Troubleshooting for Power Palette¶
When the loss analysis takes a long time¶
The loss analysis finishes when the steady state is reached.
The steady state is determined by the setting value of Tolerance.
If the steady state is not reached, check the following items.
Check the setting of Saturation Gate Voltage¶
A common mistake is the setting of the parameter Saturation Gate Voltage of a detail switch part.
Please set Saturation Gate Voltage to the same value as the amplitude of the gate drive pulse.
Check the parameters of the detail switch parts (Detail Nch Si/SiC-FET, Detail Nch GaN-FET, and so on)¶
The analysis may not finish because of a mistake in the parameter settings of a detail switch part.
Confirm that the steady state is reached in the ideal analysis¶
The loss analysis of Scideam is performed in the steady state.
Please note that the loss analysis cannot be performed correctly in a circuit where oscillation or the like occurs.
Confirm that the loss analysis is performed in a state that is sufficiently in the steady state¶
Perform a Transient analysis in advance to check the time at which the circuit becomes sufficiently in the steady state, and set the time you checked in Start Time.
Check with Steady analysis turned OFF¶
Even when a Steady analysis is performed, it may not converge to the steady state and the loss analysis may not work well.
In such a case, turn the Steady analysis OFF, perform a Transient analysis,
check the time at which the circuit becomes sufficiently in the steady state, set Start Time, and then run the analysis.
Increase the value of Tolerance¶
While the loss analysis is running, check in the History window whether Storage Rate tends to decrease (it increases and decreases at first, but gradually starts to decrease as the analysis continues) and watch how it goes.
If it does not converge even after several tens of Base Cycle, or if it converges at a large value, stop the analysis and check the Storage Rate that is displayed.
Set the value of Tolerance to a value larger than the Storage Rate. (A value of 5 or less is recommended for Tolerance.)
When the load is a current source or a voltage source, check that its power is set as a loss¶
Voltage sources and current sources are not analyzed as losses, so when you want to use them as a load, you need to explicitly incorporate them into the loss analysis.
For a configuration example, see the sample When you want to use a voltage source or current source as a load.
Check that circuit parameters such as the dead time are set appropriately¶
Even if you try the countermeasures above, depending on the circuit it may not converge.
In that case, you need either to stop the loss analysis and evaluate it with that result, or to change the circuit configuration and parameter values so that the loss analysis is not affected, in order to improve the situation.
Check that the pinch-off voltage condition is satisfied¶
If the pinch-off voltage condition is not satisfied, the loss may become large. Please set the values so that the following condition is satisfied.
| Variable | Description |
|---|---|
| Ron | On Resistance |
| Idr | Drain Current at Rise/Fall Time |
| Toff | Fall Time |
| Vgsat | Saturation Gate Voltage |
| Vth | Threshold Voltage |