Fault short-circuit current calculation method based on virtual synchronous generator (VSG) control

Abstract

Based on the fault short-circuit current calculation method of virtual synchronous generator VSG control, in the dq coordinate system, the related equations are combined to obtain the relationship between the actual short-circuit current output value and the internal potential amplitude generated by the virtual synchronous generator VSG; according to the internal potential amplitude equation, the virtual internal potential amplitude expression is solved; the short-circuit current analytical expression in the dq coordinate system is obtained, and the short-circuit current analytical expression in the abc coordinate system is obtained through the park inverse transformation. This method is based on the control architecture of a typical virtual synchronous generator VSG. When a short circuit occurs in the power system, the method accurately calculates the fault short-circuit current expression of the virtual synchronous generator VSG for the condition where the excitation electromotive force is limited due to low voltage ride-through, without considering the electromechanical transient process, but only considering the electromagnetic transient process.

Images