Energetic Semiconductor bridge(ESCB)based on reactive multilayered films(RMFs)has a promising application in the miniature and intelligence of initiator and pyrotechnics device.Understanding the ignition enhancement m...Energetic Semiconductor bridge(ESCB)based on reactive multilayered films(RMFs)has a promising application in the miniature and intelligence of initiator and pyrotechnics device.Understanding the ignition enhancement mechanism of RMFs on semiconductor bridge(SCB)during the ignition process is crucial for the engineering and practical application of advanced initiator and pyrotechnics devices.In this study,a one-dimensional(1D)gas-solid two-phase flow ignition model was established to study the ignition process of ESCB to charge particles based on the reactivity of Al/MoO_(3) RMFs.In order to fully consider the coupled exothermic between the RMFs and the SCB plasma during the ignition process,the heat release of chemical reaction in RMFs was used as an internal heat source in this model.It is found that the exothermal reaction in RMFs improved the ignition performance of SCB.In the process of plasma rapid condensation with heat release,the product of RMFs enhanced the heat transfer process between the gas phase and the solid charge particle,which accelerated the expansion of hot plasma,and heated the solid charge particle as well as gas phase region with low temperature.In addition,it made up for pressure loss in the gas phase.During the plasma dissipation process,the exothermal chemical reaction in RMFs acted as the main heating source to heat the charge particle,making the surface temperature of the charge particle,gas pressure,and gas temperature rise continuously.This result may yield significant advantages in providing a universal ignition model for miniaturized ignition devices.展开更多
In this paper, the zero voltage switching (ZVS) region of a dual active bridge (DAB) converter with wide band-gap (WBG) power semiconductor device is analyzed. The ZVS region of a DAB converter varies depending on out...In this paper, the zero voltage switching (ZVS) region of a dual active bridge (DAB) converter with wide band-gap (WBG) power semiconductor device is analyzed. The ZVS region of a DAB converter varies depending on output power and voltage ratio. The DAB converters operate with hard switching at light loads, it is difficult to achieve high efficiency. Fortunately, WBG power semiconductor devices have excellent hard switching characteristics and can increase efficiency compared to silicon (Si) devices. In particular, WBG devices can achieve ZVS at low load currents due to their low parasitic output capacitance (C<sub>o,tr</sub>) characteristics. Therefore, in this paper, the ZVS operating resion is analyzed based on the characteristics of Si, silicon carbide (SiC) and gallium nitride (GaN). Power semiconductor devices. WBG devices with low C<sub>o,tr</sub> operate at ZVS at lower load currents compared to Si devices. To verify this, experiments are conducted and the results are analyzed using a 3 kW DAB converter. For Si devices, ZVS is achieved above 1.4 kW. For WBG devices, ZVS is achieved at 700 W. Due to the ZVS conditions depending on the switching device, the DAB converter using Si devices achieves a power conversion efficiency of 91% at 1.1 kW output. On the other hand, in the case of WBG devices, power conversion efficiency of more than 98% is achieved under 11 kW conditions. In conclusion, it is confirmed that the WBG device operates in ZVS at a lower load compared to the Si device, which is advantageous in increasing light load efficiency.展开更多
The plasma temperature of the semiconductor bridge (SCB) was measured in real-time according to relative intensity ratio of dual lines of atomic emission spectrum.The plasma temperature under different discharge pulse...The plasma temperature of the semiconductor bridge (SCB) was measured in real-time according to relative intensity ratio of dual lines of atomic emission spectrum.The plasma temperature under different discharge pulses and the influence of discharge pulse energy on it were studied.The results show that the plasma peak temperature rises gradually with the increase of initial discharging voltage and charging capacitance.For the capacitance of 22 μF,if the initial discharging voltage increases from 21 V to 63 V,the plasma peak temperature rises from 2 000 K to 6 200 K.For the discharging voltage of 39 V,the peak temperature rises from 2 200 K to 3 800 K when the capacitance increases from 6.8 μF to 100 μF.The change of pulse discharge has a very small effect on the plasma temperature at the late time discharge (LTD).In view of the change of plasma temperature with the pulse energy,the discharging voltage has a greater effect on the plasma temperature than the capacitance.The results provide some experimental basis for the further research on SCB ignition and detonation mechanisms.展开更多
The response characteristics of resistance is observed by the analysis of experimental data of micro scale semiconductor bridge （MSCB） under different voltage inputs. Two critical voltages are found. One is called e...The response characteristics of resistance is observed by the analysis of experimental data of micro scale semiconductor bridge （MSCB） under different voltage inputs. Two critical voltages are found. One is called exploding voltage, above which the MSCB can be melted and vaporized without generating a plasma, and the other is called producing a plasma voltage, above which the MSCB is entirely vaporized, and then the current flows through the vapor producing the plasma. Based on the non Fourier heat conduction theory, the electrothermal energy conversion model is es tablished for the stage from heating to exploding, and then the correlation of MSCB and time is ob tained by graphic calculation. Importantly, the critical exploding voltage and exploding time are also derivate. With the comparison between the analytical result from the theoretical model and that from experimental data, it has been demonstrated that the theoretical model is reasonable and feasible for designing the exploding voltage and exploding time.展开更多
Aiming to know the requirement of penetrating the munition semiconductor bridge detonator under the impact overload environment, the impact overload simulation device and the structural finite element software ANSYS/A...Aiming to know the requirement of penetrating the munition semiconductor bridge detonator under the impact overload environment, the impact overload simulation device and the structural finite element software ANSYS/AUTODYN are used to study the variation of the axial dimension, charge and the chip gap of the semiconductor bridge detonator under the impact overload environment. The typical semiconductor bridge detonator is affected by the acceleration, and the strain increases with the increase of the acceleration. The semiconductor bridge detonator shows axial compression, in which the size becomes smaller, and the structural deformation occurs at the output end of the semiconductor bridge detonator. The typical semiconductor bridge detonator is elastically deformed when the acceleration is less than 40 000 g. When the acceleration is more than40 000 g, the semiconductor bridge detonator housing is plastically deformed. The gap between the drug column and the chip is divided into three stages with the increase of the acceleration. Initially,with the increase of the acceleration, the gap rises rapidly until the acceleration reaches 43 000 g,and when the gap reaches the maximum, the gap decreases rapidly with the increase of the acceleration. When the acceleration reaches 57 000 g, the gap tends to be 0 μm in the initial state, and then the gap does not change with the acceleration to keep tending to 0 μm.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.22275092,52102107 and 52372084)the Fundamental Research Funds for the Central Universities(Grant No.30923010920)。
文摘Energetic Semiconductor bridge(ESCB)based on reactive multilayered films(RMFs)has a promising application in the miniature and intelligence of initiator and pyrotechnics device.Understanding the ignition enhancement mechanism of RMFs on semiconductor bridge(SCB)during the ignition process is crucial for the engineering and practical application of advanced initiator and pyrotechnics devices.In this study,a one-dimensional(1D)gas-solid two-phase flow ignition model was established to study the ignition process of ESCB to charge particles based on the reactivity of Al/MoO_(3) RMFs.In order to fully consider the coupled exothermic between the RMFs and the SCB plasma during the ignition process,the heat release of chemical reaction in RMFs was used as an internal heat source in this model.It is found that the exothermal reaction in RMFs improved the ignition performance of SCB.In the process of plasma rapid condensation with heat release,the product of RMFs enhanced the heat transfer process between the gas phase and the solid charge particle,which accelerated the expansion of hot plasma,and heated the solid charge particle as well as gas phase region with low temperature.In addition,it made up for pressure loss in the gas phase.During the plasma dissipation process,the exothermal chemical reaction in RMFs acted as the main heating source to heat the charge particle,making the surface temperature of the charge particle,gas pressure,and gas temperature rise continuously.This result may yield significant advantages in providing a universal ignition model for miniaturized ignition devices.
文摘In this paper, the zero voltage switching (ZVS) region of a dual active bridge (DAB) converter with wide band-gap (WBG) power semiconductor device is analyzed. The ZVS region of a DAB converter varies depending on output power and voltage ratio. The DAB converters operate with hard switching at light loads, it is difficult to achieve high efficiency. Fortunately, WBG power semiconductor devices have excellent hard switching characteristics and can increase efficiency compared to silicon (Si) devices. In particular, WBG devices can achieve ZVS at low load currents due to their low parasitic output capacitance (C<sub>o,tr</sub>) characteristics. Therefore, in this paper, the ZVS operating resion is analyzed based on the characteristics of Si, silicon carbide (SiC) and gallium nitride (GaN). Power semiconductor devices. WBG devices with low C<sub>o,tr</sub> operate at ZVS at lower load currents compared to Si devices. To verify this, experiments are conducted and the results are analyzed using a 3 kW DAB converter. For Si devices, ZVS is achieved above 1.4 kW. For WBG devices, ZVS is achieved at 700 W. Due to the ZVS conditions depending on the switching device, the DAB converter using Si devices achieves a power conversion efficiency of 91% at 1.1 kW output. On the other hand, in the case of WBG devices, power conversion efficiency of more than 98% is achieved under 11 kW conditions. In conclusion, it is confirmed that the WBG device operates in ZVS at a lower load compared to the Si device, which is advantageous in increasing light load efficiency.
基金Sponsored by the Anhui Province Colleges Young Talents Fund(2011SQRL121)
文摘The plasma temperature of the semiconductor bridge (SCB) was measured in real-time according to relative intensity ratio of dual lines of atomic emission spectrum.The plasma temperature under different discharge pulses and the influence of discharge pulse energy on it were studied.The results show that the plasma peak temperature rises gradually with the increase of initial discharging voltage and charging capacitance.For the capacitance of 22 μF,if the initial discharging voltage increases from 21 V to 63 V,the plasma peak temperature rises from 2 000 K to 6 200 K.For the discharging voltage of 39 V,the peak temperature rises from 2 200 K to 3 800 K when the capacitance increases from 6.8 μF to 100 μF.The change of pulse discharge has a very small effect on the plasma temperature at the late time discharge (LTD).In view of the change of plasma temperature with the pulse energy,the discharging voltage has a greater effect on the plasma temperature than the capacitance.The results provide some experimental basis for the further research on SCB ignition and detonation mechanisms.
基金Supported by the National Basic Research Program of China("973"Program)(51299)
文摘The response characteristics of resistance is observed by the analysis of experimental data of micro scale semiconductor bridge （MSCB） under different voltage inputs. Two critical voltages are found. One is called exploding voltage, above which the MSCB can be melted and vaporized without generating a plasma, and the other is called producing a plasma voltage, above which the MSCB is entirely vaporized, and then the current flows through the vapor producing the plasma. Based on the non Fourier heat conduction theory, the electrothermal energy conversion model is es tablished for the stage from heating to exploding, and then the correlation of MSCB and time is ob tained by graphic calculation. Importantly, the critical exploding voltage and exploding time are also derivate. With the comparison between the analytical result from the theoretical model and that from experimental data, it has been demonstrated that the theoretical model is reasonable and feasible for designing the exploding voltage and exploding time.
文摘Aiming to know the requirement of penetrating the munition semiconductor bridge detonator under the impact overload environment, the impact overload simulation device and the structural finite element software ANSYS/AUTODYN are used to study the variation of the axial dimension, charge and the chip gap of the semiconductor bridge detonator under the impact overload environment. The typical semiconductor bridge detonator is affected by the acceleration, and the strain increases with the increase of the acceleration. The semiconductor bridge detonator shows axial compression, in which the size becomes smaller, and the structural deformation occurs at the output end of the semiconductor bridge detonator. The typical semiconductor bridge detonator is elastically deformed when the acceleration is less than 40 000 g. When the acceleration is more than40 000 g, the semiconductor bridge detonator housing is plastically deformed. The gap between the drug column and the chip is divided into three stages with the increase of the acceleration. Initially,with the increase of the acceleration, the gap rises rapidly until the acceleration reaches 43 000 g,and when the gap reaches the maximum, the gap decreases rapidly with the increase of the acceleration. When the acceleration reaches 57 000 g, the gap tends to be 0 μm in the initial state, and then the gap does not change with the acceleration to keep tending to 0 μm.
