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a PID controller for an Ohmic heating system

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I want to add a PID controller for an Ohmic heating system. I want to control the system based on the center temperture of the heated sample, for example 70 °C in a range of ±0.5°C. However, when I set the controller parameters, I am getting an error massage "All active controll parameters must have consistent units".

Would anyone help me to solve this issue?

Thank you



2 Replies Last Post 22.11.2023, 13:10 GMT-5
Magnus Ringh COMSOL Employee

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Posted: 1 year ago 17.11.2023, 02:50 GMT-5

Hi,

I'm not sure how the entire setup of the model is done, but if, for example, you want your control variable for a temparture controller to be a heating device with an SI unit of W (watt) (it could be or something similar depending on the model setup but let's assume W here). Then K_P should have a unit of W/K, K_I should have a unit of W/(K*s), and K_D should have a unit of W*s/K. When you have set up the PID Controller with consistent settings, the deduced unit for the controller appears in the Information section at the bottom of the Settings window.

Best regards,

Magnus

Hi, I'm not sure how the entire setup of the model is done, but if, for example, you want your control variable for a temparture controller to be a heating device with an SI unit of W (watt) (it could be W/m^3 or something similar depending on the model setup but let's assume W here). Then `K_P` should have a unit of `W/K`, `K_I` should have a unit of `W/(K*s)`, and `K_D` should have a unit of `W*s/K`. When you have set up the PID Controller with consistent settings, the deduced unit for the controller appears in the **Information** section at the bottom of the **Settings** window. Best regards, Magnus

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Posted: 1 year ago 22.11.2023, 13:10 GMT-5

Thank you very much Magnus for your replay and help. It wokred.

Thank you very much Magnus for your replay and help. It wokred.

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