Fine regulation with ac_dimmer

[eldarmusin]

I would like to contribute for those who cares in 4 steps.

T Sensor For an experimental purpose, a used a DHT22 than switched for a 18ds20. Kept in code for the better comprehension.

T Regulator I have used the same pid component for the regulation, but as output used the ac_dimmer component. To set up the PID values Kp, Kd, Ki please see below.

Dimmable Output I used the ac_dimmer component because of the triac hardware. The main advantages are:

• Price 2.5 € vs 10 € for an SSR
• The on state voltage is about 0.85V versus 1.6V of an SSR. And the power dissipation is than twice lower, as well as the dissipator for it
• You manage the max voltage on it. So you can reduce the wear of the oven (see max_power parameter)
• You manage the min voltage on it. So you can avoid the high frequency oscillations due to approaching the set point

Set up PID I referred to the file [Russian] .

1. Set Kp = 100, Kd = Ki = 0 and let the system heat
2. You will see a Temperature curve of your sensor like this
3. After 4-5 oscillations, calculate the values as follows and report them to the code:
   • Kp = 1.2 * DeltaT
   • Ki = 1.5 * Tau
   • Kd = 0.2 * Tau

Here is my code sensor:

• platform: dht pin: GPIO14 temperature: id: sauna_temperature_sensor name: "Sauna temperature" humidity: name: "Sauna humidity" update_interval: 1s model: DHT22

output:

• platform: ac_dimmer id: dimmer1 max_power: 0.8 min_power: 0.2 gate_pin: GPIO32 zero_cross_pin: number: GPIO33 mode: input: true inverted: yes

climate:

• platform: pid id: pid_climate name: "PID Sauna Controller" visual: min_temperature: 40 °C max_temperature: 90 °C temperature_step: 1 °C sensor: sauna_temperature_sensor default_target_temperature: 70°C heat_output: dimmer1 control_parameters: kp: 1.44 ki: 13.5 kd: 1.8

[killee]

Hi @eldarmusin

Thanks for your suggestions!

I didn't think about a triac control. The power losses will be better and the power control is better.

Private people has also no responsibility about a not in Phase current.

I don't like this kind of triac power control, but that's my issue 😉. Can you hear some line noise?

Why didn't you use the auto PID tune from esphome?

Regards

[eldarmusin]

Yes I'm hearing a regulation noise. But after some time, just ignoring it.

The Auto PID hasn't worked for me for some reason. Had to find another solution.