• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.352-356
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• 1990

In this paper proposed a new analysis method that can be controlled DC separately excited motor using DC chopper. An analysis method can be broadly divided the state variables method and the state space averaging method. The state variable method is largely used for analysis method in the time area, but it is complicated analysis of the nonlinear circuit and modeling of the system. Therefore a boundary of the current continuous mode and discontinuous mode can be definited by the state space averaging method. Also this paper proposed a new approximation analysis method using state space averaging method in the discontinuous mode.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.54 no.4
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• pp.171-178
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• 2005

The proposed dual-output DC-DC converter that bases on flyback converter can obtain two output voltage with non-isolated main-output and isolated sub-output at the same time using single-winding high frequency transformer. It can solve problems in multi-winding converter that use one main-switch, and also control quality of isolated sub-output voltage can be improved by additional sub-switch to the second. For analysis and design of the proposed converter system, converters are classified as operation mode from switching state and are become modeling by applying state space averaging method. Steady-state characteristics and dynamic characteristics are analyzed by DC component and perturbation component from state space averaging model. From experiment converter, validity of analysis and design for the propose converter system is confirm.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.9
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• pp.701-709
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• 1989

The time-averaged behavior of the three-phase Inductor-Converter Bridge (ICB) circuit has been analyzed by using the state-space averaging method. Especially, a second order approximation in the matrix expansion makes the analysis possible. The results are in a closed form which is quite different from the conventional solution obtained by using the Fourier Series. Therefore, the computational difficulties in evaluating the infinite Fourier series can be avoided and the results derived in this paper are available expecially in real time control. By comparing with the Fourier result, it has been verified that the analysis by means of the state-space averaging method is more accurate and simple. The digital simulation and the equivalent experiments have also been carried out to confirm the theoretical results.

• Journal of Electrical Engineering and Technology
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• v.2 no.2
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• pp.231-240
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• 2007

This paper presents an advanced modeling and simulation technique applied to DC/DC power electronic converters fed through renewable energy power sources. The distributed generation (DG) system at the Illinois Institute of Technology, which employs a phase-l system consisting of a photovoltaic-based power system and a phase-2 system consisting of a fuel cell based primary power source, is studied. The modeling and simulation of the DG system is done using the generalized state space averaging (GSSA) method. Furthermore, the paper compares the results achieved upon simulation of the specific GSSA models with those of popular computer aided design software simulations performed on the same system. Finally, the GSSA and CAD software simulation results are accompanied with test results achieved via experimentation on both, the PV-based phase-l system and the fuel cell based phase-2 power system.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.5
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• pp.387-396
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• 2009

The life and performance of lithium battery are greatly influenced by the formation process which is essential in the process of manufacture. Charge/discharge system for the lithium battery are required for the formation process. To simulate such a system in a conventional method takes very long time and requires huge memory space to save data files. So the simulation may be impossible with a general-purpose PC. In this paper, the lithium battery is modelled to a resistor-capacitor serial circuit and the lithium battery charge/discharge system is analyzed and simulated by using state space averaging method. As a result, the simulation time is reduced dramatically and the simulation of the lithium battery charge/discharge system becomes possible on a general-purpose PC within 3 hours. Also, both the charge/discharge characteristics and the time required to charge/discharge of the lithium battery charge/discharge system can be observed. To verify the propriety of resistor-capacitor serial circuit modeling method for lithium battery and the validity of the analysis and simulation based on state space averaging, the lithium battery charge/discharge system is composed and experimentations are carried out.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1146-1155
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• 2017

Normally, the artificial intelligence algorithms are widely applied to the optimal controller design. Then, it is expected that the best output performance is achieved. Unfortunately, when resulting controller parameters are implemented by using the practical devices, the output performance cannot be the best as expected. Therefore, the paper presents the optimal controller design using the combination between the state-space averaging model and the adaptive Tabu search algorithm with the new criteria as two penalty conditions to handle the mentioned problem. The buck-boost converter regulated by the cascade PI controllers is used as the example power system. The results show that the output performance is better than those from the conventional design method for both input and load variations. Moreover, it is confirmed that the reported controllers can be implemented using the realistic devices without the limitation and the stable operation is also guaranteed. The results are also validated by the simulation using the topology model of MATLAB and also experimentally verified by the testing rig.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.152-154
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• 2009

태양광발전 시스템에서 사용되는 컨버터는 기존의 입출력 관계로 모델링할 수 없다. 이는 태양광 전지를 컨버터의 입력단으로 사용하여, 모델의 입력 전류와 전압이 수시로 변동하기 때문이다. 이런 오류가 있는 방법으로 모델링하여 설계한 제어기가 좋은 성능을 내기는 어렵다. 본 논문에서는 기존의 입출력 관계를 반대로 한 벅 컨버터의 새로운 모델을 제시한다. 모델링은 상태공간평균화 방법(State-Space Averaging Method)을 사용하였다.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.560-573
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• 2015

In this paper, a battery charger is introduced for an interleaved DC-DC converter with an LCLC filter. To improve the overall performance of the DC-DC converter for battery charger, a method is proposed. First, the structure of the system is presented. Second, an LC filter is compared to an LCLC filter in terms of the response characteristics and size. Third, the small-signal model of a bidirectional DC-DC converter using a state-space averaging method and the required transfer functions are introduced. Next, the frequency characteristics of the converter are discussed. Finally, the simulation and experimental results are analyzed to verify the proposed state space of the bidirectional converter.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.7 no.1
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• pp.77-84
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• 2007

In this paper, Takagi-Sugeno (TS) fuzzy integral control is investigated to regulate the output voltage of an asymmetric half-bridge (AHB) DC/DC converter; First, we model the dynamic characteristics of the AHB DC/DC converter with state-space averaging method and small perturbation at an operating point. After introducing an additional integral state of the output regulation error, we obtain the $5^{th}$-order TS fuzzy model of the AHB DC/DC converter. Second, the concept of the parallel distributed compensation is applied to design the fuzzy integral controller, in which the state feedback gains are obtained by solving the linear matrix inequalities (LMIs). Finally, simulation results are presented to show the performance of the considered design method as the output voltage regulator and compared to the results for which the conventional loop gain method is used.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.10
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• pp.595-600
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• 2002

This paper presents the analyzed results of dynamic characteristics including steady state characteristics of the boost input type ZVS converter using the active clamp circuit by the state space averaging method. From the results, it can be seen that the converter has the 5th order transfer functions and the stable closed loop characteristic is obtained by using the compensated error amplifier with 2-pole and 1-zero. The validity of all analyzed results are verified by measurement.