Synchrophasor Data Based Distributed Droop Control in Grid Integrated Wind Farms to Improve Primary Frequency Response

Abstract

In power system, the wind power generation is gradually increasing to encourage the sustainable growth of electricity production, resulting shut down of fossil fuel based conventional plants. Due to this, system inertia reduces which degrades stability of the grid. To overcome the situation, interest is on droop control mechanism for the wind turbines (WT). This paper proposes a synchrophasor data based distributed droop control (SDDC) for the grid integrated wind farms (WFs), to improve primary frequency response (PFR) of power system. The method uses phasor measurement unit (PMU) data to obtain load-generation mismatch in the power system. Thereby, ratio of power reserve (RPR) is calculated for the WFs. The RPRs are based on power reserve (PR) and installed capacity of the WFs. The RPR is further used to obtain power share for each WT, based on their wind speed, inside the respective WF. The power share is used to calculate required change in droop at the WTs to generate the allocated share. The performance of the proposed SDDC is verified for a load disturbance, variation in wind speed at a WF and a synchronous generator outage. In these situations, the proposed method is found to be more effective, as compared to the available distributed Newton (DN) method.