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Dynamic overload capabilityBasic task 1 - Known quantities:
Converter, cycle time, overload factor, overload period - Quantities to be found:
(min.) base load duty period and max. base load current - Solution:
see table 2
Example for basic task 1 - Known quantities:
- 30 A converter
- Cycle time 113.2 s
- Overload factor 1.45
- Overload period 20 s
- Quantities to be found:
- (min.) base load duty period
- max. base load current
- Solution:
- Limit characterisitic
30 A converter - Overload factor 1.5
- Overload period 300 =
300 s/113.2 s) x 20 s =
53 s -> - max. base-load current =
44 % IBem = 13.2 A
Basic task 2 - Known quantities:
Converter, cycle time, overload factor, overload period - Quantities to be found:
max.. base load duty period and max. base load current - Solution see table 3
Example for basic task 2 - Known quantities:
- 30 A converter
- Cycle time 140 s
- Overload factor 1.15
- Base load current =
0.6 Irated = 18 A
- Quantities to be found::
- Maximum overload period
- Minimum base-load period
Solution: - Limit characteristic for 30 A converter
- Overload factor 1.2
- Base-load current = 60 % Irated ->
- Overload period300 = 127 s
- Max. overload period =
- (140 s/300 s) x 127 s = 59 s
- Min. base-load duty period =
- 140 s – 59 s = 81 s
| | Definition | |
|---|
Base load duty period300 | Min. base-load duty period for 300 s cycle time
(300 s overload period | | Overload period300 | Max. overload period for 300 s cycle time | |
Table 1
Explanation of terms | | Cycle time | |
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| | < 300 s | >=300 s | 1. Determine curve | Selection of limit characteristic for specific converter and overload factor | | 2. Overload period 300 = | 300 s/cycle time x overload period | Overload period300 | 3. Base load duty 300= | | 300 s Overload period300 | 4. Base load duty period300<
Base load duty period300 for max. base load current = 0 | Yes: Required cycle time not configurable No: Read off max. baseload current for overload period300 from limit characteristic | | 5. Determine percentage for base-load current | Read of percentage for base-load current from diagram | |
Table 2
Steps to solve basic task 1 | | Cycle time | |
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| | < 300 s | >= 300 s | 1. Determine curve | Selection of limit characteristic for specific converter and overload factor | | 2. Max. Overload period = | 300 s/cycle time x overload period300 | 300 s base-load duty period 300 | 3. Min. Overload period = | Cycle time - max. overload period | Cycle time - max. overload period |
Table 3
Steps to solve basic task 2
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