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Energy harvesting applications based on Dielectric ElectroActive Polymer (DEAP) generators have been in the spotlight in recent years after the latter ones' documented advantages against competing electromagnetic and field-activated technologies. Yet, the need for bidirectional energy flow under high step-up and high step-down voltage conversion ratios, accompanied by low-average but relatively high-peak...
This paper investigates the effects of ringing on the switching losses of wide band-gap (WBG) devices in a phase-leg configuration. An analytical switching loss model considering the parasitic inductance, stray resistance, devices' junction capacitances, and reverse recovery characteristics of the freewheeling diode is derived to identify the switching energy dissipation induced by damping ringing...
A high frequency, high efficiency bi-directional battery charger for Plug-in Hybrid Electric Vehicle (PHEV) is built with high voltage normally-off GaN-on-Si HFETs. The battery charger topology consists of a 500 kHz Full Bridge (FB) AD/DC stage and a 500 kHz Dual Active Bridge (DAB) DC/DC stage. The system functionality is verified and measured efficiency is 97% for the AC/DC stage and 97.2% for the...
Soft-switching ac-link buck-boost converters, also known as ac-link universal power converters and partial resonant ac-link converters, have received remarkable attention during the last few years. These converters can be configured as dc-dc, dc-ac, ac-dc, or ac-ac (single-phase or multi-phase). Among the numerous advantages of these converters are compactness, higher reliability, and longer lifetime...
This paper discusses a development for high output of 2.5 MHz inverter without fast-switching semiconductor switches. This inverter consists of a multi-phase inverter using conventional silicon semiconductor switches and multiple core transformers. In this paper, a principle of drop in inverter output voltage which reduces the inverter output voltage due to a relationship between dead-time and a leakage...
This paper extends the Universal Serial Bus (USB) standard to the contactless domain by combining bidirectional data communication with a capacitive power transfer interface. This work first addresses the power transfer with analysis, simulations, and experiment, based on a secondary side phase feedback series resonant topology. This gives the advantage of simple circuitry to regulate output voltage...
Bearing currents cause a reduction of ball bearing's lifetime in electronically commutated permanent magnet motors. To compensate the lifetime decreasing factors, a tradeoff between special bearings and additional changes in the machine design have to be found. Stator grounding, for example, keeps the bearing voltage low and thus guarantees a long fan system's lifetime, however, results in a higher...
With voltage-balancing control, the voltage difference among sub-module (SM) capacitors in a modular multilevel converter can be reduced. However, this comes at the cost of increased device switching frequency. In this paper, the relationship between the switching frequency and SM capacitor unbalanced voltage is investigated. As the relationship depends on the voltage-balancing control schemes, a...
In high power HB LED lighting applications, low output voltage LED drivers are preferred due to its low voltage stress and safety requirement, high reliability and safety requirements. However, most LED modules are packaged in low power module, such as 1W and 3W modules. Therefore, more LED strings are required to reduce the forward voltage drop. Since the currents in different LED strings should...
A new solid state variable capacitor (SSVC) with minimum dc capacitance is proposed. A variable ac capacitor (with capacitance variable from 0 to Cac) is traditionally implemented by an H-bridge inverter and a large electrolytic dc capacitor with capacitance of 20 times the ac capacitance value, Cac to absorb the 2ω dc ripple. The proposed SSVC consists of an H-bridge and an additional phase leg connected...
A new GaAs power switching device, the gFET™ switch was introduced at APEC 2013. This paper describes devices developed since APEC 2013 including depletion mode devices with nominal on resistances of 7, 14 and 40 MΩ as well as an enhancement mode device with a nominal on resistance of 40 MΩ. The enhancement mode device is particularly well suited for use as a control switch in buck converters. The...
Gallium nitride (GaN) based power devices are becoming common place due to their ability to achieve higher efficiencies and higher switching frequencies than is possible with silicon (Si) power MOSFETs. With discrete eGaN® FETs capable of switching at slew rates beyond 40V/ns, the system performance is greatly impacted by aspects outside the power devices, such as high speed gate drivers and printed...
The 15 kV SiC N-IGBT is the state-of-the-art high voltage power semiconductor device developed by Cree. The SiC IGBT is exposed to a peak stress of 10–11 kV in power converter systems, with punch-through turn-on dv/dt over 100 kV/μs and turn-off dv/dt about 35 kV/μs. Such high dv/dt requires ultralow coupling capacitance in the dc-dc isolation stage of the gate driver for maintaining fidelity of the...
Typical AC traction drive electrical components include the motor, inverter, dc link and filter elements. Drive design parameters and component values are chosen to minimize system-level drive losses. This paper presents a systematic approach for selecting rotor flux magnitude and passive component values in an induction motor drive using a comprehensive loss-minimization algorithm. The total losses...
In this paper, a current-fed asymmetric full-bridge LLCC resonant converter is proposed for the dielectric barrier discharge (DBD) applied to the surface treatment. Compared with a previous design, the asymmetric structure with no front-end buck circuit and only two reverse-voltage blocking diodes is adopted to reduce the component count and circuit complexity. Moreover, the phase-shift control of...
GaN HEMT devices exhibit improved performance in terms of switching speed and reduced on-state resistance, especially if low-voltage and high-frequency conditions are considered. In this paper, a high-power density quasi-resonant converter is proposed in order to improve both the maximum output power and the maximum operating frequency with GaN HEMT devices. Since the proposed converter operates as...
There is a current movement within the scientific, engineering, educational and entrepreneurial communities called “making.” Most electronics makers are familiar with hardware offerings Arduino™ and Xbee™, which are user friendly rapid prototyping platforms for microcontrollers and wireless networks respectively; however an equivalent solution for power electronics is not available at comparable cost...
LLC Resonant converters have been popular in recent years by providing highly-efficient, compact isolated power conversion for numerous applications. 48V to 12V and 400V to 12V step-down isolated converters are often required in server, telecom and automotive applications. While the switching losses in LLC converters are eliminated due to zero-voltage switching, the primary-side switch output capacitance...
In this paper, the common mode (CM) EMI noise characteristic of three popular topologies of resonant converter (LLC, CLL and LCL) is analyzed. The comparison of their EMI performance is provided. A state-of-art LLC resonant converter with matrix transformer is used as an example to further illustrate the CM noise problem of resonant converters. The CM noise model of LLC resonant converter is provided...
Transformer parameters such as leakage inductance and self-capacitance are rarely calculated in advance during the design phase, because of the complexity and huge analytical error margins caused by practical winding implementation issues. Thus, choosing one transformer architecture over another for a given design is usually based on experience or a trial and error approach. This work presents equations...
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