In this paper, the problem of designing a fractional order PID-type controller is considered for a boost converter. By using the output capacitance and input inductance values this paper characterizes integer order PID-type control gains which will make the closed-loop system transfer function approximately equal to a first order system with a unit DC gain and prescribed time constant τ . Next, a procedure to compute the design parameters of a fractional order PID-type controller is given together with a descritized control algorithm for DSP implementation. By using a floating-point DSP, the proposed control algorithm is implemented in real time. Finally, experimental results are given to show the practical feasibility and effectiveness of the proposed fractional order PID-type control system under several operating conditions. The results illuminate that the proposed controller can be better than a conventional integer order PID-type controller.

In this paper, a high-efficiency DC/DC converter with low voltage stress is designed for green power applications. The proposed non-isolated high step-up DC/DC converter combines the advantages of switched capacitors, coupling inductors, and voltage multiplier techniques. Adding the cells of the switched capacitor not only increases the voltage gain but reduces the voltage stress of the semiconductor devices. High voltage gain can be achieved by adding a coupled inductor method to adjust the turns ratio. When these are combined with a voltage multiplier circuit, the leakage energy of the coupled inductor is recirculated to the output terminal with lossless passive clamping performance. The leakage inductance of the coupled inductor controls the current dropping rate of the output diode turn OFF so that the reverse-recovery problem is mitigated. The proposed converter integrates these three techniques to achieve high voltage gain without operating at maximum duty cycle. In addition, switching loss reduction is realized through zero current switching turn ON soft switching performance with low voltage stress of semiconductor devices. Finally, this paper verifies the performance of the proposed converter for theoretical analysis by using a 35~45V input, 380V output, and 1kW power prototype circuit. INDEX TERMS Boost converter, high step-up, coupled inductor, switched capacitor, voltage multiplier cell.

In this paper, a non-isolated high step-up interleaved DC-DC converter for distributed generation applications such as solar cells and fuel cells. The proposed converter mixes the benefits of magnetic coupling, voltage multiplier, and voltage lift techniques to conventional interleaved schemes. The proposed converter's voltage lift technique can increase the voltage gain while guaranteeing low voltage stress of the switches. And the magnetic coupling method can combine the switched capacitor of the voltage multiplier technique with the lossless clamp circuit to achieve high voltage gain and reuse the leakage inductance energy to the output terminal. In addition, this leakage inductance energy can achieve zero current switching turn on soft switching performance and mitigate the output diode reverse recovery problem. The proposed converter avoids the extreme duty cycles that cause conduction losses in power devices and can give very low voltage stresses. Therefore, the use of low voltage rated MOSFETs and diodes not only reduces switching losses and costs, but also improves efficiency. INDEX TERMS High voltage gain, magnetic coupling, non-isolated, voltage lift (VL) technique, zero current switching (ZCS).

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This paper proposes a high voltage step-up DC/DC converter by combining a coupled inductor and a voltage multiplier rectifier. The input side of the proposed converter operates in an interleaved manner with two coupled inductors connected in parallel, and the output side is composed of a voltage multiplier rectifier where two voltage doubler rectifiers are merged in series. By changing the turns ratio of the coupled inductor of the proposed converter, the voltage gain can be increased, and additional voltage gain can be obtained by combining it with a voltage multiplier rectifier. Due to the passive lossless clamping performance of the proposed method, it is possible to recycle the leakage inductance energy of the coupled inductor and voltage stress reduction can be achieved along with zero current turn-ON and turn-OFF of switches and diodes. Finally, this paper evaluates the effectiveness and practicality of the proposed method by operating a prototype circuit with an input voltage of 20V, an output voltage of 400V, and an output power of 320W. The maximum efficiency of the proposed converter is 97.2% and the efficiency at maximum power is 94.1%.INDEX TERMS DC/DC converter, high step-up, coupled inductor, voltage multiplier rectifier.

Abstract-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.

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