QT40.361 Datasheet, PDF (21/27 Pages) PULS GmbH – THREE PHASE INPUT

Q-Series
QT40.361
36V, 26.7A, THREE PHASE INPUT
24. APPLICATION NOTES
24.1. REPETITIVE PULSE LOADING
Typically, a load current is not constant and varies over time. This power supply is designed to support loads with a
higher short-term power demand (=BonusPower^®). The short-term duration is hardware controlled by an output
power manager and is available on a repeated basis. If the BonusPower^® load lasts longer than the hardware
controller allows it, the output voltage will dip and the next BonusPower^® is available after the BonusPower^® recovery
time (see chapter 6) has elapsed.
To avoid this, the following rules must be met:
a) The power demand of the pulse must be below 150% of the nominal output power.
b) The duration of the pulse power must be shorter than the allowed BonusPower^® time. (see output section)
c) The average (R.M.S.) output current must be below the specified continuous output current.
If the R.M.S. current is higher, the unit will respond with a thermal shut-down after a period of time. Use the
maximum duty cycle curve (Fig. 24-2) to check if the average output current is below the nominal current.
d) The duty cycle must be below 0.75.
Fig. 24-1 Repetitive pulse loads, definitions
P_PEAK T_PEAK
T₀
max.
150%
100%
P₀
P₀
P_PEAK
T₀
T_PEAK
Base load (W)
Pulse load (above 100%)
Duration between pulses (s)
Pulse duration (s)
Fig. 24-2 Max. duty cycle curve
Duty Cycle
0.75
0.6
P₀ = 10%
P₀ = 50%
P₀ = 75%
0.4
0.2
P₀ = 100%
P_PEAK
0
100 110 120 130 140 150%
Tpeak
DutyCycle =
Tpeak + T0
T₀ =
Tpeak - (DutyCycle x Tpeak)
DutyCycle
Example:
A load is powered continuously with 480W (= 50% of the rated output load). From time to time a peak
power of 1440W (= 150% of the rated output load) is needed for 1 second.
The question is: How often can this pulse be supplied without overloading the power supply?
- Make a vertical line at PPEAK = 150% and a horizontal line where the vertical line crosses the P0 = 50%
curve. Read the max. duty cycle from the duty cycle-axis (= 0.37)
- Calculate the required pause (base load) length T0:
- Result: The required pause length = 1.7s
- Max. repetition rate = pulse +pause length = 2.7s
Tpeak - (DutyCycle x Tpeak) 1s - (0.37 x 1s)
T₀=
DutyCycle
=
= 1.7s
0.37
More examples for pulse load compatibility:
PPEAK
1440W
P0
TPEAK
960W 1s
T0
>25s
PPEAK
1440W
1440W 0W 1s
>1.3s
1440W
1200W 480W 1s
> 0.75s
1440W
P0
480W
480W
480W
TPEAK
0.1s
1s
3s
T0
>0.16s
>1.6s
>4.9s
Dec. 2016 / Rev. 1.3 DS-QT40.361-EN
All parameters are specified at 36V, 26.7A, 3x400Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone [phone] Germany
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