Ching-Tsai Pan

Bio: Ching-Tsai Pan is an academic researcher from National Tsing Hua University. The author has contributed to research in topics: Flyback converter & Ćuk converter. The author has an hindex of 26, co-authored 100 publications receiving 2505 citations.

A High-Efficiency High Step-Up Converter With Low Switch Voltage Stress for Fuel-Cell System Applications

Abstract: In this paper, a novel high step-up converter is proposed for fuel-cell system applications. As an illustration, a two-phase version configuration is given for demonstration. First, an interleaved structure is adapted for reducing input and output ripples. Then, a C?uk-type converter is integrated to the first phase to achieve a much higher voltage conversion ratio and avoid operating at extreme duty ratio. In addition, additional capacitors are added as voltage dividers for the two phases for reducing the voltage stress of active switches and diodes, which enables one to adopt lower voltage rating devices to further reduce both switching and conduction losses. Furthermore, the corresponding model is also derived, and analysis of the steady-state characteristic is made to show the merits of the proposed converter. Finally, a 200-W rating prototype system is also constructed to verify the effectiveness of the proposed converter. It is seen that an efficiency of 93.3% can be achieved when the output power is 150-W and the output voltage is 200-V with 0.56 duty ratio.

A linear maximum torque per ampere control for IPMSM drives over full-speed range

Abstract: In this paper, a linear torque control strategy is first proposed for interior permanent magnet synchronous motor drives to fully utilize the reluctance torque and simplify the controller design. The proposed linear torque control strategy also extends the existing maximum torque per ampere control in the constant torque limit region up to the entire field-weakening region. It is found that in an intermediate speed region, called partial field-weakening region, the existing maximum torque per ampere control can still be applied under lighter load condition. In addition, the proposed control can also achieve the objective of minimum copper loss (i.e., maximum torque per ampere) for the entire speed range. Sound theoretical basis is given in the context. Moreover, an adaptive limiter is proposed for efficiently implementing the proposed control strategy over the entire speed range. Finally, a prototype is also constructed by using a fixed-point DSP TMS320F240 and some experimental results are given to verify the validity of the proposed control strategy.

High-Efficiency Modular High Step-Up Interleaved Boost Converter for DC-Microgrid Applications

Abstract: In this paper, a modular interleaved boost converter is first proposed by integrating a forward energy-delivering circuit with a voltage-doubler to achieve high step-up ratio and high efficiency for dc-microgrid applications. Then, steady-state analyses are made to show the merits of the proposed converter module. For closed-loop control design, the corresponding small-signal model is also derived. It is seen that, for higher power applications, more modules can be paralleled to increase the power rating and the dynamic performance. As an illustration, closed-loop control of a 450-W rating converter consisting of two paralleled modules with 24-V input and 200-V output is implemented for demonstration. Experimental results show that the modular high step-up boost converter can achieve an efficiency of 95.8% approximately.

Modeling and Coordinate Control of Circulating Currents in Parallel Three-Phase Boost Rectifiers

Abstract: In this paper, definition of the circulating currents of multiphase paralleled converters is first presented, and the circulating-current-generating mechanism is clearly explained. Thus, based on this definition, an averaged model of the circulating current is proposed. It is seen from this model that the circulating current consists of not only the zero-sequence but also the nonzero-sequence components. The governing differential equation also shows explicitly the relation between the circulating currents and the affecting factors such as different pulse width-modulation strategies. With this understanding, a simple coordinate control is then presented to reduce the circulating current. The phenomenon of the intrinsic circulating current is also explained. Furthermore, a prototype system is constructed, and the proposed control is implemented using TMS320F2812 DSP. Both simulation and experimental results verify the validity of the proposed theory and control

An improved hysteresis current controller for reducing switching frequency

Abstract: In this paper, an improved invertor hysteresis current controller is proposed. It coordinates the switching of the three-phase switches in the d-q phase plane. In addition to the current error, information of the current error derivative is further employed so that one can take more advantage of adding the zero voltage vector for reducing the switching frequency. A simple hardware implementation of the improved hysteresis current controller is also proposed such that merits of the conventional hysteresis current controller can still be kept. Theoretical basis and some simulation and experimental results are presented to demonstrate the validity of the improved hysteresis current controller. >

Comparison of Photovoltaic Array Maximum Power Point Tracking Techniques

Abstract: The many different techniques for maximum power point tracking of photovoltaic (PV) arrays are discussed. The techniques are taken from the literature dating back to the earliest methods. It is shown that at least 19 distinct methods have been introduced in the literature, with many variations on implementation. This paper should serve as a convenient reference for future work in PV power generation.

Review of Battery Charger Topologies, Charging Power Levels, and Infrastructure for Plug-In Electric and Hybrid Vehicles

Abstract: This paper reviews the current status and implementation of battery chargers, charging power levels, and infrastructure for plug-in electric vehicles and hybrids. Charger systems are categorized into off-board and on-board types with unidirectional or bidirectional power flow. Unidirectional charging limits hardware requirements and simplifies interconnection issues. Bidirectional charging supports battery energy injection back to the grid. Typical on-board chargers restrict power because of weight, space, and cost constraints. They can be integrated with the electric drive to avoid these problems. The availability of charging infrastructure reduces on-board energy storage requirements and costs. On-board charger systems can be conductive or inductive. An off-board charger can be designed for high charging rates and is less constrained by size and weight. Level 1 (convenience), Level 2 (primary), and Level 3 (fast) power levels are discussed. Future aspects such as roadbed charging are presented. Various power level chargers and infrastructure configurations are presented, compared, and evaluated based on amount of power, charging time and location, cost, equipment, and other factors.

Current control techniques for three-phase voltage-source PWM converters: a survey

Abstract: The aim of this paper is to present a review of current control techniques for three-phase voltage-source pulsewidth modulated converters. Various techniques, different in concept, have been described in two main groups: linear and nonlinear. The first includes proportional integral (stationary and synchronous) and state feedback controllers, and predictive techniques with constant switching frequency. The second comprises bang-bang (hysteresis, delta modulation) controllers and predictive controllers with on-line optimization. New trends in current control-neural networks and fuzzy-logic-based controllers-are discussed, as well. Selected oscillograms accompany the presentation in order to illustrate properties of the described controller groups.

A review of single-phase improved power quality AC-DC converters

Abstract: Solid-state switch-mode rectification converters have reached a matured level for improving power quality in terms of power-factor correction (PFC), reduced total harmonic distortion at input AC mains and precisely regulated DC output in buck, boost, buck-boost and multilevel modes with unidirectional and bidirectional power flow. This paper deals with a comprehensive review of improved power quality converters (IPQCs) configurations, control approaches, design features, selection of components, other related considerations, and their suitability and selection for specific applications. It is targeted to provide a wide spectrum on the status of IPQC technology to researchers, designers and application engineers working on switched-mode AC-DC converters. A classified list of more than 450 research publications on the state of art of IPQC is also given for a quick reference.