Multimode Control of PV-STATCOM for Stabilization of Remote Critical Induction Motor

New multimode control for PV-STATCOM operation of a photovoltaic (PV) solar plant is presented for preventing the instability of remotely located critical induction motors (IMs) whose shutdown during faults can cause significant financial loss to industries. The proposed control operates in four different modes that are determined by PV plant voltage, IM terminal voltage, and high-voltage ride-through limits of the PV plant. The proposed PV-STATCOM control ensures the stability of remote IM even if a PV plant is located up to 40 km away, a very large delay occurs in communicating motor terminal voltage to PV plant, and the system parameters and operating conditions vary over a wide range. The remote PV-STATCOM provides a similar motor stabilization as locally connected STATCOM. Furthermore, the PV plant with PV-STATCOM control can stabilize remote IM, while the dynamic current injection by PV plant as specified in grid codes' fails to do so. The effectiveness of the proposed PV-STATCOM control is examined on a realistic distribution feeder in Ontario and is field demonstrated on a 10 kW PV plant in the network of Bluewater Power Distribution Corporation, Sarnia, ON, Canada. The proposed PV-STATCOM control is a substantially cost-effective alternative to the installation of expensive STATCOMs or static var compensators for stabilizing critical motors.