Space vector pulse‐width modulation for single‐phase full‐bridge Z‐source inverter

The space vector pulse‐width‐modulation technique is extensively applied in the three‐phase power electronics circuits because of its easy digital implementation and wide linear modulation range features. However, the attempt of this technique for the single‐phase Z‐source inverter has seldom been reported because of its unique topology and operational characteristics. In this paper, based on an in‐depth mathematical derivation and theoretical explanation, the space vector pulse‐width‐modulation principles have been discussed in detail. Various implementation schemes are demonstrated, and a comparison study for selected switching patterns is conducted. In addition, the theoretical analysis is validated by both the simulation and experimental results. This work will be helpful for understanding the space vector pulse‐width‐modulation concept and modulation techniques of the single‐phase full‐bridge Z‐source inverters. Copyright © 2013 John Wiley & Sons, Ltd.     

A new fast‐response buck converter using accelerated pulse‐width‐modulation techniques

A new fast‐response buck converter using accelerated pulse‐width‐modulation techniques is proposed in this article. The benefits of the accelerated pulse‐width‐modulation technique is fast‐transient response, simple‐compensation design, and no requirement for slope compensation; furthermore, some power management problems are minimized, such as EMI (Electro Magnetic Interference), size, design complexity, and cost. The traditional voltage‐mode speed is slower with the transient response, so an accelerated pulse‐width‐modulation technique is used to solve the problem of slowed transient response in this article. The proposed buck converter has excellent conversion efficiency with a wide load conditions. The proposed buck converter has been fabricated with TSMC 0.35 µm CMOS 2P4M processes, and the total chip area is 1.32 × 1.22 mm². Maximum output current is 300 mA when the output voltage equals 1.8 V. When the supply voltage is 3.6 V, the output voltage can be 1–2.6 V. Maximum transient response is less than 5 µs. The simulation and experimental results are presented in this article. Copyright © 2011 John Wiley & Sons, Ltd.     

Unified Pulse‐Width Modulation Scheme for Improved Digital‐Peak‐Voltage Control of Switching DC‐DC Converters

Contrast to conventional dependent double‐edge (DDE) pulse‐width modulation (PWM), independent double‐edge (IDE) PWM is investigated and applied to the control of switching dc‐dc converters, with improved digital‐peak‐voltage (IDPV) controlled buck converter in this paper. IDE modulation unifies all the PWM schemes reported up to now and is thus called as unified PWM. It is revealed that conventional trailing‐edge, leading‐edge, trailing‐triangle, and leading‐triangle modulations are special cases of IDE modulation. The control laws of IDPV controlled buck converter with IDE modulation are investigated and compared with those of IDPV with DDE modulation. Their stabilities and robustness are analyzed subsequently. Digital implementation of the unified PWM is also carried out. Steady‐state and transient performances of IDPV controlled buck converters with IDE modulation and DDE modulation are compared and verified by experimental results. It is concluded that steady‐state and transient performances of IDPV with IDE are better than those of IDPV with DDE modulation. Copyright © 2012 John Wiley & Sons, Ltd.     

RF transmitter using the dual‐pulse position modulation method for low‐power smart micro‐sensing chip

This paper presents a low‐power radio frequency (RF) transmitter using dual‐pulse position modulation (DPPM) for a smart micro‐sensing chip (SMSC) with sensors and large scale integrated circuit (LSI) on the same chip. The DPPM method is presented by a fixed pulse and a variable pulse within the same time frame. The distance between the fixed pulse and the variable pulse describes the amplitude of the input signal. A modulator and a ring oscillator were designed for the RF transmitter using the DPPM method. In the modulator, the pulse width modulation (PWM) signal is generated by the intersective method, and narrow pulses are extracted at the rising and falling positions of the generated PWM signal. The designed oscillator has the function of an oscillation controller. The RF transmitter was fabricated with sensors for an SMSC by complementary metal–oxide–semiconductor (CMOS) technology. The power consumption of the fabricated modulator was 4.5 mW. The power consumption of the proposed RF transmitter was measured as 7.0–7.3 mW at an input signal of 0.8–2.5 V. The RF transmitter using the DPPM method was able to reduce the power consumption by a maximum of 50.3% compared to a transmitter using the PWM method, because in the latter the dissipated power was 8.4–14.5 mW at the same input signal. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

A novel modulation technique with interleaved‐and‐shifted shoot‐through state placement for quasi‐Z‐source inverters

In this paper, a single‐phase quasi‐Z‐source (qZS) inverter (qZSI), integrating the pulse width modulation (PWM) control with interleaved‐and‐shifted shoot‐through state (STS) placement modulation technique, is proposed to simultaneously achieve both dc voltage boost and dc‐ac inversion. Instead of placing the STS in both inverter legs simultaneously, the addressed method inserts the STS only in left/right inverter leg separately during the positive/negative half cycle of the output voltage to reduce switching losses and thermal stresses of the power devices. The STS shift is also studied to decrease the switching numbers of power devices and thus can improve the efficiency further. Theoretical analysis and design guidelines of the studied inverter are included. Improvement in effectiveness and performance of the devised scheme and modulation strategy are proved experimentally and compared with the previous studies on a built laboratory prototype.     

Dead‐time elimination SVPWM of six‐leg inverter

We present a six‐leg voltage source inverter (VSI) with a single DC link to feed a three‐phase inductive load. The space vector pulse width modulation (SVPWM) of the six‐leg inverter is studied in detail. The novel switching strategy in one sampling period for H bridge is proposed to avoid the 180° phase shift of the PWM signals for upper and lower side switches. Based on the novel switching strategy, a dead‐time elimination SVPWM is proposed, which can be easily implemented on a digital signal processor. Experimental results are presented to demonstrate the validity and features of the proposed novel SVPWM. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Switched‐capacitor‐voltage‐multiplier boost DC–AC inverter with adaptive stages

A multistage switched‐capacitor‐voltage‐multiplier inverter (SCVMI) is proposed with a variable‐conversion‐ratio phase generator and a sinusoidal pulse‐width‐modulation controller for boost DC–AC conversion and high‐efficiency regulation. Its power unit contains: SCVM booster and H‐bridge. The SCVM booster includes two m_c‐stage switched‐capacitor cells and two n_c‐stage switched‐capacitor cells in the interleaving operation to realize DC–DC boost gain of m_c × n_c at most. Here, the variable‐conversion‐ratio phase generator is suggested and adopted to change the running stage number and topological path for a suitable gain level of m × n (m = 1, 2, ?,m_c, n = 1, 2, ?,n_c) to improve efficiency, especially for the lower AC output. The H‐bridge is employed for DC–AC conversion, where four switches are controlled by sinusoidal pulse‐width‐modulation not only for full‐wave output but also for output regulation as well as robustness to source/loading variation. Some theoretical analysis and design include: SCVMI model, steady‐state/dynamic analysis, conversion ratio, power efficiency, stability, capacitance selection, output filter, and control design. Finally, the closed‐loop SCVMI is simulated, and the hardware circuit is implemented and tested. All the results are illustrated to show the efficacy of this scheme. Copyright © 2011 John Wiley & Sons, Ltd.     

A comprehensive study of space vector pulse‐width modulation technique for three‐phase Z‐source inverters

The space vector pulse width modulation (SVPWM) technique has received much attention for three‐phase Z‐source inverters (ZSIs). The differences and connections between the SVPWM technique for ZSIs and for traditional voltage source inverters have been discussed as well. By selecting different null state and shoot‐through state, three switching patterns with different switching numbers have been studied, and the harmonic spectrums of these three patterns are demonstrated. In this paper, the solutions of maximum boost control and constant boost control methods using SVPWM techniques with less switching actions have been proposed and compared with the carrier‐based strategies. Selected experimental results have been provided to validate the theoretical analysis. This work will be beneficial for understanding the SVPWM concept and modulation techniques of the three‐phase ZSIs. Copyright © 2015 John Wiley & Sons, Ltd.     

Chaotic synchronization‐based communications using constant envelope pulse

We propose use of a constant‐envelope pulse for the purpose of improving noise‐rejection property in chaotic synchronization‐based communication systems. In a conventional system where discrete‐time chaotic signals are transmitted through the pulse amplitude modulation, the correlator output variance increases as the spreading factor decreases, while the synchronization error increases as the spreading factor increases. Therefore, it is difficult to control the bit error rate only by adjusting the spreading factor. In the proposed system, use of pulse width modulation keeps the envelope of transmitted signals constant, which leads to the correlator output with zero variance. The synchronization error is kept small because the spreading factor can be set to be one without increasing the correlator output variance. We have a result of computer simulation showing that the proposed system achieves a bit error performance better than the conventional system. In addition, a new blind adaptive algorithm is proposed which suppresses intersymbol interference. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 163(3): 47– 56, 2008; Published online in Wiley InterScience ( www. interscience.wiley.com ). DOI 10.1002/eej.20318     

Gain stabilization in a quantum‐dot semiconductor optical amplifier using tapered waveguide structure

In this paper, transient gain of a quantum‐dot semiconductor optical amplifier (QD‐SOA) is studied. Waveguide of the QD‐SOA is considered to have a tapered structure in which width of the waveguide increases along the QD‐SOA. It is observed that by employing tapered waveguide, gain as the key feature of the device acquires more stability, investigated by studying the impact of a powerful optical pulse on the gain as it passes through the amplifier. Thus, by gradually increasing the width of the waveguide along QD‐SOA active region, drop in the gain, caused by the strong pulse, decreases. Transient gain of the device is obtained for several outputs to input width ratios. It is demonstrated that as the width ratio increases, gain stability improves drastically; as for width ratio of 10, stability increases over 10 times compared with the generic QD‐SOA. In addition to the gain, cross‐gain modulation as a nonlinear process, which depends on the gain instability imposed by strong pulses, is studied. In this paper, the rate equations are employed for modeling tapered waveguide QD‐SOA. MATLAB ODE (MathWorks, MA, USA) along with the finite difference method is used for studying and simulating the device. Copyright © 2013 John Wiley & Sons, Ltd.     

Suppressing harmonics in four‐quadrant AC‐DC converters with chaotic SPWM control

In this paper, a new chaotic sinusoidal pulse width modulation (chaotic SPWM) control is proposed and implemented in a four‐quadrant AC‐DC converter for harmonics suppression, where a chaotic carrier plays a key role. Further, the relationship of the harmonic distribution and carrier frequency is derived by analyzing the harmonic components of the AC‐DC converter, which is useful for revealing the operation principle of the chaotic SPWM control for harmonic suppression. Finally, the simulation and experimental results illustrate the effectiveness of the proposed chaotic SPWM control on harmonics reduction. Copyright © 2012 John Wiley & Sons, Ltd.     

A highly efficient single‐phase sine‐wave inverter with single‐switch high‐frequency modulation

This paper presents a highly efficient single‐phase sine‐wave inverter with single‐switch high‐frequency modulation. In this topology, a control circuit is connected at the lower arm of a full‐bridge inverter to control the output voltage across the full‐bridge inverter. The switch at the lower arm of the full‐bridge inverter controls the output voltage of the full‐bridge inverter by increasing or reducing the voltage level at the lower arm of the inverter. This switch of lower arm is controlled by a high‐frequency sinusoidal pulse width modulation (SPWM) switching signal, while the power switches of the full‐bridge inverter operate with a square‐wave switching signal at the line frequency to unfold DC–AC inversion, thus producing a sinusoidal voltage at the load. Both computer simulation and experiment are carried out to verify the performance of the proposed topology. Experimental results from a 1000‐W laboratory prototype are presented to testify and validate the analysis, design, and performance of the proposed topology. The results show that the proposed topology has nearly sinusoidal output voltage and current waveforms with a total harmonics distortion of less than 5%. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

A novel PWM technique with switching‐loss reduction for independent drive of two 3‐phase AC motors fed by a five‐leg inverter

This paper presents a novel pulse width modulation (PWM) technique with switching‐loss reduction for a five‐leg inverter (FLI). The PWM technique, in which the available maximum voltage for two motors adds up to DC bus voltage, has been proposed as the strategy for the FLI. Therefore, the DC bus voltage is fully available as the PWM strategy. However, the conventional PWM technique requires the frequency, phase, and amplitude of the phase voltage commands of a motor to produce zero‐sequence voltages (ZSVs). The novel PWM strategy has some efficient features. These features are discussed in this paper. The validity of the novel PWM technique will be shown by experimental results. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Single‐Stage ZVS‐PWM AC‐AC Power Converter Using All SiC Power Module for High‐Frequency Induction Heating Applications

This paper presents a novel prototype of a single‐stage zero voltage soft‐switching pulse‐width modulation ‐controlled ac‐ac converter with a silicon carbide (SiC)‐MOSFET/SiC‐SBD power module for high‐frequency (HF) induction heating (IH) applications. The newly developed ac‐ac converter can achieve higher efficiency than a Si‐IGBT/Si‐PN diode power module‐based prototype due to a low ON‐resistance of SiC‐MOSFET and a low forward voltage of SiC‐SBD under the condition of HF switching. The performances of the new prototype converter are evaluated by experiment with a single‐phase IH utensil of ferromagnetic stainless metal, after which the high‐efficiency and low switching noise characteristics due to the all SiC power module are actually demonstrated.     

Three‐stage multiphase‐switched‐capacitor boost DC‐AC inverter

A closed‐loop scheme of a three‐stage multiphase‐switched‐capacitor boost DC‐AC inverter (MPSCI) is proposed by combining the multiphase operation and sinusoidal‐pulse‐width‐modulation (SPWM) control for low‐power step‐up DC‐AC conversion and regulation. In this MPSCI, the power unit contains two parts: MPSC booster (front) and H‐bridge (rear). The MPSC booster is suggested for an inductor‐less step‐up DC‐DC conversion, where three voltage doublers in series are controlled with multiphase operation for boosting voltage gain up to 2³ = 8 at most. The H‐bridge is employed for DC‐AC inversion, where four solid‐state switches in H‐connection are controlled with SPWM to obtain a sinusoidal AC output. In addition, SPWM is adopted for enhancing output regulation not only to compensate the dynamic error, but also to reinforce robustness to source/loading variation. The relevant theoretical analysis and design include: MPSCI model, steady‐state/dynamic analysis, voltage conversion ratio, power efficiency, stability, capacitance selection, total harmonic distortion (THD), output filter, and closed‐loop control design. Finally, the closed‐loop MPSCI is simulated, and the hardware circuit is implemented and tested. All the results are illustrated to show the efficacy of the proposed scheme. Copyright © 2011 John Wiley & Sons, Ltd.     

Power‐efficient burst‐mode RF transmitter based on reference‐adaptive multilevel pulse‐width modulation

Burst‐mode operation of power amplifier (PA) based on multilevel pulse‐width modulation (MPWM) has been frequently discussed as a potential solution to achieve higher efficiency in radio frequency (RF) transmitters. In this paper, a novel multilevel PWM modulator is proposed that utilizes adaptive triangular reference waveforms. As compared with conventional MPWM modulators, the proposed architecture provides significant wider design space such that the efficiency of system can be effectively optimized. A general transmitter architecture based on the proposed concept is analyzed in terms of power efficiency. Efficiency optimization procedures are presented according to input magnitude statistics. Based on the proposed modulator, an optimized 2.4‐GHz RF transmitter is designed in a 0.18‐μm complementary metal‐oxide‐semiconductor (CMOS) process. The circuit‐level simulations show that it delivers 25.8‐dBm peak output power with 46.1% peak efficiency. For a 20‐MHz worldwide interoperability for microwave access (WiMAX) signal with 8.5‐dB peak‐to‐average‐power ratio (PAPR), this transmitter achieves 28.8% (average) efficiency at 17.3‐dBm (average) output power with an error vector magnitude (EVM) of 2.97% rms.     

High‐repetition‐frequency short pulses in a VHF discharge‐excited slab‐type carbon dioxide laser using an ultrasonic vibrator

We propose a novel method for producing high‐repetition‐frequency short pulses with a halved confocal configuration consisting of an unstable concave–convex resonator in a very high frequency (VHF) discharge‐excited slab‐type carbon dioxide laser. This method utilizes a fully reflective concave mirror with variable curvature which can be controlled by a piezoelectric device. In general, slab lasers are modulated directly by varying the pulse voltage. However, because plasma fluctuation occurs at the pulse transitions, the repetition frequency is less than 10 kHz and the minimum pulse width is 1 µs. On the other hand, in our method there is no disturbance of the plasma, because the power source is not modulated. There is also little mechanical constraint, because we use a piezoelectric device. As a result, pulse shortening with a high repetition rate is possible. The pulse shape is well reproduced by a three‐level rate equation. The mechanism of the method involves changes in ejection efficiency with periodic variation of the radius of curvature of the mirror. Good agreement between observations and calculations was also obtained for the peak power and the pulse width. In this paper we compare measurements with calculations. The possibility of achieving high repetition rate oscillation and pulse shortening by this method is examined. The results confirm the possibility of achieving a repetition frequency between 1.4 kHz and 170 kHz. The shortest pulse width that can be achieved is 160 nanoseconds. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(3): 1–7, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10127     

A cost‐effective PWM dimming method for LED lighting applications

This paper presents a novel cost‐effective pulse‐width‐modulation (PWM) dimming method for light‐emitting diode (LED) lighting applications. High efficiency, high power factor, circuit simplicity, and low cost can be achieved by a Flyback power factor correction converter with the studied adaptive PWM dimming method. The operation principles and design considerations of the proposed LED dimming method are analyzed and discussed. A 45 W laboratory prototype has been built and tested to verify the feasibility of the proposed scheme. Copyright © 2013 John Wiley & Sons, Ltd.     

Harmonic analysis of the output voltage of a third‐harmonic‐injected inverter for LSM drives

The superconducting magnetic leviation railway system (MAGLEV) under development in Japan uses pulse‐width‐modulation (PWM) inverter for driving a linear synchronous motor (LSM). The inverter output voltage contains nonnegligible harmonics which cause harmonic resonances in the LSM system, and therefore harmonics of the output voltage have been analyzed in order to control such harmonic resonances. This paper applies a third‐harmonic injection method to the inverter for the purpose of enhancing the output voltage without changing the circuit configuration. It performs harmonic analysis of the output voltage of the inverter based on the third‐harmonic injection. Validity of the harmonic analysis is verified by computer simulation. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 160(1): 71–78, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ).     

A step‐up PWM DC–DC converter for renewable energy applications

A step‐up pulse width modulation (PWM) direct current (DC)–DC converter is presented in this paper, which has its origin in quasi Z‐source inverter. Analysis of this converter in steady state is presented, and relevant expressions are derived for the proposed converter operating in continuous conduction mode. The power loss expressions for each component of the converter are derived, and thereby, obtained expressions for overall converter efficiency are presented. Further, a dynamic model is derived to design an appropriate controller for this converter. The simulation and experimental results are presented to support the theoretical analysis. The advantages such as continuous input current, high step‐up gain at lower duty ratio, and common ground for source, load, and switch makes the converter suitable for renewable energy applications. Copyright © 2015 John Wiley & Sons, Ltd.