Indirect Output Voltage Control in Negative Output Elementary Super Lift Luo Converter Using PIC plus FLC in Discontinuous Conduction Mode

In this paper, the design of a proportional integral controller (PIC) plus fuzzy logic controller (FLC) for the negative output elementary super lift Luo converter (NOESLLC) operated in discontinuous conduction mode (DCM) is presented. In spite of the many benefits viz. the high voltage transfer gain, the high efficiency, and the reduced inductor current and the capacitor voltage ripples, it natured with non-minimum phase. This characteristic makes the control of NOESLLC cumbersome. Any attempt of direct controlling the output voltage may erupt to instability. To overcome this problem, indirect regulation of the output voltage based on the two-loop controller is devised. The savvy in the inductor current control improves the dynamic response of the output voltage. The FLC is designed for the outer (voltage) loop while the inner (current) loop is controlled by the PIC. For the developed ?19.6 V NOESLLC, the dynamic performances for different perturbations (line, load and component variations) are obtained for PIC plus FLC and compared with PIC plus PIC. The study of two cases is performed at various operating regions by developing the MATLAB/Simulink model.

An Improved Modulation Strategy for Single-phase Three-level Neutral-point-clamped Converter in Critical Conduction Mode

Two-level totem-pole power factor correction(PFC)converters in critical conduction mode(CRM)suffer from the wide regulation range of switching frequency.Besides,in highfrequency applications,the number of switching times increases,resulting in significant switching losses.To solve these issues,this paper proposes an improved modulation strategy for the single-phase three-level neutral-point-clamped(NPC)converter in CRM with PFC.By optimizing the discharging strategy and switching state sequence,the switching frequency and its variation range have been efficiently reduced.The detailed performance analysis is also presented regarding the switching frequency,the average switching times,and the effect of voltage gain.A 2 k W prototype is built to verify the effectiveness of the proposed modulation strategy and analysis results.Compared with the totem-pole PFC converter,the switching frequency regulation range of the three-level PFC converter is reduced by 36.48%and the average switching times is reduced by 45.10%.The experimental result also shows a 1.2%higher efficiency for the three-level PFC converter in the full load range.

Novel Automotive High Intensity Discharge(HID) Lamps with Electronic Ballasts

A new scheme of automotive high intensity discharge(HID) lamps with electronic ballasts is proposed. The design of the proposed ballast and some experimental results are presented. The proposed scheme is consisted of the high frequency DC-DC converter and the low frequency DC-AC inverter. This system separates the input voltage of the ignitor from DC link voltage using auxiliary winding, then it could use the lower voltage rating power devices for HID lamp ballast system and reduce the size of HID lamp ballast. The proposed ballast controller using micro-controller unit(MCU) controls the frequency to operate the DC-DC converter in critical conduction mode, which reduces the noise of the circuit and improves the efficiency by 2%~4%.

Survey of the Hypertention Suffered by the Middle-aged from Suburban Areas and Its Related Pathogenesis

Objectives To investigate the related pathogenic factors of hypertension affecting the middle-aged in suburban areas in Mudanjiang City and further popularize health education with regard to hypertension. Methods A survey was conducted on 858 middle-aged people of 35 to 59 years old from such suburban areas as Jinglong village, Bada village and Fengshou village by adopting the hypertensive definition and classifying standard of an WHO/ISH hypertensive treatment guidance in 1999. Results Positive correlation was shown between occurrence of hypertension and such elements as diet in excess salt, drinking, obesity, smoking. Conclusions It is of great clinical significance to combat and prevent the hypertension by regulating one＇s diet and life style.

Constant Ripple Current Control for Switching DC-DC Converter

The adapted DC-DC converters should be smaller in size and have a small output current ripple to meet the increasing demand for low voltages with high performance and high density micro processors for several microelectronic load applications. This paper proposes a DC-DC converter using variable on-time and variable switching frequency control enhanced constant ripple current control and reduced magnetic components. The proposed converter is realized by making the turn-offtime proportional to the on-time of the converter, according to the input and output voltage, thereby reducing the corresponding current ripple on output voltage in the continuous conduction mode. A Buck DC-DC converter using the proposed control strategy is analyzed in detail, along with some experimental results to show the performance and effectiveness of this converter.

Design and Experimentation of FPGA-Based Soft-Switched Interleaved Boost Converter for Telecommunication System

This paper proposes the design and experimentation of digital control of soft-switched interleaved boost converter using FPGA for Telecommunication System. The switching devices in the proposed converter are turned on and off with Zero Voltage Switching (ZVS) and Zero Current Switching (ZCS) respectively. The circuit is operated in Continuous Conduction Mode (CCM) with various load ranges having duty cycle of more than 50%. The proposed converter is studied by developing the simulation module in MATLAB/SIMULINK. A PI controller is designed and implemented in FPGA to obtain a regulated DC output for line and load variations. Simulation and experimentation results are verified with a prototype development of the proposed converter. The results indicate that the converter performance is enhanced with closed loop control.

Momentum Search Algorithm for Analysis of Fuel Cell Vehicle-to-Grid System with Large-scale Buildings

The design and analysis of a fuel cell vehi-cle-to-grid(FCV2G)system with a high voltage conver-sion interface is proposed.The system aims to maximize the utilization of fuel cell vehicles(FCVs)as distributed energy resources,allowing them to actively participate in the energy market.The proposed FCV2G system has FCVs,power electronics interfaces,and the electrical grid.The power electronics interfaces are responsible for con-verting the low-voltage output of the fuel cell stack into high-voltage DC power,and ensuring efficient power transfer between the FCVs and the grid.To optimize the operation of the FCV2G system,the momentum search algorithm(MSA)is employed.By applying MSA,the FCV2G system can achieve optimal power dispatch,con-sidering factors such as energy efficiency,grid stability,and economic feasibility.The proposed method is tested in MATLAB.The best MSA and dynamic load profile solu-tions are run for 24 h and the results show that 100%import of FCVs 51.0%more than 100%electric vehicle.Peak-cutting and vehicle-to-grid service revenue are 30.5%and 95.0%greater,respectively.Low discharge loss,high capacity,and high discharge power are the main advantages of FCVs.The benchmark FCVs ratio of 15%is used for sensitivity analysis.The findings reveal that the overall advantages of FCV2G are improved.Index Terms—Continuous conduction mode,DC-DC converter,discontinuous conduction mode,fuel cell vehi-cle,utility-grids,vehicle-to-grid.

Designing an On-board Charger to Efficiently Charge Multiple Electric Vehicles

An on-board charger for efficiently charging multiple battery-operated electric vehicles(EVs)is introduced.It has evolved as a single-input dual-output(SIDO)integrated boost-single ended primary inductor converter(SEPIC)fly-back converter,offering cost-effectiveness,reliability,and higher efficiency compared to conventional chargers with equivalent specifications.The proposed system includes an additional regulated output terminal,in addition to an existing terminal for charging the EV battery of a 4-wheeler,which can be used to charge another EV battery,preferably a 2-wheeler.With the aid of control techniques,unity power factor operations are obtained during constant-voltage(CV)/constant-current(CC)charging for the grid-to-vehicle(G2V)operating mode.Using mathematical modelling analysis,the proposed system is developed in a Matlab/Simulink environment,and the results are validated in a real-time simulator using dSPACE-1104.The proposed system is employed for charging the batteries of two EVs with capacities of 400 V,40 A·h and 48 V,52 A·h for the 4-wheeler and 2-wheeler,respectively.Its performance is investigated under different operating modes and over a wide range of supply voltage variations to ensure safe and reliable operation of the charger.

High efficiency and low electromagnetic interference boost DC–DC converter

A synchronous boost DC-DC converter with an adaptive dead time control （DTC） circuit and antiringing circuit is presented. The DTC circuit is used to provide adjustable dead time and zero inductor current detection for power transistors and therefore, a high efficiency is achieved by minimizing power losses, such as the shoot-through current loss, the body diode conduction loss, the charge-sharing loss and the reverse inductor current loss. Simultaneously, a novel anti-ringing circuit controlled by the switching sequence of power transistors is developed to suppress the ringing when the converter enters the discontinuous conduction mode （DCM） for low electromagnetic interference （EMI） and additional power savings. The proposed converter has been fabricated in a 0.6 #m CDMOS technology. Simulation and experimental results show that the power efficiency of the boost converter is above 81% under different load currents from 10 to 250 mA and a peak efficiency of 90% is achieved at about 100 mA. Moreover, the ringing is easily suppressed by the anti-ringing circuit and therefore the EMI noise is attenuated.