PID Control in SWMM 5 for an Orifice
Click here to download: extran_pid_3_master.inp (47 KB) Subject: PID Control in SWMM 5 for an Orifice The blog http://swmm5.blogspot.com/2010/12/pid-control-in-swmm-5-for-type-3-pump.html describes the Function getPIDSetting which returns the PID setting at each time step. The PID parameter set contains three values -- a proportional gain coefficient, an integral time (in minutes), and a derivative time (in minutes) which are kp, ki and kd, respectively. More about the theory of PID controllers can be found at http://en.wikipedia.org/wiki/PID_controller . Here is an example PID Rule that will keep the node depth at 5 feet in a SWMM 5 model by changing the Orifice Setting. The Orifice setting opens and closes the orifice over time. The example file is attached in this blog. In this particular example, you can reduce the oscillations about the 5 foot rule level by lowering the integral time and derivative time coefficients in the PID control rule. An important note is that for Weirs an...