Submission 86
A Grid-Forming Control Method Based on Current Compensation for Enhancing Transient Stability
WISO25-86
Presented by: Haowen Wang
Grid-forming (GFM) grid-connected inverters (GCIs) exhibit two fundamental characteristics: voltage support and power support. Voltage support is typically achieved through virtual admittance (VA) control due to its robust and stable performance. Power support, on the other hand, is commonly realized via virtual inertia provision using second-order power synchronization controls (PSCs), such as virtual synchronous generators (VSGs) or P–f droop control with a low-pass filter. However, second-order PSCs may lead to a loss of synchronism under large disturbances, even when equilibrium points exist. Recently, hybrid synchronization control (HSC), which integrates voltage- and power-based synchronization loops, has shown effectiveness in preventing loss of synchronism. Nevertheless, the introduction of the q-axis voltage in the synchronization loop inevitably induces power droop, as perfect reference tracking cannot be guaranteed. To address this issue and enhance transient stability, this paper proposes a current-compensated hybrid synchronization control (CC-HSC) strategy. In this approach, a compensation current is injected into the output of the VA control to generate the current reference. This compensation current not only mitigates the power droop caused by the q-axis voltage but also improves system damping, thereby enhancing transient stability. Simulation results demonstrate that, prior to a fault, both the VSG and CC-HSC controlled GCIs accurately track the power reference, whereas the HSC-controlled GCI exhibits noticeable power droop. Following a voltage dip fault of the same magnitude, the VSG-controlled GCI loses synchronism. In contrast, both HSC and CC-HSC controlled GCIs maintain synchronism; moreover, only the CC-HSC controlled GCI successfully restores the power reference after the fault. These results validate that the proposed CC-HSC method ensures accurate power tracking while simultaneously improving transient stability.