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Applied Power Electronics Conference and Exposition, 2005. APEC 2005. Twentieth Annual IEEE

Date 6-10 March 2005

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  • A novel safe shutdown strategy for matrix converter even under fault condition

    Publication Year: 2005 , Page(s): 1786 - 1790 Vol. 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (237 KB) |  | HTML iconHTML  

    The reliability of power electronic devices is of paramount importance in practical application. This paper firstly presents detailed fault condition of the matrix converter-induction motor drive system. Then a novel protection strategy is proposed. The key of the proposed protection strategy is to provide a controlled free-wheeling path for the motor currents when a fault happens. By using the new protection strategy, the motor currents can be reduced to zero as soon as possible, while the safety of the semiconductors is assured. In order to avoid unexpected overvoltage fault, a clamp circuit is still needed. But in cooperation with the proposed protection strategy, the capacitance requirement of the capacitor in the protection circuit is small. And the use of an electrolytic type can be avoided. In the end, the simulation and experimental results validate the proposed strategy. View full abstract»

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  • Finite element simulation of a universal contactless battery charging platform

    Publication Year: 2005 , Page(s): 1927 - 1932 Vol. 3
    Cited by:  Papers (2)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (340 KB) |  | HTML iconHTML  

    This paper presents a finite-element (FE) simulation study of a planar contactless battery charging platform for portable consumer electronic equipment. Magnetic field plots of the charging platform are generated under no-load and loaded conditions so that the field distribution of the planar charging platform can be visualized. With new results arising from this FE simulation study, the theory of the mmf generation of the multilayer planar printed-circuit-board (PCB) winding array structure can be further understood. Experiments have been carried out to identify the loading effects and central field sag phenomenon. Magnetic field variation at the edges of the platform can now be explained. It is found that a patented shielding structure is effective in suppressing the EM field at the bottom of the charging platform. Most importantly, the FE simulation confirms the 'pancake' shape of the field distribution in the planar charging platform. Such prediction is verified with practical measurements. View full abstract»

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  • Investigation of candidate topologies for brick DC-DC

    Publication Year: 2005 , Page(s): 1537 - 1540 Vol. 3
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (216 KB) |  | HTML iconHTML  

    Characteristics of electrical specifications, which is peculiar for brick DC/DC power product, is analyzed in detail in this paper, selective requirement of topologies for this type product is presented as well. The topologies listed as follows are the presented appropriate candidate ones for brick DC/DC: active-clamped forward converter, resonant reset forward converter, symmetrical half-bridge converter, forward-flyback converter, isolated boost-buck converter, two-stage converter. The related techniques about the candidate topologies are respectively specified, furthermore in view of the applicability, both the advantage and the disadvantage are respectively compared with each other. Finally, good applicability of active-clamped forward converter to brick DC/DC is further verified by the experimental result. View full abstract»

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  • A novel control strategy of post buck converters cascading LLC-SRC

    Publication Year: 2005 , Page(s): 1628 - 1634 Vol. 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (303 KB) |  | HTML iconHTML  

    This paper presents a novel synchronous control strategy for the post buck converters directly cascading a LLC-SRC (series resonant converter) half-bridge converter, which can eliminate the input filter needed by general buck converters and decrease the ripple current flowing through the output capacitor of the front-end converter, thus leading to high overall efficiency and low cost. The separate control strategy of each post buck converter makes the standardized and modular design possible. View full abstract»

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  • A novel method for dead-time compensation based on SVPWM

    Publication Year: 2005 , Page(s): 1867 - 1870 Vol. 3
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (175 KB) |  | HTML iconHTML  

    As for a vector control system of permanent magnet synchronous motor, this paper analyzes the influence of dead-time on output voltage in detail, and discusses the relationship between the position of voltage vector and the direction of three-phase current in a space-vector figure. In addition, a method that divides three-phase current into six sectors and a control strategy that compensates only one phase voltage in every sector are proposed in the paper. At last, experiments which are uncompensated and compensated in different frequency are carrier out with a TMS320F240 chip, and the results verify this method has a good compensation effect. View full abstract»

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  • A novel DC-DC full-bridge converter using energy-recovery circuit with regenerative transformer

    Publication Year: 2005 , Page(s): 1543 - 1548 Vol. 3
    Cited by:  Papers (4)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (245 KB) |  | HTML iconHTML  

    A novel full-bridge converter with a new energy-recovery driver using a regenerative transformer is proposed to improve the efficiency for wide input voltage range and load variation compared with a conventional phase-shift (PS) full-bridge (FB) converter. In the proposed converter, the main switches achieve ZVS independent of the load current value. During the freewheeling period, conduction loss is minimized by recovering the circulating energy to the source. The principle of operation, design consideration and experimental results, including efficiency, are presented in the case of large change of the input voltage or load. A proposed 1 kW converter prototype is compared with a PS-FB converter. View full abstract»

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  • Unified analog and digital models for half bridge DC-DC converter with current doubler rectifier

    Publication Year: 2005 , Page(s): 1386 - 1392 Vol. 3
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (212 KB) |  | HTML iconHTML  

    The half bridge DC-DC topology with current doubler rectification is suitable for high current low voltage applications. In this paper, both analog and digital unified state space models and small signal models valid for symmetric, asymmetric and duty cycle shifted controlled half bridge DC-DC converter are derived. The discretized analog model and derived digital model are compared based on the digital controller design. In addition, a digital controller is designed based on the digital model for symmetric half bridge DC-DC converter. The results are verified by experiment. View full abstract»

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  • Multiphase 48 volt conversion for low noise applications in an instrument grade power supply

    Publication Year: 2005 , Page(s): 1441 - 1446 Vol. 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (253 KB) |  | HTML iconHTML  

    This paper presents a switching power supply design that meets the accuracy, response time, noise level, and current requirements for today's ATE instruments. It focuses on minimizing high frequency parasitic ringing at the switching waveform edges that interferes with the linear regulator output. The noise reduction features include a transformer with flat planar construction of interleaved coils, a full-bridge with zero-volt switching for the primary control of the transformer, multi-phase circuits to enable maximum response time, and ferrite beads on all switches to control ringing. View full abstract»

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  • A reconfigurable uninterruptible power supply system for multiple power quality applications

    Publication Year: 2005 , Page(s): 1824 - 1830 Vol. 3
    Cited by:  Papers (21)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (357 KB) |  | HTML iconHTML  

    A novel topology of an uninterruptible power supply (UPS) system is presented in this paper. The proposed UPS system presents the advantages of high power conversion efficiency as well as active front-end filtering which ensures unity input power factor (reactive power compensation) and low input total harmonic distortion (harmonic power compensation) in the voltages and currents. In addition, this UPS possess dynamic voltage sag compensation capabilities, hence eliminates any series transformer or boost converter which is normally used in conjunction with traditional stand-alone UPS systems. Meanwhile, during the backup (battery) mode of operation, this UPS has the capability of providing grid isolation without any backward power feed into the faulted utility gird, thus eliminates the needs of circuit breaker or static switch. In addition, it has the desirable characteristics of making seamless transition from normal to backup mode during power failures and vice versa, as well as providing controlled voltage charging at the dc bus link. The proposed UPS is also impervious to load variations, which enables it to operate under nonlinear load condition. Lastly, the circuit structure is simple, light weight, and can be implemented at a low cost using the standard commercial available components. A complete set of simulation as well as experimental results based on a 1 kW test prototype of the proposed UPS are presented here to demonstrate its viability and efficacy. View full abstract»

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  • Next generation high efficiency high power dc-dc converter incorporating active switch and snubbing capacitor assisted full-bridge soft-switching PWM inverter with high frequency transformer for large current output

    Publication Year: 2005 , Page(s): 1549 - 1555 Vol. 3
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (403 KB) |  | HTML iconHTML  

    This paper presents a new circuit topology of dc busline switch-assisted full-bridge soft-switching PWM inverter type dc-dc power converter which is composed of typical voltage source H full-bridge type high frequency PWM inverter in addition to a single dc busline side power semiconductor switching device for PWM scheme and a capacitive lossless snubber. Under the newly-proposed high frequency inverter link dc-dc high power conditioning and processing circuit, all active power switches in the full-bridge arms and dc busline can achieve ZVS/ZVT turn-off commutation operation. On the other hand, although the conduction power loss of dc busline switch increases a little, the total turn-off switching losses of full-bridge type PWM inverter and dc busline switch with the single lossless capacitive snubber parallel with dc busline can be significantly decreased. As a result, the switching frequency of high frequency inverter power stage using IGBTs can be actually selected more than about 10 kHz. The more the switching frequency of full-bridge inverter increases, the more newly-proposed soft-switching dc-dc power converter with a high frequency transformer link has remarkable advantage as for the power conversion efficiency and power density as compared with the conventional hard-switching inverter type dc-dc power converter. The effectiveness of this new converter topology is proved for low voltage and large current dc-dc power supplies from a practical point of views. View full abstract»

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  • A single-stage dimmable electronic ballast with high power factor

    Publication Year: 2005 , Page(s): 1758 - 1763 Vol. 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (271 KB) |  | HTML iconHTML  

    A novel fixed frequency electronic ballast that consists of a single-stage asymmetrical half-bridge inverter, a load resonant tank and a switched-capacitor dimming control circuit is proposed for driving fluorescent lamps. High efficiency and unity power factor are achieved by the proposed single-stage topology. The switched-capacitor dimming control technique in the studied high frequency electronic ballast provides better EMI features. The steady-state operating principle and design procedure for the proposed single-stage dimmable electronic ballast are analyzed and discussed in detail. A ballast prototype was implemented at the laboratory. The experimental results verify the feasibility of the proposed method. View full abstract»

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  • A new PWM method for conducted EMI reduction in inverter fed motor drive

    Publication Year: 2005 , Page(s): 1871 - 1876 Vol. 3
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (221 KB) |  | HTML iconHTML  

    With the advent of fast power devices, the high dv/dt produced by PWM inverters have been found to cause EMl noise, shaft voltage and bearing current. This paper describes the application of newly developed conducted EMI reduction technique of SVPWM in induction motor drives. The newly developed common mode voltage reduction SVPWM technique doesn't use any zero-voltage vector states for inverter control. Hence it can restrict the common mode voltage better than conventional PWM technique. The validity of the proposed technique by software approach is verified through simulation and experimental results. View full abstract»

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  • Digital current control of a voltage source converter with active damping of LCL resonance

    Publication Year: 2005 , Page(s): 1642 - 1649 Vol. 3
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (414 KB) |  | HTML iconHTML  

    LCL filters installed at converter outputs offer higher harmonic attenuation than L-filters but careful design is required to damp LCL resonance, which can cause poorly damped oscillations and even instability. A new topology is presented for a discrete-time current controller which damps this resonance, combining deadbeat current control with optimal state-feedback pole assignment. By separating the state feedback gains into deadbeat and damping feedback loops, transient overcurrent protection is realizable while preserving the desired pole locations. Moreover, the controller is shown to be robust to parameter uncertainty in the grid conductance. Experimental tests verify that fast well-damped transient response and overcurrent protection is possible at low switching frequencies relative to the resonant frequency. View full abstract»

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  • Design and implementation of simple fuzzy logic controller (SFLC) for the voltage control of resonant converter

    Publication Year: 2005 , Page(s): 1508 - 1514 Vol. 3
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (310 KB) |  | HTML iconHTML  

    In this paper a simple fuzzy logic controller (SFLC) is presented for voltage regulation of extended period zero current switching quasi resonant (EP-ZCS-QR) buck-boost converter. The effectiveness of the proposed controller is verified for load variations and supply disturbances in experimental set up using TMS320C2407 processor. The experimental results obtained by implementing conventional fuzzy logic controller (FLC) and the proposed methods are compared. It is proved that the proposed method reduces the complexity in hardware implementation and produces better results compared to the conventional FLC. View full abstract»

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  • A very simple analytical approach of thermal modeling for magnetic components

    Publication Year: 2005 , Page(s): 1944 - 1950 Vol. 3
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (413 KB) |  | HTML iconHTML  

    This work is focused on the analysis of an analytical thermal model for magnetic components. This model can be used to predict the average temperature rise in the outer surface of the device using a very simple expression. The application scope of the model is shown from a practical point of view. An analytical procedure to calculate its parameters is proposed. Finally, the model has been validated using finite element analysis and measurements. View full abstract»

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  • A simple structure of LLC resonant DC-DC converter for multi-output applications

    Publication Year: 2005 , Page(s): 1485 - 1490 Vol. 3
    Cited by:  Papers (7)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (269 KB) |  | HTML iconHTML  

    Multi-output LLC resonant topologies with asymmetrical structures dedicating to multi-output power supply systems, having limitation of lowest load, are presented in this paper. According to output power level, different configuration of secondary output end can be flexibly adapted. Consequently, the presented topology is a favorable candidate for such application as whose outputs are not symmetrical, i.e. compared with auxiliary output, power level of main output is comparatively higher. In addition, all switches of the very topology operate under the condition of ZVS and therefore it is applicable to such occasion as high frequency, high power density. Asymmetrical operating principle and ZVS operation are analyzed in detail, moreover key parameter design considerations are presented. Finally, the analysis above is verified both by simulation and experiment. View full abstract»

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  • Efficiency and EMI comparisons between prototyped 8 kW hard and soft switched buck choppers

    Publication Year: 2005 , Page(s): 1566 - 1571 Vol. 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (284 KB) |  | HTML iconHTML  

    Rapid reconfiguration makes power electronics-based DC distribution systems attractive for systems that must be highly dependable. For systems at high power levels, the development of high-performance DC-DC converters is essential. In an attempt to assess efficiency, EMI, size and complexity, the authors have simulated, prototyped, and evaluated similar hard-switched and soft-switched 8 kW buck converters. View full abstract»

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  • Sensorless operation of a PWM rectifier for en-gen set as a distributed generation

    Publication Year: 2005 , Page(s): 1782 - 1785 Vol. 3
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (201 KB) |  | HTML iconHTML  

    In this paper an engine generator (en-gen) set is used as a distributed generation system. This paper presents the interface and control strategies for the en-gen set using a PWM rectifier without any ac reactors and voltage sensors. A scheme to estimate the generator's EMF voltage from the measurement of ac line currents, a method to get a synchronous angle from the estimated EMF voltages and techniques of obtaining the integrators' initial values in the estimator are proposed. The feasibility of the overall algorithms has been verified throughout experiments using a 35 hp commercial en-gen set. View full abstract»

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  • he operation of the vector modulated and vector controlled VIENNA I rectifier under distorted and unbalanced mains voltages

    Publication Year: 2005 , Page(s): 1680 - 1686 Vol. 3
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (356 KB) |  | HTML iconHTML  

    This paper examines the operation of the vector modulated and vector controlled VIENNA I rectifier in cases of distorted and unbalanced mains voltages. The principles of the applied modulation and control methods are presented. The rectifier operation is verified by simulations and experimental measurements. The rectifier examined operates at 10 kW rated power with 650 V DC voltage and 7.14 kHz switching frequency. The digital control system and vector modulator are implemented with Motorola MPC555 microcontroller. View full abstract»

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  • Fuzzy logic peak current-mode control for dc-dc converters using an inexpensive 8-bit microcontroller

    Publication Year: 2005 , Page(s): 2000 - 2006 Vol. 3
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (412 KB) |  | HTML iconHTML  

    Described in this paper are the design and implementation of a microcontroller-based fuzzy logic peak current-mode controller (PCMC) for dc-dc converters. A fuzzy logic PCMC boost converter operating in the continuous conduction mode has been designed using an 8-bit microcontroller. A one-chip solution has been achieved. No complex algorithm is required to estimate the controlled current by using the on-board peripherals of the microcontroller. The fuzzy logic algorithm uses a rule-based description of converter operation. By using rule-based look-up tables and other techniques, the fuzzy logic algorithm is implemented on the low-cost microcontroller successfully. Experimental results indicate successful operation of the microcontroller-based fuzzy logic PCMC power converter system. View full abstract»

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  • Delayless harmonic detection based on DSP with high-accuracy for active power filter

    Publication Year: 2005 , Page(s): 1817 - 1823 Vol. 3
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (341 KB) |  | HTML iconHTML  

    This paper presents a delayless harmonic detection system based on DSP with high-accuracy for active power filter. Modified structure adopting new signal-flow is introduced, which can effectively integrate analog control and digital control. Phase-shift compensating strategy is introduced into the synchronous-reference-frame based detection algorithm to overcome time-delay induced by digital control. Some design issues such as evaluation of time delay and digital phase shift is discussed. Furthermore, to guarantee satisfactory detecting performance, low sampling rate based low pass filter design helps to realize accurate fundamental current extraction overcoming the limitation of certain DSP resource. Experimental results verify the excellent performance of the presented harmonic detection system. View full abstract»

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  • Modeling of CCFL using lamp delay and stability analysis of backlight inverter for large size LCD TV

    Publication Year: 2005 , Page(s): 1751 - 1757 Vol. 3
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (301 KB) |  | HTML iconHTML  

    Cold cathode fluorescent lamps (CCFL) for LCD TVs have a special v-i characteristic, which can make the backlight inverter system unstable. In this paper, modeling of both the cold cathode fluorescent lamp and the backlight inverter is performed in terms of incremental impedance in the frequency domain. The stability analysis of the backlight inverter and the CCFL is presented using the derived models. It is concluded that the time delay, after which the lamp voltage responds to the lamp current change, contributes to the incremental impedance of the CCFL at the high frequency region, which may cause instability of the backlight inverter. The time delay is considered as a lamp characteristic. The effect of the inverter design parameters on the stability is also investigated. The lamp model and the stability analysis results are verified from experiments with a backlight inverter for 32-inch LCD TVs. View full abstract»

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  • Study of maximum linear generator output power for Maglev emergency power supply

    Publication Year: 2005 , Page(s): 2036 - 2041 Vol. 3
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (206 KB) |  | HTML iconHTML  

    This paper presents a novel method of emergent power supply for Maglev when it cannot run. It is realized by injecting a high frequency current to the three phase stator windings and adding an extra linear generator winding to magnetic pole. Output power model of linear generator is given. Relationship between the linear generator output power and the injection harmonic current is studied. Finally, experimental results are given. View full abstract»

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  • Effect and utilization of common source inductance in synchronous rectification

    Publication Year: 2005 , Page(s): 1407 - 1411 Vol. 3
    Cited by:  Papers (27)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (212 KB) |  | HTML iconHTML  

    Synchronous rectification is widely used in low voltage high current applications to reduce conduction loss. Common source inductance is the inductance shared by gate driver loop and main power transfer path. Minimization of common source inductance has been accepted as a common design rule for power converters using power MOSFET. In this paper, the effects of commons source inductance for control and sync FETs are explored in detail. In contrary to traditional belief, common source inductance of sync FET could provide significant benefits. With sync FET common source inductance, minimal dead time, shoot through prevention and Cdv/dt immunity could be achieved, and significant switching loss reduction could be realized for all types of synchronous rectifications. View full abstract»

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  • Proposal of a hysteresis controller with constant switching frequency

    Publication Year: 2005 , Page(s): 1742 - 1747 Vol. 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (211 KB) |  | HTML iconHTML  

    This paper introduces a new control technique for power factor correction in ac-dc converters. It combines the advantages of conventional hysteresis control strategy and the prominent characteristics of constant switching frequency. This is possible because the hysteresis bandwidth can be adjusted to provide fixed switching frequency. The operating principles, theoretical analysis and results on a single-phase boost converter are presented to validate the proposal. View full abstract»

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