Example Temperature control of heating system 0 obtains temperature of hot water 0 and sends 8 ec regulate steam valve to keep constant outlet temperature load: hot water flow rate Q and outlet temperature 0 P control, opening of regulating valve u controller output 日 Q1≤Q0 steam F--- Q condenser water 100
C T condenser water steam Q V Example Temperature control of heating system T obtains temperature of hot water and sends c c regulate steam valve to keep constant outlet temperature. load: hot water flow rate Q and outlet temperature P control, opening of regulating valve controller output
Integral function Controller output is proportional to error e duse→l= soled dt Output of I control is constant only e=0, no steady state error Reduce system stability. i control is always slower than that of p control Open loop gain is proportional to So, increase So In reduce system stability
In t S e u S edt dt du 0 0 0 Integral Function Controller output is proportional to error e. • Output of I control is constant only e=0, no steady state error. • Reduce system stability. I control is always slower than that of P control, • Open loop gain is proportional to S0 , increase S0 reduce system stability