Abstract
Power grid pattern is expected to evolve from generator-based power systems towards converter-based systems in the forthcoming decades. Therefore, grid-forming converters will be pertinent to interconnected power grids in pursuance of enhancement their resilience against disturbances. This paper introduces a new efficient damping control method for grid-forming converters that provides a smooth power modulation and an efficient damping response against frequency and voltage deviations. First, an averaged state-space representation for a grid forming application in dq synchronization frame is derived. Based on this model, a new hybrid damping controller, including the concept of state feedback control and PI control, is proposed to address the main issues in existing controllers. The state feedback controller is optimally designed using a linear-quadratic regulator (LQR) approach to optimize the system performance. Moreover, the PI controller is optimally designed using the pattern search algorithm. The proposed damping control method integrates optimally between the control loops through a mapping matrix to rapidly synchronize with the grid and efficiently damp the oscillations. Simulations are carried out to prove the proposed method robustness. Finally, a comparative study using controller hardware-in-the-loop (CHiL) is employed against conventional system to validate the proposed damping method.
Highlights
Synchronous machine (SM) is one of the most prominent equipment in the conventional power grid, due to its significant contributions for preserving the grid stability against load disturbances [1]
This paper proposes a simple grid-forming converters (GFC) controller that optimally combine three damping concepts, namely, the damping through Q-V control loop as in power system stabilizer (PSS) and power oscillation damping (POD) in Static Synchronous Series Compensator (SSSC), the damping through P-f control loop as in certain types of virtual synchronous machine (VSM), and the damping through the DC-link dynamics as illustrated in the matching control method
In the proposed damping method, the synchronization angle is calculated using a linear combination between 4 signals, namely, uc(dc) that depends on the DC-link voltage regulation, uc(p) that depends on the regulation of the active power and
Summary
Synchronous machine (SM) is one of the most prominent equipment in the conventional power grid, due to its significant contributions for preserving the grid stability against load disturbances [1]. The method given in [11] has applied the difference between the virtual speed (frequency) and the nominal speed This method influences the steady state performance including inertia response and governor functions. This method does not influence the inertia response, PLL cannot properly operate in weak grids, which might cause instability problems Another method presented in [24], [25] has applied the virtual speed derivative or the active power with suitable filters for damping purposes. This method needs a tricky filter design to achieve strong damping without affecting the inertia response and steady state operating conditions.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
