Adaptive control method of VSG transient power angle based on terminal voltage information perception
Abstract
Virtual synchronous generator (VSG) is prone to transient power angle instability under grid fault, which weakens its voltage and frequency support ability to the grid. During the grid fault, the evolution characteristics of VSG transient power angle and terminal voltage are closely coupled with the grid fault voltage. Using the VSG terminal voltage to sense the grid fault information, the active control of VSG transient power angle under different fault depths can be realized without detecting the grid voltage. Therefore, this paper first analyzes the transient power angle characteristics of VSG and the transient characteristics of terminal voltage, analyzes the mapping relationship between them and the grid fault voltage, and establishes the terminal voltage information perception mechanism. Based on this, an adaptive control framework for VSG transient power angle is constructed. The active power command value is dynamically adjusted by using the terminal voltage sensing information to reduce the imbalance of VSG active power input and output during the fault period. Furthermore, a control parameter tuning method based on terminal voltage sensing information is proposed to ensure the transient stable operation of VSG under different fault depths. Finally, the correctness of the theoretical analysis and the effectiveness of the proposed method are verified by simulation and experiment.