A Hybrid Modulation Featuring Two-phase Clamped Discontinuous PWM and Zero Voltage Switching for 99% Efficient DC-Type EV Charger

Two-stage AC-DC converters are considered as a prominent solution for DC-type electric vehicle (EV) chargers. However, this kind of architecture suffers from high switching losses with large heatsink and DC-link capacitor volume. To relieve this issue, this paper presents a new hybrid modulation for DC-type EV chargers, where a two-phase...

A Carrier-based Two-Phase-Clamped DPWM Strategy With Zero-Sequence Voltage Injection for Three-Phase Quasi-Two-Stage Buck-Type Rectifiers

A three-phase buck-type rectifier features a step-down ac-dc conversion function, which is considered as a prominent solution for electric vehicle chargers and telecommunication systems integrated to the grid above 380 V line to line. However, traditional solutions for those applications employ cascaded architectures with an ac-dc boost-type...

Strength formation mechanism and performance of steel slag self-compacting epoxy resin concrete

A self-compacting steel slag epoxy resin concrete (SERC) was designed with steel slag as aggregate and epoxy resin as binder for rapid repair of road expansion joints and pavement. At the same time, a group of self-compacting basalt epoxy resin concrete (BERC) with basalt as coarse aggregate and limestone as fine aggregate was set up as the...

A theoretical study of atmospheric pollutant NO₂ on as-doped monolayer WS₂ based on DFT method

For the relevant properties of pristine and doped (Si, P, Se, Te, As) monolayer WS₂ before and after the adsorption of CO, CO₂, N₂, NO, NO₂ and O₂, density functional theory (DFT) calculations are made. Calculation results reveal that the monolayer WS₂ doped with P and As atoms...

Carbon Dots Embedded in Cellulose Film: Programmable, Performance-Tunable, and Large-Scale Subtle Fluorescent Patterning by in Situ Laser Writing

Fluorescent patterns with multiple functions enable high-security anti-counterfeiting labels. Complex material synthesis and patterning processes limit the application of multifunctional fluorescent patterns, so the technology of in situ fluorescent patterning with tunable multimodal capabilities is becoming more necessary. In this work, an...

Strain-engineered S-HfSe₂ monolayer as a promising gas sensor for detecting NH₃: A first-principles study

The development of high-performance gas sensing materials is one of the development trends of new gas sensor technology. In this work, in order to predict the gas-sensitive characteristics of HfSe₂ and its potential as a gas-sensitive material, the interactions of nonmetallic element (O, S, Te) doped HfSe₂ monolayer and...

Carrier-based Generalized Discontinuous PWM Strategy for Single-Phase Three-Legs Active Power Decoupling Converters

Three-legs active power decoupling (APD) converters are widely studied in the single-phase grid-connected systems to enhance the circuit lifetime by creating an alternative path for the typical existing dc-side power pulsating ripple. Therefore, this reduces the requirement of smoothing dc capacitors allowing compact designs even with the...

Room temperature ppt-level NO₂ gas sensor based on SnO _x/SnS nanostructures with rich oxygen vacancies

In this paper, tin oxidation (SnO x )/tin-sulfide (SnS) heterostructures are synthesized by the post-oxidation of liquid-phase exfoliated SnS nanosheets in air. We comparatively analyzed the NO2 gas response of samples with different oxidation levels to study the gas sensing mechanisms. The results show that the samples oxidized at 325 °C are...

Carrier-Based Modulated Model Predictive Control for Vienna Rectifiers

The implementation of traditional finite-control-set model predictive control (FCS-MPC) with variable switching frequency in voltage source rectifiers (VSRs) can make the system suffer from poor current harmonics performance. In fact, the resulting wide-spread voltage harmonic generated at the AC terminals makes the design of the typical multi...

Model Predictive Control for the Reduction of DC-link Current Ripple in Two-level Three-phase Voltage Source Inverters

In the applications of three-phase two-level voltage source inverters (VSIs) relatively large energy storage capacitors are used to absorb the high DC-link current ripples mainly caused by the circulating reactive power, the switched AC phase current flowing to the DC-link, and other dynamic and/or asymmetric operating conditions. Especially for...