Guan-Chyun Hsieh

Fuzzy-controlled Li-ion battery charge system with active state-of-charge controller

A fuzzy-controlled active state-of-charge controller (FC-ASCC) for improving the charging behavior of a lithium-ion (Li-ion) battery is proposed. The proposed FC-ASCC is designed to replace the general constant-voltage charging mode by two kinds of modes: sense and charge. A fuzzy-controlled algorithm is built with the predicted charger performance to program the charging trajectory faster and to keep the charge operation in a proposed safe-charge area (SCA). A modeling work is conducted for analyzing and describing the Li-ion battery in charging process. A three-dimensional Y-mesh diagram for describing the charging trajectories of the proposed FC charger is simulated. A prototype of a Li-ion battery charger with FC-ASCC is simulated and realized to assess the predicted charging performance. Experiment shows that the charging speed of the proposed FC charger compared with the general one increases about 23% and the charger can safely work in the SCA.

Harmonized strategy for breaking the striations in the fluorescent lamp

A harmonized strategy for breaking the striations in the fluorescent lamp is proposed. The harmonized circuit (HC) presented is a dependent current source and is used to modulate the lamp current by making the amplitudes of the even harmonics nearly the same as the neighboring odd harmonics. The time and frequency responses of the lamp current without and with HC are respectively simulated and experimented for describing the striation behavior. The dimmer system with HC can actually provide better immunity from striation for the lamp during a wide dimming range from 10% to 100%. In addition, the lighting efficiency increases up to 16.2%.

Primary-side charge-pump dimming controller for the cold-cathode fluorescent lamp ballast

A primary-side charge-pump controller built into a cold-cathode fluorescent lamp (CCFL) ballast is presented for widening the dimmer range while stabilizing the dynamic feedback regulation for the lamp luminance in uniform distribution without thermometer effect. The proposed controller consists of a linear error amplifier for dynamic feedback control regulation and a shunt amplifier for dimmer control. A dimming strategy is explored for extending the dimming range above 1:50 far higher than the conventional 1:10. Besides, floating the CCFL alone at the secondary side also raises the lamp efficiency without parasitic effect.

A design of fast‐locking without overshoot frequency‐locked servo system by fuzzy control technique

Abstract In this paper, a Fuzzy Pulse Pump Controller (FPPC) is proposed to realize a Fuzzy‐Controlled Frequency‐Locked Servo system (FC‐FLS) for getting a fast locking response without overshoot. A prototype FC‐FLS is designed and built to assess the system performance. In comparison with the Frequency Pump Controller‐based FLS (FPC‐FLS) and Variable Slope Pulse Pump Controller‐based FLS (VSPPC‐FLS), the acquisition times of the FC‐FLS are improved over 40%. In particular, there is no overshoot in the FC‐FLS for any servo distance. This means that a fast‐locking FLS, without overshoot, has been successfully implemented as theoretical prediction.

Fuzzy-controlled active state-of-charge controller for fasting the charging behavior of Li-ion battery

A fuzzy-controlled active state-of-charge controller (FC-ASCC) is presented to adaptively program the charging behavior of the Li-ion battery. The proposed FC-ASCC can provide two charging modes (SM and CM) instead of the usual CV mode for improving the charging trajectory of the Li-ion battery. A fuzzy-controlled strategy is built with a set of membership functions to prescribe the charging process in a safe charging region. A design example is conducted with simulation and experiment for accessing the predicted charging performance of the Li-ion battery. The FC-ASCC can actually increase the charging speed over 23% comparing with the traditional charging system.

Modeling and implementation of sigma-delta modulation controller for DC/AC inverter

A sigma-delta modulation controlled DC/AC inverter is proposed. Modeling and analysis of sigma-delta modulation (SDM) controller are explored. The pulse width of the SDM formed by cycle-by-cycle integration loop is clearly described. System stability is studied by root-locus and Bode plot techniques. An approach to reducing the THD is conducted by Fourier analysis. A prototype of 1 kVA SDM controlled DC/AC inverter is designed and examined. Simulation and experiment are close to the theoretical predictions. The proposed inverter can provide high efficiency up to 90% under the rated power and still keep the total harmonic distortion (THD) without EMI filter within 2%.

ZCS-PWM full-wave boost rectifier with unity power factor and low conduction losses

A full-wave boost rectifier (FWBR) realized by zero-current-switching pulsewidth-modulation (ZCS-PWM) control to achieve unity power factor is presented. Two resonant cells are configured in the presented FWBR to perform ZCS in the power switches and to preregulate the input current to follow up the input voltage. Only one diode and one power switch loss are included in the proposed FWBR during the rectification. Four transition states for describing the behavior of the ZCS-PWM FWBR in one switching period are described. A small-signal model is built for the system analysis, and an average-current-mode control is employed to formulate the input current waveform with low harmonics. The control strategy and design consideration are programmed to realize a 600-W ZCS-PWM FWBR, which provides high power efficiency of 95% and high power factor over 0.99.

Asymmetrical group-pulse-width-modulated technique for eliminating striation in the dimmable fluorescent lamps

An asymmetrical group-pulse-width-modulated (AGPWM) control strategy is proposed for eliminating the striation in a dimmable fluorescent lamp. The approach is executed by alternately modulating the pulse-width of a group-driving signal with a suitable period to reduce the odd harmonic amplitudes of the lamp current and increase the even ones. The striation in the lamp disappears due to all amplitudes of the distributed harmonics in the lamp current spectrum are close to each other. Therefore, the lighting efficiency increases and the total harmonic distortion is reduced. In this paper, a half-bridge series-resonant inverter (HB-SRI) is used for realizing the ballast operation with the proposed controller. A modeling work and a control strategy for system analysis and performance evaluation are clearly conducted. The examined prototype with simulation and experiment is presented for assessing the theoretical predictions. Experiment shows that no striation occurs during wide-range dimmer of 1%-100%.

Genetic algorithm-based fuzzy pulse-pump controller for phase/frequency-locked servomechanism

A fuzzy clustering-based genetic algorithm (FC-GA) is presented to build a genetic algorithm-based fuzzy pulse-pump controller (GA-FPPC) for achieving a fuzzy control-based phase/frequency-locked servomechanism (FC-PFLS). A weighted integral absolute error (WIAE) is presented as the objective function of FC-GA for optimizing the locking behavior of the genetic algorithm-based FC-PFLS (GFC-PFLS). A mixed elitist and fuzzy clustering selection strategy is proposed to achieve high diversity of the FC-GA. A tuning strategy by FC-GA can minimize the overshoot and speed-up the locking performance of the GFC-PFLS. A design example of two-dimensional X-Y mode GFC-PFLS is realized. Simulation and experiment are conducted to assess the system performance, which is close to the theoretical prediction.

A study of phase/frequency-locked servo system by fuzzy control technique

A novel fuzzy pulse pump controller (FPPC) is proposed to achieve a fuzzy-control-based phase/frequency-locked servo system (FC-PFLS). Three sets of membership functions are constructed according to the locking performance indexes, position error, discrete time change of position error, and the output crisp value. A set of fuzzy rules is built in the fuzzy-logic controller (FLC) to process the detected position error and provide a suitable pump voltage for the motor drives. The FPPC can fuzzilly provide the motion profiles, such as acceleration, constant, and deceleration for the motor in a fast response without overshoot and with nearly zero steady-state error. The physical model and the linearized model of the presented FC-PFLS are built. A design example of realizing an X-Y mode FC-PFLS is constructed. The experiments of the FC-PFLS comparing with DPPLS and SPSCS are conducted. In comparison with the DPPLS, the acquisition times of the presented FC-PFLS for the short, middle and long distance servos are improved by 30%, 53% and 57%, respectively. For the SPSCS, the acquisition times are improved by 30%, 14%, and the same, respectively.