• Journal of Electrical Engineering and Technology
• /
• 제5권3호
• /
• pp.468-476
• /
• 2010

This paper presents a direct single-stage power converter using single-phase isolated full-bridge converter modules, with inherent power factor correction (PFC) for a 12 kW switched mode power supply (SMPS). The advantages of the proposed converter are its simple control strategy, reduction in number of conversion stage, low input line current harmonics, and improvement in power factor. Analysis of the single-stage converter is carried out in continuous conduction mode of operation. Steady-state analysis of the proposed converter is conducted to obtain converter parameters. A systematic design procedure is also presented for a 12k W converter with a design example. The effect of load variation on SMPS is also studied in order to demonstrate the effectiveness of the proposed converter for the complete range of load conditions. A set of power quality indices on input ac mains for an SMPS fed from a single-stage converter is also presented for easy comparison of their performance.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
• /
• pp.171-175
• /
• 1998

This paper proposes the advanced PWM method that can reduce common-mode voltage in three-phase PWM converter-inverter system. By the proper distribution of the zero-voltage vector of inverter, it is possible to cancel out a common-mode voltage pulse in a sampling period. Since the proposed PWM method maintains the effective-voltage vector, it does not affect the control performance of converter-inverter system. Without any extra hardware, overall common-mode voltage can be decreased by one-third compared with conventional PWM scheme.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 B
• /
• pp.1005-1008
• /
• 2001

This paper presents average current-mode control AC/DC ZVT(Zero Voltage Transition) Boost Converter. This boost converter perceives feed forward signal of input and feedback signal of output for average current-mode control proposed converter employs active-clamp method for ZVT. This converter gives the good PFC(Power Factor Correction), low line current hormonic distortions and tight output voltage regulations. This converter also has a high efficiency by active-clamp method. The principle of operation, feature, and design considerations are illustrated and verified through the experiment with a 150W, 120kHz prototype converter.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2000년도 ITC-CSCC -2
• /
• pp.559-562
• /
• 2000

The problem of noise generation due to PWM switched-mode power converter has been widely noticed from the viewpoint of Electromagnetic Interference(EMI). Many kings of topologies for resonant converters have been developed both to overcome this noise problem and to attain high power efficiency. It is reported in references that resonant converters which are derived from PWM converter using resonant switch show much lower noise characteristics than PWM converter, and that current-mode resonant converter is more sensitive to stored charge in rectifying diode than voltage-mode counterpart concerning surge generation at diode’s turn-off. On the other hand, above mentioned resonant converters have defect of high-voltage stress on semiconductor switch and complicated circuit configuration. Hence, the simplified Forward-type resonant converter has been proposed and investigated due to its prominent features of simplicity of circuit configuration, low voltage stress and high stability. However, its noise characteristics still remain unknown. The purpose of this paper is to study quantitatively the noise characteristics of this simplified Forward-type resonant converter by experiment and analysis. The influence of parasitic elements and stored charge in rectifying diode on noise generation has been clarified.

• Journal of Electrical Engineering and Technology
• /
• 제3권2호
• /
• pp.243-253
• /
• 2008

This paper deals with the analysis, design, and implementation of a single phase AC-DC Zeta converter with high frequency transformer isolation and power factor correction(PFC) in two modes of operation, discontinuous current mode of operation(DCM), and continuous current mode of operation(CCM). A Digital Signal Processor(DSP) based implementation is carried out for validation of the Zeta converter developed design in discontinuous mode of operation. A comparison of both modes of operation is presented for a 1kW power rating from the point of view of steady state and dynamic behavior, power quality, simplicity, control technique, device rating, and converter size. The experimental results of a developed prototype of Zeta converter are presented for validation of the developed design. It is observed that CCM is most suitable for higher power applications where it requires some complex control and sensing of the additional variables.

• Journal of Power Electronics
• /
• 제10권1호
• /
• pp.27-33
• /
• 2010

This paper presents a bidirectional DC-DC converter suitable for low-voltage super capacitor-based electric energy storage systems. The DC-DC converter presented here consists of a full-bridge circuit and a current-fed push-pull circuit with a high frequency (HF) transformer-link. In order to reduce the device-conduction losses due to the large current of the super capacitor as well as unnecessary ringing, synchronous rectification is employed in the super capacitor-charging mode. A wide range of voltage regulation between the battery and the super capacitor can be realized by employing a Phase-Shifting (PS) Pulse Width Modulation (PWM) scheme in the full-bridge circuit for the super capacitor charging mode as well as the overlapping PWM scheme of the gate signals to the active power devices in the push-pull circuit for the super capacitor discharging mode. Essential performance of the bidirectional DC-DC converter is demonstrated with simulation and experiment results, and the practical effectiveness of the DC-DC converter is discussed.

• Journal of Power Electronics
• /
• 제5권3호
• /
• pp.180-189
• /
• 2005

In this paper a DSP based control scheme for the interleaved boost converter is presented. The mathematical model for the interleaved boost converter operating in a continuous inductor current mode is developed. A state-space averaging technique is used for modeling the converter system. A fixed frequency sliding mode controller is designed to ensure current distribution between the two converter modules and to achieve the load voltage regulation simultaneously. Necessary and sufficient conditions, using variable structure theory, are derived for the sliding mode to exist. The range of sliding mode controller coefficients is also determined. The designed controller capability, load distribution among the individual boost cells and load voltage regulation against source and load disturbances, are demonstrated through PSIM simulation results. A real-time controller based on ADMC401 DSP is developed. Experimental results are provided to validate the proposed control scheme.

• Journal of Power Electronics
• /
• 제15권1호
• /
• pp.39-53
• /
• 2015

This paper presents the regulation of the output voltage and inductor currents in a Single Ended Primary Inductor Converter (SEPIC), operating in the continuous conduction mode (CCM) using a sliding mode controller. Owing to the time varying nature of the SEPIC converter, designing a feedback controller is a challenging task. In order to improve the dynamic performance of the SEPIC, a Sliding Mode Controller (SMC) is developed. The developed SMC is designed by using a state space average model. The performance of the developed controller with the SEPIC converter is validated at different working conditions through Matlab simulations. It is also compared with the performance while using a PI controller. The results show that the designed controller gives very good output voltage regulation under different operating conditions such as a varying input voltage, changes in the load and component variations. A 48V, 46W experimental setup for has been developed in an analog platform to validate the performance of the proposed SMC.

• 전기학회논문지
• /
• 제67권12호
• /
• pp.1729-1734
• /
• 2018

Recently, interest in environmentally friendly transportation systems has been increasing, and study on railway systems has been aggressively conducted. Therefore, lots of studies have been done in railway advanced countries to improve performance of PWM converter. The research on the PWM converter for railway vehicle was mainly carried out on the converter mounted on railway vehicle such as the high-speed railway and metropolitan railway. In also, a lot of study has been carried out to improve converter performance installed in the ground. The high-capacity transform used in this paper converted from AC 22.9kV to AC 590V. The converter changed from AC 590V to DC 950V. In general, in the case of rectifier, the DC power supply system has a negative impact on inverter control characteristics because it can not avoid the pulsating component. In this study, it was performed current control for high-capacity converter using Matlab Simulink. The PWM converter is normally performed through the voltage and current at starting mode, powering mode, and braking mode. In the light-load test and the on-line test, we have studied for the PWM converter characteristics. Using this research, we have founded that the converter has excellent performance.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.493-498
• /
• 2004

The EMI noise source in a switching mode power supply is dominated by a common mode noise. If we can understand the common mode noise occurring mechanism, it is resulted to find out the method to suppress the EMI noise source in the switching mode power supply. The common mode noise is occurring mostly due to circuit is unbalanced which is caused by the capacitive coupling to frame ground, which passes through a heatsink of the switching devices. This research paper presents a new effective balancing method of buck converter circuit by mean of grounding the parasitic and compensation capacitors in correct proportion which is called that the common mode impedance balance (CMIB). The CMIB can be achieved by source, transmission line and termination balanced, such balancing, the common mode current will be cancelled out in the frame ground. The greatly reduced common mode noise can be confirmed by the experimental results.