Sinusoidal Pulse Width Modulation Inverter Research Articles

Dual-Mode Double-Carrier-Based Sinusoidal Pulse Width Modulation Inverter With Adaptive Smooth Transition Control Between Modes

Three dual-mode boost-buck-derived inverters with smooth transition between modes have been proposed: 1) boost-full bridge inverter; 2) boost-H5 inverter; 3) boost-dual buck inverter. For the same topologies, in conventional control method, the first stage is needed to boost input voltage to a constant high voltage, and the second stage is for sinusoidal inverting. However, in the proposed three inverters, either buck or boost mode works at a single time, thus, only one switch works at a high switching frequency. In this way, a lot switching loss can be reduced, and moreover, since the voltage across the middle capacitor is smaller than the conventional constant high voltage, the further switching loss mitigation is possible. In order to achieve smooth transition between the two modes, a double-carrier-based sinusoidal pulse width modulation (SPWM) is proposed. Other than this, three advanced modulation methods are proposed: 1) double-carrier with different frequencies; 2) double-carrier with different magnitudes; and 3) double-carrier with different frequencies and magnitudes. Following that, the loss distribution in every component is provided and the California Energy Commission efficiency of these inverters under different input voltage conditions is compared. Finally, the experimental results show the dual-mode double-carrier-based SPWM inverter can improve the efficiency by 2% than the traditional constant dc bus voltage solutions.

Transformerless Uninterruptible Power Supply with Reduced Power Device Count

This article presents a transformerless off-line uninterruptible power supply with a reduced power device count. The operation of the proposed uninterruptible power supply is divided into two modes. The first is the charging mode, where a pulse width modulation rectifier and a buck converter are controlled to charge the battery bank with a sinusoidal supply current at a unity power factor. The second mode is the inverting mode, where a boost converter is used to regulate the DC-link voltage to a level suitable for a sinusoidal pulse width modulation inverter to generate the rated load voltage. The inverter is working at a constant modulation index to provide a high-quality output voltage to the load during the interruption. The use of buck and boost converters eliminates the need for a transformer to adjust the DC voltage level for the charging process or the AC voltage level across the load. A hardware setup is implemented to evaluate the dynamic behavior of the proposed uninterruptible power supply system. Furthermore, the proposed uninterruptible power supply system is simulated using the PSCAD/EMTDC (Manitoba, Canada) software package. Several test cases with different load types are conducted to study the effectiveness of the proposed control system. Accurate performance and fast dynamics are revealed from both the simulation and experimental results.

A Novel Control Technique for Soft-switching Sinusoidal Pulse Width Modulation Inverter

This article presents a new zero-current switching technique for a single-phase full-bridge sinusoidal pulse width modulation inverter. Two auxiliary switches and a resonant branch are attached to a conventional single-phase full-bridge inverter. The resonant branch can be controlled independently from the main power switches. This technique decreases turn-on and turn-off switching losses and does not require any snubber capacitor. The technique can be applied to DC/DC converters and DC/AC inverters with suitable switching algorithms. Both theoretical analysis and application of the proposed technique have been realized. It was seen that the proposed technique has 45% less switching losses and better performance than the hard-switching technique for the same load and switching frequency. The experimental results also approve the effectiveness of the zero-switching technique.

Computational Modeling and Polarization Characteristics of Proton Exchange Membrane Fuel Cell with Evaluation of its Interface Systems

This paper presents a computational model of proton exchange membrane (PEM) fuel cell stack. The proposed model is simple and at the same time includes all the important phenomena present in the fuel cell. The fuel cell electrical output voltage and current (V-I) characteristic is described for the first time by a simplified closed form suitable for modeling and computation. The characteristics obtained through simulation are compared with the experimental results obtained on a commercial Ballard Nexa 310–0027 power module as well as to the manufacturer available data. Close agreement between the simulation, manufacturer and experimental results confirms the validity and usefulness of the proposed model. In addition, the paper explores several power interface options for fuel cell power generation systems and proposes a power conditioning unit composed of boost DC-DC converter cascaded sinusoidal PWM inverter.

Some system design considerations for a high switching frequency PWM inverter

A sinusoidal PWM inverter is required to faithfully reproduce the control waveforms at the output with minimum distortion. This paper presents some design considerations for such an inverter. The choice of switching frequency is the main criterion which affects the output voltage harmonic distortion at high switching frequencies. This paper shows that there exists an optimum switching frequency above which the output harmonic distortion becomes more visible. The dead time generator circuit for a low cost inverter and effect of driver circuits on the output waveform are discussed. Experimental results from laboratory models are presented.

Characteristics of PM synchronous motor drives with a trapezoidal EMF

AbstractA permanent magnet synchronous motor (PMSM) with nonsinusoidal electromotive force (EMF) generates torque ripple even if the sinusoidal PWM inverter drives the PMSM. A new modified trapezoidal modulating signal for PWM inverter suitable for PMSM drive with nonsinusoidal EMF is proposed in this paper. A new modulating signal for the PMSM drive is determined by the condition of reducing torque ripple of the motor with various trapezoidal EMF. When the PWM inverter using modified trapezoidal modulating signal drives the PMSM having a nonsinusoidal EMF, the torque ripple of the motor can be reduced, the DC link voltage utilization is improved, and reduction of switching loss can be obtained. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(1): 62–71, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20441

Sinusoidal Waveform Following Method for Digital Control of PWM inverter

Fast responses without any steady-state errors are required for control of a sinusoidal PWM inverter. Its reference voltage waveform is not constant but sinusoidal. The output voltage is controlled to coincide with a reference waveform. However the reference varies to be a further value when the output reaches the value. So there is always a deviation between the reference and the output voltages. It is necessary to design a compensator by considering these sinusoidal variations of the reference waveform to get a good steady-state and fast transient response. This paper proposes a sort of digital repetitive control systems for a sinusoidal PWM inverter control. It is based on the internal model principle to realize a response with no deviation for a periodic sinusoidal reference input. It has a simple numerator and a denominator z2-2z cos ωT + 1 of a transfer function which is equal to the z function of a sinusoidal waveform of the angular frequency ω and the sample time T. Compensator and feedback gains of the inverter are determined by the optimal control principle. The proposed method is investigated for actual performances and it is validated through theoretical and experimental results for linear and nonlinear loads by using a DSP system at the switching frequency of 20kHz.

Sinusoidal Tracking Control of a PWM Inverter with Inverse System Feedforward Compensation

Fast responses without any steady-state errors are required for control of a sinusoidal PWM inverter. There are two key points. One is that its reference voltage waveform is not constant but sinusoidal. It is necessary to design a compensator by considering these sinusoidal variations of the reference waveform to get a good steady-state and fast transient response. A sinusoidal tracking compensator which is based on the optimal control and the internal model principle has been proposed by the authors to realize a response with no deviation for a periodic sinusoidal reference input. The other is that compensator and feedback (FB) gains have a trade-off between responses and sensitivities to noises and they can not be too large. Feedforward(FF) compensation can improve responses without alternating system stabilities. This paper proposes a PWM control system which has a sinusoidal FB and an inverse system FF compensators. According to the inverse system FF compensation, appropriate nominal control input values are determined to give the reference steady-state response. Therefore the input values are computed by deconvolving a set of system response equations inversely. The proposed system is investigated and validated through theoretical and experimental results for a rated, an unbalanced, and a rectifier loads by using a simulator Matlab and a DSP system at the switching frequency of 20kHz. The proposed control showed better performances than the original FB and the preview controls.

Characteristics of PM Synchronous Motor Drives with a trapezoidal EMF

A permanent magnet synchronous motor (PMSM) with non-sinusoidal electromotive force (EMF) generates torque ripple even if the sinusoidal PWM inverter drives the PMSM. A new modified trapezoidal modulating signal for PWM inverter suitable for PMSM drive with non-sinusoidal EMF is proposed in this paper. A new modulating signal for the PMSM drive is determined by the condition of reducing torque ripple of the motor with various trapezoidal EMF. When the PWM inverter using modified trapezoidal modulating signal drives the PMSM having a non-sinusoidal EMF, the torque ripple of the motor can be reduced, the DC link voltage utilization is improved and reduction of switching loss can be obtained.

Modeling and analysis of a single stage step-up/down three-phase AC to DC converter

In this paper, first the apportioning of null-space-vector duty ratio between two null-space-vectors for the conventional three-phase voltage source sinusoidal pulse width modulation inverter is derived. To achieve clean sinusoidal input current, adjustable power factor and bidirectional power flow and step-up/down output DC voltage, analytic duty cycle control laws based on the derived null-space-vector duty ratio are then derived. As a result, the popularly used state-space technique can be extended easily for modeling a process that allows to obtain any kind of the desired transfer functions and dynamic responses. Based on these dynamic responses obtained the regulators of closed loop control system can be designed or adjusted properly. Finally, some simulated and measured results are presented for demonstration.

A New Flexible and Compact High-Frequency Link On-Line UPS System

This paper introduces a new high-frequency (HF) link on-line Uninterruptible Power Supply (UPS) configuration based on one HF transformer with three windings. The HF link is established using a resonant inverter during normal operation of the UPS and a sinusoidal pulse-width modulation (SPWM) inverter during mains failure. A cycloconverter is used to construct the low-frequency output voltage. Another configuration of the system is also presented such that the system becomes more compact and flexible where the switch-mode operation of the SPWM inverter is avoided by replacing it with a resonant one. In this case, the two inverters are integrated into only one HF resonant inverter and the output is constructed and controlled using a SPWM cycloconverter. The choice of the switching frequency as well as the HF transformer material are investigated. Simulation of the UPS circuit was carried out and verified with experimental results for a 500 VA, 20kHz link frequency.

PWM technique for power MOSFET inverter

A sinusoidal PWM (pulsewidth-modulated) inverter suitable for use with power MOSFETs is described. The output waveforms in the proposed PWM inverter are investigated both theoretically and experimentally. A modulating signal for the three-phase PWM inverter is obtained by adding the harmonic components of integer multiples of three to the three-phase sine waves. By using the proposed modulating signal, the amplitude of the fundamental component is increased about 15% more than that of a conventional sine-wave inverter and the commutation number of the inverter is decreased to two-thirds of a conventional one. >

A new SPWM inverter with minimum filter requirement

Abstract A new sinusoidal pulsewidth modulation (SPWM) control technique for simplifying the implementation of the SPWM method and minimizing the requirement of the voltampere rating of the inverter input filter is described and analysed. With the proposed modulation scheme, the regeneration of low-order harmonics caused by the input voltage fluctuation can be suppressed and the peak fundamental output voltage can be regulated rapidly and precisely by the dual voltage feedback control. Only a minimum voltampere rating of the inverter input filter is required for avoiding overmodulation. The theoretical results of the proposed approach with open-loop self-regulating property are discussed and experimentally verified.

A Microcomputer—Controlled Drive Signal Generator for 3-Phase Sinusoidal Pulse-Width Modulated Inverters

The width and frequency of the drive-signal pulses for 3-phase sinusoidal PWM inverter is varied in the proposed circuit by changing the output data from a single-board microcomputer (SBC). This provides independent control of the output voltage and frequency of the inverter. The circuit described here generates 8 or 16 pulses per cycle resulting in increased effective fundamental voltage, reduced harmonic voltages and reduced Switching losses of the power switches used. The number of pulses per cycle can be easily increased. Moreover, this circuit circumvents the ‘shoot-through’ problem by providing an ‘interlock-delay’ at the leading edge of each pulse. The special merit of this circuit lies in freeing the SBC from the large time-consuming job of drive-pulse generation. The micro-computer can then be left to control and monitor the overall system. It is suitable for both adjustable speed and uninterruptible power supply applications.

Deadbeat controlled PWM inverter with parameter estimation using only voltage sensor

A technique based on deadbeat control theory is proposed to obtain a nearly sinusoidal PWM (pulsewidth-modulated) inverter output voltage using only a voltage sensor. The closed loop sampled-data feedback scheme inherently results in very fast response to load disturbance and nonlinear load, producing low total harmonic distortion. Parameter estimation of the plant provides a type of self-tuning of the proposed controller. A theoretical analysis, simulation, and experimental results are presented for a single-phase PWM inverter controlled by an Intel 8086 microprocessor.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

PWM inverter controlled by a small saturable core

A sinusoidal PWM inverter with MOSFETs controlled by an extremely small magnetic core is presented, which is simple and of high efficiency under high frequency switching. The circuit is based on the principle of the transistor core multivibrator. However the saturable core is used for PWM in the gate drive circuit. This inverter is especially suitable for small UPS system.

Dead Beat Microprocessor Control of PWM Inverter for Sinusoidal Output Waveform Synthesis

A new control technique based on dead beat control theory to obtain a nearly sinusoidal PWM inverter output voltage is described. The closed-loop digital feedback system measures the output and controls the inverter switches to generate the required pulsewidth-modulated (PWM) pattern to produce low total harmonic distortion (THD) sinusoidal output voltage. This scheme inherently provides very good voltage regulation, phase positioning, and compensation for load disturbances and nonlinear loads. A theoretical analysis, computer simulation, and experimental results for a single-phase bridge inverter controlled by an Intel 8086 microprocessor-based system is presented.

Evaluation of low noise in three phase induction motor by employing 20kHz carrier sinusoidal PWM inverter.

Evaluation of low noise in three phase induction motor by employing 20kHz carrier sinusoidal PWM inverter.

三相正弦波ＰＷＭインバータのための変調信号

三相正弦波ＰＷＭインバータのための変調信号

Microprocessor Based Sinusoidal PWM Inverter by DMA Transfer

The implementation of three-phase sinusoidal pulse-width-modulated inverter control strategy using microprocessor is discussed in this paper. To save CPU time, the DMA technique is used for transferring the switching pattern from memory to the pulse amplifier and isolation circuits of individual thyristors in the inverter bridge. The method of controlling both voltage and frequency is discussed here.