摘要 :
One major challenge regarding series-connected IGBTs is the protection against over-current faults, besides voltage balancing among the devices. In this paper, an over-current protection method based on desaturation detection is p...
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One major challenge regarding series-connected IGBTs is the protection against over-current faults, besides voltage balancing among the devices. In this paper, an over-current protection method based on desaturation detection is proposed for series-connected IGBTs which are controlled by a digital signal processor (DSP) to realize voltage sharing. A hardware test platform was built, which is capable of generating current spikes of various magnitudes and durations. Different aspects of system behavior under fault are characterized to provide design guidance to ensure safety. Finally, experimental results show that the proposed series IGBT control can achieve voltage balance without slowing down the switching transients. Additionally, the desaturation circuit can detect an over-current in less than 1 μs. Furthermore, with the proposed protection method, the fault can be fully cleared depending solely on voltage balancing circuits, while maintaining voltage balance during the entire process.
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摘要 :
One major challenge regarding series-connected IGBTs is the protection against over-current faults, besides voltage balancing among the devices. In this paper, an over-current protection method based on desaturation detection is p...
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One major challenge regarding series-connected IGBTs is the protection against over-current faults, besides voltage balancing among the devices. In this paper, an over-current protection method based on desaturation detection is proposed for series-connected IGBTs which are controlled by a digital signal processor (DSP) to realize voltage sharing. A hardware test platform was built, which is capable of generating current spikes of various magnitudes and durations. Different aspects of system behavior under fault are characterized to provide design guidance to ensure safety. Finally, experimental results show that the proposed series IGBT control can achieve voltage balance without slowing down the switching transients. Additionally, the desaturation circuit can detect an over-current in less than 1 μs. Furthermore, with the proposed protection method, the fault can be fully cleared depending solely on voltage balancing circuits, while maintaining voltage balance during the entire process.
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摘要 :
One major challenge regarding series-connected IGBTs is the protection against over-current faults, besides voltage balancing among the devices. In this paper, an over-current protection method based on desaturation detection is p...
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One major challenge regarding series-connected IGBTs is the protection against over-current faults, besides voltage balancing among the devices. In this paper, an over-current protection method based on desaturation detection is proposed for series-connected IGBTs which are controlled by a digital signal processor (DSP) to realize voltage sharing. A hardware test platform was built, which is capable of generating current spikes of various magnitudes and durations. Different aspects of system behavior under fault are characterized to provide design guidance to ensure safety. Finally, experimental results show that the proposed series IGBT control can achieve voltage balance without slowing down the switching transients. Additionally, the desaturation circuit can detect an over-current in less than 1 μs. Furthermore, with the proposed protection method, the fault can be fully cleared depending solely on voltage balancing circuits, while maintaining voltage balance during the entire process.
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摘要 :
Describes a topological matrix decomposition method for ladder based transconductor-C filter design and for an equally terminated ladder prototype filter this gives a realisation in which all the transconductance values are identi...
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Describes a topological matrix decomposition method for ladder based transconductor-C filter design and for an equally terminated ladder prototype filter this gives a realisation in which all the transconductance values are identical. Both conventional and low-impedance input transconductor sections can be utilised in filter and equaliser design. Fewer transconductors are required by the topological decomposition method than by the other ladder based transconductor-capacitor design techniques. The low sensitivity properties common to all the ladder based methods are preserved and comparative sensitivity studies including cascade biquad circuits are shown. The problem of realising such ladder based structures with a canonic number of transconductors is addressed.
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Modular multilevel converters (MMC) and series-connected IGBTs are two promising solutions to high-voltage dc (HVDC) transmission. It has been shown that, when integrated with series IGBTs, a MMC can benefit from a reduced number ...
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Modular multilevel converters (MMC) and series-connected IGBTs are two promising solutions to high-voltage dc (HVDC) transmission. It has been shown that, when integrated with series IGBTs, a MMC can benefit from a reduced number of sub-modules (SMs), simpler control, and improved reliability. In this paper, a MMC prototype, with the capability to integrate series IGBTs to replace single IGBTs in the sub-modules, is designed and developed. The MMC control is realized with a real-time simulator for versatile software implementation. The voltage sharing among the series IGBTs is regulated locally without the intervention of the central control. Furthermore, voltage balance under bi-directional current through the series strings is achieved. Experiments were conducted where individual IGBTs in one sub-module were replaced with a series of three IGBTs each. The results verify that the MMC is functional since the local series IGBT control and the MMC central control are independent. It is also verified that both series strings can maintain voltage balance at the same time even though the string currents shift directions.
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摘要 :
Modular multilevel converters (MMC) and series-connected IGBTs are two promising solutions to high-voltage dc (HVDC) transmission. It has been shown that, when integrated with series IGBTs, a MMC can benefit from a reduced number ...
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Modular multilevel converters (MMC) and series-connected IGBTs are two promising solutions to high-voltage dc (HVDC) transmission. It has been shown that, when integrated with series IGBTs, a MMC can benefit from a reduced number of sub-modules (SMs), simpler control, and improved reliability. In this paper, a MMC prototype, with the capability to integrate series IGBTs to replace single IGBTs in the sub-modules, is designed and developed. The MMC control is realized with a real-time simulator for versatile software implementation. The voltage sharing among the series IGBTs is regulated locally without the intervention of the central control. Furthermore, voltage balance under bi-directional current through the series strings is achieved. Experiments were conducted where individual IGBTs in one sub-module were replaced with a series of three IGBTs each. The results verify that the MMC is functional since the local series IGBT control and the MMC central control are independent. It is also verified that both series strings can maintain voltage balance at the same time even though the string currents shift directions.
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摘要 :
Modular multilevel converters (MMC) and series-connected IGBTs are two promising solutions to high-voltage dc (HVDC) transmission. It has been shown that, when integrated with series IGBTs, a MMC can benefit from a reduced number ...
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Modular multilevel converters (MMC) and series-connected IGBTs are two promising solutions to high-voltage dc (HVDC) transmission. It has been shown that, when integrated with series IGBTs, a MMC can benefit from a reduced number of sub-modules (SMs), simpler control, and improved reliability. In this paper, a MMC prototype, with the capability to integrate series IGBTs to replace single IGBTs in the sub-modules, is designed and developed. The MMC control is realized with a real-time simulator for versatile software implementation. The voltage sharing among the series IGBTs is regulated locally without the intervention of the central control. Furthermore, voltage balance under bi-directional current through the series strings is achieved. Experiments were conducted where individual IGBTs in one sub-module were replaced with a series of three IGBTs each. The results verify that the MMC is functional since the local series IGBT control and the MMC central control are independent. It is also verified that both series strings can maintain voltage balance at the same time even though the string currents shift directions.
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摘要 :
Relex studio 2009 is applied in this paper to analyze the reliability problems of automotive braking system. Firstly, the components of braking system are analyzed and the reliability model is established. Secondly, the Fault Tree...
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Relex studio 2009 is applied in this paper to analyze the reliability problems of automotive braking system. Firstly, the components of braking system are analyzed and the reliability model is established. Secondly, the Fault Tree Analysis (FTA) is done both qualitatively and quantitatively, which helps identify the weakness to avoid accidents occurrence and minimize losses. Thirdly, the failure modes and effects analysis (FMEA) is processed. Significant data are collected including failure rate, the evaluation of failures paths and the Risk Priority Number (RPN) values. Some important conclusions are presented and serve as instructions to the braking system design.
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摘要 :
Relex studio 2009 is applied in this paper to analyze the reliability problems of automotive braking system. Firstly, the components of braking system are analyzed and the reliability model is established. Secondly, the Fault Tree...
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Relex studio 2009 is applied in this paper to analyze the reliability problems of automotive braking system. Firstly, the components of braking system are analyzed and the reliability model is established. Secondly, the Fault Tree Analysis (FTA) is done both qualitatively and quantitatively, which helps identify the weakness to avoid accidents occurrence and minimize losses. Thirdly, the failure modes and effects analysis (FMEA) is processed. Significant data are collected including failure rate, the evaluation of failures paths and the Risk Priority Number (RPN) values. Some important conclusions are presented and serve as instructions to the braking system design.
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Molybdenum disulfide/carbon (MoS_2/C) submicrosphere was synthesized through a PVP-assisted hydrothermal reaction of sodium molybdate and thiourea (CS(NH_2)_2), The structure and morphology of MoS_2 composites were characterized b...
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Molybdenum disulfide/carbon (MoS_2/C) submicrosphere was synthesized through a PVP-assisted hydrothermal reaction of sodium molybdate and thiourea (CS(NH_2)_2), The structure and morphology of MoS_2 composites were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The lithium intercalation/de-intercalation behavior of as-prepared MoS_2 submicrosphere electrode was also investigated. It was found that the MoS_2 submicrosphere electrode exhibited the best electrochemical performance, retaining a specific capacity of 575 mAh/g after 100 cycles, with higher first charge capacity (1037 mAh/g), which was better than those of the MoS_2 prepared without PVP.
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