• Journal of Electrical Engineering and Technology
• /
• v.13 no.2
• /
• pp.677-687
• /
• 2018

This paper presents a novel power decoupling control scheme with the bidirectional buck-boost converter for primary-side regulation photovoltaic (PV) micro-inverter. With the proposed power decoupling control scheme, small-capacitance film capacitors are used to overcome the life-span and reliability limitations of the large-capacitance electrolytic capacitors. Then, an improved flyback PV inverter is employed in continuous conduction mode with primary-side regulation for the PV power conditioning. The proposed power-decoupling controller shares the reference for primary side current regulation of the flyback PV inverter. The decoupling controller shapes the input current of the bidirectional buck-boost converter. The shared reference eliminates the phase-delay between the input current to the bidirectional buck-boost converter and the double frequency current at the PV primary current. The elimination of the phase-delay in dynamic response enhances the ripple rejection capability of the power decoupling buck-boost converter even with small film capacitor. With proposed power decoupling control scheme, the additional advantage of the primary-side regulation of flyback PV inverter is that there is no need to have an extra current sensor for obtaining the ripplecurrent reference of the decoupling current-controller of the power-decoupling buck-boost converter. Therefore, the proposed power decoupling control scheme is cost-effective as well as the size benefit. A new transient analysis is carried out which includes the source voltage dynamics instead of considering the source voltage as a pure voltage source. For verification of the proposed control scheme, simulation and experimental results are presented.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.2
• /
• pp.84-94
• /
• 2013

In case when the existing TRIAC phase controlled dimmer is drove for the LED lighting equipments, there are many problems such as the LED flicker in low phase-angles, the acoustic noise and elements damage by increase of the peak voltage in the input filter capacitor, mulfunction by insufficiency of the TRIAC holding current, and the abnormal oscillation by LC resonant. In this paper, we proposes the single-stage quasi-resonant PSR(Primary Side Regulation) PWM converter, and the design, the simulation and experiment are performed. As a result, it could confirm that the proposed PWM converter is the lighting equipments for LED drive which can alternate the existing 60W class incandescent bulbs and it has the high drive performance of the efficiency 80% and over, the power factor 0.95 and over under the normal voltage 220V. Finally, total harmonic distortion(THD) is gratified with a standard[1] of the lighting equipments and the durability is evaluated as the high reliablilty of 150,000 hours and over.

• Journal of Power Electronics
• /
• v.17 no.6
• /
• pp.1469-1479
• /
• 2017

Primary-side regulation (PSR) scheme is widely applied in low power applications, such as cell phone chargers, network adapters, and LED drivers. However, the efficiency and standby power requirements have been improved to a high standard due to the new trends of DOE (Department Of Energy) Level VI and COC (Code Of Conduct specifications) V5. The major drawbacks of PSR include poor regulation due to inaccurate feedback and difficulty in acquiring acceptable regulation. A novel adaptive blanking strategy for constant current and constant voltage regulation is proposed in this paper. An accurate model for the sample blanking time related to transformer leakage inductance and the metal-oxide-semiconductor field-effect transistor (MOSFET) parasitic capacitance is established. The proposed strategy can achieve accurate detection for ultra-low standby power. In addition, numerous control factors are analyzed in detail to eliminate the influence of leakage inductance on the loop stability. A dedicated controller integrated circuit (IC) with a power MOSFET is fabricated to verify the effectiveness of the proposed control strategy. Experimental results demonstrated that the prototype based on the proposed IC has excellent performance.

• Journal of Power Electronics
• /
• v.16 no.3
• /
• pp.840-848
• /
• 2016

A primary-side regulation AC-DC converter operating in the PFM (Pulse Frequency Modulation) mode with a high precision output current is designed, which applies a novel inductance compensation technique to improve the precision of the output current, which reduces the bad impact of the large tolerance of the transformer primary side inductance in the same batch. In this paper, the output current is regulated by the OSC charging current, which is controlled by a CC (constant current) controller. Meanwhile, for different primary inductors, the inductance compensation module adjusts the OSC charging current finely to improve the accuracy of the output current. The operation principle and design of the CC controller and the inductance compensation module are analyzed and illustrated herein. The control chip is implemented based on a TSMC 0.35μm 5V/40V BCD process, and a 12V/1.1A prototype has been built to verify the proposed control method. The deviation of the output current is within ±3% and the variation of the output current is less than 1% when the inductances of the primary windings vary by 10%.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.28 no.1
• /
• pp.30-38
• /
• 2023

In this paper, a constant current(CC) and constant voltage(CV) control method using a primary-side regulated(PSR) fly-buck converter is proposed. Because the primary-side structure of the fly-buck converter is the same as that of the synchronous buck converter, it always operates in continuous conduction mode(CCM). Therefore, in the proposed method, the load information on the secondary side can always be easily estimated by measuring the primary inductor current at the midpoint of the switch-on period. An accurate CC/CV control can be achieved through simple calculations based on this estimated information. Consequently, the proposed method is advantageous for optimizing the control performance of the PSR converter. The validity of the proposed control was verified using a 5 W prototype of a PSR fly-buck converter. The experimental results confirmed that the current reference of 500 mA was followed within the error range of 1.2%, and that the voltage reference of 12 V was followed within the error range of 1.8% despite the indirect control of the load current and output voltage from the primary side.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.460-461
• /
• 2012

플라이백 컨버터는 SMPS의 전원회로 중 가장 많이 쓰이고 있는 컨버터이다. 최근 들어 원가 절감을 위한 Primary Side Regulation(이하 PSR)기술이 활발히 진행 중이다. 이 기술의 단점 중 하나는 직접적으로 제어하는 전압이 출력전압이 아니라 보조권선 전압이므로 변압기 커플링에 따라 실제출력전압에 약간의 오차가 생길 수도 있다는 것이다. 본 논문은 이를 감안하여 플라이백 컨버터의 트랜스포머를 기존의 방식들이 아닌 동축권선 방식을 적용하여 만듦으로써 보다 우수한 커플링으로 인해 출력전압의 오차가 거의 없음을 보여준다. 간단한 PSR의 원리에 대해 설명하고 커플링 계수를 비교한 후 UC3844를 이용한 Flyback converter를 이용하여 검증하였다.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.564-565
• /
• 2012

본 논문에서는 이미 설치되어 있는 TRIAC 위상제어 조광기에 LED조명장치를 적용할 경우 발생되는 낮은 위상 각에서의 LED플리커 현상, 입력 필터단 캐패시터의 피크 전압 상승으로 인한 부품 손상 및 소음 발생, TRIAC 유지전류 부족으로 인한 오동작 그리고 LC공진에 의한 비정상 오실레이션 등의 원인을 해결하기 위한 방안을 제시하였다. 그리고 이를 개선할 수 있는 Single Stage PSR PWM 컨버터를 설계하였으며 구현에 의하여 타당성을 입증하였다.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.425-426
• /
• 2012

기존 1차 측 제어(Primary Side Regulation: PSR) 방식 중 최고의 성능을 보이는 i사의 방식은 DCM에서 동작하는 전류가 0A에 도달했을 때 3차 권선을 통해 1차 측에서 출력전압을 검출하는 방식이다. 기존 방식은 전류가 0A가 되는 시점을 예측하여 검출하는 방법을 사용하기 때문에 트랜스포머의 자화인덕턴스 값의 허용오차에 따라 변동 폭이 커질 수 있다. 본 논문에서는 자화인덕턴스의 크기에 관계없이 기존 방식보다 더 정확하게 검출하는 방법을 제시하고, PSIM을 사용한 모의실험을 통하여 검증한다.

• Nuclear Engineering and Technology
• /
• v.50 no.6
• /
• pp.981-988
• /
• 2018

An experiment was performed for the OECD/NEA ROSA-2 Project with the large-scale test facility (LSTF), which simulated a steam generator tube rupture (SGTR) accident due to a double-ended guillotine break of one of steam generator (SG) U-tubes with operator recovery actions in a pressurized water reactor. The relief valve of broken SG opened three times after the start of intact SG secondary-side depressurization as the recovery action. Multi-dimensional phenomena specific to the SGTR accident appeared such as significant thermal stratification in a cold leg in broken loop especially during the operation of high-pressure injection (HPI) system. The RELAP5/MOD3.3 code overpredicted the broken SG secondary-side pressure after the start of the intact SG secondary-side depressurization, and failed to calculate the cold leg fluid temperature in broken loop. The combination of the number of the ruptured SG tubes and the HPI system operation difference was found to significantly affect the primary and SG secondary-side pressures through sensitivity analyses with the RELAP5 code.

• Proceedings of the KIPE Conference
• /
• 2007.11a
• /
• pp.121-123
• /
• 2007

In this paper, a multiple-output converter using a coupledinductor is proposed. The Asymmetrical Half-Bridge Converter (AHBC), which is used as a master converter, obtains ZVS in the primary side switches. For the tight output voltage regulation of the slave output, the Secondary Side Post Regulator (SSPR) is adopted. The proposed magnetically coupled output filter inductor reduces the number of semi-conductor devices and magnetic components. Also, the circuit enables ZCS off switching in the SSPR MOSFET and rectifying diodes. The modes of operation which are caused by the coupled-inductor and post regulator are explained. The analyzed modes of operation of the proposed multiple-output converter are verified by the simulation and experimental results.