• Journal of Power Electronics
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• 제12권4호
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• pp.538-547
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• 2012

This paper presents two different robust controllers for boost converters with two stages in a cascade. The first robust controller is monovariable; that is, the duty-cycle is the same for the two switches. The monovariable controller ensures that some prescribed constraints on pole placement and control effort are met, and optimizes the load disturbance rejection, while takes into account the uncertainty in certain parameters. The first controller is then compared with a multivariable robust controller; that is, with independent duty cycles in each switch. The multivariable controller takes into account the same uncertainty, constraints and optimization function. The comparison shows that the multivariable controller performs better at the expense of a slightly more complex implementation; that is, the multivariable controller provides a better rejection of the load disturbance. The paper also describes simulations and experimental results that are in perfect agreement with theoretical derivations.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.925-934
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• 2015

This paper considers the robust controller design problem for a boost DC-DC converter. Based on the Takagi-Sugeno fuzzy model-based approach, a fuzzy controller as well as a fuzzy load conductance observer are designed. Sufficient conditions for the existence of the controller and the observer are derived using Linear Matrix Inequalities (LMIs). LMI parameterizations of the gain matrices are obtained. Additionally, LMI conditions for the existence of the fuzzy controller and the fuzzy load observer guaranteeing α-stability, quadratic performance are derived. The exponential stability of the augmented fuzzy observer-controller system is shown. It is also shown that the fuzzy load observer and the fuzzy controller can be designed independently. Finally, the effectiveness of the proposed method is verified via experimental and simulation results under various conditions.

• Journal of Power Electronics
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• 제19권6호
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• pp.1366-1379
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• 2019

High-gain DC/DC converters have become one of the key technologies for the grid-connected operation of new energy power generation, and its research provides a significant impetus for the rapid development of new energy power generation. Inspired by the transformer effect and the ripple-suppressed ability of a coupled inductor, a double-coupled inductor high gain DC/DC converter with a ripple absorption circuit is proposed in this paper. By integrating the diode-capacitor voltage multiplying unit into the quadratic Boost converter and assembling the independent inductor into the magnetic core of structure coupled inductors, the adjustable range of the voltage gain can be effectively extended and the limit on duty ratio can be avoided. In addition, the volume of the magnetic element can be reduced. Very small ripples of input current can be obtained by the ripple absorption circuit, which is composed of an auxiliary inductor and a capacitor. The leakage inductance loss can be recovered to the load in a switching period, and the switching-off voltage spikes caused by leakage inductance can be suppressed by absorption in the diode-capacitor voltage multiplying unit. On the basis of the theoretical analysis, the feasibility of the proposed converter is verified by test results obtained by simulations and an experimental prototype.

• Journal of Power Electronics
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• 제12권1호
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• pp.145-156
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• 2012

These days, the application of electronic power transformers (EPTs) is expanding in place of ordinary power transformers. These transformers can transmit power via three or four wire converters. Their dynamic performance is extremely important, due to their complex structure. In this paper, a new method is proposed for improving the dynamic performance of distribution electronic power transformers (DEPT) by using sliding mode control (SMC). Hence, to express the dynamic characteristics of a system, different factors such as the voltage unbalance, voltage sag, voltage harmonics and voltage flicker in the system primary side are considered. The four controlling aims of the improvement in dynamic performance include: 1) maintaining the input currents so that they are in sinusoidal form and in phase with the input voltages so they have a unity power factor, 2) keeping the dc-link voltage within the reference amount, 3) keeping the output voltages at a fixed amount and 4) keeping the output voltages in sinusoidal and symmetrical forms. Simulation results indicate the potential and capability of the proposed method in improving DEPT behavior.

• 한국지진공학회논문집
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• 제3권3호
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• pp.63-74
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• 1999

대형구조물의 진동감소를 위한 슬라이딩 모드 퍼지 제어기(Sliding Mode Fuzzy Control SMFC)에 대하여 연구하였다 본 제어기에 사용된 퍼지 추론기의 규칙은 비선형 제어기법의 하나인 슬라이딩 모드 제어기를 기반으로 하여 구성되었다 그결과 제어기의 퍼지성은 제어시스템을 시스템 계수의 불확실성과 구조물에 작용되는 외부하중의 불확실성에 대하여 강인한 성질은 갖게 하였으며 제어 규칙의 비선형성으로 인하여 제어기는 선형제어기에 비하여 보다 효율적인 되었다 복잡한 수학 해석에 기반한 종래의 제어기법에 비하여 퍼지 이론에 기반한 본 제어기법은 제어기의 설계절차가 매우 편리하다는 장점을 갖게 된다. 제안된 제어기법의 검증을 위하여 미국 토목학회 산하 구조제어위원회(ASCE Committee on Structural Control)에서 주도한 벤치마크 문제에 대하여 적용시켜 보았다 본 연구의 제어결과를 다른 연구자들에 의하여 발표된 {{{{ ETA _mixed _2$\infty$ }}, optimal polynomial control neural networks control 슬라이딩 모드 제어의 벤치마크 결과와 비교하였으며 그 결과 제안된 제어기법이 구조물의 진동을 매우 효율적으로 감소시키며 제어기의 설계절차가 쉽고 편리함을 확일 할 수 있었다.