Research

21772 KiB

Open AccessArticle

Novel Frequency Swapping Technique for Conducted Electromagnetic Interference Suppression in Power Converter Applications

by Ming-Tse Kuo and Ming-Chang Tsou

Energies 2017, 10(1), 24; https://doi.org/10.3390/en10010024 - 27 Dec 2016

Cited by 7 | Viewed by 7004

Abstract

Quasi-resonant flyback (QRF) converters have been widely applied as the main circuit topology in power converters because of their low cost and high efficiency. Conventional QRF converters tend to generate higher average conducted electromagnetic interference (EMI) in the low-frequency domain due to the [...] Read more.

Quasi-resonant flyback (QRF) converters have been widely applied as the main circuit topology in power converters because of their low cost and high efficiency. Conventional QRF converters tend to generate higher average conducted electromagnetic interference (EMI) in the low-frequency domain due to the switching noise generated by power switches, resulting in the fact they can exceed the EMI standards of the European Standard 55022 Class-B emission requirements. The presented paper develops a novel frequency swapping control method that spreads spectral energy to reduce the amplitude of sub-harmonics, thereby lowering average conducted EMI in the low-frequency domain. The proposed method is implemented in a control chip, which requires no extra circuit components and adds zero cost. The proposed control method is verified using a 24 W QRF converter. Experimental results reveals that conducted EMI has been reduced by approximately 13.24 dBμV at 498 kHz compared with a control method without the novel frequency swapping technique. Thus, the proposed method can effectively improve the flyback system to easily meet the CISPR 22/EN55022 standards. Full article

(This article belongs to the Special Issue Power Electronics Optimal Design and Control)

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6541 KiB

Open AccessArticle

Modeling and Controller Design of PV Micro Inverter without Using Electrolytic Capacitors and Input Current Sensors

by Faa Jeng Lin, Hsuang Chang Chiang and Jin Kuan Chang

Energies 2016, 9(12), 993; https://doi.org/10.3390/en9120993 - 25 Nov 2016

Cited by 10 | Viewed by 5787

Abstract

This paper outlines the modeling and controller design of a novel two-stage photovoltaic (PV) micro inverter (MI) that eliminates the need for an electrolytic capacitor (E-cap) and input current sensor. The proposed MI uses an active-clamped current-fed push-pull DC-DC converter, cascaded with a [...] Read more.

This paper outlines the modeling and controller design of a novel two-stage photovoltaic (PV) micro inverter (MI) that eliminates the need for an electrolytic capacitor (E-cap) and input current sensor. The proposed MI uses an active-clamped current-fed push-pull DC-DC converter, cascaded with a full-bridge inverter. Three strategies are proposed to cope with the inherent limitations of a two-stage PV MI: (i) high-speed DC bus voltage regulation using an integrator to deal with the 2nd harmonic voltage ripples found in single-phase systems; (ii) inclusion of a small film capacitor in the DC bus to achieve ripple-free PV voltage; (iii) improved incremental conductance (INC) maximum power point tracking (MPPT) without the need for current sensing by the PV module. Simulation and experimental results demonstrate the efficacy of the proposed system. Full article

(This article belongs to the Special Issue Power Electronics Optimal Design and Control)

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9539 KiB

Open AccessArticle

A Current Control Approach for an Abnormal Grid Supplied Ultra Sparse Z-Source Matrix Converter with a Particle Swarm Optimization Proportional-Integral Induction Motor Drive Controller

by Seyed Sina Sebtahmadi, Hanieh Borhan Azad, Didarul Islam, Mehdi Seyedmahmoudian, Ben Horan and Saad Mekhilef

Energies 2016, 9(11), 899; https://doi.org/10.3390/en9110899 - 02 Nov 2016

Cited by 12 | Viewed by 4411

Abstract

A rotational d-q current control scheme based on a Particle Swarm Optimization- Proportional-Integral (PSO-PI) controller, is used to drive an induction motor (IM) through an Ultra Sparse Z-source Matrix Converter (USZSMC). To minimize the overall size of the system, the lowest [...] Read more.

A rotational d-q current control scheme based on a Particle Swarm Optimization- Proportional-Integral (PSO-PI) controller, is used to drive an induction motor (IM) through an Ultra Sparse Z-source Matrix Converter (USZSMC). To minimize the overall size of the system, the lowest feasible values of Z-source elements are calculated by considering the both timing and aspects of the circuit. A meta-heuristic method is integrated to the control system in order to find optimal coefficient values in a single multimodal problem. Henceforth, the effect of all coefficients in minimizing the total harmonic distortion (THD) and balancing the stator current are considered simultaneously. Through changing the reference point of magnitude or frequency, the modulation index can be automatically adjusted and respond to changes without heavy computational cost. The focus of this research is on a reliable and lightweight system with low computational resources. The proposed scheme is validated through both simulation and experimental results. Full article

(This article belongs to the Special Issue Power Electronics Optimal Design and Control)

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5215 KiB

Open AccessArticle

Time-Domain Minimization of Voltage and Current Total Harmonic Distortion for a Single-Phase Multilevel Inverter with a Staircase Modulation

by Milan Srndovic, Yakov L. Familiant, Gabriele Grandi and Alex Ruderman

Energies 2016, 9(10), 815; https://doi.org/10.3390/en9100815 - 12 Oct 2016

Cited by 23 | Viewed by 6038

Abstract

This paper presents the optimization technique for minimizing the voltage and current total harmonic distortion (THD) in a single-phase multilevel inverter controlled by staircase modulation. The previously reported research generally considered the optimal THD problem in the frequency domain, taking into [...] Read more.

This paper presents the optimization technique for minimizing the voltage and current total harmonic distortion (THD) in a single-phase multilevel inverter controlled by staircase modulation. The previously reported research generally considered the optimal THD problem in the frequency domain, taking into account a limited harmonic number. The novelty of the suggested approach is that voltage and current minimal THD problems are being formulated in the time domain as constrained optimization ones, making it possible to determine the optimal switching angles. In this way, all switching harmonics can be considered. The target function expression becomes very compact and existing efficient solvers for this kind of optimization problems can find a solution in negligible processor time. Current THD is understood as voltage frequency weighted THD that assumes pure inductive load—this approximation is practically accurate for inductively dominant RL-loads. In this study, the optimal switching angles and respective minimal THD values were obtained for different inverter level counts and overall fundamental voltage magnitude (modulation index) dynamic range. Developments are easily modified to cover multilevel inverter grid-connected applications. The results have been verified by experimental tests. Full article

(This article belongs to the Special Issue Power Electronics Optimal Design and Control)

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3251 KiB

Open AccessArticle

Smooth Switching Technique for Voltage Balance Management Based on Three-Level Neutral Point Clamped Cascaded Rectiﬁer

by Xu Peng, Xiaoqiong He, Pengcheng Han, Aiping Guo, Zeliang Shu and Shibin Gao

Energies 2016, 9(10), 803; https://doi.org/10.3390/en9100803 - 03 Oct 2016

Cited by 21 | Viewed by 4416

Abstract

This paper discussed the topology of in the three-level neutral point clamped cascaded rectiﬁer (3LNPC-CR) for designing the Chinese Power Electronic Traction Transformer (PETT). To balance the DC-link voltage (Vdc) in 3LNPC-CR, a smooth switching technique is proposed in this paper. The controlling [...] Read more.

This paper discussed the topology of in the three-level neutral point clamped cascaded rectiﬁer (3LNPC-CR) for designing the Chinese Power Electronic Traction Transformer (PETT). To balance the DC-link voltage (Vdc) in 3LNPC-CR, a smooth switching technique is proposed in this paper. The controlling processes of each module are relatively independent when the proposed technique is applied in 3LNPC-CR. The proposed technique can keep the switching frequency constant and change the switch state smoothly while balancing Vdc. The Vdc balance ability is analyzed by calculating the unbalance degree of the loads. Simulation and experiment of three-module 3LNPC-CR are built, and then the effectiveness of the proposed technique is veriﬁed. Full article

(This article belongs to the Special Issue Power Electronics Optimal Design and Control)

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3559 KiB

Open AccessArticle

Design and Optimization of an Efﬁcient (96.1%) and Compact (2 kW/dm3) Bidirectional Isolated Single-Phase Dual Active Bridge AC-DC Converter

by Jordi Everts

Energies 2016, 9(10), 799; https://doi.org/10.3390/en9100799 - 03 Oct 2016

Cited by 16 | Viewed by 9013

Abstract

The growing attention on plug-in electric vehicles, and the associated high-performance demands, have initiated a development trend towards highly efﬁcient and compact on-board battery chargers. These isolated ac-dc converters are most commonly realized using two conversion stages, combining a non-isolated power factor correction [...] Read more.

The growing attention on plug-in electric vehicles, and the associated high-performance demands, have initiated a development trend towards highly efﬁcient and compact on-board battery chargers. These isolated ac-dc converters are most commonly realized using two conversion stages, combining a non-isolated power factor correction (PFC) rectiﬁer with an isolated dc-dc converter.This, however, involves two loss stages and a relatively high component count, limiting the achievable efﬁciency and power density and resulting in high costs. In this paper, a single-stage converter approach is analyzed to realize a single-phase ac-dc converter, combining all functionalities into one conversion stage and thus enabling a cost-effective efﬁciency and power density increase. The converter topology consists of a quasi-lossless synchronous rectiﬁer followed by an isolated dual active bridge (DAB) dc-dc converter, putting a small ﬁlter capacitor in between. To show the performance potential of this bidirectional, isolated ac-dc converter, a comprehensive design procedure and multi-objective optimization with respect to efﬁciency and power density is presented, using detailed loss and volume models. The models and procedures are veriﬁed by a 3.7kW hardware demonstrator, interfacing a 400Vdc-bus with the single-phase 230V,50Hz utility grid. Measurement results indicate a state-of-the-art efﬁciency of 96.1% and power density of 2 kW/dm3, conﬁrming the competitiveness of the investigated single-stage DAB ac-dc converter. Full article

(This article belongs to the Special Issue Power Electronics Optimal Design and Control)

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2948 KiB

Open AccessArticle

A High-Precision Control for a ZVT PWM Soft-Switching Inverter to Eliminate the Dead-Time Effect

by Baoquan Kou, Hailin Zhang and He Zhang

Energies 2016, 9(8), 579; https://doi.org/10.3390/en9080579 - 25 Jul 2016

Cited by 8 | Viewed by 5610

Abstract

Attributing to the advantages of high efficiency, low electromagnetic interference (EMI) noise and closest to the pulse-width-modulation (PWM) converter counterpart, zero-voltage-transition (ZVT) PWM soft-switching inverters are very suitable for high-performance applications. However, the conventional control algorithms intended for high efficiency generally results in [...] Read more.

Attributing to the advantages of high efficiency, low electromagnetic interference (EMI) noise and closest to the pulse-width-modulation (PWM) converter counterpart, zero-voltage-transition (ZVT) PWM soft-switching inverters are very suitable for high-performance applications. However, the conventional control algorithms intended for high efficiency generally results in voltage distortion. Thus, this paper, for the first time, proposes a high-precision control method to eliminate the dead-time effect through controlling the auxiliary current in the auxiliary resonant snubber inverter (ARSI), which is a typical ZVT PWM inverter. The dead-time effect of ARSI is analyzed, which is distinguished from hard-switching inverters. The proposed high-precision control is introduced based on the investigation of dead-time effect. A prototype was developed to verify the effectiveness of the proposed control. The experimental results shows that the total harmonic distortion (THD) of the output current of the ARSI can be reduced compared with that of the hard-switching inverter, because the blanking delay error is eliminated. The quality of the output current and voltage can be further improved by utilizing the proposed control method. Full article

(This article belongs to the Special Issue Power Electronics Optimal Design and Control)

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13097 KiB

Open AccessArticle

Implementation of Rapid Prototyping Tools for Power Loss and Cost Minimization of DC-DC Converters

by Amruta V. Kulkarni, Weiqiang Chen and Ali M. Bazzi

Energies 2016, 9(7), 509; https://doi.org/10.3390/en9070509 - 01 Jul 2016

Cited by 7 | Viewed by 6436

Abstract

In this paper, power loss and cost models of power electronic converters based on converter ratings and datasheet information are presented. These models aid in creating rapid prototypes which facilitate the component selection process. Through rapid prototyping, users can estimate power loss and [...] Read more.

In this paper, power loss and cost models of power electronic converters based on converter ratings and datasheet information are presented. These models aid in creating rapid prototypes which facilitate the component selection process. Through rapid prototyping, users can estimate power loss and cost which are essential in design decisions. The proposed approach treats main power electronic components of a converter as building blocks that can be arranged to obtain multiple topologies to facilitate rapid prototyping. In order to get system-level power loss and cost models, two processes are implemented. The first process automatically provides minimum power loss or cost estimates and identifies components for specific applications and ratings; the second process estimates power losses and costs of each component of interest as well as the whole system. Two examples are used to illustrate the proposed approaches—boost and buck converters in continuous conduction mode. Achieved cost and loss estimates are over 93% accurate when compared to measured losses and real cost data. This research presents derivations of the proposed models, experimental validation of the models and demonstration of a user friendly interface that integrates all the models. Tools presented in this paper are expected to be very useful for practicing engineers, designers, and researchers, and are flexible and adaptable with changing or new technologies and varying component prices. Full article

(This article belongs to the Special Issue Power Electronics Optimal Design and Control)

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11275 KiB

Open AccessArticle

Analysis and Controller Design of a Universal Bidirectional DC-DC Converter

by Kou-Bin Liu, Chen-Yao Liu, Yi-Hua Liu, Yuan-Chen Chien, Bao-Sheng Wang and Yong-Seng Wong

Energies 2016, 9(7), 501; https://doi.org/10.3390/en9070501 - 29 Jun 2016

Cited by 23 | Viewed by 18492

Abstract

In this paper, first the operating principles of a non-isolated universal bidirectional DC-DC converter are studied and analyzed. The presented power converter is capable of operating in all power transferring directions in buck/boost modes. Zero voltage switching can be achieved for all the [...] Read more.

In this paper, first the operating principles of a non-isolated universal bidirectional DC-DC converter are studied and analyzed. The presented power converter is capable of operating in all power transferring directions in buck/boost modes. Zero voltage switching can be achieved for all the power switches through proper modulation strategy design, therefore, the presented converter can achieve high efficiency. To further improve the efficiency, the relationship between the phase-shift angle and the overall system efficiency is analyzed in detail, an adaptive phase-shift (APS) control method which determines the phase-shift value between gating signals according to the load level is then proposed. As the modulation strategy is a software-based solution, there is no requirement for additional circuits, therefore, it can be implemented easily and instability and noise susceptibility problems can be reduced. To validate the correctness and the effectiveness of the proposed method, a 300 W prototyping circuit is implemented and tested. A low cost dsPIC33FJ16GS502 digital signal controller is adopted in this paper to realize the power flow control, DC-bus voltage regulation and APS control. According to the experimental results, a 12.2% efficiency improvement at light load and 4.0% efficiency improvement at half load can be achieved. Full article

(This article belongs to the Special Issue Power Electronics Optimal Design and Control)

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10779 KiB

Open AccessArticle

Analysis and Minimization of Output Current Ripple for Discontinuous Pulse-Width Modulation Techniques in Three-Phase Inverters

by Gabriele Grandi, Jelena Loncarski and Milan Srndovic

Energies 2016, 9(5), 380; https://doi.org/10.3390/en9050380 - 19 May 2016

Cited by 4 | Viewed by 8661

Abstract

This paper gives the complete analysis of the output current ripple in three-phase voltage source inverters considering the different discontinuous pulse-width modulation (DPWM) strategies. In particular, peak-to-peak current ripple amplitude is analytically evaluated over the fundamental period and compared among the most used [...] Read more.

This paper gives the complete analysis of the output current ripple in three-phase voltage source inverters considering the different discontinuous pulse-width modulation (DPWM) strategies. In particular, peak-to-peak current ripple amplitude is analytically evaluated over the fundamental period and compared among the most used DPWMs, including positive and negative clamped (DPWM+ and DPWM−), and the four possible combinations between them, usually named as DPWM0, DPWM1, DPWM2, and DPWM3. The maximum and the average values of peak-to-peak current ripple are estimated, and a simple method to correlate the ripple envelope with the ripple rms is proposed and verified. Furthermore, all the results obtained by DPWMs are compared to the centered pulse-width modulation (CPWM, equivalent to the space vector modulation) to identify the optimal pulse-width modulation (PWM) strategy as a function of the modulation index, taking into account the different average switching frequency. In this way, the PWM technique providing for the minimum output current ripple is identified over the whole modulation range. The analytical developments and the main results are experimentally verified by current ripple measurements with a three-phase PWM inverter prototype supplying an induction motor load. Full article

(This article belongs to the Special Issue Power Electronics Optimal Design and Control)

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14085 KiB

Open AccessArticle

Open Fault Detection and Tolerant Control for a Five Phase Inverter Driving System

by Seung-Koo Baek, Hye-Ung Shin, Seong-Yun Kang, Choon-Soo Park and Kyo-Beum Lee

Energies 2016, 9(5), 355; https://doi.org/10.3390/en9050355 - 10 May 2016

Cited by 8 | Viewed by 5039

Abstract

This paper proposes a fault detection and the improved fault-tolerant control for an open fault in the five-phase inverter driving system. The five-phase induction machine has a merit of fault-tolerant control due to its increased number of phases. This paper analyzes an open [...] Read more.

This paper proposes a fault detection and the improved fault-tolerant control for an open fault in the five-phase inverter driving system. The five-phase induction machine has a merit of fault-tolerant control due to its increased number of phases. This paper analyzes an open fault pattern of one switch and proposes an effective fault detection method based upon this analysis. The proposed fault detection method using the analyzed patterns is applied in the power inverter. In addition, when the open fault occurs in the one switch of the induction machine driving system, the proposed fault-tolerant control method is used to operate the induction machine using the remaining healthy phases, after performing the fault detection method. Simulation and experiment results are provided to validate the proposed technique. Full article

(This article belongs to the Special Issue Power Electronics Optimal Design and Control)

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