PV-Solar based Hybrid Telecom Power Plant for Roof-top Mobile Towers

The exponential growth in smartphone usage over GSM networks has significantly increased the energy demands of expanding telecom infrastructure. Concurrently, the adoption of green energy from renewable sources has become a key trend in the telecom industry. This paper presents the design and implementation of a hybrid PV-solar/Grid powered Telecom Power Plant (TPP) suitable for operation at modern roof-top mobile base stations. The conventional grid-powered telecom hardware is efficiently modified to operate on PV-solar power during daylight hours. The proposed TPP supports three rectifiers, each with a 2 kW capacity giving overall power of 6 kW, connected in parallel with hot-plugging features for redundancy, flexibility, and ease of maintenance. The power supply automatically switches between the PV source and the grid supply, based on the available voltage at the PV panels. The Power Factor Correction (PFC) stage in grid-mode is optimized for PV integration using Maximum Power Point Tracking (MPPT) control via a synchronous boost converter. The system employed by PFC stage, followed by an LLC resonant converter topology for a 400V to 54V DC-DC converter with synchronous rectifiers at the output. A multi-mode digital control system, implemented on a DSP controller, regulates the output voltage and current. This system utilizes pulse frequency modulation to meet the dynamic energy requirements of the telecom load over a wide current range, including boost-charging of the battery in Constant Current/Constant Voltage mode. A prototype 2 kW system was designed and implemented using Silicon Carbide power MOSFETs for most power switches. It was tested with a 3.3 kWp polycrystalline PV solar panel array and a 100Ah 48V Sealed Maintenance Free battery pack, supporting a 48V/60A 5G mobile-tower base-station. The proposed system operates at around 94% efficiency, utilizing an average 12–15 kWh of green energy per day.