학술논문

Analysis of 0.1-Hz Var Oscillations in Solar Photovoltaic Power Plants
Document Type
Periodical
Source
IEEE Transactions on Sustainable Energy IEEE Trans. Sustain. Energy Sustainable Energy, IEEE Transactions on. 14(1):734-737 Jan, 2023
Subject
Power, Energy and Industry Applications
Geoscience
Computing and Processing
Oscillators
Reactive power
Voltage control
Delays
Impedance
Voltage measurement
Voltage
Grid integration
solar photovoltaic
oscillations
plant control
Language
ISSN
1949-3029
1949-3037
Abstract
Oscillations with very low frequency at 0.1 Hz, have been observed in voltage and var in practical solar photovoltaic (PV) systems when power exporting ramps up to a certain level. This letter provides an explanation on the formation of 0.1-Hz oscillations and identifies three critical factors that lead to the oscillations: communication delay between the plant-level control and the inverter-level control, high volt/var sensitivity at a high power exporting level, and the volt-var feedback system consisting of the plant control, inverter control and the grid impact. Furthermore, a critical feature of the 0.1-Hz oscillation is also explained: why oscillations appear only in voltage and var, but not in real power.