Abstract: A method for estimating the junction temperature on-line on an insulated gate bipolar transistor (IGBT) power module, including the following steps. Estimate the junction temperature by the temperature sensitive electrical parameter method, set the space thermal model of the extended state, and apply the Kalman filter to the junction temperature estimation. The temperature sensitive electrical parameter method estimates the junction temperature of the IGBT power module in real time, selects the IGBT conduction voltage drop VCE(ON) as the temperature sensitive electrical parameter, and provides a VCE(ON) on-line measuring circuit. The power loss of the diode and IGBT and the estimated value of junction temperature obtained by the temperature sensitive electrical parameter method are taken as the input of the Kalman filter, and measurement noise and process noise are considered to obtain an optimal estimated value of junction temperature.

Abstract: The present disclosure relates to a method for growing and doping a strained diamond based on a chemical vapor deposition (CVD) method. The method comprises: depositing a gradient buffer layer and a relaxation layer on a substrate layer in sequence by the CVD method; and finally, depositing a CVD strained diamond layer on the relaxation layer and performing doping by the CVD method. According to the method, a lattice constant of the relaxation layer prepared by utilizing the CVD method is greater than a lattice constant of the diamond, so that a diamond generates a stretching strain. In growing and doping processes, the CVD strained diamond is in a stretching strain state. Therefore, a formation energy of a doped element is low, and it is easy to dope the diamond, so that a doping concentration of the diamond is high.

Abstract: This disclosure provides a PSR-PWM technique for high power active front-end inverters to damp a specific inter-harmonic that may cause relative sub-synchronous resonance in power system. Due to the strong interaction between wind power converters, photovoltaic converters, FACTS devices and HVDC transmission, low-frequency oscillations occur from a few Hz to dozens of Hz, or even high-frequency oscillations ranging from about 300-2000 Hz. Meanwhile, low-frequency oscillations ranging from 0.6 Hz to 7 Hz occur in the power supply systems of many electric locomotives. Even in the case of large-scale train outage, low-frequency oscillation will lead to abnormal locomotive dispatching system; in addition, the power grid voltage disturbance and flicker caused by a large number of high-power are furnaces and other nonlinear loads in the industrial field with a passband inter-harmonic frequency ranging from 0.05 Hz-90 Hz and so on are detected.

Abstract: This disclosure provides a PSR-PWM technique for high power active front-end inverters to damp a specific inter-harmonic that may cause relative sub-synchronous resonance in power system. Due to the strong interaction between wind power converters, photovoltaic converters, FACTS devices and HVDC transmission, low-frequency oscillations occur from a few Hz to dozens of Hz, or even high-frequency oscillations ranging from about 300-2000 Hz. Meanwhile, low-frequency oscillations ranging from 0.6 Hz to 7 Hz occur in the power supply systems of many electric locomotives. Even in the case of large-scale train outage, low-frequency oscillation will lead to abnormal locomotive dispatching system; in addition, the power grid voltage disturbance and flicker caused by a large number of high-power are furnaces and other nonlinear loads in the industrial field with a passband inter-harmonic frequency ranging from 0.05 Hz-90 Hz and so on are detected.

Abstract: A method for estimating the junction temperature on-line on an insulated gate bipolar transistor (IGBT) power module, including the following steps. Estimate the junction temperature by the temperature sensitive electrical parameter method, set the space thermal model of the extended state, and apply the Kalman filter to the junction temperature estimation. The temperature sensitive electrical parameter method estimates the junction temperature of the IGBT power module in real time, selects the IGBT conduction voltage drop VCE(ON) as the temperature sensitive electrical parameter, and provides a VCE(ON) on-line measuring circuit. The power loss of the diode and IGBT and the estimated value of junction temperature obtained by the temperature sensitive electrical parameter method are taken as the input of the Kalman filter, and measurement noise and process noise are considered to obtain an optimal estimated value of junction temperature.