DocID027309 Rev 1

9/23

AN4638

V series IGBTs on a 4 kW welder

23

for more details regarding these IGBTs, please refer to the relevant datasheet available at

www.st.com.

5.1

Overview of thermal and electrical measurements

The electrical measurements for the input power, input current and power factor (PF) taken

by the power meter at the input of the welder as well as the temperature and time values

achieved by the STGW40V60DF IGBTs during the electro-thermal analysis carried out on

the board are detailed in the following table and graph; the operating conditions for the

•

full load steady state operation under 2 kW input power conditions;

•

full load steady state operation under 3 kW input power conditions;

•

full load steady state operation under maximum power absorbed in input conditions.

The case temperatures measurements were taken by a thermo camera once thermal

stability had been achieved by the devices running on the board. Operating times were

measured for maintained maximum input power (~4 kW), starting from a cold state

condition, until the thermal protection interrupted operation.

Table 3. STGW40V60DF main parameters

Device

Package

@25 °C

STGW40V60DF

TO-247

600 V

40 A

175 °C

1.8 V

Table 4. Thermal and electrical measurements

Device

Input power

(kW)

Input current

(A)

PF

Temp (°C)

Time (min: s)

STGW40V60DF

2

15.4

0.58

62°

3

22.2

0.61

83°

~3.8(max)

26.3

0.66

10 min17 s