Controller Design and Stability Analysis of Electric Spring with Switchable Smart Load

Abstract

Aiming at the characteristics of the traditional electric spring (ES) to stabilize the voltage of critical load (CL), electric spring with switchable smart load (SSL) is studied. The basic principle of ES with SSL is discussed, a control strategy is proposed to use one PR controller to control different loads respectively by using the indirect voltage control method. The controller parameters are deduced by the method of root locus, the stability of the controller is analyzed by using the method of state space modeling, and Matlab is used to compare and analyze the stability of the system when stabilizing different load voltages when the R/X ratio of line impedance is different. The results show that the switching of smart load (SL) and the voltage stabilization of different loads can be realized under the designed controller parameters.