P2-type Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)is considered as a potential cathode material for sodium-ion batteries due to the merits of high voltage,low cost,and air stability.However,the unsatisfied cycling stability and...P2-type Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)is considered as a potential cathode material for sodium-ion batteries due to the merits of high voltage,low cost,and air stability.However,the unsatisfied cycling stability and rate performance caused by the destructive phase transition and side reactions hinder its practical application.Herein,we present a feasible dual strategy of Mg^(2+)doping integrated with ZrO_(2)surface modification for P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2),which can well address the issues of phase transition and side reactions benefitting from the enhanced structural and interfacial stabilities.Specifically,it exhibits a decent cycling stability with a capacity retention of 81.5%at 1 C and promising rate performance with a discharge capacity of 76.6 mA h g^(−1)at 5 C.The in situ X-ray diffraction measurement confirms that the damaged P2-O2 phase transition is suppressed with better reversibility in high-voltage region,whereas the side reactions are inhibited due to the protective ZrO_(2)surfacemodification.Commendably,the full cell achieves an outstanding operating voltage of 3.57 V and a fabulous energy density of 238.91 W h kg^(−1)at 36.73 W kg^(−1),demonstrating great practicability.This work is expected to provide a new insight for designing stable high-voltage cathode materials and high energy density full cells for sodium ion batteries.展开更多
Aiming at resolving the limitation of the speed regulation range of sensorless control technology,a new composite sensorless control strategy is proposed to realize a control method for a permanent magnet synchronous ...Aiming at resolving the limitation of the speed regulation range of sensorless control technology,a new composite sensorless control strategy is proposed to realize a control method for a permanent magnet synchronous motor(PMSM)in full speed range.In the medium-and high-speed range,the improved new sliding mode observer method is used to estimate the motor speed and rotor position information.In the zero and low speed range,in order to avoid the defects of the sliding mode method,the rotating high-frequency voltage signal injection method is used.When switching between low,medium,and high speed,the fuzzy control algorithm is adopted to achieve smooth transitions.The simulation experiment results show that the hybrid mode combining the sliding mode observer and rotating high-frequency voltage injection methods,can effectively reduce the jitter in the algorithm switching process,and realize the smooth control of a PMSM in full speed range.展开更多
A full on-chip CMOS low-dropout（LDO） voltage regulator with high PSR is presented.Instead of relying on the zero generated by the load capacitor and its equivalent series resistance,the proposed LDO generates a zero...A full on-chip CMOS low-dropout（LDO） voltage regulator with high PSR is presented.Instead of relying on the zero generated by the load capacitor and its equivalent series resistance,the proposed LDO generates a zero by voltage-controlled current sources for stability.The compensating capacitor for the proposed scheme is only 0.18 pF,which is much smaller than the capacitor of the conventional compensation scheme.The full on-chip LDO was fabricated in commercial 0.35μm CMOS technology.The active chip area of the LDO（including the bandgap voltage reference） is 400×270μm^2.Experimental results show that the PSR of the LDO is-58.7 dB at a frequency of 10 Hz and-20 dB at a frequency of 1 MHz.The proposed LDO is capable of sourcing an output current up to 50 mA.展开更多
The way of neutral point to earth via full compensation arc suppression coil can solve the problem of residual current compensation in coal mine power network effectively. Based on the analysis on the grounding curren...The way of neutral point to earth via full compensation arc suppression coil can solve the problem of residual current compensation in coal mine power network effectively. Based on the analysis on the grounding current detection results of Xieqiao coal mine, the conclusion that harmonic component of grounding current is dominated by higher harmonics with complex harmonic sources in coal mine power network system was obtained. The influences of harmonic source type and fault point position on harmonic voltage and harmonic current were analyzed theoretically. The influences of earthed fault feeder detection result and the estimation errors of parameters to earth on residual current compensation were analyzed. A new thought of residual current prediction and the selections of model method and control method were proposed on this basis. The simulation results prove that harmonic amplitudes of zero sequence voltage and zero sequence current are determined by harmonic source type as well as fault point position in coal mine power network, and also prove that zero sequence voltage detection can avoid the unstable problem of coal mine power network system caused by undercompensation of capacitive current. Finally, the experimental device of full compensation arc suppression coil is introduced.展开更多
This paper proposes a novel implementation strategy for soft switching PFC whose circuit is simple and can achieve low voltage output directly. The main circuit adopts current mode full-bridge converter and all the po...This paper proposes a novel implementation strategy for soft switching PFC whose circuit is simple and can achieve low voltage output directly. The main circuit adopts current mode full-bridge converter and all the power switches can realize ZCS or ZVS in the way of phase-shlfted control, using the leakage inductance of the transformer, the junction capacitor of the switches and the stored energy of the output capacitor. The problems such as the function of phase-shlfted link in control circuit, the implementation conditions of soft switching and bias restrained are analyzed. The adoption of constant frequency PWM control makes the design of the input and output filter link and the high frequency transformer simple. The transformation ratio regulation so as to achieve low voltage output and electrical insulation can be realized by using high frequency transformer.展开更多
Scaling problems and limitations of conventional silicon transistors have led the designers to exploit novel nano-technologies. One of the most promising and feasible nano-technologies is CNT(Carbon Nanotube) based tr...Scaling problems and limitations of conventional silicon transistors have led the designers to exploit novel nano-technologies. One of the most promising and feasible nano-technologies is CNT(Carbon Nanotube) based transistors. In this paper, a high-speed and energy-efficient CNFET(Carbon Nanotube Field Effect Transistor) based Full Adder cell is proposed for nanotechnology. This design is simulated in various supply voltages, frequencies and load capacitors using HSPICE circuit simulator. Significant improvement is achieved in terms of speed and PDP(Power-Delay-Product) in comparison with other classical and state-of-the-art CMOS and CNFET-based designs, existing in the literature. The proposed Full Adder can also drive large load capacitance and works properly in low supply voltages.展开更多
This paper proposes a zer o current and zero voltage switching (ZCZVS) PWM Boost full bridge (FB) conve rter. With series inductors, the leading switches can realize zero current swit ching (ZCS) in a wide load ra...This paper proposes a zer o current and zero voltage switching (ZCZVS) PWM Boost full bridge (FB) conve rter. With series inductors, the leading switches can realize zero current swit ching (ZCS) in a wide load range using the energy of the output capacitor. Ma king use of parasitic capacitors of the lagging switches and parallel auxiliary i nductance with the primary winding of the transformer, the lagging switches can realize zero voltage switching (ZVS) under any load. Compared with the ZCS PWM Boost FB converter, the new converter has no current duty cycle loss. Operat ional principle and parameter design are analyzed. Experimental results verify the effectiveness of the proposed converter.展开更多
Using composite field arithmetic in Galois field can result in the compact Rijndael S-Box. However, the power con- sumption of this solution is too large to be used in resource-limited embedded systems. A full-custom ...Using composite field arithmetic in Galois field can result in the compact Rijndael S-Box. However, the power con- sumption of this solution is too large to be used in resource-limited embedded systems. A full-custom hardware implementation of composite field S-Box is proposed for these targeted domains in this paper. The minimization of power consumption is implemented by optimizing the architecture of the composite field S-Box and using the pass transmission gate (PTG) to realize the logic functions of S-Box. Power simulations were performed using the netlist extracted from the layout. HSPICE simulation results indicated that the proposed S-Box achieves low power consumption of about 130 μW at 10 MHz using 0.25 μm/2.5 V technology, while the consumptions of the positive polarity reed-muller (PPRM) based S-Box and composite field S-Box based on the conventional CMOS logic style are about 240 μW and 420 μW, respectively. The simulations also showed that the presented S-Box obtains better low-voltage operating property, which is clearly relevant for applications like sensor nodes, smart cards and radio frequency identification (RFID) tags.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:51772284Recruitment Program of Global ExpertsFundamental Research Funds for the Central Universities,Grant/Award Number:WK2060190081。
文摘P2-type Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)is considered as a potential cathode material for sodium-ion batteries due to the merits of high voltage,low cost,and air stability.However,the unsatisfied cycling stability and rate performance caused by the destructive phase transition and side reactions hinder its practical application.Herein,we present a feasible dual strategy of Mg^(2+)doping integrated with ZrO_(2)surface modification for P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2),which can well address the issues of phase transition and side reactions benefitting from the enhanced structural and interfacial stabilities.Specifically,it exhibits a decent cycling stability with a capacity retention of 81.5%at 1 C and promising rate performance with a discharge capacity of 76.6 mA h g^(−1)at 5 C.The in situ X-ray diffraction measurement confirms that the damaged P2-O2 phase transition is suppressed with better reversibility in high-voltage region,whereas the side reactions are inhibited due to the protective ZrO_(2)surfacemodification.Commendably,the full cell achieves an outstanding operating voltage of 3.57 V and a fabulous energy density of 238.91 W h kg^(−1)at 36.73 W kg^(−1),demonstrating great practicability.This work is expected to provide a new insight for designing stable high-voltage cathode materials and high energy density full cells for sodium ion batteries.
基金Supported by the National Natural Science Foundation of China(51907061)Natural Science Foundation of Hunan Province(2018JJ2100,2019JJ50119).
文摘Aiming at resolving the limitation of the speed regulation range of sensorless control technology,a new composite sensorless control strategy is proposed to realize a control method for a permanent magnet synchronous motor(PMSM)in full speed range.In the medium-and high-speed range,the improved new sliding mode observer method is used to estimate the motor speed and rotor position information.In the zero and low speed range,in order to avoid the defects of the sliding mode method,the rotating high-frequency voltage signal injection method is used.When switching between low,medium,and high speed,the fuzzy control algorithm is adopted to achieve smooth transitions.The simulation experiment results show that the hybrid mode combining the sliding mode observer and rotating high-frequency voltage injection methods,can effectively reduce the jitter in the algorithm switching process,and realize the smooth control of a PMSM in full speed range.
基金Project supported by the National Science and Technology Major Project,China(No.2009ZX03007-002).
文摘A full on-chip CMOS low-dropout（LDO） voltage regulator with high PSR is presented.Instead of relying on the zero generated by the load capacitor and its equivalent series resistance,the proposed LDO generates a zero by voltage-controlled current sources for stability.The compensating capacitor for the proposed scheme is only 0.18 pF,which is much smaller than the capacitor of the conventional compensation scheme.The full on-chip LDO was fabricated in commercial 0.35μm CMOS technology.The active chip area of the LDO（including the bandgap voltage reference） is 400×270μm^2.Experimental results show that the PSR of the LDO is-58.7 dB at a frequency of 10 Hz and-20 dB at a frequency of 1 MHz.The proposed LDO is capable of sourcing an output current up to 50 mA.
基金The financial support from the National Natural Science Foundation of China (No. 51107143)
文摘The way of neutral point to earth via full compensation arc suppression coil can solve the problem of residual current compensation in coal mine power network effectively. Based on the analysis on the grounding current detection results of Xieqiao coal mine, the conclusion that harmonic component of grounding current is dominated by higher harmonics with complex harmonic sources in coal mine power network system was obtained. The influences of harmonic source type and fault point position on harmonic voltage and harmonic current were analyzed theoretically. The influences of earthed fault feeder detection result and the estimation errors of parameters to earth on residual current compensation were analyzed. A new thought of residual current prediction and the selections of model method and control method were proposed on this basis. The simulation results prove that harmonic amplitudes of zero sequence voltage and zero sequence current are determined by harmonic source type as well as fault point position in coal mine power network, and also prove that zero sequence voltage detection can avoid the unstable problem of coal mine power network system caused by undercompensation of capacitive current. Finally, the experimental device of full compensation arc suppression coil is introduced.
基金Sponsored by the Power Electronics Science and Education Development Program of Delta Environmental & Educational Foundation ( Grant No.DREO2006010).
文摘This paper proposes a novel implementation strategy for soft switching PFC whose circuit is simple and can achieve low voltage output directly. The main circuit adopts current mode full-bridge converter and all the power switches can realize ZCS or ZVS in the way of phase-shlfted control, using the leakage inductance of the transformer, the junction capacitor of the switches and the stored energy of the output capacitor. The problems such as the function of phase-shlfted link in control circuit, the implementation conditions of soft switching and bias restrained are analyzed. The adoption of constant frequency PWM control makes the design of the input and output filter link and the high frequency transformer simple. The transformation ratio regulation so as to achieve low voltage output and electrical insulation can be realized by using high frequency transformer.
文摘Scaling problems and limitations of conventional silicon transistors have led the designers to exploit novel nano-technologies. One of the most promising and feasible nano-technologies is CNT(Carbon Nanotube) based transistors. In this paper, a high-speed and energy-efficient CNFET(Carbon Nanotube Field Effect Transistor) based Full Adder cell is proposed for nanotechnology. This design is simulated in various supply voltages, frequencies and load capacitors using HSPICE circuit simulator. Significant improvement is achieved in terms of speed and PDP(Power-Delay-Product) in comparison with other classical and state-of-the-art CMOS and CNFET-based designs, existing in the literature. The proposed Full Adder can also drive large load capacitance and works properly in low supply voltages.
文摘This paper proposes a zer o current and zero voltage switching (ZCZVS) PWM Boost full bridge (FB) conve rter. With series inductors, the leading switches can realize zero current swit ching (ZCS) in a wide load range using the energy of the output capacitor. Ma king use of parasitic capacitors of the lagging switches and parallel auxiliary i nductance with the primary winding of the transformer, the lagging switches can realize zero voltage switching (ZVS) under any load. Compared with the ZCS PWM Boost FB converter, the new converter has no current duty cycle loss. Operat ional principle and parameter design are analyzed. Experimental results verify the effectiveness of the proposed converter.
基金Project supported by the Hi-Tech Research and Development Program (863) of China (No. 2006AA01Z226)the Scientific Research Foundation of Huazhong University of Science and Technol-ogy (No. 2006Z001B), China
文摘Using composite field arithmetic in Galois field can result in the compact Rijndael S-Box. However, the power con- sumption of this solution is too large to be used in resource-limited embedded systems. A full-custom hardware implementation of composite field S-Box is proposed for these targeted domains in this paper. The minimization of power consumption is implemented by optimizing the architecture of the composite field S-Box and using the pass transmission gate (PTG) to realize the logic functions of S-Box. Power simulations were performed using the netlist extracted from the layout. HSPICE simulation results indicated that the proposed S-Box achieves low power consumption of about 130 μW at 10 MHz using 0.25 μm/2.5 V technology, while the consumptions of the positive polarity reed-muller (PPRM) based S-Box and composite field S-Box based on the conventional CMOS logic style are about 240 μW and 420 μW, respectively. The simulations also showed that the presented S-Box obtains better low-voltage operating property, which is clearly relevant for applications like sensor nodes, smart cards and radio frequency identification (RFID) tags.
