How can I model a constant-power load with the "Three-Phase Dynamic Load" block using the Specialized Power Systems library in Simscape Electrical R2022b?

I have followed the example "Dynamic Load and Programmable Voltage Source" in Simulink R2022b and observed that the block "Three-Phase Dynamic Load" behaves as a constant-current load. As per the documentation, a constant current load and a constant impedance load behavior can be achieved by setting the exponents “np” and “nq” to 1 and 2, respectively.

How can I model a constant-power load with the "Three-Phase Dynamic Load" block using the Specialized Power Systems library in Simscape Electrical R2022b?

Answer 1

[MathWorks Support Team]

To model a constant-power load, it is recommended to use the “External control of PQ” parameter in the "Three-Phase Dynamic Load" block. The following steps are a guide to achieve this workflow:

1. Open the Properties window by double-clicking the block "Three-Phase Dynamic Load".
2. Check the box “External control of PQ”.
3. Click Apply, and then OK.
4. Connect the new input PQ port to a “Constant” block, indicating the target power values as a vector [P Q] that contains the "P" and "Q" power components in Watts.

More information about the "External control of PQ" parameter and other parameters used in the "Three-Phase Dynamic Load" block is available on the following documentation page:

https://www.mathworks.com/help/releases/R2022b/sps/powersys/ref/threephasedynamicload.html#f3-2406128