This paper presents a fast fuzzy logic control algorithm for a Takagi-Sugeno-Kang fuzzy controller, which is applied to integrated LED drivers with the purpose of getting a good dynamic response and the reduction in the low-frequency (120 Hz) ripple. The algorithm uses the highspeed mathematical engine of a digital signal controller (DSC) that is capable to achieve fast multiplications during a common one-cycle instruction. Therefore, the execution time of the controller is improved with the use of a DSC. A scaling procedure is included in the program in order to use and to improve the accuracy of the multiplications and divisions in the DSC mathematical engine. A low-range DSC was used to program the proposed controller; therefore, the cost is affordable for LED driver applications. The fuzzy control curve was approximated to the sliding mode control (SMC) curve with the purpose of getting some of the good advantages of the SMC strategy like a good dynamic performance. The proposed controller is used to regulate the LED current. Simulation and experimental results are shown.

This paper describes a nonlinear model of high-intensity discharge (HID) lamps based on electrical variables. The proposal, oriented to the engineering area, has a special application for the design of electronic ballast. Parameters are obtained from straightforward measurement of electrical variables as power, current, and voltage in the lamp. The lamp resistance is obtained as a function of electrical power; which is estimated from the Saha equation. This model, which can be simulated using software such as ¿Simulink¿ or ¿Pspice,¿ takes into account some important dynamic behaviors of HID lamps, which are normally omitted in some other models suggested in literature nowadays. Experimental and simulation results are shown.

Renewable energy sources in DC microgrids require high-performance conversion systems to increase their capacity and reliability. Among other characteristics in conversion systems, the current ripple is a characteristic that must be considered since it affects the performance of PV panels and batteries. In this paper, a high-voltage-gain DC–DC boost converter for performing current ripple elimination that is based on a variable inductor is proposed. The topology is composed of a diode–capacitor voltage multiplier and a modified cascaded boost converter. To achieve voltage regulation, a reduced-order switched model is obtained considering the switched capacitor’s dynamics. To address the inductance variation and external disturbances, the $H_{\infty }$ control theory is adapted to systematically design a robust proportional–integral (PI) controller. Details of the working principles and the sizing of passive components are presented. The simulation and experimental results demonstrate that the input current ripple of the proposed converter can be removed in both transitory and steady states.

A zero-ripple input current is known to improve the lifetime of battery sets and fuel cells and to assure maximum power point tracking in PV panels. To perform current ripple elimination in a floating interleaved boost converter (FIBC), one of the typical linear inductors is substituted by a variable inductor, and phases of the converter have complementary duty cycles. This variable inductor is controlled using a switched current-source converter, which adjusts the input current ripple. An equivalent model for the variable inductor is presented, including uncertainties in the component description. To achieve current stabilization, a variable inductor controller was designed using the sliding modes approach via fixed frequency. An experimental prototype is implemented and tested with an output voltage controller to compare with the conventional FIBC. The results demonstrate that the input current ripple of the proposed converter is eliminated without significantly decreasing the efficiency.

The dual active bridge (DAB) is a dc/dc converter frequently employed in multiple applications due to its advantages of isolation, power flexibility, and input and output voltage defined by design. Different multi-phase modulations have been reported to increase DAB efficiency and reduce components stress but, certainly, the control and implementation complexity increases with every displacement angle added because of the multiple variable measurements. This paper presents two-stage modulations based on the single phase-shift (SPS), which allows maintaining simplicity while improving the efficiency of the DAB converter depending on the design conditions. The paper also gives a direction for selecting the proper modulation to achieve the best efficiency for each situation. The different two-stage modulations are described, analyzed, and experimentally tested.