Indirect grid power factor tuning with PV-STATCOM using shift mode phase locking strategy

Reactive power supervision and regulation within the disciplined borderlines have captivated phenomenal attention for the sake of running the power system at stable and efficient potential. Energy sources furnished with advanced power and control architectures present robust and versatile features for load sharing, command-based control, reactive power compensation and power factor tuning for a wide range of loads. Photovoltaic (PV) module integrated with advanced inverter technologies has the ability to indirectly tune the reactive power from the grid with strict precision which is impossible to achieve with conventional passive compensators. This paper presents a novel method for active and/or reactive power compensation from PV-based STATCOM embedded with maximum power point tracking (MPPT) algorithm and having the capability of power injection into the grid. The modeling initiates with the implementation of phase locked loop, detection of load current components and inverter reference generation based on the command signal to control the grid current. The effect of enabling the MPPT command causes generation of maximum active power from PV module irrespective of the load demand which sinks to the grid in case of its surplus availability. Finally, the reactive power supply from the grid is indirectly controlled by implanting a phase shift equivalent to the set power factor in the PLL output which rotates both the inverter and the grid current vectors. The proposed methodology of command-based tuning of power factor is open loop by nature which eliminates instability issues, produces least steady-state error and is fast enough to converge in a reasonable time.