WESTCODE An IXYS Company
Medium Voltage Thyristor Types K0566L#440 to K0566L#520
9.0 Computer Modelling Parameters
9.1 Device Dissipation Calculations
∆T
Rth
2
−VT 0 + VT 0 + 4⋅ ff 2 ⋅r ⋅WAV
WAV =
T
IAV =
and:
2⋅ ff 2 ⋅r
T
∆T = Tj max −THs
Where VT0=1.36V, rT=1.79mΩ,
Rth = Supplementary thermal impedance, see table below and
ff = Form factor, see table below.
Supplementary Thermal Impedance
Conduction Angle
30°
60°
90°
120°
180°
270°
d.c.
Square wave Double Side Cooled
Square wave Single Side Cooled
Sine wave Double Side Cooled
Sine wave Single Side Cooled
0.0480
0.0790
0.0415
0.0735
0.0436
0.0769
0.0394
0.0718
0.0413
0.0740
0.0378
0.0701
0.0388
0.0716
0.0355
0.0679
0.0360
0.0688
0.0320
0.0640
0.0345
0.0665
0.0320
0.0640
Form Factors
Conduction Angle
Square wave
Sine wave
30°
3.464
3.98
60°
2.449
2.778
90°
2
2.22
120°
1.732
1.879
180°
1.414
1.57
270°
1.149
d.c.
1
9.2 D.C. Thermal Impedance Calculation
p=n
−t
τ p
r = r ⋅ 1− e
∑
t
p
p=1
Where p = 1 to n, n is the number of terms in the series and:
t = Duration of heating pulse in seconds.
rt
= Thermal resistance at time t.
rp = Amplitude of pth term.
τp = Time Constant of rth term.
The coefficients for this device are shown in the tables below:
D.C. Double Side Cooled
Term
rp
τp
1
2
3
4
0.01771901
0.7085781
4.240625×10-3
0.1435833
6.963806×10-3
0.03615196
3.043661×10-3
2.130842×10-3
D.C. Single Side Cooled
3
0.01022837
1.078983
Term
rp
τp
1
2
4
5
0.03947164
4.090062
8.789912×10-3
0.08530917
4.235162×10-3
0.01128791
1.907609×10-3
1.240861×10-3
Provisional Data Sheet. Types K0566L#440 to K0566L#520 Issue 1
Page 4 of 11
July, 2008