High-Frequency Loading Strategy of Electric Load Simulator Based on Improved Active Disturbance Rejection Control

Applying Active Disturbance Rejection Control (ADRC) to the load torque control of the Electric Load Simulator (ELS) can effectively suppress the surplus torque caused by the active motion of the device under test. However, due to the bandwidth limitation of the State Error Feedback (SEF) control law, the torque loading accuracy cannot meet the double-ten indicators when the loading frequency is high. To further increase the loading frequency of ELS, this paper further analyzes the SEF control law, designs a third-order linear tracking differentiator (TD) to introduce the second-order differential signal of the instruction, and proposes a Second-order State Error Feedback (SSEF) control law. Based on SSEF, the correction factor is introduced to adjust the position of the closed-loop zero point of the system, the closed-loop transfer function of the system is derived and the frequency domain characteristics are analyzed, and finally an Improved Active Disturbance Rejection Control (IADRC) based on the Improved State Error Feedback (ISEF) control law is proposed. According to the frequency response curves of the closed-loop system with different correction factor values, the correction factor value is reasonably selected to ensure that the frequency domain characteristic curve of the system remains flat and the system still has a good dynamic response in the high-frequency loading condition. An ELS experimental platform is built and a comparative experiment is conducted to verify the effectiveness of the IADRC strategy.