Reconfigurable Quadratic Converters for Electrolyzers Utilized in DC Microgrids

Abstract

In this paper, three topologies of quadratic buck DC-DC converters were proposed that are capable of reconfiguring to semi-quadratic buck-boost converters, in case of an open-circuit fault in their power switch. In other words, with the aid of graph-based circuit synthesis concepts, a topology is obtained for a safe transition from one switch to another, where all other components maintain their role in contributing to optimal power conversion. Knowing that the quadratic buck converters have been proven to be an effective DC-DC circuit to supply an electrolyser as a load with specific characteristics i.e., low-voltage and high-current, the reconfigurability feature adds an extra measure of success for safer power delivery for such a load that an undesirable shut-down would negatively impact its life-cycle. The performance of three proposed synthesised topologies were compared and validated through simulation and experiments on laboratory prototypes.INDEX TERMS DC-DC converter, DC microgrid, electrolyser, green hydrogen, reconfigurabale converter

A Quadratic Buck-Boost Converter With Continuous Input and Output Currents

“…Applying small-signal perturbations to the duty cycle and forming the standard state-space matrices ẋ = Ax + B d and y = Cx, where C is simply denoted as [0 0 0 0 0 1], one can express (12). A clearer step-by-step approach to obtain the model has been elaborated in [22].…”

“…According to the simulation results, the semiconductors' average current is obtained as (21) and (22) for the boost and buck modes, respectively.…”

“…The compatibility between the values of the semiconductors' average current obtained from the theoretical equations and simulation results can be evaluated by comparing the corresponding values of ( 19) and ( 20) with ( 21) and (22). The small differences between these values are attributed to the variations in the inductors' current in the theoretical analysis and simulation results.…”

Kendali arus dan tegangan pada konverter DC-DC boost dengan metode kaskade proportional integral derivative

“…Berbagai teknik modifikasi konverter DC-DC dapat menghasilkan output tegangan dengan sangat tinggi dan dapat terintegrasi pada sistem mikrogrid, serta konverter yang dirancang memiliki tingkat kejenuhan lebih rendah dan efisiensi yang tinggi [2]- [3]. Sebagai contoh, konverter penurun tegangan keluaran dapat direkonfigurasi menjadi konverter DC-DC quadratic buck sebagai aplikasi dalam di sistem mikrogrid [4]. Selain modifikasi pada topologi dasar dari konverter DC-DC, penambahan sistem kendali di konverter tersebut telah banyak diusulkan.…”

Review, Properties, and Synthesis of Single-Switch Non-Isolated DC-DC Converters with a Wide Conversion Range

“…Some modern applications may benefit significantly from the utilization of quadratic converters. For instance, three quadratic DC-DC buck topologies that can be reconfigured in the form of semi-quadratic buck-boost arrangements are proposed in [23] for electrolyzers in DC microgrids. The topology presented in [24] proves to be an adequate choice for the charging and discharging of batteries and supercapacitors.…”