Super-Twisting direct torque optimal L2 -gain control for self-excitation induction generation system

Abstract

The use of self-excitation induction generation system (SEIGs) was identified by many researchers as an important way to construct the high power density isolated power supply system (IPSS). However, for the wide variation range of the prime mover speed and the load power, the majority of the researchers consider it’s important to improve the power supply performance of the SEIGs. This research contributes to propose a new Super-Twisting direct torque optimal L2-gain control (ST-OP-L2-DTC) method for the SEIGs. In order to enhance the torque response speed, the Super-Twisting space vector direct torque control method is adopted in the voltage-linkage outer loop subsystem, comparing with sinusoidal angular modulation, which can improve 13.5 percent of the voltage usage ratio and raise the DC rectifier voltage. For minimizing disturbance influence, the optimal L2-gain control method is used in the current inner loop subsystem, which can minimize the impact of disturbance by solving the Linear Matrix Inequality (LMI) to obtain the optimal control law against the worst disturbance. Results of simulation and experiment show that, under the load power and the speed varying condition, comparing with traditional voltage outer loop-current inner loop (VOL-CIL) control method, ST-OP-L2-DTC method can enhance the DC output voltage transient stability, realize the derivative convergence of the sliding mode surface, shorten the stability time of the electromagnetic torque.