Efficiency Improvement of Solar-Wind based Dual-Input Converter for Telecom Power Supply B. Mangu, K. Kiran Kumar and B. G. Fernandes Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India. E-mail: bmangu@iitb.ac.in, kiran756@gmail.com, bgf@ee.iitb.ac.in Abstract— Uninterrupted power supply for the telecom base transceiver stations (BTS) is required to ensure reliable com- munication services. The challenge becomes severe if the BTS is located in remote areas where access to continuous power supply from grid is not available. To address this need, this paper presents a hybrid solar-wind energy telecom power supply with battery storage. An improved dual-input Cuk-buck converter (IMDICB) topology is proposed and it’s efficiency is compared with Dual-input Cuk-buck converter (DICB) topology. A detailed component wise comparison between these topologies is presented to establish reduction in size of energy storage elements and device ratings. These topologies can extract maximum power from two renewable sources, simultaneously or individually. In order to evaluate the performance of these topologies, simulation studies are carried out and the results are presented. The efficiencies achieved by the DICB and IMDICB are 93.39% and 96.72% respectively, thus indicating an improvement in efficiency. Index Terms—Telecom power supply, renewable side con- verter, dual-input Cuk-buck converter, grid side converter. I. I NTRODUCTION Modern telecommunication networks have wide geograph- ical reach, covering both urban hubs as well as remote areas. Base transceiver stations (BTS) are the backbone in energizing telecommunication networks. Availability of power supply to the BTS is critical for reliable communication services, especially in remote areas where access to continuous grid supply may not be possible. Hence, diesel generators (DG) are used to provide continuous power supply. However, use of DGs is expensive, subject to heavy pilferage, require regular maintenance and causes CO 2 emission. Therefore, a reliable and cost effective solution for powering telecommunication systems in remote areas is required. Recent research in the area of harnessing energy from renewable energy sources has shown encouraging results. Further, multi-source hybrid alternative energy systems have higher capability of delivering continuous power with reduced energy storage requirements. For providing power to BTS in remote locations, one of the viable solutions is to deploy integrated solar and wind systems [1]. As per the report on green power solutions by the department of telecommunica- tions in India, the use of the solar-wind with utility grid/diesel as backup system is an economically attractive alternative to dedicated diesel generators for mobile telecom base station for rural areas [2]. For achieving the integration of multiple renewable sources, the traditional approach involves using dedicated single-input converters one for each source, which Fig. 1. Architecture of grid interactive hybrid solar-wind system. are connected to a common dc bus. However, such systems are costly and their control is complex [3]. The use of a multiple-input converter (MIC) for hybrid power systems is attracting increasing attention because of reduced components, compactness and centralized control [4]. The MICs proposed in [5]-[8] are essentially based on parallel connection at the output of a number of boost converters and buck-boost converters. Such MICs do not enjoy the advantage of reduced device and element counts. For the multi-input buck-boost converter reported in [9], [10] the available dc voltage sources have different magnitudes, and hence, cannot be connected directly in parallel, the dc voltage sources are connected in parallel through a series-connected active switch and diode, and only one power source is allowed to transfer energy to the load at a time, thus preventing more than two dc voltage sources from being connected in parallel. Further, two diodes are always conducting which increases conduction losses. A single dual-input Cuk-buck converter was reported in [11]. This converter allows the two sources to transfer power to load simultaneously or individually. Enslin and Snyman in [12], [13] have reported that converter efficiency can be enhanced by use of parallel power transfer technique (PPT). This technique uses two parallel paths for transfer of power from source to load i.e. (a) power flowing directly to the load and (b) power flowing to the load through the converter. Improvement in efficiency from 85% to 95% while transferring power to 36 V battery system using PPT 978-1-4577-1829-8/12/$26.00 ©2012 IEEE