Design of a PV fed Hybrid DC Bus Power Supply with the High Voltage Ride Through Capability

Reliability and power quality of DC bus power supply is foremost important in the applications such as autonomous industrial automation, cloud computing, communication towers, uninterrupted power supply system of control panels/substations, robotics, auxiliary loads of propulsion systems, etc. The capacity of these power supplies is ranging from 20 to 2000 Watts in rating. Further, the voltage level has also increased from 12V/24V to 48V at the DC rail. The voltage regulating equipment and protection against short circuit and overvoltage is a backbone for the DC bus supply. Many standalone and fully autonomous applications such as communication towers, monitoring system, remote weather stations, etc., are powered by solar photovoltaic (SPV). In view of today's state of art and future requirement, this paper proposes the design and development of high power quality DC bus supply system which provides a regulated bus voltage, high dynamic response against switching and load variations and fault ride-through capability. Highly intermittent and inertia-less SPV is supported with battery for prolong back-up and ultracapacitor to enhance the voltage ride-through capacity of the DC bus. Detail modelling and analytically established control strategy for the entire system is presented in this paper, which mainly focuses on dynamic performance of the DC rail against fault in load-lines.