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ABSTRACT: The multi-phase implementation in the quasi resonant (QR) zero current switching (ZCS) switched capacitor (SC) bidirectional DC-DC converter structure has been proposed to reduce current ripple, switching loss and significantly increase the converter efficiency and power density. This approach provides a more precise output voltage to obtain voltage conversion ratios from the double mode versus half-mode to n-mode versus 1/n mode. This is accomplished by adding a different number of switched capacitors and power MOSFET switches with a small series connected resonant inductor for forward and reverse schemes. The size and cost can be reduced when the proposed converter has designed with the coupled inductors. The simulation and experimental results have been used to demonstrate the performance of the two-phase with and without coupled inductor interleaved QR ZCS SC converters for bidirectional power flow control application, and an extending structure for N-phase is mentioned.
Power Electronics and ECCE Asia (ICPE & ECCE), 2011 IEEE 8th International Conference on; 07/2011
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ABSTRACT: This paper proposes a zero-current-switching (ZCS) quasi-resonant (QR) bidirectional converter with secondary output power amplifier. For implantable biomedical devices applications, the proposed device could be regarded as a power regulator with power amplifier. The bidirectional converter could provide voltage conversion ratio double-mode/half-mode and also be employed as a secondary output power amplifier. The forward and reverse power conversion modes and power amplifier operating principles are described. Simulations and experiments are carried out to verify the concept and performance for the bidirectional power conversions and secondary output power amplifier. This device can be applied to wireless energy transfer for a battery management system (BMS) in an implantable electronics system.
Power Electronics Conference (IPEC), 2010 International; 07/2010
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ABSTRACT: A DSP is adopted to construct a fuzzy controlled lithium-ion battery charging system. By using this intelligent charging system, the data collection, calculation and peripheral circuit control are performed for the battery charging status. According to the lithium-ion battery charging specifications, two hours are required for battery charging. A fuzzy logic controller (FLC) is constructed by using the battery protection cell voltage and voltage difference among the batteries. They are used as the input variable to shorten the charging and equalizing time and assure that the battery will be operated within the safety voltage range.
Power Electronics and Drive Systems, 2009. PEDS 2009. International Conference on; 12/2009
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ABSTRACT: We use DSP to construct an intelligent Lithium-ion battery charging system. By adopting this intelligent charging system, we perform the data collection, calculation and peripheral circuit control for the battery charging status. According to the lithium-ion battery charging specifications, two hours are required for battery charging. A fuzzy controller constructed using the battery protection voltage and voltage difference among the batteries is used as the input variable to shorten the charging and equalizing time and assure that the battery will be operated within the safety voltage range.
Telecommunications Energy Conference, 2009. INTELEC 2009. 31st International; 11/2009
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IEICE Transactions. 01/2009; 92-B:1326-1336.
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ABSTRACT: In this paper, a soft computing technique for estimating battery state-of-charge of individual batteries in a battery string is proposed. The soft computing approach uses a fusion of a fuzzy neural network (FNN) with B-spline membership functions (BMFs) and a reduced-form genetic algorithm (RGA). The algorithm is employed to tune both control points of the BMFs and the weights of the FNNs. The traditional multiple-input multiple-output FNN (MIMOFNN) cannot directly be used in this paper. The main reason is that there are too many free parameters in the MIMOFNN to be trained if many inputs are required. In this paper, a merged multiple-input single-output (MISO) FNN is proposed and can be trained by the RGA optimization approach. The merged MISO FNN with RGA (FNNRGA) can achieve faster convergence and lower estimation error than neural networks with the back propagation method. From experimental results, the proposed merged MISO FNNRGA is superior, more robust than the traditional method, and the overfitting suppression features are significantly improved.
IEEE Transactions on Industrial Electronics 02/2008; · 5.16 Impact Factor
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IEICE Transactions. 01/2008; 91-B:2380-2392.
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ABSTRACT: A current mode control ( CMC) integrated circuit (IC) with accuracy current sensing circuit (CSC) for buck converter is presented in this paper. With the proposed accurate integrated current sensor, the sensed inductor current, combined with the internal ramp signal, can be used for current mode DC-DC converter feedback control. The proposed CSC does not need an operational amplifier to implement, and has been fabricated with a standard 0.35 mum CMOS process. Simulation results show that the switching converter can be operated up to 1MHz. Which is suitable for signal cell lithium-ion battery supply applications, the power efficiency is over 85% for supply voltage from 2.5 V to 5 V and the output current is 200 mA. The performance of the proposed circuit is the good compared to the other circuits.
Power Electronics and Drive Systems, 2007. PEDS '07. 7th International Conference on; 12/2007
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ABSTRACT: The proposed quasi-resonant (QR) zero current switching (ZCS) switched-capacitor (SC) converter is a new type of bi-directional power flow control conversion scheme. They are able to provide the voltage conversion ratios from 2 versus 1/2 (double-mode/half-mode) to n versus 1/n (n-mode/1/n-mode) by adding a different number of switched-capacitors and power MOSFET switches with a small series connected resonant inductor for forward and reverse schemes. The low current stress and balance resonance current are the advantage of the proposed quasi resonant switched-capacitor converter. The principle of operation, theoretical analysis of the proposed bi-directional power conversion scheme is described in detail with circuit model analysis. Simulation and experimental results are carried out to verify the performance of the new type ZCS SC bi-directional QR converters.
Power Electronics and Drive Systems, 2007. PEDS '07. 7th International Conference on; 12/2007
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ABSTRACT: This article proposes multiple output zero-current switching (ZCS) bi-directional power flow control conversion schemes. This method possesses the conventional features of resonant switched-capacitor converters: low weight, small volume, high efficiency, low EMI emission and current stress. This multiple output zero-current switching bi-directional converter can improve the current stress problem during bi-directional power flow control processing. It can provide a double mode voltage conversion ratio using four power MOSFET main switches, a switched-capacitor, series connected with a small resonant inductor. The principle of proposed bi-directional power conversion scheme is described in detailed circuit model analysis. Simulation and experimental results are carried out to verify the validity and the soft switching performance of the proposed double mode two output zero-current switching bi-directional converter. The maximum efficiency can achieve about 93% and 92% for the forward and reverse power flow control schemes, respectively.
Industrial Electronics Society, 2007. IECON 2007. 33rd Annual Conference of the IEEE; 12/2007
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ABSTRACT: To solve learning problems with vast number of inputs, this paper proposes a novel learning structure merging a number of small fuzzy neural networks (FNNs) into a hierarchical learning structure called a merged-FNN. In this paper, the merged-FNN is proved to be a universal approximator. This computing approach uses a fusion of FNNs using B-spline membership functions (BMFs) with a reduced-form genetic algorithm (RGA). RGA is employed to tune all free parameters of the merged-FNN, including both the control points of the BMFs and the weights of the small FNNs. The merged-FNN can approximate a continuous nonlinear function to any desired degree of accuracy. For a practical application, a battery state-of-charge (BSOC) estimator, which is a twelve input, one output system, in a lithium-ion battery string is proposed to verify the effectiveness of the merged-FNN. From experimental results, the learning ability of the newly proposed merged-FNN with RGA is superior to that of the traditional neural networks with back-propagation learning.
IEEE Transactions on Energy Conversion 10/2007; · 2.27 Impact Factor
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ABSTRACT: An intelligent battery equalization scheme is presented, based on and accordingly designed as fuzzy logic controlled battery equalization controller (FLC-BEC). It can effectively reduce equalization time. The proposed individual cell equalization (ICE) scheme is a bidirectional dc-dc converter, based on the Cuk converter operated at discontinuous inductor current mode (DICM). A state space approach is adopted to inspect the stability of the proposed FLC-BEC. Matlab/Simulink simulation and experimental results can be used to verify the stability of FLC-BEC. In this article, an 8-bit micro-controller unit (MCU) is used to accomplish the FLC-BEC, which can reduce volume and complexity of the hardware used for the FLC-BEC.
Systems, Man and Cybernetics, 2006. SMC '06. IEEE International Conference on; 11/2006
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IEICE Transactions. 01/2006; 89-B:2913-2921.
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ABSTRACT: This paper presents the new topologies of zero-current switching switched-capacitor (ZCS SC) quasi-resonant converters with bidirectional power flow control conversion schemes. It possesses the features of quasi resonant switched-capacitor converters: low weight, small volume, high efficiency, low EMI emission and low current stress. A family of zero-current switching switched-capacitor bidirectional converters is proposed to improve the current stress problem during the bidirectional power flow control processing. They are able to provide the voltage conversion ratios from double-mode/half-mode to n-mode/1/n mode by using four power MOSFET main switches and a set of switched-capacitors with a small series connected resonant inductor for non-inverting or inverting modes. The operation principle of converter operation of the proposed bi-directional power conversion scheme is described in detail with circuit model analysis for non-inverting mode. Simulation and experimental results are carried out to verify the concept and the performance of the proposed double-mode/half-mode ZCS SC bi-directional quasi-resonant converters.
Power Electronics and Drives Systems, 2005. PEDS 2005. International Conference on; 12/2005
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ABSTRACT: A TRIAC-based voltage phase speed controller is typically used to control the voltage of the winding of a variable speed single phase induction motor. Transient voltage and highly harmonic current will be produced when TRIAC switches turn on and off. This will result in significantly conducted emissions, causing serious problems concerning the EMI issue. This paper presents a measurement and mitigation method of the conducted electromagnetic interference (EMI) for the voltage phase controlled capacitor-run single-phase induction motor (CR SPIM). The conventional and improved voltage phase controlled schemes, for the speed control of the SPIM driving system are investigated. The measuring results of the common mode (CM) and differential mode (DM) are compared and used to design a power line filter to improve the conducted EMI performance, compliant with the regulatory requirement of CISPER 22/EN5502.
Power Electronics and Drives Systems, 2005. PEDS 2005. International Conference on; 12/2005
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ABSTRACT: This article discusses how to use a digital oscilloscope to match the time-domain measurement computer-aided technique and Fourier transformation to measure the conducted EMI. Taking advantage of the multi-channel oscilloscope and the computer, it will deal with the Line and Neutral lines synchronization. It can mitigate the phase coherency problem to separate the common-mode (CM) and differential-mode (DM) EMI noise at the same time without any hardware implementations. Due to the time-domain measuring method, which allows the noise amplitude and phase in parallel processing for the whole spectrum range, measuring time is reduced. The computerized time-domain measurement environment is based upon the LabVIEW test and measurement system. The separation results are compared with the frequency-domain measurements. The proposed time-domain measured system can provide a user friendly and convincible approach for fast EMI measurement and countermeasures.
Power Electronics and Drives Systems, 2005. PEDS 2005. International Conference on; 12/2005
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ABSTRACT: An intelligent battery equalization scheme based on fuzzy logic control is presented to adaptively control the equalizing process of series-connected lithium-ion batteries. The proposed battery equalization scheme is a bidirectional dc-dc converter with energy transferring capacitor that can be used to design the bidirectional nondissipative equalizer for a battery balancing system. Furthermore, it can be designed as a ripple-free converter for improving the input current distortion of the battery charge supply power system. A fuzzy-logic-controlled strategy is constructed with a set of membership functions to prescribe the cells equalizing behavior within a safe equalizing region for rapid cell voltage balancing. The simulation and experimental results show the advantage of the predicted equalizing performance of the lithium-ion battery stacks. The proposed fuzzy logic control battery equalization controller can abridge the equalization time about 32%. The proposed method maintains safe operation during the charge/discharge state in each lithium-ion cell of the battery strings.
IEEE Transactions on Industrial Electronics 11/2005; · 5.16 Impact Factor
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ABSTRACT: A systematic approach to the analysis and design of a bi-directional Cuk converter for the cell voltage balancing control of a series-connected battery string is presented in this paper. The proposed individual cell equalizers (ICE) are designed to operate at discontinuous-capacitor-voltage mode (DCVM) to achieve the zero-voltage turn-off switching (ZVS) for reducing the switching loss of the bi-directional DC/DC converters. Simulation and experimental results show that the proposed battery equalization scheme can not only enhance the bi-directional battery equalization performance, but also can reduce the switching loss during the equalization period. The switch power is significantly reduced by about 52.8% from MOSFETs and the equalization efficiency can be improved by 68-72% using the proposed DCVM ZVS battery equalizer under the specified cell equalization process
Power Electronics Specialists Conference, 2005. PESC '05. IEEE 36th; 07/2005
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ABSTRACT: This paper presents a new method for estimating the individual battery state-of-charge (SOC) of electric scooter (ES). The proposed method is to model ES batteries by using the fuzzy inference neural network system. A reduced form genetic algorithm (RGA) is employed to tune control point of the B-spline membership functions (BMFs) and the weightings of the fuzzy neural network (FNN). The proposed FNN with RGA (FNNRGA) optimization approach can achieve the faster learning rate and lower estimating error than the conventional gradient descent method. The validity of the SOC estimator is further verified by a constructed multiple input multiple output (MIMO) FNN structure for estimating the SOCs of battery powered ES. A fixed velocity discharging profiles of the ES batteries are investigated to train the FNN for precise estimating the SOCs of the battery strings. Furthermore, a testing data profile is used to demonstrate the superior robust and over-fitting suppressed performance of the proposed method. The estimated SOCs are directly compared with the actual SOCs under different FNN methods, verifying the accuracy and the effectiveness of the proposed intelligent modeling method.
Power Electronics Specialists Conference, 2004. PESC 04. 2004 IEEE 35th Annual; 02/2004
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ABSTRACT: A systematic approach to the analysis and design of a soft-switching bi-directional dc-to-dc converter for the cell voltage balancing control of a battery powered electric vehicle is presented in this paper. The quasi-resonant converter circuits are designed to achieve the zero current switching (ZCS) for reducing the switching loss of bi-directional converters. Results indicate that the switching loss, switching waveform and EMI emission can be substantially improved by using the quasi-resonant ZCS (QRZCS) technology in the battery charging system with a battery equalizer. The validity of the battery equalization is further verified by using an experimental installation of a three-cell lithium-ion battery string. Simulation and experimental results show that the proposed battery equalization scheme can not only achieve the bi-directional battery equalization performance, but also can reduce the switching loss during the equalization period.
Power Electronics Specialists Conference, 2004. PESC 04. 2004 IEEE 35th Annual; 02/2004
