Grid-following, Grid-forming, Hybrid control converter, Wind generator
Abstract
Wind generators are vital to fight against climate change, but they may bring stability issues to electrical systems. They are connected to the grid through converters with grid-following (GFL) control, which is necessary for them to operate at the maximum power point tracking (MPPT). The problem is that GFLs have very limited grid support capability. Grid forming (GFM) converters, on the other hand, are well suited for this task. This work proposes the Hybrid Control Converter (HCC), which enables the wind generator converter to emulate, in a single converter, the operation of two converters working in parallel and simultaneously, one GFL and one GFM. This way, the HCC can show characteristics of both at the same time: the fast and accurate power control of the GFL, and the inherent grid support capabilities of the GFM. An HCC model applied to a Type IV wind turbine was developed and simulated in PSCAD from two perspectives: a single unit operating connected to the electrical grid and three units connected to the electrical grid at different points. Simulation results have shown that the HCCs operated stably, being able to provide frequency support.
