Energy Storage for Frequency Control in High Photovoltaic Power Grids

Abstract

Frequency stability of power systems becomes more vulnerable with the increase of solar photovoltaic (PV). Energy storage provides an option to mitigate the impact of high PV penetration. Using the U.S. Eastern Interconnection (EI) and Texas Interconnection (ERCOT) power grid models, this paper investigates the capabilities of using energy storage to improve frequency response under high PV penetration. The study result helps to identify the potential and impact factors in utilizing energy storage to improve frequency response in high renewable penetration power grids.

Impact of High PV Penetration on Transient Stability — a Case Study on the U.S. ERCOT System

“…In a previous work supported by U.S. Department of Energy Solar Energy Technologies Office [12][13][14][15][16][17][18], the high PV cases for the ERCOT system were developed in PSS ® E for 5%, 25%, 45%, and 65% PV with 15% wind. The high PV cases were developed by replacing conventional synchronous generators with PV power plants, with a sequence of replacement starting from coal power plants, then gas power plants, and further nuclear power plants.…”

Recent Development of Frequency Estimation Methods for Future Smart Grid

“…The number of additions and multiplications of (14) is only 1/ of (12). With the phase angle, the frequency can be estimated based on (13). This method is accurate when the frequency is stable.…”

“…As a result, the power system inertia is anticipated to decrease as more turbine-based conventional generators will be retired and replaced by IBRs. The lower inertia will intensify the power system dynamics [12,13]. To address this challenge and provide accurate measurements under this condition, the PMU needs to track the dynamic change of variables and ensure high accuracy and low time delay.…”

Solar PV Frequency Control in the U.S. EI and ERCOT Interconnections — Case Studies and Recommendations

“…The displacement of synchronous generators with PV has direct impacts on the system inertia level and frequency regulation capability. Many power systems starts to notice the risks of insufficient system inertia and frequency regulation resources due to the increase of PV and other nonsynchronous renewable generation [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30], largely thanks to the deployment of wide-area synchrophasor measurement systems .…”