2020 International Conference on Power, Instrumentation, Control and Computing (PICC), 2020
This paper presents the use of a 1700 V silicon carbide (SiC) MOSFET in a single switch configura... more This paper presents the use of a 1700 V silicon carbide (SiC) MOSFET in a single switch configuration for a high input voltage control power supply (CPS) design in a flyback topology. Such a CPS is used to power the control and monitoring systems employed in renewable power generation, general purpose drives and uninterrupted power supply (UPS). Renewable applications often see DC bus voltages up to 1000 V. Hence, flyback topology is chosen as it provides an efficient DC voltage step-down for a wide input voltage range with low voltage ripple and desirable regulation. The performance of the flyback converter using a CoolSiCTM MOSFET is observed through appropriate simulations and verified through the hardware prototype. Further, the switching and conduction losses of the MOSFET along with system performance parameters are calculated and the results are presented in this paper.
12th IET International Conference on AC and DC Power Transmission (ACDC 2016), 2016
This paper shows the relationship between transmission line current and IGBT rated current in dif... more This paper shows the relationship between transmission line current and IGBT rated current in different package and voltage classes for VSC-HVDC application. Different semiconductor solutions for future high power systems are compared on their thermal performances, switching behaviours, power losses, chip-level current sharing and reliability. The latest development in IGBT chip and package technologies of Reverse Conducting IGBT with Diode Control (RCDC) and XHPTM are introduced. Experimental results show good current sharing amongst paralleled XHPTM modules.
2017 IEEE 3rd International Future Energy Electronics Conference and ECCE Asia (IFEEC 2017 - ECCE Asia), 2017
The latest trend in solar inverter application is to increase DC link voltage to 1500VDC for high... more The latest trend in solar inverter application is to increase DC link voltage to 1500VDC for high power output. This paper describes a design concept of NPC1 power stack for 1500VDC megawatt level solar inverter. This stack uses three latest half-bridge IGBT modules with highest power density and operation junction temperature, which enable realization of power level beyond 1MW without paralleling. Critical design concept on loop inductance is explained. Dynamic characteristics are verified by double-pulse test. Thermal characteristics and output power limits are verified by thermal test. Temperature-sensitive component on PCB as output power constraint is identified. Different PCB repositioning solutions are tested to give the overall output power thermal derating curves, which enable output power of 1.15MW at TA=55°C with 15°C thermal margin. The power stack characteristic and performance change under different thermal environment is further analyzed.
This paper shows the relationship between transmission line current and IGBT rated current in dif... more This paper shows the relationship between transmission line current and IGBT rated current in different package and voltage classes for VSC-HVDC application. Different semiconductor solutions for future high power systems are compared on their thermal performances, switching behaviours, power losses, chip-level current sharing and reliability. The latest development in IGBT chip and package technologies of Reverse Conducting IGBT with Diode Control (RCDC) and XHP TM are introduced. Experimental results show good current sharing amongst paralleled XHP TM modules.
The latest trend in solar inverter application is to increase DC link voltage to 1500VDC for high... more The latest trend in solar inverter application is to increase DC link voltage to 1500VDC for high power output. This paper describes a design concept of NPC1 power stack for 1500VDC megawatt level solar inverter. This stack uses three latest half-bridge IGBT modules with highest power density and operation junction temperature, which enable realization of power level beyond 1MW without paralleling. Critical design concept on loop inductance is explained. Dynamic characteristics are verified by double-pulse test. Thermal characteristics and output power limits are verified by thermal test. Temperature-sensitive component on PCB as output power constraint is identified. Different PCB repositioning solutions are tested to give the overall output power thermal derating curves, which enable output power of 1.15MW at T A =55°C with 15°C thermal margin. The power stack characteristic and performance change under different thermal environment is further analyzed.
This paper presents the use of a 1700 V silicon carbide (SiC) MOSFET in a single switch configura... more This paper presents the use of a 1700 V silicon carbide (SiC) MOSFET in a single switch configuration for a high input voltage control power supply (CPS) design in a flyback topology. Such a CPS is used to power the control and monitoring systems employed in renewable power generation, general purpose drives and uninterrupted power supply (UPS). Renewable applications often see DC bus voltages up to 1000 V. Hence, flyback topology is chosen as it provides an efficient DC voltage step-down for a wide input voltage range with low voltage ripple and desirable regulation. The performance of the flyback converter using a CoolSiC TM MOSFET is observed through appropriate simulations and verified through the hardware prototype. Further, the switching and conduction losses of the MOSFET along with system performance parameters are calculated and the results are presented in this paper.
A unified platform of single-and 3-phase AC input for light industrial applications can be made p... more A unified platform of single-and 3-phase AC input for light industrial applications can be made possible by keeping DC link voltage always at 540 V, and using SiC power MOSFET and diode in PFC stage. Commercial fridge inverter application at power level of 7 HP can be achieved by using 30 mΩ SiC MOSFET in PFC stage. Application to higher power application will be possible by mitigating the thermal bottleneck at PFC SiC MOSFET. The same design can be extended to commercial air conditioning system application at 7 kW, by using PFC SiC MOSFET with Rds(on) of 14 mΩ, 7 mΩ or 30 mΩ in 2pcs parallel.
A unified platform for single-and 3-phase AC input for light industrial applications is feasible ... more A unified platform for single-and 3-phase AC input for light industrial applications is feasible by using SiC MOSFETs and diodes in power factor correction (PFC) stage in order to keep the DClink voltage constantly at 540 V. System output power can be increased from 5.25 kW for commercial fridge inverter applications to 7 kW for commercial airconditioning applications with single-phase input, by changing the PFC SiC MOSFET with RDS(on) from 30 mΩ to 14 mΩ. The combination of paralleled electrolytic capacitors and film capacitors in DC link significantly reduces capacitor quantity and PCB space. The risk of anti-resonance of paralleled capacitors is influenced by equivalent series resistance (ESR) and stray inductance, and can be prevented when the ESR of the electrolytic capacitor is higher than the anti-resonant characteristic impedance.
A unified platform using single and 3-phase AC input for light industrial applications can be des... more A unified platform using single and 3-phase AC input for light industrial applications can be designed using a 1200 V SiC MOSFET and a diode in the PFC stage to keep the DC link voltage at 540 V always. Commercial fridge applications of 5.25 kW can be realized using a 30 mΩ SiC MOSFET in the PFC stage. Use of low RDS(ON) 14 mΩ, 7 mΩ, or two 30 mΩ SiC MOSFETs in parallel can mitigate the thermal bottleneck at PFC, and extend the output power to 7 kW for commercial air conditioner applications. Paralleling SiC MOSFETs gives better thermal performance by effectively reducing the case-to-heat sink thermal resistance by half.
2020 IEEE 9th International Power Electronics and Motion Control Conference (IPEMC2020-ECCE Asia), 2020
Recently a main trend for solar inverter development is higher power rating and higher power dens... more Recently a main trend for solar inverter development is higher power rating and higher power density which can reduce system cost. The state of art technology of IGBT comes into 7th generation, which can increase power rating of IGBT modules around 30% higher compare to last generation. NPC1 topology is widely used in 1500VDC solar inverter to meet cosmic reliability and high efficiency requirements. However this topology need 6 devices in one phase leg which lead to complex control and may have short circuit failure if turn off sequence is not correct. In this paper, a new stack for solar inverter is built using latest IGBT technologies and NPC2 topology to realize highest power density. 2.3kV voltage rating IGBTs are selected in this stack to solve cosmic failure issue in NPC2 topology. The max power rating of this stack can reach 2MW through electrical and thermal test.In this paper, a new stack for solar inverter is built using latest IGBT technologies and NPC2 topology to realize highest power density. 2.3kV voltage rating IGBTs are selected in this stack to solve cosmic failure issue in NPC2 topology. The max power rating of this stack can reach 2MW through electrical and thermal test.
2021 4th International Conference on Mechatronics, Robotics and Automation (ICMRA), 2021
To improve the design of light industrial applications, such as showcase fridge and commercial ai... more To improve the design of light industrial applications, such as showcase fridge and commercial air-conditioning (CAC) systems, the focus is on reducing the size and weight of boost PFC inductors, and on unifying the design platform for different input voltages at the same power rating. Increasing switching frequency is the key, enabled by new-generation IGBTs and SiC diodes, to reduce the boost PFC inductor size for power ratings below 7 HP. Using SiC diodes for PFC enables switching frequency to be increased to 40 kHz with the same output power. Operating with SiC MOSFETs at 540 V DC link voltage in PFC and inverter stages will result in similar total power losses as when using Si-IGBTs at 380 V DC link voltage, making it possible to use the same design in a unified platform for both single- and 3-phase input
This paper examines the approach, enabled by using SiC power devices, to unify the inverter desig... more This paper examines the approach, enabled by using SiC power devices, to unify the inverter design for central air conditioning (CAC) system for both singleand 3-phase input, and reduce the PFC inductor size to be PCB-mountable. By using SiCinstead of Si-diode in PFC stage, it is possible to increase the switching frequency from 16kHz to 60kHz to reduce the required PFC inductance from 0.93mH to 0.25mH, thus enable PCBmounting of inductor. With the next step of using 1200V SiC MOSFET instead of Si-IGBT, the DC link voltage can be boosted from 311Vdc to 550Vdc in PFC stage, allowing the inverter and compressor used in 3-phase input CAC be used for single-phase input as well. Furthermore, using SiC MOSFET in inverter stage can further reduce total loss system total loss to 200.8 W. Simulation and experimental results are presented in the paper.
Recently a main trend for solar inverter development is higher power rating and higher power dens... more Recently a main trend for solar inverter development is higher power rating and higher power density which can reduce system cost. The state of art technology of IGBT comes into 7th generation, which can increase power rating of IGBT modules around 30% higher compare to last generation. NPC1 topology is widely used in 1500VDC solar inverter to meet cosmic reliability and high efficiency requirements. However this topology need 6 devices in one phase leg which lead to complex control and may have short circuit failure if turn off sequence is not correct. In this paper, a new stack for solar inverter is built using latest IGBT technologies and NPC2 topology to realize highest power density. 2.3kV voltage rating IGBTs are selected in this stack to solve cosmic failure issue in NPC2 topology. The max power rating of this stack can reach 2MW through electrical and thermal test.In this paper, a new stack for solar inverter is built using latest IGBT technologies and NPC2 topology to reali...
This paper describes the design, design qualification, manufacturing inspections, burn-in and fie... more This paper describes the design, design qualification, manufacturing inspections, burn-in and field tracking of DC/DC power converter modules for telecommunication and other demanding applications to achieve high reliability. In a highly reliable DC/DC power converter module, components are substantially temperature- and voltage-derated. Case temperature is kept low by having sufficient surface area for efficient heat dissipation. Rugged mechanical design protects the module against damages in handling and application. Conformal coating, potting or transfer molding are used to protect the power module against harsh environmental conditions. Stress testing in design qualification will uncover potential design and manufacturing defects. Manufacturing inspections and 100% burn-in and final test will screen out manufacturing defects and control outgoing quality. A quality and reliability process is set up to establish the reliability performance of power converter modules by means of re...
The design, analysis and trade-offs of a novel method to sense the inductor and DC output current... more The design, analysis and trade-offs of a novel method to sense the inductor and DC output currents of PWM converters are presented. By sensing and adding appropriately the currents in the transistor, rectifier and capacitors of a converter using current transformers, ...
2020 International Conference on Power, Instrumentation, Control and Computing (PICC), 2020
This paper presents the use of a 1700 V silicon carbide (SiC) MOSFET in a single switch configura... more This paper presents the use of a 1700 V silicon carbide (SiC) MOSFET in a single switch configuration for a high input voltage control power supply (CPS) design in a flyback topology. Such a CPS is used to power the control and monitoring systems employed in renewable power generation, general purpose drives and uninterrupted power supply (UPS). Renewable applications often see DC bus voltages up to 1000 V. Hence, flyback topology is chosen as it provides an efficient DC voltage step-down for a wide input voltage range with low voltage ripple and desirable regulation. The performance of the flyback converter using a CoolSiCTM MOSFET is observed through appropriate simulations and verified through the hardware prototype. Further, the switching and conduction losses of the MOSFET along with system performance parameters are calculated and the results are presented in this paper.
12th IET International Conference on AC and DC Power Transmission (ACDC 2016), 2016
This paper shows the relationship between transmission line current and IGBT rated current in dif... more This paper shows the relationship between transmission line current and IGBT rated current in different package and voltage classes for VSC-HVDC application. Different semiconductor solutions for future high power systems are compared on their thermal performances, switching behaviours, power losses, chip-level current sharing and reliability. The latest development in IGBT chip and package technologies of Reverse Conducting IGBT with Diode Control (RCDC) and XHPTM are introduced. Experimental results show good current sharing amongst paralleled XHPTM modules.
2017 IEEE 3rd International Future Energy Electronics Conference and ECCE Asia (IFEEC 2017 - ECCE Asia), 2017
The latest trend in solar inverter application is to increase DC link voltage to 1500VDC for high... more The latest trend in solar inverter application is to increase DC link voltage to 1500VDC for high power output. This paper describes a design concept of NPC1 power stack for 1500VDC megawatt level solar inverter. This stack uses three latest half-bridge IGBT modules with highest power density and operation junction temperature, which enable realization of power level beyond 1MW without paralleling. Critical design concept on loop inductance is explained. Dynamic characteristics are verified by double-pulse test. Thermal characteristics and output power limits are verified by thermal test. Temperature-sensitive component on PCB as output power constraint is identified. Different PCB repositioning solutions are tested to give the overall output power thermal derating curves, which enable output power of 1.15MW at TA=55°C with 15°C thermal margin. The power stack characteristic and performance change under different thermal environment is further analyzed.
This paper shows the relationship between transmission line current and IGBT rated current in dif... more This paper shows the relationship between transmission line current and IGBT rated current in different package and voltage classes for VSC-HVDC application. Different semiconductor solutions for future high power systems are compared on their thermal performances, switching behaviours, power losses, chip-level current sharing and reliability. The latest development in IGBT chip and package technologies of Reverse Conducting IGBT with Diode Control (RCDC) and XHP TM are introduced. Experimental results show good current sharing amongst paralleled XHP TM modules.
The latest trend in solar inverter application is to increase DC link voltage to 1500VDC for high... more The latest trend in solar inverter application is to increase DC link voltage to 1500VDC for high power output. This paper describes a design concept of NPC1 power stack for 1500VDC megawatt level solar inverter. This stack uses three latest half-bridge IGBT modules with highest power density and operation junction temperature, which enable realization of power level beyond 1MW without paralleling. Critical design concept on loop inductance is explained. Dynamic characteristics are verified by double-pulse test. Thermal characteristics and output power limits are verified by thermal test. Temperature-sensitive component on PCB as output power constraint is identified. Different PCB repositioning solutions are tested to give the overall output power thermal derating curves, which enable output power of 1.15MW at T A =55°C with 15°C thermal margin. The power stack characteristic and performance change under different thermal environment is further analyzed.
This paper presents the use of a 1700 V silicon carbide (SiC) MOSFET in a single switch configura... more This paper presents the use of a 1700 V silicon carbide (SiC) MOSFET in a single switch configuration for a high input voltage control power supply (CPS) design in a flyback topology. Such a CPS is used to power the control and monitoring systems employed in renewable power generation, general purpose drives and uninterrupted power supply (UPS). Renewable applications often see DC bus voltages up to 1000 V. Hence, flyback topology is chosen as it provides an efficient DC voltage step-down for a wide input voltage range with low voltage ripple and desirable regulation. The performance of the flyback converter using a CoolSiC TM MOSFET is observed through appropriate simulations and verified through the hardware prototype. Further, the switching and conduction losses of the MOSFET along with system performance parameters are calculated and the results are presented in this paper.
A unified platform of single-and 3-phase AC input for light industrial applications can be made p... more A unified platform of single-and 3-phase AC input for light industrial applications can be made possible by keeping DC link voltage always at 540 V, and using SiC power MOSFET and diode in PFC stage. Commercial fridge inverter application at power level of 7 HP can be achieved by using 30 mΩ SiC MOSFET in PFC stage. Application to higher power application will be possible by mitigating the thermal bottleneck at PFC SiC MOSFET. The same design can be extended to commercial air conditioning system application at 7 kW, by using PFC SiC MOSFET with Rds(on) of 14 mΩ, 7 mΩ or 30 mΩ in 2pcs parallel.
A unified platform for single-and 3-phase AC input for light industrial applications is feasible ... more A unified platform for single-and 3-phase AC input for light industrial applications is feasible by using SiC MOSFETs and diodes in power factor correction (PFC) stage in order to keep the DClink voltage constantly at 540 V. System output power can be increased from 5.25 kW for commercial fridge inverter applications to 7 kW for commercial airconditioning applications with single-phase input, by changing the PFC SiC MOSFET with RDS(on) from 30 mΩ to 14 mΩ. The combination of paralleled electrolytic capacitors and film capacitors in DC link significantly reduces capacitor quantity and PCB space. The risk of anti-resonance of paralleled capacitors is influenced by equivalent series resistance (ESR) and stray inductance, and can be prevented when the ESR of the electrolytic capacitor is higher than the anti-resonant characteristic impedance.
A unified platform using single and 3-phase AC input for light industrial applications can be des... more A unified platform using single and 3-phase AC input for light industrial applications can be designed using a 1200 V SiC MOSFET and a diode in the PFC stage to keep the DC link voltage at 540 V always. Commercial fridge applications of 5.25 kW can be realized using a 30 mΩ SiC MOSFET in the PFC stage. Use of low RDS(ON) 14 mΩ, 7 mΩ, or two 30 mΩ SiC MOSFETs in parallel can mitigate the thermal bottleneck at PFC, and extend the output power to 7 kW for commercial air conditioner applications. Paralleling SiC MOSFETs gives better thermal performance by effectively reducing the case-to-heat sink thermal resistance by half.
2020 IEEE 9th International Power Electronics and Motion Control Conference (IPEMC2020-ECCE Asia), 2020
Recently a main trend for solar inverter development is higher power rating and higher power dens... more Recently a main trend for solar inverter development is higher power rating and higher power density which can reduce system cost. The state of art technology of IGBT comes into 7th generation, which can increase power rating of IGBT modules around 30% higher compare to last generation. NPC1 topology is widely used in 1500VDC solar inverter to meet cosmic reliability and high efficiency requirements. However this topology need 6 devices in one phase leg which lead to complex control and may have short circuit failure if turn off sequence is not correct. In this paper, a new stack for solar inverter is built using latest IGBT technologies and NPC2 topology to realize highest power density. 2.3kV voltage rating IGBTs are selected in this stack to solve cosmic failure issue in NPC2 topology. The max power rating of this stack can reach 2MW through electrical and thermal test.In this paper, a new stack for solar inverter is built using latest IGBT technologies and NPC2 topology to realize highest power density. 2.3kV voltage rating IGBTs are selected in this stack to solve cosmic failure issue in NPC2 topology. The max power rating of this stack can reach 2MW through electrical and thermal test.
2021 4th International Conference on Mechatronics, Robotics and Automation (ICMRA), 2021
To improve the design of light industrial applications, such as showcase fridge and commercial ai... more To improve the design of light industrial applications, such as showcase fridge and commercial air-conditioning (CAC) systems, the focus is on reducing the size and weight of boost PFC inductors, and on unifying the design platform for different input voltages at the same power rating. Increasing switching frequency is the key, enabled by new-generation IGBTs and SiC diodes, to reduce the boost PFC inductor size for power ratings below 7 HP. Using SiC diodes for PFC enables switching frequency to be increased to 40 kHz with the same output power. Operating with SiC MOSFETs at 540 V DC link voltage in PFC and inverter stages will result in similar total power losses as when using Si-IGBTs at 380 V DC link voltage, making it possible to use the same design in a unified platform for both single- and 3-phase input
This paper examines the approach, enabled by using SiC power devices, to unify the inverter desig... more This paper examines the approach, enabled by using SiC power devices, to unify the inverter design for central air conditioning (CAC) system for both singleand 3-phase input, and reduce the PFC inductor size to be PCB-mountable. By using SiCinstead of Si-diode in PFC stage, it is possible to increase the switching frequency from 16kHz to 60kHz to reduce the required PFC inductance from 0.93mH to 0.25mH, thus enable PCBmounting of inductor. With the next step of using 1200V SiC MOSFET instead of Si-IGBT, the DC link voltage can be boosted from 311Vdc to 550Vdc in PFC stage, allowing the inverter and compressor used in 3-phase input CAC be used for single-phase input as well. Furthermore, using SiC MOSFET in inverter stage can further reduce total loss system total loss to 200.8 W. Simulation and experimental results are presented in the paper.
Recently a main trend for solar inverter development is higher power rating and higher power dens... more Recently a main trend for solar inverter development is higher power rating and higher power density which can reduce system cost. The state of art technology of IGBT comes into 7th generation, which can increase power rating of IGBT modules around 30% higher compare to last generation. NPC1 topology is widely used in 1500VDC solar inverter to meet cosmic reliability and high efficiency requirements. However this topology need 6 devices in one phase leg which lead to complex control and may have short circuit failure if turn off sequence is not correct. In this paper, a new stack for solar inverter is built using latest IGBT technologies and NPC2 topology to realize highest power density. 2.3kV voltage rating IGBTs are selected in this stack to solve cosmic failure issue in NPC2 topology. The max power rating of this stack can reach 2MW through electrical and thermal test.In this paper, a new stack for solar inverter is built using latest IGBT technologies and NPC2 topology to reali...
This paper describes the design, design qualification, manufacturing inspections, burn-in and fie... more This paper describes the design, design qualification, manufacturing inspections, burn-in and field tracking of DC/DC power converter modules for telecommunication and other demanding applications to achieve high reliability. In a highly reliable DC/DC power converter module, components are substantially temperature- and voltage-derated. Case temperature is kept low by having sufficient surface area for efficient heat dissipation. Rugged mechanical design protects the module against damages in handling and application. Conformal coating, potting or transfer molding are used to protect the power module against harsh environmental conditions. Stress testing in design qualification will uncover potential design and manufacturing defects. Manufacturing inspections and 100% burn-in and final test will screen out manufacturing defects and control outgoing quality. A quality and reliability process is set up to establish the reliability performance of power converter modules by means of re...
The design, analysis and trade-offs of a novel method to sense the inductor and DC output current... more The design, analysis and trade-offs of a novel method to sense the inductor and DC output currents of PWM converters are presented. By sensing and adding appropriately the currents in the transistor, rectifier and capacitors of a converter using current transformers, ...
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