How can I implement a load with constant power demand for varying voltage in the simulation?
For RMS simulations the load type has to be set to 100% dynamic load, this means constant impedance Z. Additionally in the RMS dialogue of the load type the voltage dependency of P and Q can be set. Set both to zero, which indicates that there is no power variation with varying voltages. Furthermore the upper and lower voltage limits have to be specified. In this range the load will react as specified by the coefficients; outside this range the load will behave like a constant Z.
In the example attached the project includes three study cases showing the different usages of a load connected to a voltage source with a linear variation of the magnitude:
- EMT-load: The load is usually modelled as a pure inductive/capacitive load. The AC phase voltages and currents as well as P and Q of the load are shown in the predefined plots.
- RMS-load: The load type is set to constant P and Q for the voltage range specified by the upper and lower voltage limits. Outside the limits the load will be modelled as a constant Z due the fact that the current would otherwise rise to infinite values at zero voltage.
- Ext. RMS-load: Additionally the set points of the load can be set from an external DSL model, which is shown in this study case.