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Applied Power Electronics Conference and Exposition, 1994. APEC '94. Conference Proceedings 1994., Ninth Annual

Date 13-17 Feb. 1994

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Displaying Results 1 - 25 of 148
  • Analysis and evaluation of different modulation techniques for active power filters

    Publication Year: 1994 , Page(s): 894 - 900 vol.2
    Cited by:  Papers (16)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (496 KB)  

    The effectiveness of an active power filter depends basically on three characteristics: (a) the design characteristics of the PWM modulator, (b) the method implemented to generate the reference template and (c) the modulation method used. For the last characteristic there are many methods, most of them based on PWR strategies. In this paper, three of these methods, whose characteristics are their simplicity, are analyzed: periodical sampling control, hysteresis band control, and triangular carrier control. These three methods have been tested with different waveform templates: sinusoidal, quasi-square and rectifier compensation current. The paper shows that, depending on the type of current the active filter has to follow, one strategy may be better than the others. The analysis is based on using the same switching frequency and the results are compared through a THD method which takes into account the particular shape of the waveform template. Simulations and experimental results are presented in the paper.<> View full abstract»

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  • Proceedings of 1994 IEEE Applied Power Electronics Conference and Exposition - ASPEC'94

    Publication Year: 1994
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    Freely Available from IEEE
  • A SPICE compatible model of tapped-inductor PWM converters

    Publication Year: 1994 , Page(s): 1021 - 1027 vol.2
    Cited by:  Papers (15)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (396 KB)  

    An average model of tapped inductor (TI) PWM topology was developed and verified experimentally. The proposed generic and topology independent model is compatible with SPICE and can be run on any electronic circuit simulator for DC (static transfer function), AC (small signal) and TRAN (large signal, time domain) analyses. The model can also be applied to derive analytical expressions of static and dynamic transfer functions. It is shown that the classical PWM topologies are private cases of the TI topologies and can be analyzed and simulated by the TI model developed in this study. The proposed simulation methodology was applied to study the advantages and weaknesses of TI PWM topologies View full abstract»

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  • Class E2 DC/DC converter with second harmonic resonant class E inverter and Class E rectifier

    Publication Year: 1994 , Page(s): 1012 - 1018 vol.2
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (328 KB)  

    Class E amplifiers have been used as inverters for highly efficient DC/AC energy conversion. ZVS-Class E inverters need an RF choke and ZCS-types have the turn-on switching loss increasing with operating frequency. Both types have nonzero power loss in the on-state resistance of the active switch. The second harmonic resonant Class E inverter has no RF choke and has small power dissipation in parasitic resistance since the shunt capacitor and inductor resonate at the second harmonic of the operating frequency. In this paper, a new type of Class E2 converter is proposed and verified experimentally. It consists of the second harmonic resonant Class E inverter and a Class E rectifier. The maximum efficiency achieved was 81.8 percent at 1 MHz View full abstract»

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  • Indirect startup rotor position sensor for synchronous reluctance motor

    Publication Year: 1994 , Page(s): 78 - 82 vol.1
    Cited by:  Papers (3)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB)  

    This paper presents a new indirect method of sensing the rotor positions in a synchronous reluctance motor at zero speed. The method is based on a special diagnostic switching control of the drive converter. The induced phase voltages and currents from this diagnostic signal is used to determine the position of the rotor. Variations of the method also work accurately and with robustness at all speeds. This method requires no additional hardware, other than the drive circuitry and microcontroller. The theoretical foundations of the method are presented and the experimental results are shown to verify the practicality of the method View full abstract»

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  • PWM zero-voltage switching single-ended current-fed converters with output isolation

    Publication Year: 1994 , Page(s): 150 - 158 vol.1
    Cited by:  Papers (5)
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    A modified boost converter is proposed to accomplish power transfer to the load with electrical isolation, zero-voltage and zero-current switching, transformer core resetting mechanism, and identical component stresses as those in the conventional boost converters. Zero-voltage switching and proper transformer-core resetting are achieved from the resonance that exists between the parasitic capacitance of the switch and the magnetization inductance of the transformer. The transformer leakage inductances facilitate zero-current switching; thus, reducing the recovery time and current in the output rectifier, and the turn-on switching loss in the conventional main switching device. Introducing a lossless clamping circuit, the voltage stresses on the switching devices are limited to the reflected output voltage appearing across the primary View full abstract»

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  • Improvements in EMI performance of inverter-fed motor drives

    Publication Year: 1994 , Page(s): 608 - 614 vol.2
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (456 KB)  

    Measurements of conducted radio-noise emissions from a commercial PWM inverter with an induction motor are presented. It is determined that the common mode emissions predominate the noise level and the spectrum components in this type of system, which result from the derivative of the line to ground voltages at the main circuit (dv/dt) and the circuit parameters, consisting of the physical stray inductance of the main circuit conductors and distributed capacitance formed between the circuit conductors and the grounded chassis/frame, most of which concentrate in motor windings and power-semiconductor devices in this system. Modeling and simulations of the system for purpose of evaluation of EMI are presented. Several strategies suppressing conducted radio-noise emissions are proposed, which are practically feasible for cost-effective EMC designs. Both the simulation and experimental results demonstrate that high level radio-noise were significantly suppressed and the EMI performance of the system are able to meet the CISPR and FCC limits on conducted emissions for digital devices View full abstract»

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  • Class D converter with half-wave regulated synchronous rectifier

    Publication Year: 1994 , Page(s): 1005 - 1011 vol.2
    Cited by:  Papers (5)
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    A Class D series resonant converter with a controllable PWM synchronous half-wave current-driven transformer rectifier is presented, including its analysis and experimental results. Replacing the diodes in a conventional current-driven half-wave rectifier with MOSFETs allows voltage regulation for line or load swings of greater than 70% at a minimum of 50% efficiency and a maximum above 80% for a 3.3 V supply producing 15 W of power. The operating frequency was held constant at 120 kHz. The rectifier is driven by a Class D ZVS series resonant inverter and a transformer, which provides a sinusoidal current source View full abstract»

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  • Instrumentation for measurement of line impedance

    Publication Year: 1994 , Page(s): 887 - 893 vol.2
    Cited by:  Papers (24)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (616 KB)  

    This paper presents instrumentation for nondisruptively measuring the impedance of a normally operating line. A small sinusoidal current of known frequency is injected into the line, and line impedance at that frequency is calculated from the magnitude and phase of the injected current and resulting voltage as measured by a network analyzer. Line impedance as a function of frequency is found by repeating the measurement over a range of frequencies. Lumped equivalent circuit models are extracted from the measured line impedance and applied to an example analysis of line voltage distortion View full abstract»

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  • New stand-still position detection strategy for PMSM drive without rotational transducers

    Publication Year: 1994 , Page(s): 363 - 369 vol.1
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (356 KB)  

    This paper describes a new standstill rotor position detecting method for permanent magnet synchronous motor (PMSM) drives without any position sensors. Only two stator currents are required for rotor position detection and complete system operation. By injecting a test current with high frequency to the machine, the standstill rotor position can be detected with reasonable accuracy. The proposed method provides the maximum torque starting capability to the sensorless drive system by detecting the actual standstill rotor angle within ±10" error in electrical angle View full abstract»

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  • Leakage inductance and termination effects in a high-power planar magnetic structure

    Publication Year: 1994 , Page(s): 295 - 301 vol.1
    Cited by:  Papers (29)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (608 KB)  

    The leakage inductance of planar magnetic structures designed for high-frequency power electronics applications is a critical performance parameter that significantly effects circuit operation. This paper presents numerical models for a particular high power (100-500 W) transformer designed for low-profile applications. The impact that secondary winding terminations have on the leakage characteristics of the device is examined using a set of laboratory measurements. It is shown that the effective inductance the transformer presents to the circuit can be several times the inductance calculated or measured based on an ideal short-circuited winding. These results point toward some general design guidelines that are useful for minimizing leakage inductance for planar structures View full abstract»

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  • Torque ripple minimization in switched reluctance motor drives by PWM current control

    Publication Year: 1994 , Page(s): 72 - 77 vol.1
    Cited by:  Papers (20)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (440 KB)  

    Higher torque ripple is one of the few drawbacks of switched reluctance motor (SRM) drives, which otherwise possess excellent characteristics for applications in many commercial drives. This paper begins with an extensive review of torque ripple reduction methods that appear in the literature and then presents a new strategy of PWM current control for smooth operation of the drive. This method includes a current control strategy during commutation when torque ripple minimization is of utmost importance View full abstract»

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  • Soft-switched single-switch three-phase rectifier with power factor correction

    Publication Year: 1994 , Page(s): 738 - 744 vol.2
    Cited by:  Papers (28)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (464 KB)  

    Novel, zero-voltage-transition (ZVT) and zero-current-transition (ZCT) topologies of the single-switch three-phase boost power factor correction rectifier are proposed. The soft transition is achieved with a low-power auxiliary circuit employing an additional switch. The ZVT circuit is suitable for MOSFETs operating above 100 kHz, while the ZCT circuit can be used with IGBTs up to 50 kHz. Operation of the ZCT topologies is analyzed in detail and design guidelines are provided, The results are verified on a 4 kW, 50 kHz, experimental ZCT rectifier with IGBTs. Total harmonic distortion below 9% and efficiency above 95% were obtained View full abstract»

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  • EMI reduction of power supplies by Bi-Frequency modulation

    Publication Year: 1994 , Page(s): 601 - 607 vol.2
    Cited by:  Papers (10)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (352 KB)  

    In this paper, a new control (modulation) technique, called Bi-Frequency control, is proposed. By operating the converters at two fixed switching frequencies with a modulation frequency to adjust the duration ratio, the emission spectrum of the control signal is spread and the spectral power level is reduced. The spectral analysis of the Bi-Frequency control signal is given, and the spectral comparison between PWM and Bi-Frequency control is presented. A Bi-Frequency controlled buck ZVS converter is breadboarded to confirm the operation of the Bi-Frequency control View full abstract»

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  • A switch-mode ripple regulator for high-current magnet power supplies

    Publication Year: 1994 , Page(s): 917 - 923 vol.2
    Cited by:  Papers (6)
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    This paper presents the analysis and design of a switch-mode ripple regulator (SMRR) suitable for high-current magnet power supplies using phase-controlled rectifiers. The contents of this paper include the determination of the SMRR voltage control technique, selection of the gating methods, and the design of the closed-loop voltage controller and feedback filter. The theoretical results are verified with experimental results. The design procedure and a design example are provided. The application of the SMRR can reduce the harmonic content in the magnet current to less than 10 parts per million (ppm) and the system bandwidth of several kHz can be achieved View full abstract»

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  • Analysis and design of a zero voltage transition power factor correction circuit

    Publication Year: 1994 , Page(s): 591 - 597 vol.2
    Cited by:  Papers (20)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (504 KB)  

    This paper analyzes the zero voltage transition boost power converter for power factor correction and presents a method for optimal component selection. A complete circuit is shown featuring a new specifically designed control IC. Practical design issues are discussed and a design procedure is presented. Critical circuit waveforms are shown, and performance with and without zero voltage transitions are compared View full abstract»

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  • Harmonic effects of variable speed air conditioners on a single-phase lateral and on the distribution feeders in a typical residential power system. I

    Publication Year: 1994 , Page(s): 622 - 627 vol.2
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (384 KB)  

    Results of using SPICE simulation software to study the harmonic impact of variable speed air conditioners (VSAC) on a typical residential power system are presented. Results show that IEEE 519-1990 limit of 5% voltage total harmonic distortion is exceeded either at service entrances to residential homes on a single-phase lateral when 33% of the homes on that lateral contain VSACs, or on the 12.47 kV distribution feeders when 9% of the homes throughout the entire system contain VSACs View full abstract»

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  • A clamped transformer power supply producing zero voltage resonant transitions over the full-load range

    Publication Year: 1994 , Page(s): 287 - 292 vol.1
    Cited by:  Papers (2)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (392 KB)  

    A circuit is described that employs zero-voltage-resonant transition (ZVRT) switching. The full-bridge inverter drives the transformer in a manner so that the transformer primary current during the off times circulates in the low side bridge switches. The amplitude of the circulating current at light loads is sufficiently enhanced by a current doubler output rectifier circuit to maintain ZVRT. The operation of the circuit is explained and analyzed. Data is presented on a breadboard that produces 5 V at 60 A from a 150 VDC source View full abstract»

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  • Applying expert systems for designing high frequency power transformers

    Publication Year: 1994 , Page(s): 318 - 325 vol.1
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (636 KB)  

    In industry, it is becoming increasingly important to reduce concept-to-product time. The design of high frequency transformers presents a challenge due to its dependence on application and its need to be very low cost. To meet these challenges, an expert system-based design is presented which is able to capture the design process used by experts View full abstract»

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  • Technique of determining the air gap electromagnetic torque for current-fed AC drive motors

    Publication Year: 1994 , Page(s): 375 - 380 vol.1
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (316 KB)  

    A new physical approach to the electromagnetic torque identification problem for the current-fed AC motor is presented. The physical approach is based on an identification model of the three-phase bridge converter in the current source configuration, and uses a mathematical model of the AC motor at the asymmetric power supply. The identification procedure uses the measurement and processes the electrical terminal values of the inverter without participation of the drive motor parameters. The effectiveness of this identification procedure is illustrated by the laboratory test results View full abstract»

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  • Software controller for PWM converters

    Publication Year: 1994 , Page(s): 947 - 953 vol.2
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB)  

    A software controller is realized for DC-DC switching power converters. The software is capable of implementing several real-time control schemes such as the continuous/discrete switching frequency control, continuous/discrete pulse-width control and phase control of PWM converters. Implementation in software provides the capability of executing complex control schemes and supervisory functions which are easy to implement, update and adapt to different applications without much overhead View full abstract»

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  • Experimental study of a bidirectional DC-DC converter for the DC link voltage control and the regenerative braking in PM motor drives devoted to electrical vehicles

    Publication Year: 1994 , Page(s): 381 - 386 vol.1
    Cited by:  Papers (22)  |  Patents (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (348 KB)  

    The use of a bidirectional DC-DC converter operating in the DC link of CRPWM-inverter-fed motor drives devoted to electric vehicles (EVs) application allows a suitable control of both motoring and regenerative braking operations, and it can contribute to a significant increase of the motor drive overall efficiency. This paper deals with the experimental study of a bidirectional DC-DC converter prototype which has been designed for application in small-size EVs propelled by axial-flux PM motor drives. The paper discusses the converter modes of operation and reports the experimental results taken from a converter prototype which has been constructed using an IGBTs power module rated 600 V, 50 A View full abstract»

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  • Single transistor three phase power conditioners with high power factor and isolated output

    Publication Year: 1994 , Page(s): 731 - 737 vol.2
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (512 KB)  

    A favourable method of converting power from a three-phase AC input voltage source to an isolated DC voltage output source is presented. It improves the power factor at the input of the converter. The circuits are based on inductive energy storage and only use a single transistor to switch the transformer(s). A special control algorithm for the IGBT is not required as the input voltage and input current of the power factor conditioner are proportional. It is possible to determine the maximum transistor voltage by dimensioning the circuit parameters. The output voltage is isolated from the input voltage View full abstract»

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  • Current-controlled synchronous rectification

    Publication Year: 1994 , Page(s): 185 - 191 vol.1
    Cited by:  Papers (21)  |  Patents (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (424 KB)  

    This paper presents several strategies for implementing a current-controlled synchronous rectifier. One approach utilizes a current-sensing transformer in series with the rectifying MOSFET to derive the required gating signals. The second method uses the mirror current of a current-sensing MOSFET. Experimental results obtained with current-driven rectifiers in a center-tapped, full-wave configuration are presented View full abstract»

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  • A comparative study of high-frequency, low-profile planar transformer technologies

    Publication Year: 1994 , Page(s): 226 - 232 vol.1
    Cited by:  Papers (36)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (468 KB)  

    A study several of available technologies used to construct low-profile, planar transformers is presented. Finite element analysis is used to determine an appropriate winding configuration with low AC resistance and leakage inductance. The advantages and disadvantages of printed circuit board (PCB), flex-circuit and stamped-copper winding technologies are evaluated. The trade-offs between electrical and mechanical properties are emphasized. It is demonstrated that the secondary winding termination resistances for these transformers constitute a large percentage of the total AC resistance of the transformer View full abstract»

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