Showing papers by "Fengling Han published in 2017"
01 Oct 2017
TL;DR: Analytical and experimental results show that the converter can obtain high efficiency, fast load and input voltage transient response in the entire input voltage range with the four-mode control method.
Abstract: It is generally preferred for the non-inverting buck-boost converter to operate in buck mode when the input voltage is higher than the output voltage and in boost mode vice versa to improve the efficiency. However, the performance of the converter would be degraded under this operating scheme when the input voltage approaches to the output voltage due to the occurrence of the dead-zone. The four-mode control method is a potential solution to eliminate the dead-zone issue. This paper is to analyze the operating principle and the performance of the converter with four-mode control method. A prototype with 16.8V output voltage is tested in the laboratory. Analytical and experimental results show that the converter can obtain high efficiency, fast load and input voltage transient response in the entire input voltage range with the four-mode control method.
13 citations
07 Oct 2017
TL;DR: A web-based voting system, which allows voters to cast and submit their electronic ballots by ranking all candidates according to their personal preference, with each element encrypted using the ElGamal cryptosystem before submission is proposed.
Abstract: This paper, proposes a web-based voting system, which allows voters to cast and submit their electronic ballots by ranking all candidates according to their personal preference. Each ballot is treated as a square matrix, with each element encrypted using the ElGamal cryptosystem before submission. Furthermore, proof of partial knowledge and zero knowledge are used to verify the eligibility of ballots without accessing ballot contents. We also implement a prototype to test our proposed voting system. The security and performance analysis indicate the feasibility of the proposed protocols.
8 citations
18 Jun 2017
TL;DR: The online SoC estimation of Li-ion batteries is surveyed, the models, control and management of the networked rechargeable batteries are understood, and a research on decentralized secure cloud management to the end nodes of IoT is initiated.
Abstract: Enlightened by the ”Totally Innovative Cloud Things of Connectedness” from the theme of 2017 round Australian National Wide Cyber Security Challenge1, cloud back-end and the hardware devices are identified as important components for cyber security investigation On the other hand, rechargeable Lithium-ion (Li-ion) battery packs are widely used for energy storages and back-up power supplies There are numerous embedded sensors in the Battery Management Systems, which provide the first hand data for optimizing the collective performance of the battery packs Therefore, these sensor nodes are the desired initial starting points for exploring the vulnerabilities and security protections to the decentralized end nodes in IoT This paper surveys the online SoC estimation of Li-ion batteries, endeavors to understand the models, control and management of the networked rechargeable batteries This brief aims to initiate a research on decentralized secure cloud management to the end nodes of IoT
3 citations
01 Jul 2017
TL;DR: In this article, the authors proposed a full-order terminal sliding mode control for a class of uncertain nonlinear systems to address the singularity and chattering problems of traditional sliding-mode control.
Abstract: Traditional sliding-mode control has two main problems, the singularity and chattering, which hinder its applications. This paper proposes a full-order terminal sliding mode control for a class of uncertain nonlinear systems to address these problems. During the ideal sliding motion, the nonlinear systems are forced to behave as a desirable full-order dynamics rather than a reduced-order dynamics. The output signals of the proposed controllers are continuous, which attenuates the chattering. The singularity in the terminal sliding-mode control is avoided because the control strategies do not include the derivatives of fractional power terms. The effect of the measurement and calculation errors on the systems is analyzed. The simulation results validate the proposed method.
2 citations
01 Oct 2017
TL;DR: A full-order terminal sliding-mode based energy saving control for the grid-connected converter of induction motor systems is proposed and the simulation results validate the proposed method.
Abstract: This paper proposes a full-order terminal sliding-mode based energy saving control for the grid-connected converter of induction motor systems. DC-link voltage and currents controllers of the converter are designed respectively using the full-order terminal sliding manifold and the related control strategies. The chattering in the sliding-mode control is attenuated, and continuous control signals are obtained. The energy-saving operation of the induction motor systems is achieved because the regenerative energy of the induction motor is fed back to the power grid with unity power factor. The simulation results validate the proposed method.
1 citations
01 Oct 2017
TL;DR: Through applying a symmetrical configuration, the proposed PV system has a single stage structure to implement voltage boosting and inversion, which contributes to the advantages such as compact size and high power conversion efficiency.
Abstract: This paper proposes an energy storage unit integrated dual input PV system with distributed maximum power point tracking (MPPT). Through applying a symmetrical configuration, the proposed PV system has a single stage structure to implement voltage boosting and inversion, which contributes to the advantages such as compact size and high power conversion efficiency. The design of the control strategy is relative easy due to the inherently decoupled connection among all ports of the system. Moreover, the intermittent nature of the solar power can be handled well by the integrated energy storage unit. The configuration and operation principle of the proposed PV system is explained and the design of the control strategy is derived in this paper. MATLAB/SIMULINK simulation results are used to verify the performance of the proposed PV system and the accordingly designed control strategy.
1 citations
01 Oct 2017
TL;DR: A terminal sliding-mode observer (TSMO) is proposed based on a fluid-flow model of a TCP/IP network to estimate traffic flow states and a novel control strategy is proposed to fasten the convergence of the estimation error for average congestion window (ACwnd).
Abstract: Recently, the state estimation issue of a TCP/IP network has attracted much attention from different communities. In this paper, a terminal sliding-mode observer (TSMO) is proposed based on a fluid-flow model of a TCP/IP network to estimate traffic flow states. A novel control strategy is proposed to fasten the convergence of the estimation error for average congestion window (ACwnd). Furthermore, a continuous control strategy is directly used to estimates the flooding rate of additional traffic flow (ATF). The efficacy of the proposed TSMO is verified by a numerical simulation implementations via the networking simulator NS-2.
1 citations
01 Jun 2017
TL;DR: In this article, a nonsingular terminal sliding-mode observer is proposed for estimating the rotor flux of induction motors, which utilizes the terminal slidingmode manifold and the continuous control strategy.
Abstract: A nonsingular terminal sliding-mode observer is proposed for estimating the rotor flux of induction motors in this paper The observer utilizes the terminal sliding-mode manifold and the continuous control strategy The high-order sliding-mode control technique is applied to generate continuous outputs of the observer, which can be directly used for the estimation of the rotor flux The effect of the equivalent low-pass filter in the proposed observer can be optimally regulated The chattering can be attenuated effectively The simulation results validate the proposed method
01 Oct 2017
TL;DR: The proposed gain margin technique based continuous sliding-mode control method can implement high-performance position control of induction motors with improvement of steady-state and dynamic performances, control precision and robustness.
Abstract: This paper proposes a gain margin technique based continuous sliding-mode control method for position servo systems of induction motors. A systematic design method for position and current controllers is developed to implement the robust control of induction motors in the field orientation control system. In the proposed controllers design, the boundaries of disturbances and parameter perturbations in the control system can be determined in advance based on the upper-bounds of uncertainties in the induction motor model. The gain margin technique is utilized to regulate the gain of the switching control. The chattering phenomenon are attenuated by using a continuous sliding-mode control method, so continuous control signals can be generated and directly applied in servo systems of induction motors. The simulation results show that the proposed method can implement high-performance position control of induction motors with improvement of steady-state and dynamic performances, control precision and robustness.