• Smart Structures and Systems
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• v.26 no.4
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• pp.521-531
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• 2020

In this paper, a new interleaved high step-up converter with low voltage stress on the switches is proposed. In the proposed converter, soft switching is provided for all switches by just one auxiliary switch, which decreases the conduction loss of auxiliary circuit. Also, the auxiliary circuit is expanded on the converter with more input branches. In the converter all main switches operate under zero voltage switching condition and auxiliary switch operate under zero current switching condition. Because of the interleaved structure, the reliability of converter increases and input current ripples decreases. The clamp capacitor in the converter not only absorb the voltage spikes across the switch due to leakage inductance, but also improve voltage gain. The proposed converter is fully analyzed and to verify the theoretical analysis, a 100 W prototype was implemented. Also, to show the effectiveness of auxiliary circuit on conduction EMI, EMI of the proposed converter comprised with hard switching counterpart.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2133-2135
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• 1998

Many semiconductive switches are operated in series for high voltage operation. The same number of gate drivers are needed to control all the switches, hence, the drivers cause high cost and system complexity. In this study, a simple and low cost gate driver for high voltage thyristor-diode switches is investigated. This gate driver can operate several high voltage thyristor-diode switches at the same time.

• Journal of Power Electronics
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• v.16 no.3
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• pp.905-914
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• 2016

A high-performance rectifier is introduced in this study. The proposed rectifier combines the conventional pulse width modulation, soft commutation, and instantaneously average line current control techniques to promote circuit performance. The voltage stresses of the main switches in the rectifier are lower than those in conventional rectifier topologies. Moreover, conduction losses of switches in the rectifier are certainly lower than those in conventional rectifier topologies because the power current flow path when the main switches are turned on includes two main power semiconductors and the power current flow path when the main switches are turned off includes one main power semiconductor. The rectifier also adopts a ZCS-PWM auxiliary circuit to derive the ZCS function for power semiconductors. Thus, the problem of switching losses and EMI can be improved. In the control strategy, the controller uses the average current control mode to achieve fixed-frequency current control with stability and low distortion. A prototype has been implemented in the laboratory to verify circuit theory.

• International Journal of Reliability and Applications
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• v.2 no.4
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• pp.253-262
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• 2001

A k-out-of-n standby system is considered where all of its components are s-independent and classified either working or cold standby connected with imperfect switches. The probability density function of the life length for this system is established in closed form, when the underlying components have constant failure rates. Also the reliability function of the system is derived. Finally, the reliability functions for one, two and three out of four systems are deduced for perfect or imperfect switches and identical or non-identical constant failure rates for working and standby components.

• Journal of Power Electronics
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• v.6 no.3
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• pp.253-263
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• 2006

A high performance and low cost single switch current fed energy recovery circuit (ERC) for an alternating current (AC) plasma display panel (PDP) is proposed. Since it is composed of only one power switch compared with the conventional circuit consisting of four power switches and two large energy recovery capacitors, the ERC features a simpler structure and lower cost. Furthermore, since all power switches can be switched under soft switching operating conditions, the proposed circuit has desirable merits such as increased reliability and low switching loss. Specifically, there are no serious voltage notches across the PDP with the aid of gas discharge current compensation, which can greatly reduce the current stress of all inverter switches, and provide those switches with the turn on timing margin. To confirm the validity of proposed circuit, its operation and performance were verified on a prototype for 7-inch test PDP.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.3
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• pp.257-265
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• 2014

This paper proposes a simple compensation method for switches of the unclamped voltage in the three-level NPC inverter. Voltages of inner-switches can be unclamped in the three-level NPC (neutral point clamped) inverter. It can cause the problem of the switch fault accident. By adding a capacitor, switches of the unclamped voltage can be clamped. Through the analysis of the circuit, the reason behind switches being unclamped was verified which leads to the solution method that designs a compensation capacitor. The proposed method was validated through the simulation and experimental results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.11
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• pp.2079-2088
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• 2009

The optimal operation in distribution system is to select tie switches considering important elements(Load balance, Loss minimization, Voltage drop, Restoration index..) in distribution system. Optimal Tie Switches Selection is very important in operation of distribution system because that is closely related with efficiency and reliability. In this paper, a new algorithm considering important elements is proposed to find optimal location of tie switches. In the case study, the proposed algorithm has been testified using real distribution network of KEPCO for verifying algorithm and complex network for applying future distribution network.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.652-655
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• 2004

RF MEMS is a miniature device or an array of integration devices and mechanical components and fabricated with If batch-processing techniques. RF MEMS application area are in phased arrays and reconfigurable apertures for defence and telecommunication systems, switching network for satellite communication, and single-pole double throw switches for wireless application. Recently, RF MEMS switches have been developed for the application to the milimeter wave system. RF MEMS switches offer a substantilly higher performance than PM diode or FET switches. In this paper, SPDT(single-pole-double-throw) switch are designed to use 10 GHz. Actuation voltage and displacement are simulated by tool. And stress and distribution are simulated.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.4
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• pp.294-302
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• 2019

A capacitor common connected LLC resonant converter with auxiliary switches for a wide output voltage control range is presented in this paper. The proposed converter can be controlled in two ways to achieve a wide output voltage control range of Vo-3Vo. The first control method is performed through pulse width modulation of the auxiliary switches and primary switching devices. The second control method is conducted through frequency modulation of the primary switching devices configured to operate in full-bridge switching modes, when the auxiliary switches are turned off. The feasibility of the proposed converter is verified by the experimental results of a 5 kW prototype.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4C
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• pp.371-379
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• 2002

In this paper, the MMIC SPST switches operating from DC to 3GHz were designed and implemented. Prior to the design of switches, the small and large-signal switch models were needed to predict switch performance accurately. The newly proposed small-signal switch model parameters were extracted from measured S-parameters using optimization technique with estimated initial values and boundary limits. In the extraction of large-signal switch model parameters, the current source was modeled by fitting empirical equations to measured DC data and the charge model was derived from extracted channel capacitances from measured S-parameters varying the drain-source voltage. To design basic series-shunt SPST switches and isolation-improved SPST switches, we applied this model to commercial microwave circuit simulator. The improved SPST switches exhibited 0.302dB insertion loss, 35.762dB isolation, 1.249 input VSWR, 1.254 output VSWR, and about 15.7dBm PldB with 0/-3V control voltages at 3GHz.