Coordinated control to achieve stability and dynamic response enhancement of weak‐grid‐connected inverters based on sequence‐admittance models

In grid-connected inverters (GCIs), the phase-locked loop (PLL) behaves as a negative admittance at point of common coupling (PCC), composed both PLL controller and current terms. Therefore, not only dynamics, but also dynamical interactions between might trigger instabilities in weak grids, which complicates parameters regulation. The smaller bandwidth could help to mitigate instabilities, expense sacrificing system dynamic response. view this, coordinated control q-axis voltage PCC-voltage feedforward based on sequence-admittance models is proposed here. designed with simple proportional coefficient make PLL-induced insensitive parameters. other words, would be limited by stability requirements response speed ensured. Furthermore, developed coordinate phase compensation, thus achieve improvement. Finally, simulations hardware-in-the-loop tests are carried out verify enhanced modified GCI grid.