Robust Output Feedback Control Design for Inertia Emulation by Wind Turbine Generators

RoCoF-Minimizing H₂ Norm Control Strategy for Multi-Wind Turbine Synthetic Inertia

“…As commonly seen in SI studies [18], [19], this work will consider a dynamic equivalent of system frequency, particularly the model presented in [20]. This model is focused on frequency stability, and simplifies the representation of other dynamic phenomena in order to facilitates the frequency stability analysis.…”

“…The identified parameters are shown in Table 1 and the identified frequency response in Fig. 2 The model in (1) represents the CoI (Center of Inertia), as it is usually in advanced control SI studies [18], [19].…”

“…To apply the method described in Section IV-B, the system (2) must be linearized. In general, the various proposals SI consider linear equivalents of system (2), claiming that the linear representation is sufficient to represent the underlying nonlinear phenomenon [18], [19]. However, in the case presented, if one computes the gain K i using the method in Section IV-B and then implements the proportional controller in the nonlinear system (2), the control action may fail in maintaining stability because of the lack of representativeness of the linear equivalent, as shown in the scheme in Fig.…”

“…Similarly, it is difficult to assess the impact of the H ∞ control proposal on specific frequency adequacy metrics such as the RoCoF or Nadir (the lowest point of the frequency transient) as the H ∞ controller is focused on minimizing the value of the largest spectral component of the norm of the state vector. The work in [19] also considers a H ∞ -based controller in comparison to a Linear Quadratic Regulator (LQR) controller. The proposal also formulate a one-bus approximation and one controller, presenting the same limitations as [18] in terms of overlooking multi-wind turbine operation.…”

“…The proposal also formulate a one-bus approximation and one controller, presenting the same limitations as [18] in terms of overlooking multi-wind turbine operation. The LQR example in [19] uses some elements of H 2 control, but a definition of a specific frequency control performance metric is not considered. The results above have the limitations of overlooking a multi-wind turbine scenario and an explicitly representation of a frequency control performance metrics as RoCoF or Nadir.…”