A simultaneous voltage and frequency control scheme for photovoltaic distributed generation units in small-scale power systems
Photovoltaic units that are connected to the grid through dc/dc converters and inverters in distributed generation, are controlled via a synchronous-generator-like voltage control mechanism. While other control schemes such Synchronverters are used to control the inverter frequency and power at a fixed dc link voltage, the proposed approach considers both the dc-link voltage dynamics and the inverter ac voltage regulation. The dc-link capacitor stores kinetic energy similar to the rotor of a synchronous generator, providing inertia and contributes to the system stability as well as it maintains the inverter input voltage. The inverter is controlled to mimic the behaviour of the synchronous generator fluxdecay model. Then, a droop-like mechanism is applied to the DC-DC converter, which interfaces the photovoltaic source to the inverter, along with angle and automatic voltage regulator mechanisms applied to the inverter to control the ac voltage via reactive power control.
Publication Source (Journal or Book title)
2017 IEEE Energy Conversion Congress and Exposition, ECCE 2017
Saberi, H., & Mehraeen, S. (2017). A simultaneous voltage and frequency control scheme for photovoltaic distributed generation units in small-scale power systems. 2017 IEEE Energy Conversion Congress and Exposition, ECCE 2017, 2017-January, 2285-2290. https://doi.org/10.1109/ECCE.2017.8096444