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Power Electronics, IEEE Transactions on

Issue 2 • Date March 1998

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Displaying Results 1 - 19 of 19
  • PI and fuzzy estimators for tuning the stator resistance in direct torque control of induction machines

    Page(s): 279 - 287
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (298 KB)  

    Direct torque control (DTC) of induction machines uses the stator resistance of the machine for estimation of the stator flux. Variations of stator resistance due to changes in temperature or frequency make the operation of DTC difficult at low speeds. A method for the estimation of changes in stator resistance during the operation of the machine is presented. The estimation method is implemented using proportional-integral (PI) control and fuzzy logic control schemes. The estimators observe the machine stator current vector to detect the changes in stator resistance. The performance of the two methods are compared using simulation and experimental results. Results obtained have shown improvement in DTC at low speeds. View full abstract»

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  • Analytic solutions for LLCC parallel resonant converter simplify use of twoand three-element converters

    Page(s): 235 - 243
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (424 KB)  

    A practical method for steady-state design of parallel resonant DC/DC power converters is presented. The method uses a set of prederived equations from a two-inductor two-capacitor series-parallel resonant converter (LLCC-SPRC). Although four-tank elements are present in an LLCC-SPRC, only two ratios of the tank elements are needed during design. The values of the four-tank elements can be found from the design results. In addition to designing an LLCC-SPRC, the prederived equations can also be used to design and analyze the conventional one-inductor two-capacitor (LCC)-type SPRCs (LCC-SPRCs), two-inductor one-capacitor (LLC)-type PRCs (LLC-PRCs) and inductor-capacitor (LC)-type PRCs (LC-PRCs). In other words, the four converters can be designed by the same equations. A design procedure along with design examples is given. Experimental circuits are implemented and measured based on the design results to verify the validity of the derived equations and the design procedure View full abstract»

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  • A fast on-line neural-network training algorithm for a rectifier regulator

    Page(s): 366 - 371
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (128 KB)  

    This paper addresses the problem of deadbeat control in fully controlled high-power factor rectifiers. Improved deadbeat control can be achieved through the use of neural network-based predictors for the input current reference to the rectifier. In this application, online training is absolutely required. In order to achieve sufficiently fast online training, a new random search algorithm is presented and evaluated. Simulation results show that this type of network training yields equivalent performance to standard backpropagation training. Unlike backpropagation, however, the random weight change method can be implemented in mixed digital/analog hardware for this application. The paper proposes a very large-scale integration implementation which achieves a training epoch as low as 8 μs View full abstract»

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  • The state-of-the-art of power electronics in Japan

    Page(s): 345 - 356
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (292 KB)  

    Since the late 1950s, power electronics has been developing by leaps and bounds without saturation to become the key technology essential to modern society and human life as well as to electrical engineering. This paper mainly focuses on the state-of-the-art of power electronics technology and its medium to high-power applications because the author cannot survey the whole spectrum of power electronics ranging from a 5 W switching regulator to a 2.8 GW high-voltage DC transmission system now under construction in Japan. This paper also presents prospects and directions of power electronics in the 21st Century, including the personal views and expectations of the author View full abstract»

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  • A new power-factor-correction circuit for electronic ballasts with series-load resonant inverter

    Page(s): 273 - 278
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (144 KB)  

    This paper presents an efficient, small-sized and cost-effective power factor correction (PFC) scheme for high-frequency series-resonant electronic ballasts. The proposed scheme introduces additional small energy tanks processing partial power and thus can perform the function of input current shaping. Theoretical and experimental results prove that the electronic ballast incorporating with only few reactive components can achieve nearly unity power factor and very low harmonic distortion View full abstract»

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  • Decoupled technique for the simulation of PWM switching regulators using second-order-output extrapolations

    Page(s): 222 - 234
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (428 KB)  

    A hybrid time-domain simulation technique for pulse-width-modulated (PWM) switching regulators is presented. The methodology integrates the advantages of the simulation concepts for switched and nonswitched networks. A regulator is decoupled into dual-analysis components, namely, the power conversion stage (PCS) and feedback network (FN). The former component is simulated by a time-domain digital integration technique with stepwise analysis of the switches' state and automatic determination of correct topological configuration in the PCS operation while the latter one is analyzed by formulating a modified system difference equation and defining at each switching period with second-order extrapolations and corrections of the PCS and error amplifier outputs. Other superior features of this approach include: (1) elegant numerical method of determining the gate signals from the PWM modulator; (2) simple manipulations of numeric and algebraic equations; and (3) applicability to simulate regulators with multiple parameters feedback from PCS. The proposed methodology is illustrated with several examples. The simulated steady-state and large-signal transient waveforms are favorably verified with experimental measurements and available literature View full abstract»

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  • Improved active power-factor-correction circuit using a zero-voltage-switching boost converter

    Page(s): 308 - 314
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (184 KB)  

    In this paper, a zero-voltage-switching (ZVS) scheme for a boost power converter is proposed and discussed. This lossless zero-voltage scheme is shown to improve the performance of active power factor correction circuits. The results are validated by both simulation and experimental results View full abstract»

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  • Nonlinear modeling and bifurcations in the boost converter

    Page(s): 252 - 260
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    The occurrence of nonlinear phenomena like subharmonics and chaos in power electronic circuits has been reported recently. In this paper, the authors investigate these phenomena in the current-mode-controlled boost power converter. A nonlinear model in the form of a mapping from one point of observation to the next has been derived. The map has a closed form even when the parasitic elements are included. The bifurcation behavior of the boost power converter has been investigated with the help of this discrete model View full abstract»

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  • The unified power quality conditioner: the integration of series and shunt-active filters

    Page(s): 315 - 322
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (268 KB)  

    This paper deals with unified power quality conditioners (UPQCs), which aim at the integration of series-active and shunt-active power filters. The main purpose of a UPQC is to compensate for voltage flicker/imbalance, reactive power, negative-sequence current and harmonics. In other words, the UPQC has the capability of improving power quality at the point of installation on power distribution systems or industrial power systems. This paper discusses the control strategy of the UPQC, with a focus on the how of instantaneous active and reactive powers inside the UPQC. Experimental results obtained from a laboratory model of 20 kVA, along with a theoretical analysis, are shown to verify the viability and effectiveness of the UPQC View full abstract»

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  • A detailed study of losses in the reduced voltage resonant link inverter topology

    Page(s): 337 - 344
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (288 KB)  

    A new reduced voltage resonant link (RVRL) topology was reported earlier. A detailed study of the effect of various parameters such as the characteristic impedance, Q factors, input DC voltage and the resonant frequency on the link losses is presented. The voltage and current stresses on various link components are also given. The losses are determined and then compared with those of the actively clamped resonant DC link. The RVRL topology reduces the link losses by 25% under certain operating conditions. The new topology being truly resonant offers less EMI and requires less number of power devices. It is particularly suitable at high resonant frequencies with ease of control View full abstract»

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  • A high-power PWM quadrature booster phase shifter based on a multimodule AC controller

    Page(s): 357 - 365
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (280 KB)  

    Pulse-width-modulated (PWM) phase shifters allow the smooth control of power flow in a transmission line. This paper analyzes a PWM quadrature booster phase shifter based on a multimodule AC controller structure to attain high voltage levels and improve the harmonic spectrum. The modules are based on a three-phase PWM AC controller topology that employs only four force-commutated switches and is controlled by duty-cycle variation. The PWM technique is carrier based and the individual modules are gated through phase-shifted triangular carriers. As a result, harmonic cancellation takes place in the input current and output voltage. Low-order harmonics are therefore eliminated and the amplitude of remaining components reduced. An additional operating mode with negligible harmonic generation and step-like control is identified. The feasibility and advantages of the proposed phase shifter are demonstrated by means of a power system simulator View full abstract»

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  • A novel SVM-based hysteresis current controller

    Page(s): 297 - 307
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (328 KB)  

    In this paper, a novel space vector modulation (SVM)-based hysteresis current controller (HCC) for squirrel cage induction motors is proposed. This technique utilizes all advantages of the HCC and SVM technique. The controller determines a set of space vectors from a region detector and applies a space vector selected according to the main HCC. A set of space vectors including the zero vector to reduce the number of switchings is determined from the sign of the output frequency and output signals of three comparators with a little larger hysteresis band than that of the main HCC. A simple hardware implementation is proposed and experimental results of the SVM-based HCC are also shown View full abstract»

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  • Analysis and design of a new constant frequency control for QRC and MRC based on magnetic elements modification

    Page(s): 244 - 251
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (260 KB)  

    Multiresonant power converters (MRCs) and quasi-resonant power converters (QRCs) have been modified to provide constant-frequency operation. Transformer leakage inductance has been used to adapt the traditional pulse-width-modulation (PWM) control to these converters. Conventional PWM integrated circuits can be used for the power converter regulation. Several experimental results are developed to test the control method proposed View full abstract»

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  • Nonlinear-carrier control for high-power-factor rectifiers based on up-down switching converters

    Page(s): 213 - 221
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (300 KB)  

    In this paper, nonlinear-carrier (NLC) control is proposed for high-power-factor rectifiers based on flyback, Cuk, Sepic, and other up-down power converters operated in the continuous conduction mode (CCM). In the NLC controller, the switch duty ratio is determined by comparing a signal proportional to the integral of the switch current with a periodic nonlinear-carrier waveform. The shape of the NLC waveform is determined so that the resulting input-line current follows the input-line voltage, as required for unity power factor rectification. A simple exponential carrier waveform generator is described. Using the NLC controller, input-line voltage sensing, error amplifier in the current-shaping loop, and multiplier/divider circuitry in the voltage feedback loop are eliminated. The simple high-performance controller is well suited for integrated-circuit implementation, Results of experimental verification on a 150 W flyback rectifier are presented View full abstract»

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  • Loss minimization in wound-field cylindrical rotor synchronous motor drives

    Page(s): 288 - 296
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (284 KB)  

    The loss minimization problem in wound-field cylindrical rotor synchronous motor drives (SMDs) is investigated. From the theoretical analysis, a system of two loss model controllers (LMCs), for determining the optimal air-gap flux and optimal excitation current that minimizes the losses, results. The suggested LMCs are simple, and their implementation does not affect significantly the cost and complexity of the drive. Although the conception of the suggested LMCs is based on the loss model of the synchronous motor, it is shown that their implementation does not require knowledge of the loss model. All the theoretical results are verified experimentally View full abstract»

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  • Modeling and analysis of static and dynamic characteristics for buck-type three-phase PWM rectifier by circuit DQ transformation

    Page(s): 323 - 336
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    The static and dynamic characteristics of buck-type three-phase pulse width modulation (PWM) rectifier are fully analyzed based on the DC and AC circuit models developed by the circuit DQ transformation. Various static power converter characteristics such as gain, real and reactive power, power factor and unity power factor conditions are completely analyzed. Transition characteristics are also analyzed by both exact small-signal models with full set of equations and simplified output models in explicit form. The usefulness of the models is verified through computer simulations and experiments with good agreement shown View full abstract»

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  • Dynamic model of magnetic materials applied on soft ferrites

    Page(s): 372 - 379
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (208 KB)  

    A behavioral model of magnetic materials is presented. This model takes into account both hysteresis and dynamic phenomena. It predicts B(H), φ(t) and dφ(t)/dt characteristics, and a few pieces of experimental data are needed to identify its parameters. In this paper, the authors propose to validate the model for some typical applications encountered in power electronics. Results obtained are very satisfactory View full abstract»

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  • PSpice high-frequency dynamic fluorescent lamp model

    Page(s): 261 - 272
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (204 KB)  

    A new PSpice dynamic fluorescent lamp model based on high-frequency lamp characteristics is presented. The new model avoids the convergence problems found when using the Mader-Horn lamp model. A systematic approach is developed to derive the lamp model parameters from experimental data. Simulations are shown to agree closely with experimental data View full abstract»

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Aims & Scope

IEEE Transactions on Power Electronics covers fundamental technologies used in the control and conversion of electric power.

Full Aims & Scope