Characteristic Analysis and Indexing of Multimachine Transient Stabilization Using Virtual Synchronous Generator Control

Abstract

As distributed power sources via grid-connected inverters equipped with functions to support system stabilization are being rapidly introduced, individual systems are becoming more complex, making the quantification and evaluation of the stabilizing functions difficult. Therefore, to introduce distributed power sources and achieve stable system operation, a system should be reduced to a necessary but sufficient size in order to enable the quantification of its behavior supported by transient theory. In this study, a system in which multiple distributed power supplies equipped with virtual synchronous generator control are connected is contracted to a two-machine system: a main power supply and all other power supplies. The mechanical torque of each power supply is mathematically decomposed into inertia, damping, synchronization torques, and the governor effect. The system frequency deviations determined by these elements are quantitatively indexed using MATLAB/Simulink. The quantification index displayed in three-dimensioned graphs illustrates the relationships between the various equipment constants of the main power supply, the control variables of the grid-connected inverter control, and the transient time series. Moreover, a stability analysis is performed in both the time and frequency domains.

Internal Induced Voltage Modification for Current Limitation in Virtual Synchronous Machine

“…As a manifestation of GFM virtual inertia control, this study targets a VSM [9,10,28]. A VSM is a method used to control an IBR by virtually simulating a synchronous generator inside the control system in such a way so that it appears from the power system side as though the generator is connected at the point of interconnection (POI) of the inverter.…”

Review on Virtual Inertia Control Topologies for Improving Frequency Stability of Microgrid

“…The KHI community developed the inverter controller using an algebraic SG model [44] and using the phasor diagram of an SG to produce the reference current in this VSG model, as shown in Figure 4, which ensures the desired operation under any load (especially when the load is nonlinear and unbalanced). The Kawasaki Heavy Industries (KHI) lab-produced this topology.…”