Real-time online prediction method for dynamic junction temperature of semiconductor power device

A semiconductor power device system, comprising

• a semiconductor power device integrated thereon, having a dynamic junction temperature;
• a computer readable storage medium, having stored thereon a computer program and
• integrated in the semiconductor power device system, said program arranged to:
• operate a processor of the semiconductor power device to perform a method of predicting a real-time dynamic junction temperature of the semiconductor power device, comprising the following steps:
• step 1:
• sensing working state parameters of the semiconductor power device by original sampling circuits of the semiconductor power device working state parameters of the semiconductor power device:
• an output current of the power device, a bus voltage of the power device, and a temperature of a radiator just under the power device;
• step 2:
• sensing working state parameters of the semiconductor power device by original sampling circuits of the semiconductor power device loss parameters of the semiconductor power device:
• a conduction voltage drop UCE, a turn-on energy Eon, and a turn-off energy Eoff corresponding to a current IT flowing through the semiconductor power device at a given temperature;
• step 3:
• calculating a conduction loss PDC of the semiconductor power device in a calculation period TS according to the obtained conduction voltage drop UCE corresponding to the current IT flowing through the semiconductor power device:
• PDC=UCE*IT*D
• wherein D is a conduction duty cycle of the semiconductor power device in the calculation period TS;
• step 4:
• calculating a switching loss PSW of the semiconductor power device according to the obtained turn-on energy Eon and turn-off energy Eoff corresponding to the current IT flowing through the semiconductor power device:
• PSW=(Eon+Eoff)&f
• wherein f is a switching frequency of the semiconductor power device;
• step 5:
• acquiring a total loss P of the semiconductor power device according to the conduction loss and the switching loss acquired in the step 3 and the step 4:
• P=PDC+Psw
• step 6:
• calculating a temperature difference ΔTtjh1 between the junction of the semiconductor power device and the radiator surface just under the power device:
• ΔTtjh1=ΔTtjh0+P*Rthjc[@Ts]−ΔTtjh0*λ
• wherein ΔTt1h0 is the temperature difference between the junction of the power device and the radiator surface just under the power device at the end of the previous calculation period, λ is a discrete coefficient that is obtained after optimal fitting is performed on a dynamic thermal resistance curve of the power device and that is related to the calculation period TS and the dynamic thermal resistance curve, and Rthic[∩Ts] is a transient thermal resistance of the power device corresponding to the time TS;
• step 7:
• iteratively calculating the junction temperature of the power device at each moment:
• repeating the step 1 to the step 6, then adding the real time temperature of the radiator surface just under the power device to the calculation result ΔTtjh1 of the step 6, and performing real-time online prediction to obtain the junction temperature of each semiconductor power device.

An on-line real time dynamic junction temperature prediction tool

• integrated on a semiconductor power device system, for use to predict a junction temperature for a semiconductor power device, included in the semiconductor power device system, comprising
• a computer readable storage medium of the semiconductor power device system, having stored thereon a computer program, said program arranged to:
• operate a processor to perform a method of
• predicting a real-time dynamic junction temperature of the semiconductor power device, comprising the following steps:
• step 1:
• sensing working state parameters of the semiconductor power device by original sampling circuits of the semiconductor power device, working state parameters of the semiconductor power device:
• an output current of the power device, a bus voltage of the power device, and a temperature of a radiator just under the power device;
• step 2:
• sensing working state parameters of the semiconductor power device by original sampling circuits of the semiconductor power device, loss parameters of the semiconductor power device:
• a conduction voltage drop UCE, a turn-on energy Eon, and a turn-off energy Eoff corresponding to a current IT flowing through the semiconductor power device at a given temperature;
• step 3:
• calculating a conduction loss PDC of the semiconductor power device in a calculation period TS according to the obtained conduction voltage drop UCE corresponding to the current IT flowing through the semiconductor power device:
• PDC=UCE*IT*D
• wherein D is a conduction duty cycle of the semiconductor power device in the calculation period TS;
• step 4:
• calculating a switching loss Psw of the semiconductor power device according to the obtained turn-on energy Eon and turn-off energy Eoff corresponding to the current IT flowing through the semiconductor power device:
• Psw=(Eon+Eoff)*f
• wherein f is a switching frequency of the semiconductor power device;
• step 5:
• acquiring a total loss P of the semiconductor power device according to the conduction loss and the switching loss acquired in the step 3 and the step 4:
• P=PDC+Psw
• step 6:
• calculating a temperature difference ΔTtjh1 between the junction of the semiconductor power device and the radiator surface just under the power device:
• ΔTtjh1=ΔTtjh0+P*Rthjc[@Ts]−ΔTtjh0*λ
• wherein ΔTt1h0 is the temperature difference between the junction of the power device and the radiator surface just under the power device at the end of the previous calculation period, λ is a discrete coefficient that is obtained after optimal fitting is performed on a dynamic thermal resistance curve of the power device and that is related to the calculation period TS and the dynamic thermal resistance curve, and Rthic[@s] is a transient thermal resistance of the power device corresponding to the time TS;
• step 7:
• iteratively calculating the junction temperature of the power device at each moment:
• repeating the step 1 to the step 6, then adding the real time temperature of the radiator surface just under the power device to the calculation result ΔTtjh1 of the step 6, and performing real-time online prediction to obtain the junction temperature of each semiconductor power device.