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Partial shading on a photovoltaic (PV) module is known to trigger serious issues of significant reduction in power generation and occurrence of multiple power point maxima. Among various kinds of voltage equalizers that have been proposed to preclude the partial shading issues, switched capacitor converters (SCCs) are known as a simple and small solution. To achieve even smaller circuit at lower cost,...
In the case of the presence of ferroresonance in distribution transformer due to a faulty switching operation, ferroresonance signals should be discriminated among its initiations due to opened single-phase, opened two-phases, and opened three-phases, so that ferroresonance mitigation can be conducted appropriately. However, the performance of mitigation system itself is highly determined by its accuracy...
Impedance source inverters have attracted much attention in recent years due to their ability to behave as voltage elevators/reducers at their output terminals without the need of an extra dc/dc converter to accomplish this task. Among these inverters, the quasi-impedance source inverter (qZSI) is one of the most known topologies. It considers two basic operating states, the no-shoot-through state...
This paper describes the effect of MOSFET internal capacitances on the channel current during the turn-on switching transition: an intrinsic theoretical switching speed limit is found and detailed mathematically. The set of analytical equations is solved and the effect of the displacement currents is highlighted with ideal simulated waveforms. A laboratory experiment is thus performed, in order to...
A delta-structured switched-capacitor equalizer (DSSCE) is proposed to achieve the automatic any-cells-to-any-cells (AC2AC) balancing for a long battery string, leading to the fast-speed and high-efficiency balancing. Only two switches are required for each battery cell, and one capacitor is set for any two cells, materializing the delta-structured switched capacitors (SC). All MOSFETs are triggered...
A rotating electric machine built entirely of sustainable lightweight materials is presented for rotary actuator applications. The machine uses electrostatic forces instead of magnetic, enabling different materials. Here, aluminum, plastic, and printed circuit boards are used as they are low cost and easily recycled at end of life. The electrostatic machine developed is of the axial flux variety,...
This paper presents a mixed three-level neutral point clamped (NPC) inverter with hybrid modulation method. It enables traditional Si devices and wide bandgap devices integration to reduce power loss and achieve high power density. Simulation results are firstly provided to verify the validity of the proposed approach.
This paper presents a multilevel modular step-down DC-DC switched-capacitor converter that utilizes soft switching resonant operation. Previous versions of traditional multilevel modular switched-capacitor dc-dc converters (MMSCC) have a low switching device voltage rating. Moreover, capacitor voltage stress increases proportionally as the voltage conversion ratio increments. Significant advantage...
Multi-megawatt scale isolated DC-DC converters are likely to become increasingly popular as means to interconnect the MVDC grids of different voltage levels. Three-phase dual active bridge DC-DC (3DAB) converters operating with the zero-voltage switching (ZVS) is a promising candidate for the target multi-megawatt application. This paper presents a systematic approach of the design considerations...
This paper presents a hybrid multilevel inverter with DC bypass. Mixed modulation method is proposed to balance dc voltage, and enables Si devices & wide bandgap devices integration to reduce power loss and achieve high power density. Simulation results are firstly provided to verify the validity of the proposed approach.
The ability to provide accurate, rapid and dynamically-controlled impedance matching offers significant advantages to a wide range of present and emerging radio-frequency (RF) power applications. This work develops a new type of tunable impedance matching networks (TMN) that enables a combination of much faster and more accurate impedance matching than is available with conventional techniques. This...
High-voltage and high-current power converters are essential in numerous applications, including shipboard power systems and industrial motor drives. Most of the existing topologies are based on dc-link converters, and use dc-dc or dc-ac power cells to realize a multilevel power converter. Therefore, they require a large number of capacitors with high capacitances. This paper proposes a new modular...
This paper focuses on the design and implementation of a digital closed-loop control scheme to maintain the 180° phase shift of an interleaved Boundary-Conduction-Mode (BCM) boost converter. The closed-loop control scheme operates by differentially modulating the on-time of each phase to adjust the phase-shift. Zero-Current-Detection (ZCD) circuits control the turn-on instant for the MOSFET of each...
In single-phase photovoltaic (PV) systems, power mismatching between input and output terminal leads to power pulsation, seriously affecting maximum power point tracking (MPPT). Paralleling an electrolytic capacitor (e-cap) across PV panel to smooth power pulsation seems to be an unreliable method owing to its short lifetime. Various power decoupling methods used in micro-inverters have been proposed...
Capacitive DC links provide the only low-impedance current path connected with an input source during the start-up of many voltage source converters. A soft-start circuit is usually implemented to limit the inrush current. A two-terminal active capacitor is recently proposed which can directly replace conventional passive capacitors in DC links, with reduced cost or size for a given application. The...
Hybrid DC circuit breakers have the advantages of fast fault current interruption with the solid-state semiconductor devices and low conducting loss with the mechanical switches. Therefore it is suitable to be used in the multi-terminal DC transmission system. The objective of this paper is to determine a voltage sharing between the mechanical switch and the IGBTs in a proposed topology of hybrid...
Two gallium oxide (Ga2O3) MOSFETs, a non field plated (NFP) device and a field plated (FP) device, are proposed and simulated in Silvaco TCAD. The static characteristics of the devices were obtained from Silvaco TCAD and the characterization of switching performance was conducted in Silvaco mixed-mode with inductive load test circuit. To study the influence of the thickness of the field plate oxide...
A comparative study of modified models for calculating the switch capacitance of electrostatically actuated fixed-fixed beam MEMS shunt switch has been presented considering the effect of beam perforation and dielectric layer simultaneously. Two different capacitance calculation methods using Yang model and Mejis model have been considered in the analysis incorporating fringing field effect due to...
A new generation of vanadium dioxide phase change switches have been designed, fabricated, and characterized. These switches were designed to dramatically reduce on-state shunt-capacitance associated with the switch's heater while also increasing the off-state resistance. The result is a switch architecture whose channel dimensions can be scaled to increase power handling while maintaining unparalleled...
Microbial fuel cells (MFCs) are sources harvesting energy from organic matters and showing great promise in powering environmental sensors. Because of the low power and voltage issues (100μW at 0.3V for 20 cm2 electrodes), an electrical interface is required to extract the maximum power delivered by the MFC and boost the output voltage. However the switching operation of most converters induces a...
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