How do I create a custom three-phase Varying Load?

I am trying to create a three phase varying load, in Simscape Electrical, with either the Three-Phase Dynamic Load or the Wye-Connected Variable Load. It seems that the type of PQ signal that the Three-Phase Dynamic Load block can take in is in compatable with the kind of load varation data, I am trying to input. I want to mimic the average daily load fluctuation of a household. Different power demand at different times of the day. Is there a way to make this work with the Three-Phase Dynamic Load? If not, is there a way to make the black lines be compatable with the blue lines so the Wye-Connected Variable Load can be connected to the system? Or is there an entierly different way thats better than both?

[Vinay]

Hi @Alexander Galvin,

Could you please provide the .slx file of the model? This would help in understanding the parameters and the active power block more effectively.

[Alexander Galvin]

Yes

[Vinay]

Thanks @Alexander Galvin for the model file.

I also need the file 'C:\DieselGeneratorProject\DynamicLoad.mat' used in the signal editor block

[Alexander Galvin]

Here is the file for the signal editor block

Answer 1

[Vinay]

Hi @Alexander Galvin

The "Three Phase Varying Load" is modeled using the Three Phase Dynamic Load block, where the active and reactive power are functions of the positive sequence voltage.

This dynamic load allows external control of the 'PQ' parameter by providing a vector composed of two signals: [P Q]. In Simulink, you can combine the time series data of 'P' and 'Q' into a vector using the 'Mux' block as shown in the below figure

The Simscape Electrical Specialized Power Systems blocks (3- phase lines) can be connected to the Simscape Electrical blocks (wye connected variable load) using the ‘Current-Voltage Simscape Interface’ block. The MATLAB answer provided below elaborates on how to use this block.

https://in.mathworks.com/matlabcentral/answers/1851713-how-can-i-convert-between-simscape-electrical-and-simscape-specialized-power-systems-domains?s_tid=answers_rc1-1_p1_Topic

Here are the relevant documentation links for the R2024b version:

• 3-phase dynamic load : https://in.mathworks.com/help/releases/R2024b/sps/powersys/ref/threephasedynamicload.html
• Current-Voltage interface block :https://in.mathworks.com/help/sps/powersys/ref/currentvoltagesimscapeinterface.html

Hope this would resolve the issue!