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In photovoltaic (PV) systems consisting of multiple strings connected in parallel, partial shading even on a single PV panel would hinder a whole string from generating power, significantly deteriorating energy yield of systems. To maximize energy yield from strings, PV systems require not only voltage equalizers to preclude partial shading issues but also converters for string control (or MPPT operation),...
A semi-active hybrid energy storage system, consisting of a Li-ion battery pack, dc/dc converter, and Li-ion capacitor pack is developed for a range extended plug-in vehicle application. The vehicle has a series-parallel drivetrain with two electric motors, a gas engine, gearbox, and a clutch to allow the engine to run decoupled from the gearbox in range extending mode. The peak dc electrical requirement...
Wireless charger for Electric Vehicles (EVs) is an off-line application and it needs power factor correction (PFC) function, which usually consists of a front-end boost PFC and a cascaded DC/DC converter. Z-source resonant converter (ZSRC), a single-stage solution with low cost and high efficiency, was proposed for EV wireless charger lately. The Z-source capacitors in the ZSRC are designed to absorb...
This paper introduces a large air-gap capacitive wireless power transfer (WPT) system for electric vehicle charging that achieves a power transfer density exceeding the state-of-the-art by more than a factor of four. This high power transfer density is achieved by operating at a high switching frequency (6.78 MHz), combined with an innovative approach to designing matching networks that enable effective...
An extended-duty-ratio (EDR) boost is a unique combination of interleaved, multiphase boost converter and switched capacitor configuration that achieves a high converter gain without increased switching losses as most of the switches experience only fractions of the output voltage depending on the number of phases M. For an M-phase EDR converter with different combinations of the operating modes,...
An inverter prototype, 2.9 L in size, for driving an 80-kW motor was fabricated, and its common mode current was reduced by up to 15 dB compared with that of a basic inverter. In this paper, the two main features of the electromagnetic interference (EMI) reduction structure are described. The first feature is that the P and N bus bars of the inverter prototype are designed to avoid a differential...
As a new actuator driven by Ampere force, Electro Magnetic Force driving Actuator (EMFA) is applicable to medium-high-voltage system with powerful output force, long stoke, simple structure and high reliability. In the paper, a new type of EMFA for 126kV VCB with single break is proposed on the basis of the mature manufacturing technology of 126kV vacuum interrupter. The model of EMFA is established...
Aiming at the phenomenon that the arcing time is different when SF6 circuit breaker interrupts capacity current under the conditions of positive and negative polarity. So the capacity current breaking test by SF6 circuit breaker is used to study it, which can provide reference for the optimization of SF6 arc extinguishing chamber. In this paper, the interrupter structure of test prototype is introduced...
In this work, a novel dc-dc converter topology, an adaptation of the Hybrid Switched Capacitor Circuit (HSCC), is considered for use in high-gain, high voltage applications that also require high efficiency and superior power density. In particular, a bipolar HSCC design is described, and a candidate control methodology is set forth and developed analytically. The converter performance is demonstrated...
Researches on electromagnetic repulsion mechanisms are drawing more and more attention globally. The objective of this paper is to develop an electromagnetic repulsion mechanism for a 40.5 kV vacuum circuit breaker and then to make an optimization. Design of experiments (DOE) method are used to screen the prominent factors. Result shows that three impact factors are the prominent factors, which include...
A start up method is presented, which is suitable for a single-phase single-stage full-bridge boost PFC converter with multiple-level clamp circuits. In this converter, the flyback inductors are added to the boost inductor and the coupled inductor respectively. When starting, it operates in flyback mode, and the output capacitor is charged by the adding inductors. Operational principle of this converter...
Photovoltaic (PV) systems consist of multiple dc-dc converters, including a front-end converter for PV string control, a bidirectional converter for battery regulation, and voltage equalizer to preclude partial-shading issues, and hence they are prone to be complex and costly. To cope with this issue, this paper proposes the PWM- and PFM-controlled switched capacitor converter (SCC)-based multiport...
This paper introduces an architecture and design for high resolution, high linearity Nyquist rate SAR ADCs requiring only a single simple calibration at startup. The proposed architecture benefits from an intrinsically linear 1.5 bit ΣΔ DAC to resolve the fine bits of the SAR ADC after a coarse conversion phase with a monotonically switched capacitive DAC. The ΣΔ DAC is also used for a single shot...
This paper describes two methods intended to obtain the coupling factor k of an inductive coupling stage constructed to transfer power to a load in a 2-kW experimental prototype designed for wireless battery charging of electric vehicles. The air gap between the primary and the secondary windings of the inductive coupling is set to 125 mm. The first approach, purely analytical, relies on Neumann's...
A digital-analog hybrid neural network exploits efficient analog computation and digital intra-network communication for feature extraction and classification. Taking advantage of the inherently low SNR requirements of the Locally Competitive Algorithm (LCA), the internally-analog neuron is 3x smaller and 7.5x more energy efficient than an equivalent digital design. This work demonstrates large-scale...
The article deals with a microstrip high-pass filter with two identical spiral resonators and two interdigitated capacitors located on the side of the substrate that is opposite to resonators. The filter is installed on the substrate with dielectric conductivity ε=4.4 and thickness h=1.5 mm. The filter has cutoff frequency 1 GHz and compact sizes 60 × 40 = 2400 mm2. The structure was created with...
The PWM half-bridge zeta (HBZ) converter is one of the most attractive dc-dc converters for wide-input-voltage applications due to its extended duty ratio above 0.5 and soft switching capability. However, it suffers from large peak current stress in the primary and secondary devices. To relieve these drawbacks, a PWM resonant HBZ converter is proposed. The proposed converter can effectively reduce...
Conventional photovoltaic (PV) systems using a micro-inverter tend to be complex and costly as three separate converters (i.e., a boost converter, inverter, and voltage equalizer to prevent partial shading issues) are necessary. This paper proposes a novel micro-inverter integrating a voltage equalizer to achieve not only system-level but also circuit-level simplifications. The voltage can be boosted...
The Y-source converter is one of the recent proposed impedance source converters. It has some advantages as having a high voltage gain between the input and output voltage sides using very small duty cycle ratios. For many applications, the input voltage needs to be boosted to higher output voltage, such as for fuel cell, battery electric vehicles and renewable energy applications. Understanding the...
In this paper, a novel Capacitance-to-Frequency Converter (CFC) with high linearity is presented. In the CFC, the capacitance to frequency conversion is obtained using a negative feedback mechanism. In this feedback, the frequency of the output controls the current delivered by a Switched-Capacitor (SC) network such that the difference error is automatically minimized. The proposed converter uses...
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