User Manual of EM760 High-Performance Inverter Fig. 6-7 Block Diagram of Process PID PID control is a kind of closed-loop control. The output signal (Out) of the object controlled by the system is fed back to the PID controller, and the output of the controller is adjusted after PID operation, thus forming one or more closed loops. This function is to make the output value (Out) of the object controlled by the system consistent with the set target value (Ref). The specific block diagram is as shown above. The PID controller is used for control by calculating the control quantity with three calculation factors, i.e.
proportion (P), integral (I) and differential (D), according to the difference between the set target (Ref) and feedback signal (Fdb). The features of each calculation factor are as follows: Proportion (P): Proportional control is one of the simplest control modes. The output of the controller is proportional to the input error signal. When only proportional control is enabled, there are steady-state errors in the system output. Integral (I): In the integral control mode, the output of the controller is proportional to the integral of the input error signal. Steady-state errors can be eliminated, so that the system has no steady-state errors while operating in the steady state.
However, drastic changes cannot be tracked. Differential (D): In the differential control mode, the output of the controller is proportional to the differential (i.e. change rate of the error) of the input error signal. This can predict the trend of changes in errors,quickly respond to drastic changes, and improve the dynamic features ofthe system in the control process. F09.00=0: digital PID setting F09.01 The PID setting depends on the digital PID setting (F09.01), and the specific percentage is F09.01/F09.03 * 100.00%. 87 Function code Function codename Parameter description Unit Default setting Attribute F09.00 PID setting source 0: digital PID setting 1: AI1 2: AI2 3: AI3 4:
AI4 (expansion card) 5: PULSE, high-frequency pulse (X7) 6: communication setting (percentage setting) 0 〇 F09.01 Digital PID setting 0.0 to PID setting feedback range F09.03 0.0 ● F09.03 PID setting feedback range 0.1~6000.0 100.0 ●