The zero-voltage quasi-resonant boost switching DC-DC converter has been inves-tigated by using the time averaging equivalent circuit approach of periodically switching linearnetworks.The DC steady state and AC small ...The zero-voltage quasi-resonant boost switching DC-DC converter has been inves-tigated by using the time averaging equivalent circuit approach of periodically switching linearnetworks.The DC steady state and AC small signal characteristics of the converter are also given.展开更多
In comparison with several zero-voltage transition （ZVT） inverter topologies, a double-PWM converter is presented using a simple ZVT topology. The rectifier and inverter of this double-PWM share a set of commutation...In comparison with several zero-voltage transition （ZVT） inverter topologies, a double-PWM converter is presented using a simple ZVT topology. The rectifier and inverter of this double-PWM share a set of commutation circuit which can provide soft-switching for the power devices and the diodes. The commutation circuit consists of 1 auxiliary device, 6 resonant inductors, and 12 diodes. Its topology is simpler than the conventional auxiliary resonant converter, leading to low loss and easy control. The control strategy and resonant working modes are analyzed. Experimental results show good performance of the system.展开更多
This paper presents a new ZVT （zero-voltage transition） single-stage ac-to-dc converter using PWM （pulse width modulation） and HF （high frequency） transformer isolation with capacitive output filter. In this con...This paper presents a new ZVT （zero-voltage transition） single-stage ac-to-dc converter using PWM （pulse width modulation） and HF （high frequency） transformer isolation with capacitive output filter. In this converter a front-end power factor corrected boost stage integrates with a cascaded dc-to-dc bridge HF converter. The front-end boost converter operates in discontinuous current mode and ensures natural power factor correction with very simple control. The auxiliary circuit of this topology deals with very small power and is placed out of the main power path. As a result, the auxiliary circuit components have smaller power rating as opposed to main converter components. Also, output rectifier voltage is clamped to output voltage due to capacitive output filter. Identification and analyses of different operating modes of this converter are presented. Based on these analyses design example of a 50 kHz, 48 V, 1 kW ac-to-dc converter is presented. PSPICE simulation results of the designed converter are presented and explained to verify the performance of this converter.展开更多
This paper presents an improved,energy-efficient Model Predictive Current Control(MPCC)strategy based on centroid-based virtual voltage vector synthesis for three-phase inverter-fed induction motor drives in electric ...This paper presents an improved,energy-efficient Model Predictive Current Control(MPCC)strategy based on centroid-based virtual voltage vector synthesis for three-phase inverter-fed induction motor drives in electric vehicle(EV)applications.Unlike conventional finite-set MPCC methods that rely on cost function evaluation over discrete switching states,the proposed approach eliminates the need for look-up tables by employing a pre-defined set of virtual vectors.These centroid-based virtual voltage vectors are synthesized by combining two adjacent active vectors and two nonzero voltage vectors in opposite directions adjacent to the sector replacing the traditional switching set.They approximate the reference voltage vector in both magnitude and phase angle,thereby reducing current tracking error through a simplified cost function.The number of candidate vectors is reduced,preserving computational efficiency.Furthermore,the scheme ensures zero average common-mode voltage(CMV)per sampling interval by completely avoiding zero-voltage vectors(ZVVs).The proposed method reduces torque ripple by up to 17%compared to the conventional approach and lowers stator current total harmonic distortion(THD)by 37%,while ensuring evenly distributed switching transitions among inverter legs.This results in reduced switching losses and enhanced drive efficiency-particularly advantageous in EV applications.Experimental validation under the high-speed extra urban driving cycle(EUDC)and low-speed ECE-R15 cycle,including torque ripple and energy consumption analysis,confirms the effectiveness of the approach,achieving an overall efficiency of 83.3%.展开更多
For electric vehicles (EVs),it is necessary to improve endurance mileage by improving the efficiency.There exists a trend towards increasing the system voltage and switching frequency,contributing to improve charging ...For electric vehicles (EVs),it is necessary to improve endurance mileage by improving the efficiency.There exists a trend towards increasing the system voltage and switching frequency,contributing to improve charging speed and power density.However,this trend poses significant challenges for high-voltage and high-frequency motor controllers,which are plagued by increased switching losses and pronounced switching oscillations as consequences of hard switching.The deployment of soft switching technology presents a viable solution to mitigate these issues.This paper reviews the applications of soft switching technologies for three-phase inverters and classifies them based on distinct characteristics.For each type of inverter,the advantages and disadvantages are evaluated.Then,the paper introduces the research progress and control methods of soft switching inverters (SSIs).Moreover,it presents a comparative analysis among the conventional hard switching inverters (HSIs),an active clamping resonant DC link inverter (ACRDCLI) and an auxiliary resonant commuted pole inverter (ARCPI).Finally,the problems and prospects of soft switching technology applied to motor controllers for EVs are put forward.展开更多
Traveling Wave Tubes(TWTs) are widely used in the radar and communications system as RF power amplifiers. A highly sophisticated power supply is required by TWT. In order to meet the severe requirements of Traveling W...Traveling Wave Tubes(TWTs) are widely used in the radar and communications system as RF power amplifiers. A highly sophisticated power supply is required by TWT. In order to meet the severe requirements of Traveling Wave Tube Amplifier(TWTA), a novel two-stage topology high voltage converter for TWTA is proposed.The converter is based on Zero-Voltage Switching and Zero-Current Switching(ZVS/ZCS) resonant techniques. The high voltage converter operation principles are investigated and major features of the converter are discussed. The power switching mode of ZVS/ZCS is obtained. The experimental results show that the converter has good soft switching characteristics. Compared to the conventional hard switched Pulse Width Modulation(PWM) techniques, the high efficiency and low ripple of the converter for TWTA are realized. The efficiency of High Voltage Electronic Power Conditioners(HV-EPC) over 93.5% under the condition of 38~46 V input voltage and 260~300 W input power. The switching frequency of first-stage(preregulator) of HV-EPC is 89 k Hz and the switching frequency of second-stage(postregulator) is 44.5 k Hz. The highest output voltage of the HV-EPC is helix voltage which is about –6.8 kV. It is especially suitable for TWTA utilized in space satellite applications due to its high switching frequency and high power density.展开更多
Owing to the advantages of high efficiency,high energy density,electrical isolation,low electromagnetic interference(EMI)and harmonic pollution,magnetic integration,wide output ranges,low voltage stress,and high opera...Owing to the advantages of high efficiency,high energy density,electrical isolation,low electromagnetic interference(EMI)and harmonic pollution,magnetic integration,wide output ranges,low voltage stress,and high operation frequency,the LLC resonant converters are widely used in various sectors of the electronics-based industries.The history and development of the LLC resonant converters are presented,their advantages are analyzed,three of the most popular LLC resonant converter topologies with detailed assessments of their strengths and drawbacks are elaborated.Furthermore,an important piece of research on the industrial applications of the LLC resonant converters is conducted,mainly including electric vehicle(EV)charging,photovoltaic systems,and light emitting diode(LED)lighting drivers and liquid crystal display(LCD)TV power supplies.Finally,the future evolution of the LLC resonant converter technology is discussed.展开更多
The fast switching behaviors of wide bandgap devices bring some challenges such as high du/dt and limited short-circuit current withstand capability to the reliable operation of the motor drives.The current-source-inv...The fast switching behaviors of wide bandgap devices bring some challenges such as high du/dt and limited short-circuit current withstand capability to the reliable operation of the motor drives.The current-source-inverter(CSI)provides a promising solution in mitigating those challenges by owning the DC-link choke,the reverse-voltage blocking switches and AC commutation capacitors.To further reduce du/dt on switches of CSI fed motor drives,the technique of partial charging of capacitors have been investigated in this paper.By designing the series-connected and the parallel-connected partial-charging circuit for capacitors in DC-link,the voltage profile of CSI could be improved.Specifically,the zero-voltage-switching(ZVS)is achieved for main power switches,the du/dt is reduced and the overvoltage protection is presented.The working mechanism of the technique of partial charging of capacitor is described and one example is discussed on the dual three-phase motor drive.The experimental verification is presented to show the performance of partial charging technique for improving voltage profile of CSI fed motor drives.展开更多
To increase the transmission efficiency of a wireless power transmission system while ensuring high stability and low cost,a two-degree-of-freedom two-sided control strategy to control the phase-shift duty ratio of th...To increase the transmission efficiency of a wireless power transmission system while ensuring high stability and low cost,a two-degree-of-freedom two-sided control strategy to control the phase-shift duty ratio of the triggered pulse of the primary inverter and the angle between the resonant current and the AC voltage of the secondary side is proposed.The control strategy does not require additional DC-DC converters and components,and only some parameters of the basic circuit can be adjusted.The zero-voltage switching(ZVS)of all the MOSFETs in the system can be achieved by adjusting the shift duty ratio and power angle,and the current and voltage on the load side can be adjusted in real time.First,the basic principle of the two-sided control and the relationship of the phase angle are analyzed,and the operating range is determined by analyzing the operating modes on both sides.Second,the power loss of each link is analyzed,and the best operating point is determined.Subsequently,the system structure and the control strategy of the proposed method are presented.The two-sided control strategy is verified experimentally,which shows that the system can achieve the ZVS of all the MOSFETs while maintaining a constant current output.展开更多
文摘The zero-voltage quasi-resonant boost switching DC-DC converter has been inves-tigated by using the time averaging equivalent circuit approach of periodically switching linearnetworks.The DC steady state and AC small signal characteristics of the converter are also given.
基金Project supported by the Shanghai Post Doctoral Scientific Research Project (Grant No.05R214122)the Shanghai Leading Academic Discipline Project (Grant No.T0103)
文摘In comparison with several zero-voltage transition （ZVT） inverter topologies, a double-PWM converter is presented using a simple ZVT topology. The rectifier and inverter of this double-PWM share a set of commutation circuit which can provide soft-switching for the power devices and the diodes. The commutation circuit consists of 1 auxiliary device, 6 resonant inductors, and 12 diodes. Its topology is simpler than the conventional auxiliary resonant converter, leading to low loss and easy control. The control strategy and resonant working modes are analyzed. Experimental results show good performance of the system.
文摘This paper presents a new ZVT （zero-voltage transition） single-stage ac-to-dc converter using PWM （pulse width modulation） and HF （high frequency） transformer isolation with capacitive output filter. In this converter a front-end power factor corrected boost stage integrates with a cascaded dc-to-dc bridge HF converter. The front-end boost converter operates in discontinuous current mode and ensures natural power factor correction with very simple control. The auxiliary circuit of this topology deals with very small power and is placed out of the main power path. As a result, the auxiliary circuit components have smaller power rating as opposed to main converter components. Also, output rectifier voltage is clamped to output voltage due to capacitive output filter. Identification and analyses of different operating modes of this converter are presented. Based on these analyses design example of a 50 kHz, 48 V, 1 kW ac-to-dc converter is presented. PSPICE simulation results of the designed converter are presented and explained to verify the performance of this converter.
文摘This paper presents an improved,energy-efficient Model Predictive Current Control(MPCC)strategy based on centroid-based virtual voltage vector synthesis for three-phase inverter-fed induction motor drives in electric vehicle(EV)applications.Unlike conventional finite-set MPCC methods that rely on cost function evaluation over discrete switching states,the proposed approach eliminates the need for look-up tables by employing a pre-defined set of virtual vectors.These centroid-based virtual voltage vectors are synthesized by combining two adjacent active vectors and two nonzero voltage vectors in opposite directions adjacent to the sector replacing the traditional switching set.They approximate the reference voltage vector in both magnitude and phase angle,thereby reducing current tracking error through a simplified cost function.The number of candidate vectors is reduced,preserving computational efficiency.Furthermore,the scheme ensures zero average common-mode voltage(CMV)per sampling interval by completely avoiding zero-voltage vectors(ZVVs).The proposed method reduces torque ripple by up to 17%compared to the conventional approach and lowers stator current total harmonic distortion(THD)by 37%,while ensuring evenly distributed switching transitions among inverter legs.This results in reduced switching losses and enhanced drive efficiency-particularly advantageous in EV applications.Experimental validation under the high-speed extra urban driving cycle(EUDC)and low-speed ECE-R15 cycle,including torque ripple and energy consumption analysis,confirms the effectiveness of the approach,achieving an overall efficiency of 83.3%.
基金funded by Tsinghua University-Weichai Power Intelligent Manufacturing Joint Research Institute (WCDL-GH-2022-0131)。
文摘For electric vehicles (EVs),it is necessary to improve endurance mileage by improving the efficiency.There exists a trend towards increasing the system voltage and switching frequency,contributing to improve charging speed and power density.However,this trend poses significant challenges for high-voltage and high-frequency motor controllers,which are plagued by increased switching losses and pronounced switching oscillations as consequences of hard switching.The deployment of soft switching technology presents a viable solution to mitigate these issues.This paper reviews the applications of soft switching technologies for three-phase inverters and classifies them based on distinct characteristics.For each type of inverter,the advantages and disadvantages are evaluated.Then,the paper introduces the research progress and control methods of soft switching inverters (SSIs).Moreover,it presents a comparative analysis among the conventional hard switching inverters (HSIs),an active clamping resonant DC link inverter (ACRDCLI) and an auxiliary resonant commuted pole inverter (ARCPI).Finally,the problems and prospects of soft switching technology applied to motor controllers for EVs are put forward.
文摘Traveling Wave Tubes(TWTs) are widely used in the radar and communications system as RF power amplifiers. A highly sophisticated power supply is required by TWT. In order to meet the severe requirements of Traveling Wave Tube Amplifier(TWTA), a novel two-stage topology high voltage converter for TWTA is proposed.The converter is based on Zero-Voltage Switching and Zero-Current Switching(ZVS/ZCS) resonant techniques. The high voltage converter operation principles are investigated and major features of the converter are discussed. The power switching mode of ZVS/ZCS is obtained. The experimental results show that the converter has good soft switching characteristics. Compared to the conventional hard switched Pulse Width Modulation(PWM) techniques, the high efficiency and low ripple of the converter for TWTA are realized. The efficiency of High Voltage Electronic Power Conditioners(HV-EPC) over 93.5% under the condition of 38~46 V input voltage and 260~300 W input power. The switching frequency of first-stage(preregulator) of HV-EPC is 89 k Hz and the switching frequency of second-stage(postregulator) is 44.5 k Hz. The highest output voltage of the HV-EPC is helix voltage which is about –6.8 kV. It is especially suitable for TWTA utilized in space satellite applications due to its high switching frequency and high power density.
基金Supported by the National Natural Science Foundation of China(51907032)the Natural Science Foundation of Guangdong Province(2018A030313365).
文摘Owing to the advantages of high efficiency,high energy density,electrical isolation,low electromagnetic interference(EMI)and harmonic pollution,magnetic integration,wide output ranges,low voltage stress,and high operation frequency,the LLC resonant converters are widely used in various sectors of the electronics-based industries.The history and development of the LLC resonant converters are presented,their advantages are analyzed,three of the most popular LLC resonant converter topologies with detailed assessments of their strengths and drawbacks are elaborated.Furthermore,an important piece of research on the industrial applications of the LLC resonant converters is conducted,mainly including electric vehicle(EV)charging,photovoltaic systems,and light emitting diode(LED)lighting drivers and liquid crystal display(LCD)TV power supplies.Finally,the future evolution of the LLC resonant converter technology is discussed.
基金Supported by the Jiangsu Natural Science Foundation of China(BK20180013)in part by Shen Zhen Science and Technology Project(CYJ20180306174439784).
文摘The fast switching behaviors of wide bandgap devices bring some challenges such as high du/dt and limited short-circuit current withstand capability to the reliable operation of the motor drives.The current-source-inverter(CSI)provides a promising solution in mitigating those challenges by owning the DC-link choke,the reverse-voltage blocking switches and AC commutation capacitors.To further reduce du/dt on switches of CSI fed motor drives,the technique of partial charging of capacitors have been investigated in this paper.By designing the series-connected and the parallel-connected partial-charging circuit for capacitors in DC-link,the voltage profile of CSI could be improved.Specifically,the zero-voltage-switching(ZVS)is achieved for main power switches,the du/dt is reduced and the overvoltage protection is presented.The working mechanism of the technique of partial charging of capacitor is described and one example is discussed on the dual three-phase motor drive.The experimental verification is presented to show the performance of partial charging technique for improving voltage profile of CSI fed motor drives.
基金Supported by the National Natural Science Foundation of China(51877070,U20A20198,51577048)the Natural Science Foundation of Hebei Province of China(E2024208079).
文摘To increase the transmission efficiency of a wireless power transmission system while ensuring high stability and low cost,a two-degree-of-freedom two-sided control strategy to control the phase-shift duty ratio of the triggered pulse of the primary inverter and the angle between the resonant current and the AC voltage of the secondary side is proposed.The control strategy does not require additional DC-DC converters and components,and only some parameters of the basic circuit can be adjusted.The zero-voltage switching(ZVS)of all the MOSFETs in the system can be achieved by adjusting the shift duty ratio and power angle,and the current and voltage on the load side can be adjusted in real time.First,the basic principle of the two-sided control and the relationship of the phase angle are analyzed,and the operating range is determined by analyzing the operating modes on both sides.Second,the power loss of each link is analyzed,and the best operating point is determined.Subsequently,the system structure and the control strategy of the proposed method are presented.The two-sided control strategy is verified experimentally,which shows that the system can achieve the ZVS of all the MOSFETs while maintaining a constant current output.
