Applicability of Droop Regulation Technique in Microgrid - A Survey

Abstract

Currently, the worth of power generation on the basis of renewable sources is rapidly growing. Correspondingly the microgrids and the DG units are impressed the researchers for their peculiar features. Power sharing is the major concern when various DGs are connected to the microgrid via power electronic converters. It is mandatory to achieve an appropriate power sharing when the manifold DGs are activated in parallel. For that, the two ultimate quantities-power angle δ and voltage magnitude V are regulated to acquire the real and reactive power sharing correspondingly. Many innovative control techniques have been used for load sharing. The most common method of local load sharing is the droop characteristics. Subsequently, there is a swift momentum in the advancement of researchers to meet the challenges of the droop control techniques in the power sharing concerns, an extensive literature review on active and reactive power sharing, voltage and frequency control in microgrid has been emphasized. The various conventional and modified droop control techniques/strategies that relates to power sharing issues have been highlighted in this work.

A Comprehensive Review on Micro Grid Operation, Challenges and Control Strategies

“…Hence modified droop controls arise by changing the parameters of the conventional droop control as per their system requirement. The modified droop control [41] referred in this work are :P-V and Q-F droop control, angle droop control and generalized droop control.…”

Review on the Coordination and Energy Management of Microgrids Broad Based on PQ Controller and Droop Control. Some Useful Information Is Given in This Paper

“…The main purpose of this control method is to enhance dynamic performance of the system and sort out the problem related to the sharing power in the distributed energy storage system and to improve the life time of some storage devices [17]. The state of charge is one way to recognize time for charging and discharging according to the criteria determined by a designer and for some storage devices can be used in backup system when the main micro sources become incapable to satisfy the load demand [1].…”

“…But the SoC-based droop control, the frequency gradually deviate from its nominal value. So, an auxiliary control has been integrated in order to restore the frequency and amplitude of the AC bus voltage so this effect, made the frequency and amplitude of the point of common coupling to be restored [17].…”

Application of Model Predictive Control to BESS for Microgrid Control

“…To control the frequency of the microgrid, the frequency droop control scheme is suitable for a BESSs control system. However, conventional droop control can cause a steady-state error [33]. Thus, this study proposes an improved droop control scheme in which the steady-state error is removed by a new feedback signal through the PI regulator [9].…”