77 research outputs found
A New Evaluation Circuit with a Low-Voltage Inverter Intended for Capacitors Used in a High-power Three-phase Inverter
DC-link capacitors in power electronic converters are a major constraint on improvement of power density as well as reliability. Evaluation of the dc-link capacitors in terms of power loss, ageing, and failure rate will play an important role in design stages of the next-generation power converters. This paper proposes a new evaluation circuit for dc-link capacitors used in a high-power three-phase inverter, which is intended for testing power loss, failure rate, ageing, and so on. The evaluation circuit produces a practical ripple current waveform and a dc bias voltage into a capacitor under test, in which the ripple current is equivalent to that generated by the three-phase inverter on the dc link. The evaluation circuit employs a full-scale current-rating and downscaled voltage-rating inverter for producing the ripple current, so that the power rating of the evaluation circuit is much smaller than that of a full-scale current rating and full-scale voltage rating inverter.2016 IEEE Applied Power Electronics Conference and Exposition (APEC 2016), March 20-24, 2016, Long Beach, California, US
A New Evaluation Circuit with a Low-Voltage Inverter Intended for Capacitors Used in a High-power Three-phase Inverter
016 IEEE Applied Power Electronics Conference and Exposition (APEC 2016), March 20-24, 2016, Long Beach, California, USADC-link capacitors in power electronic converters are a major constraint on improvement of power density as well as reliability. Evaluation of the dc-link capacitors in terms of power loss, ageing, and failure rate will play an important role in design stages of the next-generation power converters. This paper proposes a new evaluation circuit for dc-link capacitors used in a high-power three-phase inverter, which is intended for testing power loss, failure rate, ageing, and so on. The evaluation circuit produces a practical ripple current waveform and a dc bias voltage into a capacitor under test, in which the ripple current is equivalent to that generated by the three-phase inverter on the dc link. The evaluation circuit employs a full-scale current-rating and downscaled voltage-rating inverter for producing the ripple current, so that the power rating of the evaluation circuit is much smaller than that of a full-scale current rating and full-scale voltage rating inverter
Design and Analysis of a New Evaluation Circuit for Capacitors Used in a High-Power Three-Phase Inverter
DC-link capacitors in power electronic converters are a major constraint on improvement of power density as well as reliability. Evaluation of the dc-link capacitors in terms of power loss, ageing, and failure rate will play an important role in design stages of the next-generation power converters. This paper proposes a new evaluation circuit for dc-link capacitors used in a high-power three-phase inverter, which is intended for testing power loss, failure rate, ageing, and so on. The evaluation circuit produces a practical ripple current waveform and a dc bias voltage into a capacitor under test, in which the ripple current is equivalent to that generated by the three-phase inverter on the dc link. The evaluation circuit employs a full-scale current-rating and downscaled voltage-rating inverter for producing the ripple current, so that the power rating of the evaluation circuit is much smaller than that of a full-scale current-rating and full-scale voltage-rating inverter. Theoretical analysis and simulated results verify the effectiveness of new evaluation circui
A Simplified Model for the Battery Ageing Potential Under Highly Rippled Load for Battery Management and Active Degradation Control
Whereas in typical standardized tests batteries are almost exclusively loaded
with constant current or relatively slowly changing cycles, real applications
involve rapid load ripple, which do not contribute to the net energy. The trend
to reduced filter capacitors and even dynamically reconfigurable batteries
further increases the ripple. The influence of rippled load on lithium
batteries is therefore receiving increased attention. According to recent
studies, accelerated ageing strongly depends on the frequency of the ripple. We
use electrochemical models to derive a highly simplified regression model that
catches the asymptotic behavior and allows parameter identification and
calibration to specific cells. The model allows quantitative monitoring of the
additional ageing due to ripple current in battery management systems.
Furthermore it enables active control of the ageing potential by influencing
the frequency content in modern battery systems, such as reconfigurable
batteries.Comment: 7 page
A comparison of online electrochemical spectroscopy impedance estimation of batteries
This paper compares methods of undertaking on-line electrochemical impedance spectroscopy that have been published in literature. This work describes the different published methodologies and sorts
these into categories. The paper looks at the theoretical analysis of the circuits and control techniques and follows up with simulation and/or experimental studies of these methods. This work focuses on battery systems
Impact of Partial Power Processing Dual-Active Bridge Converter on Li-ion Battery Storage Systems
Partial Power Processing converters (PPPCs) provide economical and highly efficient solutions to integrate battery energy storages systems (BSSs) into DC grids. Beside these significant advantages, direct connection of the batteries by PPPCs to DC grids imposes challenges on the operation of batteries which need more evaluation. DC grid imperfections such as harmonics and faults may directly propagate into BSS and result in battery capacity fade acceleration and/or battery failure. In this paper, low voltage (LV) grid imperfection impacts are compared for conventional dual-active bridge (DAB) and Partial Power Processing DAB (PPP-DAB) converters. Both theoretical and experimental studies are carried out. The obtained results show that PPP-DAB exposes the BSS to high amount of current harmonics and safety issues
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