Influence analysis of working state control angle on electric spring with switchable smart load

Abstract

Traditional electric springs can only stabilize the voltage of critical loads (CL), while sacrificing the operational stability of non‐critical loads (NCL), the status of these two loads is obviously unequal, exposure to fluctuating voltages for extended periods of time can be hazardous to NCL. To solve this problem, a control method based on electric spring (ES) with switchable smart load (SSL) that does not distinguish between CL and NCL is proposed. This paper briefly introduces first the definition, principle and control strategy of the ES with SSL. Then, the relationship between the working state control angle in this control strategy and the working state of ES is analysed in detail. A method to obtain reasonable value ranges of working state control angle by setting boundary conditions is studied. Finally, an experimental platform is built based on DSP TMS320F28069 for experiments, experimental results show that ES can stabilize the voltage of different loads in different time by adopting this control strategy, the working state of ES can be adjusted and the four‐quadrant operation of electric spring can be realized by changing the working state control angle.