Static Error Mechanism Analysis and Simulation Research Based on PI Control

Due to its simple and practical algorithm, PI control has long been welcomed by the engineering community, and its application in engineering is very common. There must be static error in the proportional control. In order to eliminate the static error in the proportional control system, based on the proportional control, the integral control is introduced, and the control system is changed to PI control. First, the static error in proportional control is analyzed. Then, the static error mechanism of PI control is analyzed in the time domain and the frequency domain, respectively. In the frequency domain analysis, the time domain static error formula is transformed into the frequency domain static error formula, and its feasibility is verified by mathematics and simulation. The calculation is simplified using the frequency domain static difference formula. Studies have shown that PI control can completely eliminate static error. PI controls have very good static performance.