• Journal of Power Electronics
• /
• 제17권2호
• /
• pp.323-333
• /
• 2017

This paper proposes a model-based optimal control algorithm for the clamp switch of a zero-voltage switching (ZVS) bidirectional DC-DC converter. The bidirectional DC-DC converter (BDC) can accomplish the ZVS operation using the clamp switch. The minimum current for the ZVS operation is maintained, and the inductor current is separated from the input and output voltages by the clamp switch in this topology. The clamp switch can decrease the inductor current ripple, switching loss, and conduction loss of the system. Therefore, the optimal control of the clamp switch is significant to improve the efficiency of the system. This paper proposes a model-based optimal control algorithm using phase shift in a micro-controller unit. The proposed control algorithm is demonstrated by the results of PSIM simulations and an experiment conducted in a 1-kW ZVS BDC system.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2007년도 춘계학술대회 학술발표 논문집 제17권 제1호
• /
• pp.485-488
• /
• 2007

최근 Analog Sampled-Data 신호처리를 위하여 주목되고 있는 SI(Switched-Current) circuit은 저전력 동작을 하는 장점이 있지만, 반면에 SI circuit에서의 기본 회로인 Current Memory는 Charge Injection에 의한 Clock Feedthrough이라는 치명적인 단점을 갖고 있다. 따라서 본 논문에서는 Current Memory의 문제점인 Clock Feedthrough의 일반적인 해결방안으로 Dummy Switch의 연결을 검토하였고, Austria Mikro Systeme(AMS)에서 $0.35{\mu}m$ CMOS process BSIM3 Model로 제작하기 위하여 Current Memory의 Switch MOS와 Dummy Switch MOS의 적절한 Width을 정의하여야 하므로, 그 값을 도출하였다. Simulation 결과, Switch의 Width는 $2{\mu}m$, Dummy Switch의 Width는 $2.35{\mu}m$로 정의될 수 있음을 확인하였다.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2009년도 추계학술대회 논문집
• /
• pp.327-329
• /
• 2009

A first short stoke current which has a 10/350 ${\mu}s$ waveform is able to be generated by using the crowbar switch in R-L-C circuit. In this paper, a peaking circuit has been applied to make crowbar switch. Operate effective for generating 10/350 ${\mu}s$ waveform. According to simulation with PSpice, we have found that some value of inductance were more effective to trigger a crowbar switch. As a result of experimental test using crowbar switch with peaking circuit, the success rate of triggering crowbar switch is higher than the normal crowbar switch without peaking circuit.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.965_966
• /
• 2009

In this paper, a new soft-switching Two-switch Forward converter topology has been proposed. Compared with conventional two-switch forward converter, the proposed converter employs an auxiliary switch and a clamp capacitor to instead of two reset diodes, not only its duty cycle can exceed 0.5 to achieve wide range input voltage, but also soft switching can be achieved for all switches. Especially, voltage stress across main switches can be clamped at $1/2V_{in}$, voltage stress across auxiliary switch can be clamped at $V_{in}$. In addition, due to clamp capacitor series with the transformer, duty ratio can be extended with equation $V_o=\frac{V_{in}(1-D}D{N}$. Therefore, as a kind of better cost-effective approach, it is very attractive for high input, wide range and high efficiency application.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 B
• /
• pp.950-952
• /
• 2001

This paper proposes a new zero-current transition (ZCT) pulse-width modulation (PWM) switch cell that overcomes the limitations of the conventional ZCT converters. The proposed ZCT cell provides zero-current-switching (ZCS) condition for the main switch and the auxiliary switch. The conduction loss and current stress of the main switch are minimized, since the circulating current for the soft switching does not flow through the main switch. The proposed ZCT PWM switch cell is suitable for the high power applications employing IGBTs. Design guidelines with a design example are described and verified by experimental results from the 1 kW prototype boost converter operating at 70kHz.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.1334-1338
• /
• 2005

A limit switch box is used for an indicator of a valve actuator. This device indicates an opening and closing of a valve or a throttle in the valve actuator. In a ship, equipments require safety and robustness because of a rough environment and a specific condition during a voyage. However, the limit switch box has been used in an indoor environment generally. This study developed a new limit switch box which can be used at an outdoor environment. This study designed the new limit switch box. The housing of the limit switch box was made by an aluminum die cast method with surface painting after anodizing or chromate coating. In order to evaluate the endurance of the housing, the endurance tests against salt water have been conducted. Experiment results showed that the proposed device provides a reliable performance against salt water.

• ETRI Journal
• /
• 제28권1호
• /
• pp.84-86
• /
• 2006

This letter presents a small-sized, high-power single-pole double-throw (SPDT) switch with defected ground structure (DGS) for wireless broadband Internet application. To reduce the circuit size by using a slow-wave characteristic, the DGS is used for the quarter-wave (${\lambda}$/4) transmission line of the switch. To secure a high degree of isolation, the switch with DGS is composed of shunt-connected PIN diodes. It shows an insertion loss of 0.8 dB, an isolation of 50 dB or more, and power capability of at least 50 W at 2.3 GHz. The switch shows very similar performance to the conventional shunt-type switch, but the circuit size is reduced by about 50% simply with the use of DGS patterns.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2002년도 전력전자학술대회 논문집
• /
• pp.759-762
• /
• 2002

A ZCT(Zero Current Transition) PWM(Pulse-Width-Modulation) boost converter using parallel MOSFET switch is proposed in this paper. The IGBT(main switch) of the proposed converter is always turned on with zero current switching and turned off with zero current/zero voltage switching. The MOSFET(auxiliary switch) is also operates with soft switching condition. In addtion to, the proposed converter eliminates the reverse recovery current of the freewheeling diode by adding the resonant inductor, Lr, in series with the main switch. Therefore, the turn on/turn off switching losses of switches are minimized and the conduction losses by using IGBT switch are reduced. In addition to, using parallel MOSFET switch overcomes the switching frequency limitation occurred by current tail. As mentioned above, the characteristics are verified through experimental results.

• 전력전자학회논문지
• /
• 제21권1호
• /
• pp.10-18
• /
• 2016

In this study, an efficient clamp is proposed to reduce the switch voltage stress of a forward converter. The proposed clamp consists of a conventional LC snubber, a tertiary winding, and a diode. When the switch is turned OFF, the magnetizing inductor energy of the transformer is recovered directly into the flyback output, which is the tertiary winding and diode network, instead of circulating in the LC snubber. Therefore, switch voltage stress and circulating current caused by the magnetizing inductor energy are reduced. This condition improves the efficiency of the forward converter with limited switch voltage stress. A theoretical analysis and the design guidelines of the proposed converter are provided. Experimental results are also reported.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
• /
• pp.594-596
• /
• 1998

In this paper, a path control switch has been developed for self-healing operation in SDH-based transmission system. The proposed switch is suitable for self-healing operations in both an Unidirectional Path Switched Ring and a 2-fiber Bidirectional Line Switched Ring. The path control switch is implemented with $0.8{\mu}m$ CMOS LSI chip. The self-healing operation of the switch is effectively done by the configuration information stored in the registers of the switch. The switch has an AU-3(51.84Mb/s) TSI(Time Slot Interchange) and has 1.25Gb/s throughput. But the higher throughput can be realized by combining two identical switches or more with the parallel architecture.