By integrating a temperature-adaptive function, an active gate driver (AGD) enhances the switching performance of silicon carbide (SiC) MOSFETs under varying temperature conditions. However, the lack of analytical exp...By integrating a temperature-adaptive function, an active gate driver (AGD) enhances the switching performance of silicon carbide (SiC) MOSFETs under varying temperature conditions. However, the lack of analytical expressions describing the coupling between AGD parameters and temperature variation limits the broader application of this method, particularly in SiC modules that exhibit complicated device transient behaviors. To address this challenge, a mathematical model of the transient behavior of an SiC module is developed to investigate the relationship among AGD parameters, junction temperature, and switching performance. The analysis reveals that the impact of temperature on switching performance is directly linked to the duration of each gate resistance. Accordingly, a temperature-adaptive AGD for SiC MOSFET modules is proposed. Online junction temperature monitoring is achieved using turn-on delay detection, and the duration of each gate’s driving resistance is dynamically adjusted. The proposed temperature-adaptive AGD is validated experimentally using a commercial 1.2 kV/560 A SiC MOSFET at 600 V/200 A. Experimental results across a temperature range of 20 ℃ to 100 ℃ demonstrate that electrical stress variation remains within 15%, while loss variation does not exceed 10%.展开更多
MOSFETs are widely used in power electronics converters.Due to the high di/dt and dv/dt of the MOSFET and parasitic parameters in the circuit,drain voltage spikes and oscillations will be generated during turn-off,whi...MOSFETs are widely used in power electronics converters.Due to the high di/dt and dv/dt of the MOSFET and parasitic parameters in the circuit,drain voltage spikes and oscillations will be generated during turn-off,which can affect the safety of the device and degrade the system's electromagnetic compatibility.This paper first studies the relationship between drain voltage spike and gate voltage during turn-off.Based on the effect of gate voltage on drain voltage spike,a new active gate driver that optimizes gate voltage is proposed.The proposed active gate driver detects the slope of the drain voltage and generates a positive pulse in the drain current fall phase to increase the gate voltage,thereby suppressing drain voltage spike and oscillation.In order to verify the effectiveness of the proposed active gate driver,a simulation circuit and an experimental platform are constructed and compared with the conventional gate driver.Simulation and experimental results show that the new active gate driver can effectively suppress the drain voltage spike and oscillation of MOSFETs,and can effectively reduce high-frequency EMI.展开更多
High-frequency switching of power transistors in power electronic systems can cause electromagnetic emissions.Simple approaches for reducing high-frequency disturbances,such as inserting an additional gate resistor,le...High-frequency switching of power transistors in power electronic systems can cause electromagnetic emissions.Simple approaches for reducing high-frequency disturbances,such as inserting an additional gate resistor,lead to increased power losses.This makes achieving both electromagnetic compatibility and power efficiency difficult.Active gate drivers help to find a trade-off between these two.Typically,only narrow-band disturbances must be reduced.Accordingly,a target signal with a spectrum notched at some frequencies can be defined.The target signal can be reached by a target-signal-oriented control of the transistor’s gate.This leads to steeper switching slopes,such that the power losses are less increased.Generating arbitrary target signals is impossible.The transistor signal exhibits some physical limitations.A constraint satisfaction problem must be solved,and the gate drive signal must be optimized by applying a residual and Newton’s method.The proposed optimization process in the frequency domain is based on the circuit simulation method named“harmonic balance”.Measurements on a DC/DC converter exhibit the benefits of this method.展开更多
With the continual increase in switching speed and rating of power semiconductors, the switching voltage spike becomes a serious problem. This paper describes a new technique of driving pulse edge modulation for insul...With the continual increase in switching speed and rating of power semiconductors, the switching voltage spike becomes a serious problem. This paper describes a new technique of driving pulse edge modulation for insulated gate bipolar transistors(IGBTs). By modulating the density and width of the pulse trains, without regulating the hardware circuit, the slope of the gate driving voltage is controlled to change the switching speed. This technique is used in the driving circuit based on complex programmable logic devices(CPLDs), and the switching voltage spike of IGBTs can be restrained through software, which is easier and more flexible to adjust. Experimental results demonstrate the effectiveness and practicability of the proposed method.展开更多
基金Supported by the National Natural Science Foundation of China (52177199).
文摘By integrating a temperature-adaptive function, an active gate driver (AGD) enhances the switching performance of silicon carbide (SiC) MOSFETs under varying temperature conditions. However, the lack of analytical expressions describing the coupling between AGD parameters and temperature variation limits the broader application of this method, particularly in SiC modules that exhibit complicated device transient behaviors. To address this challenge, a mathematical model of the transient behavior of an SiC module is developed to investigate the relationship among AGD parameters, junction temperature, and switching performance. The analysis reveals that the impact of temperature on switching performance is directly linked to the duration of each gate resistance. Accordingly, a temperature-adaptive AGD for SiC MOSFET modules is proposed. Online junction temperature monitoring is achieved using turn-on delay detection, and the duration of each gate’s driving resistance is dynamically adjusted. The proposed temperature-adaptive AGD is validated experimentally using a commercial 1.2 kV/560 A SiC MOSFET at 600 V/200 A. Experimental results across a temperature range of 20 ℃ to 100 ℃ demonstrate that electrical stress variation remains within 15%, while loss variation does not exceed 10%.
基金Supported in part by the General Program of National Natural Science Foundation of China under Grant 51577010,51777012in part by the Fundamental Research Funds for the Central Universities under Grant 2017JBM054.
文摘MOSFETs are widely used in power electronics converters.Due to the high di/dt and dv/dt of the MOSFET and parasitic parameters in the circuit,drain voltage spikes and oscillations will be generated during turn-off,which can affect the safety of the device and degrade the system's electromagnetic compatibility.This paper first studies the relationship between drain voltage spike and gate voltage during turn-off.Based on the effect of gate voltage on drain voltage spike,a new active gate driver that optimizes gate voltage is proposed.The proposed active gate driver detects the slope of the drain voltage and generates a positive pulse in the drain current fall phase to increase the gate voltage,thereby suppressing drain voltage spike and oscillation.In order to verify the effectiveness of the proposed active gate driver,a simulation circuit and an experimental platform are constructed and compared with the conventional gate driver.Simulation and experimental results show that the new active gate driver can effectively suppress the drain voltage spike and oscillation of MOSFETs,and can effectively reduce high-frequency EMI.
文摘High-frequency switching of power transistors in power electronic systems can cause electromagnetic emissions.Simple approaches for reducing high-frequency disturbances,such as inserting an additional gate resistor,lead to increased power losses.This makes achieving both electromagnetic compatibility and power efficiency difficult.Active gate drivers help to find a trade-off between these two.Typically,only narrow-band disturbances must be reduced.Accordingly,a target signal with a spectrum notched at some frequencies can be defined.The target signal can be reached by a target-signal-oriented control of the transistor’s gate.This leads to steeper switching slopes,such that the power losses are less increased.Generating arbitrary target signals is impossible.The transistor signal exhibits some physical limitations.A constraint satisfaction problem must be solved,and the gate drive signal must be optimized by applying a residual and Newton’s method.The proposed optimization process in the frequency domain is based on the circuit simulation method named“harmonic balance”.Measurements on a DC/DC converter exhibit the benefits of this method.
基金Project supported by the National Natural Science Foundation of China(No.51177147)the Zhejiang Key Science and Technology Innovation Group Program,China(No.2010R50021)
文摘With the continual increase in switching speed and rating of power semiconductors, the switching voltage spike becomes a serious problem. This paper describes a new technique of driving pulse edge modulation for insulated gate bipolar transistors(IGBTs). By modulating the density and width of the pulse trains, without regulating the hardware circuit, the slope of the gate driving voltage is controlled to change the switching speed. This technique is used in the driving circuit based on complex programmable logic devices(CPLDs), and the switching voltage spike of IGBTs can be restrained through software, which is easier and more flexible to adjust. Experimental results demonstrate the effectiveness and practicability of the proposed method.
