A hybrid adaptive virtual inertia controller for virtual synchronous generators

Abstract

Summary This paper proposes a hybrid adaptive strategy to control virtual inertia of virtual synchronous generators (VSGs). The proposed technique can provide low frequency oscillation (LFO) damping and simultaneously improve primary frequency control (PFC) performance metrics. To this end, a control variable is defined to control extremum values of the VSG inertia during PFC process. The control variable uses an estimation of the grid frequency gradient to identify the PFC process stages following a power deficit event. The extremum of the VSG inertia to provide LFO damping is governed based on the control variable. In particular, the minimum value of the VSG inertia is restricted to its base value during the frequency arresting process in order to moderate the frequency rate of change. In contrast, the maximum value of the VSG inertia is limited to its base value in frequency recovery period to achieve a faster frequency recovery. The efficiency of the suggested method is validated through a power system with VSG penetration level as 50% of the system generation rating. The achieved results verify the superiority of the proposed scheme in the PFC improving and the LFO damping in comparison to the conventional strategy. Moreover, the suggested approach can efficiently decrease the required size of the VSG energy storage by about 50%.

Microgrid Stability Improvement Using a Deep Neural Network Controller Based VSG

“…Simulations are performed on the two microgrids shown in Figure 7 in MATLAB/SIMULINK to demonstrate the efficiency of the suggested DNNC. e results of the suggested DNNC are compared with the results obtained from VSG proposed in [62] and conventional VSG [56]. In Figure 7(b), the same characteristics and parameters are selected for both DGs.…”

“…erefore, considering these problems, it is preferable to resolve the issue of reactive power sharing in a less costly and simpler way and without telecommunication. In [56], VSG control incorporates an extra power loop and an auxiliary inertia unit. In [57], a hybrid adaptive strategy is proposed to control the virtual inertia of VSGs.…”

Mountain gazelle optimisation‐based 3DOF‐FOPID‐virtual inertia controller for frequency control of low inertia microgrid

“…To improve frequency stability, LIMGs are provided with virtual inertia control (VIC) [4]. Several VIC techniques are already in place, conventionally using PID controllers [4][5][6]. Additionally, virtual damping (VD) loop along with conventional VIC is used in Ref.…”

An adaptative control strategy for interfacing converter of hybrid microgrid based on improved virtual synchronous generator

“…The inertial power is provided to the DC microgrid by adaptively swinging the droop curve according to the variation of the DC bus voltage, but the inertial response performance of this method essentially originates from the droop regulation rather than the inertia itself [20]. According to [7], a control strategy for modulating the virtual inertia is proposed to improve the LFO damping of the bang-bang inertia control using the VSG damper winding current. In addition, another control variable is defined to distinguish the frequency suppression and frequency recovery phases after a grid outage event, and the maximum and minimum values of the two phases are restricted to their base values to improve the frequency stability.…”

“…The frequent switching of IC is reduced by segmenting the operating interval of IC and setting thresholds around the reference values of AC frequency and DC voltage [5]. However, the droop control response is very rapid and lacks the inertia in conventional synchronous generators, and as more and more new energy sources are connected to the grid, the distributed generation system with power electronic converters as the interface makes the rotational inertia of the whole grid lower [6,7], which affects the stability of normal operation especially during a generation tripping or heavy load tripping event [8][9][10].…”