A control strategy for GFM photovoltaic units without energy storage considering reserved power

Abstract

In engineering applications， the use of energy storage to support grid-forming photovoltaic （GFM PV） units faces challenges such as high construction costs and difficulties in land negotiations. However， without energy storage， grid-forming control struggles to find the operating point of maximum power point tracking （MPPT） during weather changes. To address this， a grid-forming control strategy that considers reserved power and integrates virtual synchronous control （VSC） is proposed. Additionally， a controller is designed to prevent DC bus voltage collapse， stabilizing the DC bus voltage. A control model for GFM PV units without energy storage， considering reserved power， is developed in Simulink， and simulations are conducted on the RT-LAB platform in conjunction with physical power electronics to obtain the simulation waveform. The simulation results demonstrate that the proposed strategy can find the operating point of MPPT in various scenarios， ensuring stable outputs of active and reactive power， thereby verifying the effectiveness of the control strategy.

Keywords

• pv
• grid-forming
• improved constant voltage method
• maximum power point tracking
• energy storage