Integration of power decoupling buffer and grid-tied photovoltaic inverter with single-inductor dual-buck topology and single-loop direct input current ripple control method

To balance the cost and volume when applying a low output current ripple, the power supply design should be able to eliminate the current ripple under any duty cycle in medium and high switching frequencies, and considerably reduce filter volume to improve power density. A stacked buck converter was eventually selected after reviewing the existing solutions and discussing their advantages and disadvantages. A stacked buck converter is used as a basis to propose the transient response and output current ripple elimination effect, boundary limit control method, and low output ripple dead time modulation method to make individual improvements. The principle, mathematical derivation, small-signal model, and compensator design method of the improvement method are presented in detail. Moreover, simulation results are used to mutually verify the correctness and effectiveness of the improvement method. A stacked buck converter with 330-V input, 50-V output, and 1-kW output power was implemented to verify the effect of the low output current ripple dead time modulation. Experimental results showed that the peak-to-peak value of the output current ripple was reduced from 2.09 A to 559 mA, and the RMS value was reduced from 551 mA to 91 mA, thereby effectively improving the output current ripple.

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Optimal Operation of the Voltage-Doubler Boost Converter through an Evolutionary Algorithm

Mathematics ◽

10.3390/math9040423 ◽

2021 ◽

Vol 9 (4) ◽

pp. 423

Author(s):

Cesar Ibarra-Nuño ◽

Alma Rodríguez ◽

Avelina Alejo-Reyes ◽

Erik Cuevas ◽

Juan M. Ramirez ◽

...

Keyword(s):

Evolutionary Algorithm ◽

Numerical Optimization ◽

Boost Converter ◽

Optimal Operation ◽

Input Current ◽

Voltage Gain ◽

Duty Cycles ◽

Switching Functions ◽

Voltage Doubler ◽

Current Ripple

This manuscript presents the numerical optimization (through a mathematical model and an evolutionary algorithm) of the voltage-doubler boost converter, also called the series-capacitor boost converter. The circuit is driven by two transistors, each of them activated according to a switching signal. In the former operation, switching signals have an algebraic dependence from each other. This article proposes a new method to operate the converter. The proposed process reduces the input current ripple without changing any converter model parameter, only the driving signals. In the proposed operation, switching signals of transistors are independent of each other, providing an extra degree of freedom, but on the other hand, this produces an infinite number of possible combinations of duty cycles (the main parameter of switching signals) to achieve the desired voltage gain. In other words, this leads to a problem with infinite possible solutions. The proposed method utilizes an evolutionary algorithm to determine the switching functions and, at the same time, to minimize the input current ripple of the converter. A comparison made between the former and the proposed operation shows that the proposed process achieves a lower input current ripple while achieving the desired voltage gain.

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