• Journal of Power Electronics
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• 제14권6호
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• pp.1217-1223
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• 2014

A novel half load-cycle worked dual input single output (DISO) DC/AC inverter is presented. The basic circuit consists of a dual buck regulator, which works in continuous current mode. The working principle of DISO DC/AC inverter has been used. The control method applied for half load-cycle worked DISO DC/AC inverter has been studied. The control effects of the open-loop proportional control and closed-loop proportional-integral control are compared by using PSIM software. The parameters are adopted in the realistic simulation and experiment test. Moreover, the waveforms, such as voltage of modulation reference signal and output voltage, were given. The simulation and experiment results proved that the half load-cycle worked DISO DC/AC inverter could achieve good performance, gain a line frequency of 50 Hz, and verify the correctness of theoretical analysis.

• 전기학회논문지
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• 제57권6호
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• pp.915-923
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• 2008

This paper focuses on optimal tuning of nonlinear parameters of a dual-input power system stabilizer(dual-input PSS), which can improve the system damping performance immediately following a large disturbance. Until recently, various PSS models have developed to bring stability and reliability to power systems, and some of these models are used in industry applications. However, due to non-smooth nonlinearities from the interaction between linear parameters(gains and time constants of linear controllers) and nonlinear parameters(saturation output limits), the output limit parameters cannot be determined by the conventional tuning methods based on linear analysis. Only ad hoc tuning procedures('trial and error' approach) have been used. Therefore, the steepest descent method is applied to implement the optimal tuning of the nonlinear parameters of the dual-input PSS. The gradient required in this optimization technique can be computed from trajectory sensitivities in hybrid system modeling with the differential-algebraic-impulsive-switched(DAIS) structure. The optimal output limits of the dual-input PSS are evaluated by time-domain simulation in both a single machine infinite bus(SMIB) system and a multi-machine power system in comparison with those of a single-input PSS.

• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.143-149
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• 2016

The two-stage converter is widely used in traditional DC/AC inverter. It has several disadvantages such as complex topology, large volume and high loss. In order to overcome these shortcomings, a novel half load-cycle worked dual SEPIC single-stage inverter, which is based on the analysis of the relationship between input and output voltages of SEPIC converters operating in the discontinuous conduction mode (DCM), is presented in this paper. The traditional single-stage inverter has remarkable advantages in small and medium power applications, but it can’t realize boost DC/AC output directly. Besides one pre-boost DC/DC converter is needed between the DC source and the traditional single-stage inverter. A novel DC/AC inverter without pre-boost DC/DC converter, which is comprised of two SEPIC converters, is studied. The output of dual SEPIC converters is connected with anti-parallel and half load-cycle control is used to realize boost and buck DC/AC output directly and work properly, whatever the DC input voltage is higher or lower than the AC output voltage. The working principle, parameter selection and the control strategy of the inverters are analyzed in this paper. Simulation and experiment results verify the feasibility of the new inverter.

• Journal of Power Electronics
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• 제15권2호
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• pp.309-318
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• 2015

This study proposes a dual-output single-stage bridgeless single-ended primary-inductor converter (DOSSBS) that can completely remove the front-end full-bridge alternating current-direct current rectifier to accomplish power factor correction for universal line input. Without the need for bridge diodes, the proposed converter has the advantages of low component count and simple structure, and can thus significantly reduce power loss. DOSSBS has two uncommon output ports to provide different voltage levels to loads, instead of using two separate power factor correctors or multi-stage configurations in a single stage. Therefore, this proposed converter is cost-effective and compact. A magnetically coupled inductor is introduced in DOSSBS to replace two separate inductors to decrease volume and cost. Energy stored in the leakage inductance of the coupled inductor can be completely recycled. In each line cycle, the two active switches in DOSSBS are operated in either high-frequency pulse-width modulation pattern or low-frequency rectifying mode for switching loss reduction. A prototype for dealing with an $85-265V_{rms}$ universal line is designed, analyzed, and built. Practical measurements demonstrate the feasibility and functionality of the proposed converter.

• 전력전자학회논문지
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• 제18권6호
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• pp.515-522
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• 2013

In this paper, a new PCS is proposed which is consisted of high boost dual converter and single phase half-bridge inverter. The proposed PCS is configured in parallel input / serial output, using two interleaved voltage doubler converter. Converter of the proposed PCS is distribute input current by configuring parallel input and reduced turn ratio of transformer by configuring serial output. Also, compositions of the inverter are composed of serial output capacitor of converter and half-bridge inverter. The dual converter and single phase half-bridge inverter is designed and characteristic of the new PCS is analysed. The system of the 1.5[kW] PCS is verified through an experimental about operation and stability.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.46-51
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• 2001

To reach high areal density, less track pitch is expected and more servo bandwidth is required. One approach to overcoming the problem is by using dual stage servo system. In this system, a voice coil motor (VCM) is used as the primary stage while a milliactuator is used as the secondary stage. We have suggested new milliactuator based on the shear mode of piezoelectric elements to drive the head suspension assembly. In this paper, we introduce controller design method, PQ method. PQ method reduces the controller design problem for DISO(dual-input/single-output) systems to two standard controller design problems for SISO(single-input/single-output) problems. The first part of PQ method directly address the issue of actuator output contribution, and the second part allows the use of traditional loop shaping to achieve the overall system performance. This paper shows how to employ the PQ method to meet aggressive close-loop performance specifications for a disk drive system with a VCM and piezoelectric milliactuator.

• 전기전자학회논문지
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• 제18권2호
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• pp.220-227
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• 2014

이 논문은 Dead-time을 갖는 톱니파 발생기를 이용하여 공통모드와 차동모드 피드백 루프를 구현한 Single-Inductor Dual-Output DC-DC Converter 설계에 관한 내용을 제시하고 있다. 제어회로에는 공통모드와 차동모드 피드백 루프를 Dead-time을 갖는 톱니파 발생기를 이용하여 동시에 사용하였다. 차동모드 피드백 루프에서 duty를 생성하기 위해서 전류 분배기 회로를 사용하여 공통모드 피드백에 의한 duty에 따라 dead-time이 유동적으로 변하는 톱니파형을 만드는 회로인 Dead-time을 갖는 톱니파 발생기를 추가하여 차동모드 피드백 회로를 구성하였다. 0.35um 공정을 사용하여 설계한 SIDO DC-DC Converter는 2.5V 입력으로부터 2.8V와 4.2V의 전압을 출력하며 최대 전력변환 효율은 95%이다. 출력간의 Cross regulation은 출력전류가 2배씩 증가할 경우 Boost1과 Boost2의 출력전압은 각각 3.57%, 4% 수준을 보이고 있다.

• Journal of Power Electronics
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• 제17권6호
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• pp.1433-1444
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• 2017

A family of non-isolated DC-DC three-port converters (TPCs) that allows for a more flexible power flow among a renewable energy source, an energy storage device and a current-reversible DC bus is introduced. Most of the reported non-isolated topologies in this area consider only a power consuming load. However, for applications such as hybrid-electric vehicle braking systems and DC microgrids, the load power generating capability should also be considered. The proposed three-port family consists of one unidirectional port and two bi-directional ports. Hence, they are well-suited for photovoltaic (PV)-battery-DC bus systems from the power flow viewpoint. Three-port converters are derived by combining different commonly known power converters in an integrated manner while considering the voltage polarity, voltage levels among the ports and the overall voltage conversion ratio. The derived converter topologies are able to allow for seven different modes of operation among the sources and load. A three-port converter which integrates a boost converter with a buck converter is used as a design example. Extensions of these topologies by combining the soft-switching technique with the proposed design example are also presented. Experiment results are given to verify the proposed three-port converter family and its analysis.

• Journal of electromagnetic engineering and science
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• 제13권2호
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• pp.93-103
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• 2013

This paper presented a novel approach for the design of a tunable dual-band bandpass filter (BPF) with independently tunable passband center frequencies and bandwidths. The newly proposed dual-band filter principally comprised two dual-mode single band filters using common input/output lines. Each single BPF was realized using a varactor-loaded transmission line resonator. To suppress the harmonics over a broad bandwidth, a defected ground structure was used at the input/output feeding lines. From the experimental results, it was found that the proposed filter exhibited the first passband center frequency tunable range from 1.48 to 1.8 GHz with a 3-dB fractional bandwidth (FBW) variation from 5.76% to 8.55%, while the second passband center's frequency tunable range was 2.40 to 2.88 GHz with a 3-dB FBW variation from 8.28% to 12.42%. The measured results of the proposed filters showed a rejection level of 19 dB up to more than 10 times the highest center frequency of the first passband.

• Journal of Power Electronics
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• 제18권4호
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• pp.1015-1026
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• 2018

A family of dual-DC-input (DI) dual-buck inverters (DBIs) is proposed by employing a DI switching cell as the input of traditional DBIs. Three power ports, i.e. a low voltage DC input port, a high voltage DC input port and an AC output port, are provided by the proposed DI-DBIs. A low voltage DC source, whose voltage is lower than the peak amplitude of the AC side voltage, can be directly connected to the DI-DBI. This supplies power to the AC side in single-stage power conversion. When compared with traditional DBI-based two-stage DC/AC power systems, the conversion stages are reduced, and the power rating and power losses of the front-end Boost converter of the DI-DBI are reduced. In addition, five voltage-levels are generated with the help of the two DC input ports, which is a benefit in terms of reducing the voltage stresses and switching losses of switches. The topology derivation method, operation principles, modulation strategy and characteristics of the proposed inverter are analyzed in-depth. Experimental results are provided to verify the effectiveness and feasibility of the proposed DI-DBIs.