with prediction of PV cell behaviour under different physical and environmental parameters. The PV model is based on mathematical equations and is described through an equivalent circuit including a photocurrent source, a diode, a series resistor and a shunt resistor. The developed model can also be used to extract the physical parameters for a given solar PV cell as a function of temperature and solar radiation. Three PV strings are cascaded together in parallel configuration and connected to a five-level inverter to produce output voltage in five levels of Vdc. That was equivalent to the amplitude of the triangular carrier signal were used to generate PWM signals for the switches. The inverter offers much less total harmonic distortion and can operate at near-unity power factor.

Efficient hybrid sinusoidal pulse-width modulation control schemes for cascaded five-level H-bridge inverter-fed industrial drives

The performance of a pulse-width modulation (PWM) technique for soft switched cascaded five-level inverters are emphasised. The hybrid PWM topologies have been on spot light in industrial drives, the cascaded multilevel inverter can be asserted due to high power medium voltage applications. The proposed modulation schemes are hybrid alternative phase opposition disposition, hybrid phase shift carrier, hybrid single carrier sinusoidal PWM (SPWM) schemes. It inherits the switching loss reduction along with reduced harmonic performance of cascaded multilevel inverter fed drive system. The effectiveness of the novel concepts are validated experimentally. Simulation study of the inverter employing the proposed hybrid alternative phase opposition disposition and hybrid single carrier SPWM strategies has been done in MATLAB/Simulink. Among the existing design the efficient strategy is employed in the hardware implementation of hybrid multilevel inverter.

Inverse Watkins–Johnson Topology-Based Inverter

A Z-source inverter (ZSI) uses an L-C impedance network between the source and the voltage source inverter (VSI). It has the property of stepping down or stepping up the input voltage, as a result, the output can be either higher or lower than the input voltage as per requirement. This topology also possesses robust electromagnetic interference noise immunity, which is achieved by allowing shoot through of the inverter leg switches. This letter proposes an inverter circuit based on the inverse Watkins-Johnson (IWJ) topology that can achieve similar advantages as that of a ZSI. The proposed circuit requires two switches and one pair of an LC filter apart from the VSI. The systematic development of this inverter topology is described starting from the basic IWJ circuit. Steady-state analysis and implementation of the proposed topology are also described. The pulse width modulation control strategy of the inverter is explained. An experimental prototype is used to validate the proposed circuit.

Study and control of 5-level PWM rectifier-5-level NPC active power filter cascade using feedback control and redundant vectors

The purpose of this paper is to develop a control and regulation method for the input DC voltages of a 5-level neutral point clamping (NPC) active power filter (APF). This APF is applied for the enhancement of medium-voltage network power quality by compensation of harmonic currents produced by an induction motor speed variator. In the first part, the authors present a topology of a 5-level NPC voltage source inverter and its simplified space vector pulse width modulation (SVPWM) control strategy. In the second part, the control strategy of the 5-level pulse width modulation current rectifier is presented. In the third part, to remedy to instability problem of the input DC voltages of the APF, the authors propose the feedback control of the 5-level rectifier associated with a simplified SVPWM with the redundant vectors method for the 5-level APF. After that, the sliding mode regulator used to control the APF is developed. The application of the proposed control algorithm offers the possibility of stabilizing the DC voltages of the APF. The stable DC bus supply associated with the sliding regulator of the APF allows the obtainment of low-harmonic content network currents with unity power factor. The instability problem associated with the use of the multilevel APF is solved. The obtained results are full of promise for the use of the multilevel APF in medium-voltage and high-power applications.

The Design and Research of Switching Power Amplifier Used on Magnetic Suspension Support

This paper focuses on the switching power amplifier of magnetic suspension support. The principle of magnetic suspension support was described. Due to the particularity that the load of magnetic suspension support is inductive, the response speed, efficiency and stability should be considered when the switching power amplifier is designed. In the power amplifier, PI circuit can make feedback current follow the given signal in time. In this paper, the amplifier adopts pulse width modulation (PWM) control strategy. The design of PI circuit, PWM circuit as well as the driving circuit were presented in the paper. After completing the designs of all parts, we choose MULTISIM as simulation software, which can establish an accurate circuit model. The simulation results show that the switching power amplifier designed in this paper has bigger bandwidth and less distortion and it can respond timely.

An Integration SPWM Strategy for High-Frequency Link Matrix Converter With Adaptive Commutation in One Step Based on De-Re-Coupling Idea

When matrix converter (MC) and high-frequency link (HFL) are combined together, they become more complex and gain a safe commutation for the use of high-frequency transformer. To realize energy conversion and transmission, and to achieve reliable and safe commutation at the same time are particularly important and desirable. HFL matrix converter (HFLMC) can be divided into two types: high-frequency link matrix inverter (HFLMI) and high-frequency link matrix rectifier (HFLMR). A three-phase output HFLMI is selected as the object of this study, and a novel integration sinusoidal pulse width modulation (SPWM) control strategy with one-step adaptive commutation based on De-Re-coupling idea is proposed for it. After expounding on the De-Re-coupling idea, a kind of HFLMC equivalent circuit model based on the high-frequency transformer equivalent circuit is built up. Then, a detailed analysis of the voltage stress on power devices of the HFLMC by using this model is performed. A safe operation evaluation criterion of HFLMC is also gained. A suggestion of how to select carrier wave for integration SPWM is ascertained through detail discussion, and two kinds of specific Re-coupling logic circuits are presented, and at last some experimental results are shown to make a certification for feasibility and effectiveness of the new proposed SPWM strategy.

A Pulse Width Modulation Control Scheme for Three-Way Catalyst Systems

A closed-loop pulse width modulated control scheme for three-way automotive catalyst control utilizing feedback from a post-catalyst heated exhaust gas oxygen (HEGO) sensor is presented in this work. The controller manipulates the duty cycle of the pre-catalyst air fuel ratio target perturbations across stoichiometry to regulate the post-catalyst HEGO sensor voltage to a desired target. The controller is demonstrated using an experimental Ford 2.0l Duratec I4 engine with a dual-brick three-way catalyst configuration.

New Circuit Topology for Fault Tolerant H-Bridge DC–DC Converter

This paper describes a new design for a fault tolerant H-bridge dc-dc converter. Fault tolerance is achieved using a multilevel converter topology in combination with a pulsewidth modulation control strategy allowing a large set of converter switching states to produce bidirectional power flows at any required output voltage. For a given converter open-circuit or short-circuit fault, all potential switch combinations are compared in terms of converter losses and output voltage harmonics to identify the most suitable switching combinations to achieve the prefault output voltage level. The fault tolerant ability of the proposed converter to recover the required output voltage is verified by both computer simulations and experimentally using a 1 kW laboratory set.

The Output Characteristics of Transcranial Magnetic Stimulation with Voltage Variable Capacitor-Charging System

In this study, a Magnetic stimulation Pulse Train control technique is introduced and applied to Flyback converter operating in discontinuous conduction mode. In contrast to the conventional pulse width modulation control scheme, the principal idea of a Magnetic stimulation Pulse Train is to achieve output voltage regulation using high and low power pulses. The proposed technique is applicable to any converter operating in discontinuous conduction. However, this work mainly focuses on Flyback topology. In this paper, the main mathematical concept of the new control algorithm is introduced and simulations as well as experimental results are presented.

PWM Control and Application Research on Ground Simulation Experiment of Equivalent Space Heat Sink for Nano-satellite

Equivalent space heat sink for nano-satellite(ESHS-nS) is a space environment simulator applicable to dynamic characteristic ground-testing research of nano-satellite thermal system.In detail the operation principle of ESHS-nS is described,and for the core components thermoelectric cooler(TEC) and force cooling fan,the pulse width modulation(PWM) control strategy and the hardware implementation are proposed.Then,as a platform for a nano-satellite simulator,the ESHS-nS is utilized to carry out ground-testing research on closed-loop temperature control strategy.The results show that ESHS-nS with PWM control can satisfy the requirement of experiment research on nano-satellite temperature control in ground environment,and the ESHS-nS provides a new technical approach for space environment simulation experiment of micro spacecraft thermal systems.

KY Converter and Its Derivatives

In this paper, a voltage-boosting converter, named KY converter (i.e., 1-plus- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</i> converter), is presented. Unlike the traditional nonisolated boost converter, this converter possesses fast load transient responses, which is similar to the buck converter with synchronous rectification. In addition, it possesses nonpulsating output current, thereby not only decreasing the current stress on the output capacitor but also reducing the output voltage ripple. Besides, 1-plus-2 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</i> and 2-plus- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</i> converters, derived from the KY converter, are presented based on the same structure but different pulsewidth-modulation control strategies. Above all, the main difference between the KY converter and its derivatives is that the latter ones possess higher output voltages than the former one under the same duty cycle. A detailed description of the KY converter and its derivatives is presented along with some simulated and experimental results.

Topology for current-source grid-connected inverter with improved efficiency and pulse width modulation control strategy

A novel topology of the current-source grid-connected inverter is proposed based on the immittance converter theory. A control strategy of sine-sine pulse width modulation (PWM) is studied. Compared with the traditional current-source inverter, the power frequency inductors and power frequency transformer are replaced with high frequency inductors and a high frequency transformer. Thus, the proposed inverter has advantages of small volume, low cost, low total harmonic distortion (THD), low power losses, high power factor (PF) and simple control. Furthermore, grid voltage cannot influence output current of the grid-connected inverter and the current-source inverter with a high PF that approaches one has been realized. Finally, validity of the theory analysis and feasibility of the control scheme are shown by simulation and experimental results.