EPE Association: EPE 2018 - DS1a: Active Components

EPE 2018 - DS1a: Active Components
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2018 ECCE Europe - Conference > EPE 2018 - Topic 01: Devices, Packaging and System Integration > EPE 2018 - DS1a: Active Components

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   Analysis of gate voltage oscillation in a module with combination of Si-IGBT and SiC Schottky Diodes
By Shunta HORIE [View]
[Download]

Abstract: In recent years, oscillation phenomena are often observed in IGBT power modules at turn-on, turn-offand short-circuit. This oscillation phenomenon causes not only electromagnetic interference (EMI) toother electronic devices due to radiated electromagnetic waves but also a gate breakdown in the worstcase.According to experimental result, a high frequency oscillation during turn-on was observed in amodule with the combination of Si-IGBT and SiC schottky barrier diode. The oscillation was not seenwith the combination of Si-IGBT and Si-FWD. The oscillation was reproduced in simulation and theamplitude was depends on the large junction capacitance of SiC schottky barrier diode.

   Characterization of 1200 V RB-IGBTs with Different Irradiation Levels under Hard and Soft Switching Conditions
By Andrei BLINOV [View]
[Download]

Abstract: This paper presents characterisation of 1200 V, 25 A RB IGBT devices with various irradiation levels under hard and soft switching conditions using a double-pulse test circuit with an additional current clamp. The switching behaviour, particularly turn-on and turn-off characteristics, of these devices under various conditions are evaluated. Obtained results allow to assess the impact of irradiation level and di/dt on the conduction, turn-on and reverse recovery characteristics.

   Concept for an IGBT Desaturation Pulse to Reduce Turn-OFF Losses
By Daniel LEXOW [View]
[Download]

Abstract: This paper introduces an 'IGBT desaturation pulse' which tends to reduce turn-OFF losses for regular and Reverse Conducting IGBTs. Hereby, the effect of the desaturation pulse is compared between conventional IGBT-types and innovative 'low-saturation' IGBT-types with an increased emitter-sided plasma concentration due to injection enhancement. Device simulations for 6.5 kV IGBTs of both types, a gate control scheme to implement the IGBT desaturation pulse into the timing diagram as well as a proposal for a gate-drive unit are elaborated and presented.

   Device-Package Interaction and Gate Driver Layout Analysis in SiC MOSFET Power Modules for More Electric Aircraft Motor Drive Applications
By Shane O'DONNELL [View]
[Download]

Abstract: This paper presents measurements and comparison analysis of 1200 V SiC MOSFET gate drive signalsin two different integrated power solutions designed for More Electric Aircraft motor drive applications.The modules are designed to accommodate a 540 V high voltage DC bus and have a maximum outputphase current of 25 A peak. Both modules comprise of typical three-phase inverter bridgeconfigurations, with 40 mO MOSFETs and 20 A anti-parallel diodes. However, their gate drivers,printed circuit board layouts and substrate designs are different and the effect these elements have onthe performance is presented. The results illustrate that gate resistances, package interactions and PCBlayout can have a major effect on performance while variations in switching frequency, from 10 kHz to50 kHz, and a reduction in dead-time, from 500 ns to 375 ns, have negligible impacts.

   Driver stage implementation with improved turn-on and turn-off delay for wide band gap devices
By Ole Christian SPRO [View]
[Download]

Abstract: This paper presents a driver topology intended for WBG devices with the goal of improving the switchingperformance. In particular, the initial delay time of the switching transient was targeted. In high powerand high frequency bridge converters, the dead time causes output voltage waveform distortion and increases losses. Shorter delay time leads to shorter dead time requirement. Simulations show that the delay time can be minimised by correctly implementing the suggested driver stage. For the experimental validation, an improvement of 6-8 ns was demonstrated while keeping the same di/dt and dv/dt as a conventional gate driver. The improvement increases with increasing gate resistance.

   Effect of P-type island on SEE failure in n-MOSFET
By Yun TANG [View]
[Download]

Abstract: A novel n-MOSFET structure with P-type island in the buffer layer is proposed and simulation studies have been performed in this paper. Simulation results show that the peak current induced by heavy ions can be reduced owing to field modification effects of P-type island.

   Gate Driver Architectures Impacts on Voltage Balancing of SiC MOSFETs in Series Connection
By Luciano ALVES [View]
[Download]

Abstract: In power converter configurations like multi-cell, multi-level, series connection of power devices etc.under very high switching speeds, several dv/dt sources generated at different floating points produceconducted EMI perturbations from the power part to the control part through the many gate drivercircuitries. The modifications of the parasitic capacitive propagation paths between the power and thecontrol sides have impacts on the circulating current produced by high dv/dt, which, in turns, affects thevoltages distributions (static and transient) among the power devices. This paper presents newsarchitectures for gate drivers power supplies implementations in series connection to minimize parasiticcurrents, especially reducing the common mode currents and to minimize the unbalance voltages of SiCMOSFET devices in series connections. Simulations and experiments validate the advantages of thegate driver power supplies proposed architectures on the common mode currents and drain-to-sourcevoltages of series-connected devices.

   Hysteresis Losses in the Output Capacitance of Wide Bandgap and Superjunction Transistors
By Dennis BURA [View]
[Download]

Abstract: This paper deals with switching losses in modern power semiconductors due to a hysteresis in their output capacitance. A modified Sawyer-Tower circuit is presented, which is able to characterize this effect under large signal excitation. Three semiconductor types are analyzed: a Si superjunction MOSFET, a SiC MOSFET and a GaN HEMT. It is revealed that the output capacitance of these devices shows a hysteretic behavior which results in unavoidable losses even under zero voltage turn-on transitions. These losses become a major issue when pushing switching frequencies of power electronics into the megahertz range.

   IGCT Switching Behaviour Under Resonant Operating Conditions
By Dragan STAMENKOVIC [View]
[Download]

Abstract: In the area of medium voltage DC-DC conversion, LLC Series Resonant Converter (LLC-SRC) presents itself as an attractive topology for implementation of the DC transformer. Employing Integrated Gate Commutated Thyristor (IGCT) as a switching element one can obtain very low conduction losses with this design, while considerably lowering the switching losses. Low current turn-off of the switch previously flooded with the high quasi sinusoidal load current is explored throughout this paper. Conclusions are supported by Technology Computer Aided Design (TCAD) simulations and by waveforms obtained from a dedicated test setup designed to emulate the conduction and switching conditions present in LLC-SRC.

   Impact of Leakage Currents on Voltage Sharing in Series Connected SiC Power MOSFETs and Silicon IGBT Devices
By Zarina DAVLETZHANOVA [View]
[Download]

Abstract: Low leakage currents and reduced temperature sensitivity in SiC power devices compared to silicon devices results in the voltage sharing under series connection being more stable even under temperature variation between the series devices. Leakage currents result from impact ionization in the voltage blocking drift region, hence, the device with the higher leakage current under a series arrangement will have lower output capacitance therefore will block less voltage in the series pair. Series connected power devices are required for voltage sharing in high voltage applications like grid connected converters and DC circuit breakers. In applications where series power devices may be at different junction temperatures as a result of the physical architecture of the converter cooling system or differential degradation of the packaging, the leakage current and switching synchronization is critical in the OFF-state. Snubbers are traditionally used for static and dynamic voltage balancing in series connected power devices, however, there is increasing interest in active gate control. Therefore, the impact of the power device technology on voltage sharing in series devices is important to enable snubberless operation via active gate control. This paper investigates voltage sharing in series connected devices by comparing SiC trench MOSFETs and Si IGBTs. Series devices have been tested under different temperatures and switching rates to investigate the impact of electrothermal variation on voltage imbalance. Measurements and finite element models have been used to support the analysis.

   Impacts of Diode Surge Currents on Reverse Conducting IGBT Controlled by Optimized Gate-Drive Unit
By Daniel LEXOW [View]
[Download]

Abstract: Diode surge currents constitute a challenging demand in any inverter structure. Especially, while using an improved gate-drive control for RC-IGBTs with an implemented blanking time to delay the transition from IGBT- to diode-mode. Therefore, HV-measurements with 6.5 kV RC-IGBTs were ac-complished to ensure safe operation of this particular gate-drive concept. Furthermore, a compensa-tion technique to avoid excessive forward recovery voltage drop is introduced.

   Improved performance of new fast recovery high voltage diode chip set of 3.3kV and 6.5kV
By Ariful ISLAM [View]
[Download]

Abstract: In this paper, the development of fast recovery 6.5 and 3.3 kV diode chip integrated in IGBT moduleis presented. Based on Dynex MAX-SOA technology, the newly developed diode chip set integratedin high power IGBT module exhibits a wider range of reverse recovery safe operating area whereconduction and reverse recovery characteristics have been optimized.

   Influences of gate-circuit and parasitic inductances on turn-off current imbalances of paralleled IGBTs due to differences in their switching behaviour
By Robin SCHRADER [View]
[Download]

Abstract: Despite the usage of IGBTs selected with parallelisation criteria, current imbalances can occur betweenthem during switching transients. Those imbalances can be amplified or reduced by the load- and gate-circuits even when the circuits are symmetrical. Their influences on imbalances during turn-OFF tran-sients are analysed and explained with the help of TCAD-simulations and measurements. Moreover, it isexplained in detail that a common auxiliary emitter connection is beneficial to reduce current mismatchesduring turn-OFF.

   Investigation of Optimal Conditions for Reducing Losses and Costs of Hybrid Switch Combining Si IGBT and SiC MOSFET in Power Conversion Devices
By Aiko KUBOTA [View]
[Download]

Abstract: A hybrid switch configured by silicon insulated gate bipolar transistor (Si IGBT) and silicon carbide metal-oxide semiconductor field effect transistor (SiC MOSFET) achieves reduction of losses and costs. In this paper, it is discussed to utilize a hybrid switch for power conversion devices, aimed to reduce losses and increase the operating area. Characteristics of the hybrid switch in power conversion devices is determined to compare the proposed gate signal option with conventional one. As a result, it is confirmed that a hybrid switch reduce losses and increase the operating area under the adequate load current and gate signal option.

   Power devices comparison in synchronous half bridge topology
By Mario CACCIATO [View]
[Download]

Abstract: The aim of this paper is to investigate the efficiency improvement obtained by using wide band-gap semiconductors instead of the traditional silicon power devices in synchronous half bridge topology application. WBG technology has been focused in order to show the peculiar characteristics and most important differences between SiC and GaN and their optimal use in different types of applications. In order to evaluate the efficiency at different power levels and switching frequencies, those devices have been tested using two different experimental boards both operated in hard switching and implementing, respectively, the synchronous half bridge topology Buck and Boost converters. Finally, the impact of the device's performance on the total converter losses has been calculated, also addressing the impact of conduction or switching losses.

   Realization of a monolithic multi-terminal Si-power chip integrating a 2-phase rectifier composed of vertical PiN diodes insulated by vertical P+ walls
By Adem LALE [View]
[Download]

Abstract: This paper is within the context of mixed monolithic/hybrid integration of a generic multi-phase power converter (DC/AC or AC/DC). The technological results provided in this paper deal with the realization of a 300 µm deep P+ wall as well as with the realization of the monolithic 2-phase rectifier that consists of four vertical PiN diodes that are separated by P+ walls. These technological results are currently in use for the realization of a three terminal common cathode chip consisting of two RC-IGBTs as well as a monolithic H-bridge converter that consists of four RC-IGBTs.

   Series Short-Circuit Failures in three-level ANPC converters
By David HAMMES [View]
[Download]

Abstract: Three-level converters like the Active-Neutral-Point-Clamped type can suffer from series short-circuit failures. These cases cannot exist for the standard two-level converter except when a series connection of modules is used to increase the voltage rating. Even then, the course of the short circuits differs in some aspects due to the different structures of the converters. A series short-circuit scenario consists of two IGBTs and / or diodes, a freewheeling diode and the shorted module. It leads to different variantsof failure types and semiconductor stresses in comparison to a two-level converter. The behavior of thefaults is derived from equivalent circuits and proven by measurements on a three-level converter equipped with state-of-the-art 3.3 kV-IGBT modules including diodes. Some of the series short circuitsare yet described for the Neutral-Point-Clamped converter, but not in total for the active one. The presented investigations within this paper examine the origin, the possible trends of voltage and current as well as possible secondary failure cases.

EPE 2018 - DS1a: Active Components
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2018 ECCE Europe - Conference > EPE 2018 - Topic 01: Devices, Packaging and System Integration > EPE 2018 - DS1a: Active Components
	[return to parent folder]

	Analysis of gate voltage oscillation in a module with combination of Si-IGBT and SiC Schottky Diodes By Shunta HORIE	[View] [Download]
Abstract: In recent years, oscillation phenomena are often observed in IGBT power modules at turn-on, turn-offand short-circuit. This oscillation phenomenon causes not only electromagnetic interference (EMI) toother electronic devices due to radiated electromagnetic waves but also a gate breakdown in the worstcase.According to experimental result, a high frequency oscillation during turn-on was observed in amodule with the combination of Si-IGBT and SiC schottky barrier diode. The oscillation was not seenwith the combination of Si-IGBT and Si-FWD. The oscillation was reproduced in simulation and theamplitude was depends on the large junction capacitance of SiC schottky barrier diode.

	Characterization of 1200 V RB-IGBTs with Different Irradiation Levels under Hard and Soft Switching Conditions By Andrei BLINOV	[View] [Download]
Abstract: This paper presents characterisation of 1200 V, 25 A RB IGBT devices with various irradiation levels under hard and soft switching conditions using a double-pulse test circuit with an additional current clamp. The switching behaviour, particularly turn-on and turn-off characteristics, of these devices under various conditions are evaluated. Obtained results allow to assess the impact of irradiation level and di/dt on the conduction, turn-on and reverse recovery characteristics.

	Concept for an IGBT Desaturation Pulse to Reduce Turn-OFF Losses By Daniel LEXOW	[View] [Download]
Abstract: This paper introduces an 'IGBT desaturation pulse' which tends to reduce turn-OFF losses for regular and Reverse Conducting IGBTs. Hereby, the effect of the desaturation pulse is compared between conventional IGBT-types and innovative 'low-saturation' IGBT-types with an increased emitter-sided plasma concentration due to injection enhancement. Device simulations for 6.5 kV IGBTs of both types, a gate control scheme to implement the IGBT desaturation pulse into the timing diagram as well as a proposal for a gate-drive unit are elaborated and presented.

	Device-Package Interaction and Gate Driver Layout Analysis in SiC MOSFET Power Modules for More Electric Aircraft Motor Drive Applications By Shane O'DONNELL	[View] [Download]
Abstract: This paper presents measurements and comparison analysis of 1200 V SiC MOSFET gate drive signalsin two different integrated power solutions designed for More Electric Aircraft motor drive applications.The modules are designed to accommodate a 540 V high voltage DC bus and have a maximum outputphase current of 25 A peak. Both modules comprise of typical three-phase inverter bridgeconfigurations, with 40 mO MOSFETs and 20 A anti-parallel diodes. However, their gate drivers,printed circuit board layouts and substrate designs are different and the effect these elements have onthe performance is presented. The results illustrate that gate resistances, package interactions and PCBlayout can have a major effect on performance while variations in switching frequency, from 10 kHz to50 kHz, and a reduction in dead-time, from 500 ns to 375 ns, have negligible impacts.

	Driver stage implementation with improved turn-on and turn-off delay for wide band gap devices By Ole Christian SPRO	[View] [Download]
Abstract: This paper presents a driver topology intended for WBG devices with the goal of improving the switchingperformance. In particular, the initial delay time of the switching transient was targeted. In high powerand high frequency bridge converters, the dead time causes output voltage waveform distortion and increases losses. Shorter delay time leads to shorter dead time requirement. Simulations show that the delay time can be minimised by correctly implementing the suggested driver stage. For the experimental validation, an improvement of 6-8 ns was demonstrated while keeping the same di/dt and dv/dt as a conventional gate driver. The improvement increases with increasing gate resistance.

	Effect of P-type island on SEE failure in n-MOSFET By Yun TANG	[View] [Download]
Abstract: A novel n-MOSFET structure with P-type island in the buffer layer is proposed and simulation studies have been performed in this paper. Simulation results show that the peak current induced by heavy ions can be reduced owing to field modification effects of P-type island.

	Gate Driver Architectures Impacts on Voltage Balancing of SiC MOSFETs in Series Connection By Luciano ALVES	[View] [Download]
Abstract: In power converter configurations like multi-cell, multi-level, series connection of power devices etc.under very high switching speeds, several dv/dt sources generated at different floating points produceconducted EMI perturbations from the power part to the control part through the many gate drivercircuitries. The modifications of the parasitic capacitive propagation paths between the power and thecontrol sides have impacts on the circulating current produced by high dv/dt, which, in turns, affects thevoltages distributions (static and transient) among the power devices. This paper presents newsarchitectures for gate drivers power supplies implementations in series connection to minimize parasiticcurrents, especially reducing the common mode currents and to minimize the unbalance voltages of SiCMOSFET devices in series connections. Simulations and experiments validate the advantages of thegate driver power supplies proposed architectures on the common mode currents and drain-to-sourcevoltages of series-connected devices.

	Hysteresis Losses in the Output Capacitance of Wide Bandgap and Superjunction Transistors By Dennis BURA	[View] [Download]
Abstract: This paper deals with switching losses in modern power semiconductors due to a hysteresis in their output capacitance. A modified Sawyer-Tower circuit is presented, which is able to characterize this effect under large signal excitation. Three semiconductor types are analyzed: a Si superjunction MOSFET, a SiC MOSFET and a GaN HEMT. It is revealed that the output capacitance of these devices shows a hysteretic behavior which results in unavoidable losses even under zero voltage turn-on transitions. These losses become a major issue when pushing switching frequencies of power electronics into the megahertz range.

	IGCT Switching Behaviour Under Resonant Operating Conditions By Dragan STAMENKOVIC	[View] [Download]
Abstract: In the area of medium voltage DC-DC conversion, LLC Series Resonant Converter (LLC-SRC) presents itself as an attractive topology for implementation of the DC transformer. Employing Integrated Gate Commutated Thyristor (IGCT) as a switching element one can obtain very low conduction losses with this design, while considerably lowering the switching losses. Low current turn-off of the switch previously flooded with the high quasi sinusoidal load current is explored throughout this paper. Conclusions are supported by Technology Computer Aided Design (TCAD) simulations and by waveforms obtained from a dedicated test setup designed to emulate the conduction and switching conditions present in LLC-SRC.

	Impact of Leakage Currents on Voltage Sharing in Series Connected SiC Power MOSFETs and Silicon IGBT Devices By Zarina DAVLETZHANOVA	[View] [Download]
Abstract: Low leakage currents and reduced temperature sensitivity in SiC power devices compared to silicon devices results in the voltage sharing under series connection being more stable even under temperature variation between the series devices. Leakage currents result from impact ionization in the voltage blocking drift region, hence, the device with the higher leakage current under a series arrangement will have lower output capacitance therefore will block less voltage in the series pair. Series connected power devices are required for voltage sharing in high voltage applications like grid connected converters and DC circuit breakers. In applications where series power devices may be at different junction temperatures as a result of the physical architecture of the converter cooling system or differential degradation of the packaging, the leakage current and switching synchronization is critical in the OFF-state. Snubbers are traditionally used for static and dynamic voltage balancing in series connected power devices, however, there is increasing interest in active gate control. Therefore, the impact of the power device technology on voltage sharing in series devices is important to enable snubberless operation via active gate control. This paper investigates voltage sharing in series connected devices by comparing SiC trench MOSFETs and Si IGBTs. Series devices have been tested under different temperatures and switching rates to investigate the impact of electrothermal variation on voltage imbalance. Measurements and finite element models have been used to support the analysis.

	Impacts of Diode Surge Currents on Reverse Conducting IGBT Controlled by Optimized Gate-Drive Unit By Daniel LEXOW	[View] [Download]
Abstract: Diode surge currents constitute a challenging demand in any inverter structure. Especially, while using an improved gate-drive control for RC-IGBTs with an implemented blanking time to delay the transition from IGBT- to diode-mode. Therefore, HV-measurements with 6.5 kV RC-IGBTs were ac-complished to ensure safe operation of this particular gate-drive concept. Furthermore, a compensa-tion technique to avoid excessive forward recovery voltage drop is introduced.

	Improved performance of new fast recovery high voltage diode chip set of 3.3kV and 6.5kV By Ariful ISLAM	[View] [Download]
Abstract: In this paper, the development of fast recovery 6.5 and 3.3 kV diode chip integrated in IGBT moduleis presented. Based on Dynex MAX-SOA technology, the newly developed diode chip set integratedin high power IGBT module exhibits a wider range of reverse recovery safe operating area whereconduction and reverse recovery characteristics have been optimized.

	Influences of gate-circuit and parasitic inductances on turn-off current imbalances of paralleled IGBTs due to differences in their switching behaviour By Robin SCHRADER	[View] [Download]
Abstract: Despite the usage of IGBTs selected with parallelisation criteria, current imbalances can occur betweenthem during switching transients. Those imbalances can be amplified or reduced by the load- and gate-circuits even when the circuits are symmetrical. Their influences on imbalances during turn-OFF tran-sients are analysed and explained with the help of TCAD-simulations and measurements. Moreover, it isexplained in detail that a common auxiliary emitter connection is beneficial to reduce current mismatchesduring turn-OFF.

	Investigation of Optimal Conditions for Reducing Losses and Costs of Hybrid Switch Combining Si IGBT and SiC MOSFET in Power Conversion Devices By Aiko KUBOTA	[View] [Download]
Abstract: A hybrid switch configured by silicon insulated gate bipolar transistor (Si IGBT) and silicon carbide metal-oxide semiconductor field effect transistor (SiC MOSFET) achieves reduction of losses and costs. In this paper, it is discussed to utilize a hybrid switch for power conversion devices, aimed to reduce losses and increase the operating area. Characteristics of the hybrid switch in power conversion devices is determined to compare the proposed gate signal option with conventional one. As a result, it is confirmed that a hybrid switch reduce losses and increase the operating area under the adequate load current and gate signal option.

	Power devices comparison in synchronous half bridge topology By Mario CACCIATO	[View] [Download]
Abstract: The aim of this paper is to investigate the efficiency improvement obtained by using wide band-gap semiconductors instead of the traditional silicon power devices in synchronous half bridge topology application. WBG technology has been focused in order to show the peculiar characteristics and most important differences between SiC and GaN and their optimal use in different types of applications. In order to evaluate the efficiency at different power levels and switching frequencies, those devices have been tested using two different experimental boards both operated in hard switching and implementing, respectively, the synchronous half bridge topology Buck and Boost converters. Finally, the impact of the device's performance on the total converter losses has been calculated, also addressing the impact of conduction or switching losses.

	Realization of a monolithic multi-terminal Si-power chip integrating a 2-phase rectifier composed of vertical PiN diodes insulated by vertical P+ walls By Adem LALE	[View] [Download]
Abstract: This paper is within the context of mixed monolithic/hybrid integration of a generic multi-phase power converter (DC/AC or AC/DC). The technological results provided in this paper deal with the realization of a 300 µm deep P+ wall as well as with the realization of the monolithic 2-phase rectifier that consists of four vertical PiN diodes that are separated by P+ walls. These technological results are currently in use for the realization of a three terminal common cathode chip consisting of two RC-IGBTs as well as a monolithic H-bridge converter that consists of four RC-IGBTs.

	Series Short-Circuit Failures in three-level ANPC converters By David HAMMES	[View] [Download]
Abstract: Three-level converters like the Active-Neutral-Point-Clamped type can suffer from series short-circuit failures. These cases cannot exist for the standard two-level converter except when a series connection of modules is used to increase the voltage rating. Even then, the course of the short circuits differs in some aspects due to the different structures of the converters. A series short-circuit scenario consists of two IGBTs and / or diodes, a freewheeling diode and the shorted module. It leads to different variantsof failure types and semiconductor stresses in comparison to a two-level converter. The behavior of thefaults is derived from equivalent circuits and proven by measurements on a three-level converter equipped with state-of-the-art 3.3 kV-IGBT modules including diodes. Some of the series short circuitsare yet described for the Neutral-Point-Clamped converter, but not in total for the active one. The presented investigations within this paper examine the origin, the possible trends of voltage and current as well as possible secondary failure cases.