Passive Reactive Power Control for Grid-Connected Solar Parks: A Case-Study

The paper analyzes the reactive power management of a solar plant with an installed capacity of 8 MW connected to the national grid. The study focuses on the night-time operation of the PV plant, when it represents a large capacitive load. This is mainly caused by the long length of the medium voltage cable (10 km) connecting the solar park to a switching station of the national electricity grid. Consequently, it is proposed to passively compensate this reactive power by using three-phase compensation coils installed on the low voltage side of the transformers within the solar plant. This solution is examined in terms of both generated power quality issues and energy efficiency system requirements. Simultaneously with reactive power compensation, remedial solutions for the harmful effect of the physical degradation of solar panels induced by their electric potential are also made. In addition, the economics of this power factor correction method and the rapid rate of return on investment for the proposed passive choke system are discussed.