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The positive output elementary superlift-Luo converter (POESLLC) is a type of dc/dc converter. This dc/dc converter has an attractive advantage of a high voltage transfer gain as compared with other conventional dc/dc converters. Because of the voltage and load variations and also switching operation, the dynamic and static performances of the POESLLC are nonlinear and time varying. In order to achieve an excellent performance, a nonlinear controller is required. In this paper, a robust and fast response controller for voltage regulation of a POESLLC is presented. A proportional integral and pulse width modulation sliding mode controller are combined to control a third-order POESLLC. The proposed controller can be applied in the continuous conduction mode. Some simulations and experimental results are presented to show the effectiveness of the developed controller in different operating conditions. Furthermore, it will be shown that the developed controller is successful in suppressing the steady-state error of the output voltage of the POESLLC as well as the number of reduction of sensors. [ABSTRACT FROM PUBLISHER]

This paper presents a digital signal processor-based permanent magnet synchronous motor (PMSM)-driven satellite reaction wheel with DC-link voltage adjustable according to speed and photovoltaic voltage. After the PMSM-driven reaction wheel is established, an improved current-controlled pulse-width modulation scheme is designed to yield precise sinusoidal winding current command tracking, and a simple, robust, model-following control scheme is designed to yield good dynamic speed response. To provide an adjustable and well-regulated DC-link voltage, DC/DC boost and DC/DC buck-boost front-end converters are established and compared. The stable chopping-controlled dynamic braking mechanism is also established. [ABSTRACT FROM AUTHOR]

This paper assesses the behavior of electrical output for a Ballard Mark V 35-cell 5 kW PEMFC (proton exchange membrane fuel cell) stack-based dc-dc power conversion for applications in autonomous underwater vehicles (AUVs) under load changes. Since the fuel cell produces dc output voltage that is unregulated, pulsewidth modulated (PWM) dc-dc converters are connected to the output of the studied fuel cell for converting the unregulated voltage into a desired voltage level. The fuel cell model includes the double-layer charging effect, gases diffusion in the electrodes, and the thermodynamic characteristic. Moreover, PWM dc-dc converters are assumed to operate in continuous-conduction mode (CCM), and the compensator is designed with voltage-mode control. The models of the study's fuel cell and PWM dc-dc converters have been implemented in a Matlab/SIMULINK(TM) environment. The results show that the output voltages of the studied PEMFC connected with PWM dc-dc converters during a load change are stable. [ABSTRACT FROM PUBLISHER]

A stability analysis for a maximum power point tracking (MPPT) scheme based on extremum-seeking control is developed for a photovoltaic (PV) array supplying a dc-to-dc switching converter. The global stability of the extremum-seeking algorithm is demonstrated by means of Lyapunov's approach. Subsequently, the algorithm is applied to an MPPT system based on the ‘perturb and observe’ method. The steady-state behavior of the PV system with MPPT control is characterized by a stable oscillation around the maximum power point. The tracking algorithm leads the array coordinates to the maximum power point by increasing or decreasing linearly with time the array voltage. Off-line measurements are not required by the control law, which is implemented by means of an analog multiplier, standard operational amplifiers, a flip-flop circuit and a pulsewidth modulator. The effectiveness of the proposed MPPT scheme is demonstrated experimentally under different operating conditions. [ABSTRACT FROM AUTHOR]

Ready-to-use nonlinear and linear averaged models for a single-switch quadratic buck converter are given. The nonlinear model is obtained from an averaged equivalent circuit model of the converter using the PWM-switch (pulsewidth modulation) model. The linear model is obtained by applying a small-signal perturbation to the corresponding averaged state-space description. The result shows that this quadratic converter exhibits the transfer characteristics of a fourth-order system. The resulting models are only valid in the continuous conduction mode (C CM). The validity of the proposed models was verified by computer simulation using PSPICE and MATLAB/SIMULINK for a specified converter. Experimental results on a prototype converter are also presented. [ABSTRACT FROM AUTHOR]

Presents a study which featured a method for steady-state analysis of pulsewidth modulation (PWM) hard-switching direct current-to-direct current (dc/dc) regulators. Characteristics of the steady-analysis; Schematic representation of a PWM dc/dc switching regulators; Search of the steady-state solution; Examples of dc/dc regulators.

Presents a study that reviewed common switching techniques for direct current (DC)/DC power conversion. Background on the concept of soft-pulsewidth modulation; Information on the evolution of the forward converter; Details on the design verification and performance comparisons of converters; Summary of the development of the power management and distribution hardware.

Proposes small-signal linear models for variable-frequency constant on-time and variable-frequency constant off-time pulsewidth modulators. Principle underlying the constant off-time pulsewidth modulation; Model verification; Way to gain modulator gain for constant on-time control.

Investigates a full bridge zero-current switched (ZCS) pulse-width modulation converter which is suitable for high voltage and high power applications. Derivation of the full bridge ZCS topology; Converter operation; Details of small-signal analysis and control implementation.

Presents information on a study which proposed a random switching control strategy that lets the harmonic spectrum of the hysteresis current-controlled pulsewidth modulation (PWM) inverter be randomly distributed. Spectral analysis of hysteresis current-controlled PWM inverter; Description of the proposed random hysteresis PWM inverter; Simulated and experimental results; Conclusions.

Provides information on a study which demonstrated the use of the Fourier theory of jumps in deriving closed-form analytical equations for converter switching harmonics. Background theory; Fourier analysis of pulsewidth modulated waveforms; Conclusion.

Presents a study that examined pulsewidth modulation (PWM) control strategies for a single-phase power-factor-correction (PFC) alternating current/direct current converter. Benefits of high power density and low current distortion in industrial applications; Performance evaluation of the PWM schemes and circuit modeling equations; Results and discussion.