Browsing by Author "Li, Chung-Yi"

Now showing 1 - 7 of 7

A Simple Control Strategy Extending Intrinsic Current Balancing Characteristics to Achieve a Full Operating Range for Interleaved Voltage-Doubler Boost DC-DC Converters
(2020-01-01)
Li, Chung-Yi
;
Chen, Tien-Hung
;
Chen, Hung-Chi
;
電機工程學系
;
電控工程研究所
The interleaved voltage-doubler boost converter strategy exhibits a very good performance, namely, in a low conduction loss, an acceptable switch stress, a fast transient response, and a very high power density. However, the bottleneck for application in the interleaved topology lies in the limit of operating duty ratio. In this article, an intrinsic current-balancing control method to achieve full operating range in duty ratio is proposed, and it can be easily implemented by including a voltage limiter to the conventional control configuration. With this novel design, both voltage-doubler and the current-balancing characteristics can be achieved within full range in duty cycle without any current sensor. The proposed method is implemented in a field programmable gate array chip. The provided simulations and experimental results validate the proposed method.
Average Current Method to Detect Open-Winding Fault of Three-Phase Permanent Magnet Synchronous Motors
(2016)
Chen, Hung-Chi
;
Wu, Zhi-Xuan
;
Li, Chung-Yi
;
資訊工程學系
;
電機學院
In this paper, the average current method is proposed to detect the open-winding fault of three-phase permanent magnet synchronous motors (PMSMs). The characteristics and operational regions are studied. All the methods are implemented in FPGA-based system. The simulation and experimental results are provided to demonstrate the proposed method.
Current Sensorless Control for Dual-Boost Half-Bridge PFC Converter
(2015)
Lu, Che-Yu
;
Chen, Hung-Chi
;
Chen, Wei-Cheng
;
Li, Chung-Yi
;
電機學院
In this paper, the current sensorless control for dual-boost half-bridge (DBHB) converter with power factor correction (PFC) function is presented. The short-through problem can be avoided by the dual-boost structure for enhancing the reliability. It also reduces the power dissipation due to the body diodes\' reverse recovery current of switches. Furthermore, the intrinsic voltage-doubler characteristic of half-bridge structure is often used in high voltage application. The conventional multiloop control needs many voltage and current feedback signals. In order to simply the control loops and reduce the number of sensors, the feasibility of current sensorless control strategy should be evaluated. Therefore, the electrical characteristics of the proposed current sensorless control scheme are completely analyzed in this paper. At last, some simulation and experimental results are provided to demonstrate and illustrate the performance of the proposed current sensorless control.
Design and Implementation of Four-Switch Current Sensorless Control for Three-Phase PFC Converter
(2020-04-01)
Li, Chung-Yi
;
Chao, Nan-Chih
;
Chen, Hung-Chi
;
電機工程學系
;
電控工程研究所
Four-switch current sensorless control for three-phase four-switch converter with power factor correction (PFC) function is presented in this letter. In comparison with conventional multiloop control methods, the proposed control strategy requires sensing of two line voltages and two capacitor voltages only to achieve PFC function. As there is no sensing current, the proposed sensorless control scheme reduces the cost and complexity of design. The performance of the proposed control is validated by its implementation in digital signal processing (DSP) TMS320F28335, and the result shows that the proposed scheme is able to provide comparable PFC performance without sensing current.
Modeling and Control for Interleaved Voltage-Doubler Boost Converter
(2018-01-01)
Chen, Hung-Chi
;
Chen, Tien-Hung
;
Li, Chung-Yi
;
電機工程學系
;
電控工程研究所
In this paper, a new control method for a interleaved voltage-doubler boost converter is proposed to extend the operating range of duty ratio. Firstly, the analysis of the current-sharing mechanism is presented. Then, the averaging method is adopted to construct an average-behavior circuit model. After that, the modulation signal for current-sharing is particularly designed by amp-second balance. Besides, the average state-space equation of the voltage-doubler can be obtained. The open-loop transfer function can be derived from the small-signal analysis, and the proportional-integral (PI-type) controller parameters can be selected by Bode plots. All the algorithms are implemented in a Field Programmable Gate Array (FPGA) chip. The simulation and experimental results validate the inductor current-sharing capability of the proposed method.
Non-linear Pseudo-Random Number Generators via Coupling DX Generators with the Logistic Map
(2012)
Li, Chung-Yi
;
Chou, Hwai-Pwu
;
Deng, Lih-Yuan
;
Shiau, Jyh-Jen Horng
;
Lu, Henry Horng-Shing
This brief proposes a class of nonlinear pseudo-random number generators (PRNGs) based on coupling linear generators (DX generators) with a nonlinear generator (digitized Logistic map). By breaking the linearity, the unpredictability of the proposed generators in the family of coupling PRNGs is enhanced while the nice properties of efficiency, long period, and excellent statistical properties are preserved. Furthermore, the hardware efficiencies are validated by hardware implementations using a TSMC 0.18 mu m CMOS process with a throughput rate greater than 8,000 Mbit/s. In addition to the extremely long period length, the proposed nonlinear PRNGs can generate random sequences that fulfill all the randomness requirements of NIST SP 800-22 test suite.
Symmetrical Voltage Balancing Control for Four-level Flying Capacitor Converter Based on Phase-Shifted PWM
(2019-01-01)
Lu, Che-Yu
;
Chen, Hung-Chi
;
Li, Chung-Yi
;
電機工程學系
;
電控工程研究所
A symmetrical voltage balancing control (SVBC) method for the four-level flying capacitor (FC) converter is addressed in this paper, which is built on phase-shifted pulse width modulation (PS-PWM). However, the PS-PWM technique is hard to maintain balanced FC voltages in practice. The proposed method balances FC voltages by using a proportional (P) controller without any complicated algorithm, also achieves the output voltage regulation. Thus, the PS-PWM technique could be significantly improved by the proposed method. In addition, the averaged state-space model and small-signal model for the four-level FC converter are analyzed in details. Some experimental results are given to illustrate the proposed method.