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Negative impedance converter

About: Negative impedance converter is a research topic. Over the lifetime, 5801 publications have been published within this topic receiving 87636 citations.


Papers
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Journal ArticleDOI
TL;DR: In this article, a new pulsewidth modulation (PWM) was proposed for the complete control of the neutral point voltage in the three-level three-phase neutral-point-clamped (NPC) direct current-alternating current (dc-ac) converter.
Abstract: This paper presents a new pulsewidth modulation (PWM) for the complete control of the neutral-point voltage in the three-level three-phase neutral-point-clamped (NPC) direct current-alternating current (dc-ac) converter. The balancing of the neutral-point voltage is achieved over the full range of converter output voltages and for all load power factors with the minimum output voltage distortion at around the switching frequency. The simple phase duty-ratio expressions in d-q-0 coordinates that define this modulation are presented. The performance of this modulation approach and its benefits over other previously proposed solutions are verified through simulation and experiments.

133 citations

Patent
03 Dec 2003
TL;DR: In this article, a user-programmable control circuit for a power converter to automatically switch the converter into BURST mode when load current demand is low is presented. But it is not shown how the converter can be switched to BURST when the signal indicative of the average monitored output current decreases below a userprogrammable threshold.
Abstract: The present invention comprises a user-programmable control circuit for use in a power converter to automatically transition the converter into BURST mode when load current demand is low. The control circuit senses load current demand by monitoring the output current of the converter, and generating a signal representative of the monitored output current. The control circuit may automatically transition the converter into BURST mode when the signal indicative of the average monitored output current decreases below a user-programmable threshold. BURST mode may increase overall converter efficiency by turning OFF a plurality of electronic components, and maintaining the converter's output voltage at a regulated level by energy stored in an output capacitor.

132 citations

Journal ArticleDOI
TL;DR: The experimental results validate the feasibility of the proposed topology and its suitability for fuel cell vehicles.
Abstract: An input-parallel, output-series dc–dc Boost converter with a wide input voltage range is proposed in this paper. An interleaved structure is adopted in the input side of this converter to reduce input current ripple. Two capacitors are connected in series on the output side to achieve a high voltage gain. The operating principles and steady-state characteristics of the converter are presented and analyzed in this paper. A 400 V/1.6 kW prototype has been created which demonstrates that a wide range of voltage gain can be achieved by this converter and it is shown that the maximum efficiency of the converter is 96.62% and minimum efficiency is 94.14%. The experimental results validate the feasibility of the proposed topology and its suitability for fuel cell vehicles.

131 citations

Journal ArticleDOI
TL;DR: In this paper, a non-isolated, high boost ratio hybrid transformer dc-dc converter with applications for low-voltage renewable energy sources was proposed, which utilizes a hybrid transformer to transfer the inductive and capacitive energy simultaneously.
Abstract: This paper presents a nonisolated, high boost ratio hybrid transformer dc–dc converter with applications for low-voltage renewable energy sources. The proposed converter utilizes a hybrid transformer to transfer the inductive and capacitive energy simultaneously, achieving a high boost ratio with a smaller sized magnetic component. As a result of incorporating the resonant operation mode into the traditional high boost ratio pulsewidth modulation converter, the turn-off loss of the switch is reduced, increasing the efficiency of the converter under all load conditions. The input current ripple and conduction losses are also reduced because of the hybrid linear-sinusoidal input current waveforms. The voltage stresses on the active switch and diodes are maintained at a low level and are independent of the changing input voltage over a wide range as a result of the resonant capacitor transferring energy to the output of the converter. The effectiveness of the proposed converter was experimentally verified using a 220-W prototype circuit. Utilizing an input voltage ranging from 20 to 45 V and a load range of 30–220 W, the experimental results show system of efficiencies greater than 96% with a peak efficiency of 97.4% at 35-V input, 160-W output. Due to the high system efficiency and the ability to operate with a wide variable input voltage, the proposed converter is an attractive design for alternative low dc voltage energy sources, such as solar photovoltaic modules and fuel cells.

131 citations

Journal ArticleDOI
TL;DR: In this article, an improved power system impedance measurement technique is introduced, which injects a short duration current spike into the supply, and derives the impedance from the measured current and voltage.
Abstract: This paper introduces an improved power system impedance measurement technique. The technique injects a short duration current spike into the supply, and derives the impedance from the measured current and voltage. The method is shown to work extremely well under most conditions, by experimental evaluation using a 45-kVA laboratory prototype. Degradation is observed when a voltage-source-type power-electronic load is connected directly to the measurement equipment. An alternative signal processing strategy, based upon the Prony method is proposed to improve the estimation under these conditions. This method also reduces the overall transient data capture time, thus allowing a faster, online calculation of the impedance.

128 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202330
2022104
2021120
2020131
2019134
2018155