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A low quiescent current low-dropout regulator (LDO) applied in energy harvest system is presented in this paper. With super-source follower, the LDO has only one pole within loop unity gain bandwidth. And current buffer compensation is utilized to maintain the phase margin under the full range of load current. In order to decrease the power dissipation on the resistors of voltage divider, the resistors...
A hybrid Lyapunov control for a flying capacitor multicellular converter is presented. This control law is based on the Port-Hamiltonian (PH) formalism of power converters and allows to enhance load current quality and reduce switching losses. The proposed control is applied to a three-cell multicellular converter. A procedure for selecting the best weighting parameters in the control law according...
Grid-connected inverter is an important part of the grid-connected system. Compared with the traditional L or LC filter, LCL filter has a better high-frequency harmonic attenuation performance. However, LCL filter has resonant peak, which has a great influence on the stability of the system. This paper first analyzes the effect of passive damping method on the resonance peak; then a double closed-loop...
This paper proposes and designs a switching cell using paralleled gallium nitride (GaN) high-electron-mobility transistor (HEMTs) in the minimized, symmetric power and gate loops. Based on the design, 1Ω gate resistor was successfully applied to speed up the switching transient. The switching cell can be easy to replace on the mother board thanks to the pluggable connector and the cell owns unique...
A capacitor-isolated structure with brightness and color controlling for multicolor LED strings is proposed. Such structure mainly plays the role of current-balancing and color mixing. Moreover, in order to decrease the color shift, the current amplitude of LED strings is controlled constant. The luminous flux and chromaticity coordinates are regulated through controlling the sum and ratio of duty...
An isolated high-voltage high-frequency pulsed power converter for non-thermal plasma ozone generation is proposed in this paper. With an input of 500 VDC, the output pulsed voltage can reach −12 kV through the inductor-capacitor resonance together with a step-up transformer. The pulse duration is designed as 1.66 μs. An anti-series connected switch pair at the input terminal enables the energy stored...
Regenerative drives, also known as four-quadrant drives are integral part of many industrial applications ranging from wind power generation, elevators, escalators, pump jacks used in oil fields to centrifuges, etc. All regenerative converters need passive LCL filters to filter out PWM frequency components. One disadvantage of using an input LCL filter in front of regenerative converters is that they...
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...
This paper addresses the replacement of enhancement mode Si IGBTs with depletion mode SiC vertical junction field effect transistors (VJFETs) in a commercial motor drive in current production. A Yaskawa A1000 CIMR-AU4A0088FAA motor drive was analyzed and found to have reliability and safety features that can be exploited to introduce normally on SiC transistors with no loss in safety or reliability...
This paper presents a CMOS circuit able to magnify the value of a reference bias current. The magnification factor can be programmed via a 10bit interface in the 1–1024 range. A time domain technique is used to compare a replica of the output current and a replica of the reference current. A negative feedback circuit minimizes the errors up to 1%.
One of the most important goals for this study is to reveal an effective way to develop systematically the state equations that define the analog circuits (linear, non-linear, timeinvariant etc.) with excess elements. These equations can be depicted in various forms, like symbolic form, numeric-symbolic form, numeric-normal form. At the beginning, we designed the calculation method and afterwards...
The control of the active front-end rectifier of the three-stage solid-state transformer (SST) system is addressed in this paper. A comprehensive precharging sequence is introduced for the active front-end rectifier of the SST to limit the inrush current during the start-up process to its nominal current. The proposed precharging algorithm consists of two phases, passive and active precharging. The...
In power electronics, the compensators are required to shape the loop gain of the transfer function. The purpose of shaping the loop gain transfer function is to obtain a desired crossover frequency, phase margin and gain margin. The compensators can be constructed by the operational amplifier (op amp). There are a few commonly used compensators built up by the op amp, to be discussed herein. By using...
In this paper, a single-input dual-output rectifier for piezoelectric energy harvesting is proposed. An energy harvester often needs to feed multiple devices. The proposed rectifier provides dual outputs and the number of circuit components in the current path is reduced compared with conventional circuits. Furthermore, with this rectifier, the internal capacitance of the piezoelectric element is...
Counterfeiting or surreptitious modification of electronic systems is of increasing concern, particularly for critical infrastructure and national security systems. Such systems include avionics, medical devices, military systems, and utility infrastructure. We present experimental results from an approach to uniquely identify printed circuit boards (PCBs) on the basis of device unique variations...
This paper presents a hybrid-powered wireless sensor node using enhanced triboelectric nanogenerator (TENG) as both energy harvester and air-flow sensor and two 11 cm2 solar panels as extra power supply. A low budget commercial RF microcontroller is included for data conversion, signal processing and wireless transmission. The method of flow-rate detection depends on the vibration frequency of the...
We experimentally show the performance of a Virtual Infinite Capacitor (VIC) in suppressing the voltage ripple. VIC mainly uses a bi-directional DC-DC converter with only two small capacitors inside to mimic the filtering process of a large capacitor by applying suitable control algorithms. It was firstly proposed in [1], [2] and then improved in [3] in both control algorithms and circuit designs...
We propose a novel class-AB second-generation Current Conveyor (CCII) based on the class-AB Flipped Voltage Follower (FVF) topology, and compare it with a class-A CCII based on the conventional FVF. The AB-FVF is capable of driving larger capacitive loads, showing faster settling. Furthermore, it can drive the Z output with currents larger than the biasing ones, improving power efficiency. A modification...
Using current conveyors, we present six different current-mode circuits approximating fractional-order low-pass transfer function. Proposed circuits always use four active elements, three capacitors and seven or five resistors, whereas all are grounded. We show that the usage of only eight passive elements is sufficient to approximate a (1 + α)-order system (0 < α < 1) and can even provide better...
This paper presents a trimming correction technique to calibrate the offset in capacitive readout circuits of MEMS sensors. The technique relies on a N-bit digital voltage divider which allows to implement an equivalent variable capacitor with sub-femto Farad step variations. To reduce area occupation, a hybrid approach entailing both resistive and capacitor voltage dividers is introduced. Design...
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