When looking at the P, I and D curves with set point steps, the integral should be quite stable, P should have the biggest amplitude, and D should progressively cancel the P when P is decreasing.
My curves:
Please note I’m using an alpha version taking outdoor temperature as an additional input, to compute E = Ke * (set_point - outdoor_temp), and output = P + I + D + E
In the end the integral is reduced and seems more stable as the thermal losses of the building are compensated by E.
