• Journal of Power Electronics
• /
• 제16권5호
• /
• pp.1802-1812
• /
• 2016

Cross regulation is a key technical issue of single-inductor multiple-output (SIMO) DC-DC converters. This paper investigates the cross regulation in single-inductor dual-output (SIDO) Buck converters with continuous conduction mode (CCM) operation. The expressions of the DC voltage gain, control to the output transfer function, cross regulation transfer function, cross coupled transfer function and impedance transfer function of the converter are presented by the time averaging equivalent circuit approach. A small signal model of a SIDO CCM Buck converter is built to analyze this cross regulation. The laws of cross regulation with respect to various load conditions are investigated. Simulation and experiment results verify the theoretical analysis. This study will be helpful for converter design to reduce the cross regulation. In addition, a control strategy to reduce cross regulation is performed.

• 한국정보통신학회논문지
• /
• 제8권5호
• /
• pp.1068-1073
• /
• 2004

전원장치의 소형화 핵심기술인 반도체 스위칭 기술을 이용하여 5 V/500 mA급 트랜스리스형 파워모듈(transless type power module)을 설계하였다. 파워 모들은 강압형 chopper 방식을 이용하였으며, 스위칭회로, 제어회로, 전압검출회로, 그리고 정전압 회로 등으로 구성되어 었다. 본 연구에서 설계한 스위칭 파워모듈은 0.2 V의 load regulation, 0.1 V의 line regulation, 85 mVp-p의 output ripple 전압, 64.7 kHz의 스위칭 주파수, 최대 58% 정도의 효율을 나타내었으며, 신뢰성 및 EMC 평가항목을 만족하였다.

• Journal of Power Electronics
• /
• 제2권1호
• /
• pp.46-54
• /
• 2002

In this paper a neural network controller for achieving maximum power tracking as well as output voltage regulation, for a wind energy conversion system (WECS) employing a permanent magnet synchronous generator is proposed. The permanent magnet generator (PMG) supplies a dc load via a bridge rectifier and two buck-boost converters. Adjusting the switching frequency of the first buck-boost converter achieves maximum power tracking. Adjusting the switching frequency of the second buck-boost converter allows output voltage regulation. The on-time of the switching devices of the two converters are supplied by the developed neural network (NN). The effect of sudden changes in wind speed and/ or in reference voltage on the performance of the NN controller are explored. Simulation results showed the possibility of achieving maximum power tracking and output voltage regulation simulation with the developed neural network controllers. The results proved also the fast response and robustness of the proposed control system.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
• /
• pp.656-659
• /
• 2001

In this paper a neural network controller for achieving maximum power tracking as well as output voltage regulation, for a wind energy conversion system(WECS) employing a permanent magnet synchronous generator, is proposed. The permanent magnet generator (PMG) supplies a dc load via a bridge rectifier and two buck-boost converters. Adjusting the switching frequency of the first buck-boost converter achieves maximum power tracking. Adjusting the switching frequency of the second buck-boost converter allows output voltage regulation. The on-times of the switching devices of the two converters are supplied by the developed neural network(NN). The effect of sudden changes in wind speed ,and/or in reference voltage on the performance of the NN controller are explored. Simulation results showed the possibility of achieving maximum power tracking and output voltage regulation simultaneously with the developed neural network controller. The results proved also the fast response and robustness of the proposed control system.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.1232-1233
• /
• 2007

As the number of wind turbines installed increase, the power from wind energy starts to replace conventional generation units and its influence on power system can not be neglected. Because of the intermittent nature of wind resource, the output power of wind turbine fluctuates according to wind speed variation. In this point of view, it is necessary for wind turbines to be equipped with power regulation ability. The doubly fed induction generator (DFIG) is one of the main techniques used in variable speed wind turbines. This thesis focuses on the development of modified control scheme of DFIG to regulate output power. The proposed control scheme achieves active power output regulation so as to stabilize the power system.

• 전력전자학회논문지
• /
• 제17권4호
• /
• pp.281-290
• /
• 2012

This paper describes a Cross-regulation characteristics of a multi-output LLC resonant converter widely used in consumer electronics. The output characteristics of the multi-output LLC converter is derived from the assumption that the current and voltage in the resonant network is sinusoidal and the duty loss exists. The simulation and experimental results are provided to verify the theoretic results.

• Journal of Power Electronics
• /
• 제16권5호
• /
• pp.1821-1832
• /
• 2016

This study presents a strategy using the synchronized output regulation method (SOR) for controlling inverters operating in stand-alone and grid-connected modes. From the view point of networked dynamic systems, SOR involves nodes with outputs that are synchronized but also display a desirable wave shape. Under the SOR strategy, the inverter and grid are treated as two nodes that comprise a simple network. These two nodes work independently under the stand-alone mode. An intermediate mode, here is named the synchronization mode, is emphasized because the transition from the stand-alone mode to the grid-connected mode can be dealt as a standard SOR problem. In the grid-connected mode, the inverter operates in an independent way, in which the voltage reference changes for generalized synchronization where its output current satisfies the required power injection. Such a relatively independent design leads to a seamless transfer between operation modes. The closed-loop system is analyzed in the state space on the basis of the output regulation theory, which improves the robustness of the design. Simulations and experiments are performed to verify the proposed control strategy.

• Journal of Power Electronics
• /
• 제15권4호
• /
• pp.886-898
• /
• 2015

The design feasibility of a micro unidirectional DC transmission system based on an input-parallel output-parallel (IPOP) converter is analyzed in this paper. The system consists of two subsystems: an input-parallel output-series (IPOS) subsystem to step up the DC link voltage, and an input-series output-parallel (ISOP) subsystem to step down the output voltage. The two systems are connected through a transmission line. The challenge of the delay caused by the communication in the control system is addressed by introducing a ring communication structure, and its influence on the control system is analyzed to ensure the feasibility and required performance of the converter system under practical circumstances. Simulation and experiment results are presented to verify the effectiveness of the proposed design.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.183-185
• /
• 2006

This paper presents a SISO nonlinear controller for the power system consisting of a synchronous generator connected to an infinite bus. The proposed controller is based on input-output feedback linearization, with a modified version of the terminal voltage equation used as the output. The resulting closed-loop has no internal dynamics, and thus stability is guaranteed. The controller performance is seen to be effective through simulations.

• 전력전자학회논문지
• /
• 제27권2호
• /
• pp.106-117
• /
• 2022

Multiple output converters can be utilized when various output voltages are required in applications. Recently, one of the multiple output converters called fly-buck has been proposed, and has attracted attention due to the advantage that multiple output can be easily obtained with a simple structure. When constant on-time (COT) control is applied, the output ripple voltage must be treated carefully for control stability and voltage regulation characteristics in consideration of the inherent energy transfer characteristics of the fly-buck converter. This study analyzes the operation principle of the fly-buck converter with a ripple generation network and presents the design guideline for the improved output voltage regulation. Validity of the analysis and design guideline is verified using a 5 W prototype of the COT controlled fly-buck converter with a ripple generation network for telecommunication auxiliary power supply.