The Indian telecom sector is one of the fastest growing in the economy, expanding at an annual average of 22 per cent over the last few years with cellular phone connections alone growing at 100 per cent. The country’s revenue from this sector will cross US$ 30 billion by 2013, according to a global information technology research firm. According to Gartner, the telecom subscriber base is expected to cross 770 million connections by 2013, growing at a CAGR of 14.3 per cent from 452 million in 2009.
By Srabani Sen
Friday, August 12, 2011: Power backups for telecom and mobile towers
Behind every smoothly running telecom setup and wireless network, there should be a reliable power infrastructure. The telecom sector has been experiencing skyrocketing demand for new wireless products, and in the scramble to meet these demands, there has been a massive demand for backup power solutions. The challenge is to find new backup power sources that satisfy multiple requirements—reliability, flexibility, durability and cost effectiveness—propelling the sector to continuously innovate with tailor made products and solutions to match the fast paced technological changes taking place in the telecom sector.
Fortunately, several players are emerging with the appropriate solutions that have been designed to protect equipment from downtime, damage and data loss caused by power problems. However, choosing the right power protection/management solution, brand or player with the capability to customise is a complicated and difficult process. In this article, we will try to provide fair guidance to help telecom players take the right decision.
Application areas for UPS systems
A UPS system is the major backup solution in the telecom sector—from the changeover time till direct generation takes over. The requirement for UPS systems in the telecom sector can be broadly differentiated into two categories—active and passive. In the active IT category, power backup systems are required for mobile switching centres (MSC), base station controllers (BSC) and tower sites. The UPS rating for these requirements varies. For MSCs, the UPS power requirement is in the range of 120-160 kVA; for BSCs the requirement is for up to 40 kVA; and for towers, it is up to 10 kVA. Also, small rating UPS systems of 1-2 kVA are required for the tower, which are generally installed onto the tower itself. For passive IT application areas, the size of UPS system required is bigger—400-600 kVA. Apart from these, AC and DC UPS systems are also required for mobile equipment. Energy management for outdoor and indoor telecom BTS sites are vital applications.
Types of UPS systems required
According to B Venkat Rao, country manager for medium and large UPS systems, Emerson Network Power, India, the type of UPS systems and other power backup solutions that are required in the telecom sector depend on the requirements and applications of the network. The typical UPS configurations that are required are an MSC of 40-160 kVA; data centre UPS systems of 40-240 kVA; CSC of 1-20 kVA; and UPS systems of 1-200 kVA for offices and other purposes. As telecom sites also face power shortages, especially in rural areas, inverters ranging between 3-15 kVA are extensively deployed for shelter applications to ensure power continuity.
“For critical applications, generally parallel redundant type UPS systems are used, in which, in case of failure of one UPS system, the other takes care of the load,” informs RK Bansal, managing director, Uniline Energy Systems Pvt Ltd.
Deepak Sharma, country head, UPS systems, Delta Power Solutions (India) Pvt Ltd, says, “Double conversion online UPS systems are the right solution for this sector. Conventionally, legacy type UPS (centralised and large) systems are usually used. Today, the trend is to use modular, scalable and highly energy efficient systems with N+X redundancy, remote monitoring and controls for power management solutions. With such UPS solutions, we can grow as the load grows, and have reduced CAPEX (initial investment) and OPEX (running costs). Delta can offer comprehensive and integrated solutions to suit any specific customer need,” he adds.
In mobile towers, operators are more concerned about power saving aspects. Each tower has a transmitter, power supply related equipment, air conditioner, generator, etc. UPS vendors critically examine the power saving aspects of these power gadgets. This is a critical function, which is linked to other important functions of the mobile service, which are monitored by TRAI.
To reduce the overall energy costs (which contributes to the operational cost) of individual towers, telecom operators usually share the tower infrastructure. Besides, power saving efforts are also applied for air conditioning equipment and generators. However, these efforts have not yielded better results. So, some players offer solar power as additional power backup alternatives for mobile towers. Various operators are actively considering this, as it is cost effective and sustainable.
What’s new in this segment
As a technology breakthrough, Delta has introduced Delta Ultron DPS. Delta Ultron DPS series is a double conversion, IGBT rectifier three phase UPS, incorporated with state of art triple level inverter (TLI) topology. With such advanced technology, Ultron DPS is a new benchmark of data centre backup power solution, featuring high efficiency of up to 96 per cent in double conversion mode or up to 99 per cent in eco-mode. Delta supports its customers through a dedicated team of field application engineers, who examine and study the load profile, the existing supply conditions and the environment, before suggesting a reliable power management solution. “It is an ideal solution for MCS and data centre applications that meet critical requirements of tiers I-IV. It is easy to maintain and service, and helps in improving uptime performance and reducing mean time to repair (MTTR),” points out Sharma.
Emerson has recently introduced its Chloride Trinergy UPS range, which is a dynamic ‘three mode operation’ solution that delivers up to 99 per cent efficiency. Chloride Trinergy is designed to protect mission critical infrastructure, such as in data centres. It automatically selects the most appropriate of the three industry standard operating configurations—maximum power control (VFI), maximum energy saving (VFD) and power conditioning (VI). Its modular or adaptable design helps it to grow from 200 KW up to a maximum of 9.6 MW of active power, minimising initial capital costs and avoiding the loss of efficiency that usually results from operating UPS systems at partial loads.
Emerson also offers the NX and ADAPT UPS series, which suit all requirements due to their low footprint and high efficiency. “These systems are based on adaptive architecture. The ADAPT series is available in rack mountable configuration as a ready solution,” adds Venkat Rao.
Inverters are now a common substitute for DG sets at telecom towers as they are more efficient, and do not require daily maintenance, unlike DG sets. Emerson offers the Inpulse inverter series in 10, 15, 20, and 30 kVA capacities. The series comprises a transformer less and bidirectional range of inverters with DSP controls for quick power switching, which also allow remote monitoring.
For telecom towers, Uniline offers UPS systems with 1-2 hour backup periods and with an IP-55 enclosure to take care of the harsh environmental conditions like heat, etc.
With the competitive nature of the telecom business, the capital cost of equipment and installation is a major concern for many corporations. The exact power requirements of a site are difficult to predict. “Any power system capable of incremental expansion without incurring any additional installation cost will offer tremendous financial benefits. Telecom companies look for scalable, reliable and energy efficient power systems for data centre applications, software and intelligent network systems, apart from what is required at the towers,” says Jerome Rodriguez, managing director, Socomec UPS India Pvt Ltd.
The granularity of the system for small power ratings and autonomies gives a sure and fast return on investment. This is aided by the system’s certified high efficiency (96 per cent), which yields reduced air conditioning expenses and further improves the performance of the entire system, consequently reducing the total cost of ownership (TCO). Standard long life batteries improve the reliability of the installation, and reduce maintenance as well as environmental costs. The intelligent battery controller further optimises the investment’s lifespan.
Socomec offers Modulys Green Power UPS systems that range from 20-240 kVA. Modulys Green Power is an online three phase double conversion UPS system, with high power density. It is a totally versatile, redundant, modular architecture for both power and batteries, with exceptional vertical and horizontal scalability. This system guarantees unbeatable energy efficiency, certified 96 per cent (TÜV SÜD) in true online double conversion mode.
Socomec also offers the NeTYS RT online UPS range (rack mountable), ranging from 1.1-11 kVA, with double conversion technology. “The technology ensures a perfectly stable sinusoidal waveform at the output of the NeTYS RT, regardless of the quality of the mains supply. The system includes built-in back feed protection, in compliance with the latest UPS system regulations. This feature protects against reverse current flow without the need for additional external devices,” explains Jerome Rodriguez.
For the telecom tower, Su-Kam offers the Static Bypass Switch, which takes two sources of power at the input and monitors them continuously to provide the better of the two available power sources to the electrical load connected at the output. “One source is used as the master and other as the slave. The load runs normally on the master, and in case of any deviation of voltage and frequency from defined thresholds, the load is instantly transferred to the slave source to provide uninterrupted supply to the load. It is based on the solid state switch’s silicon controlled rectifier (SCR) devices, so it has no mechanical moving parts and requires minimal maintenance,” explains Kunwer Sachdev, managing director, Su-Kam Power Systems Ltd.
The single phase and three phase Static Bypass Switch has a high overload handling capability for safety, and is suitable for applications that require a redundant power supply with a fast transfer time so that the load connected at the output does not experience any power break.
Su-Kam also offers the Sinclair i Series, which provides safe and break free power for devices with very high efficiency and built-in batteries. It is highly efficient in both the mains mode and battery mode, with an extra wide input voltage window. Su-Kam’s Colossal series, with reliable, regulated and stabilised pure sine wave output, is a complete power generation system that is suitable for telecom and mobile towers. Su-Kam’s DSP sine wave inverter is also suitable for telecom and mobile towers.
Innovations that are taking place
The trend today is to move more and more towards compact systems and rack based solutions to minimise the space required. As networks are becoming more complex, far flung and are being managed from remote control sites, UPS systems need to be flexible enough to incorporate diagnostics and predictive failure analysis and be equipped with multiple network management protocols. UPS systems are now available with higher capacity chargers, add-on chargers and accessories that provide the user the capability to manage, diagnose and optimise medium to large battery bank installations.
“The challenges of flexible capacity enhancements and the lowest MTTR demands are best addressed by modular and scalable UPS systems like Delta’s Ultron DPS series and Modulon NH Plus series,” says Deepak Sharma. “Delta’s UPS product portfolio meets all the above challenges and is apt for future needs. All Delta product lines have features like wide input voltage range, which helps to extend the life of the batteries; high energy efficiency, which results in lower wastage of electricity and, hence, lower electricity bills for consumers; high power density and compact dimensions, which help in saving precious flow space, reduce rentals and enable better space utilisation,” he adds.
To meet the changing technologies in the telecom sector, the topology of changes is also being used, resulting in a readily identifiable pattern/lifecycle, that is offline, online and line interactive.
“Modularity is the most critical requirement of modern power management systems. To cater to this, Emerson’s solutions are based on the adaptive architecture model, which guarantees cost effective upgradation,” says Venkat Rao. The adaptive architecture range of products, like the Liebert PeX DS, Liebert CRV, Liebert NXr and OptimizeIT, have attributes like modularity, scalability and higher efficiency, and reduce the total cost of ownership.
“Any solution that we deploy in telecom projects is inbuilt on Emerson’s ‘Energy Logic’ model, which entails the selection of the right IT equipment with low power consumption, hardware consolidation, server power management, high density cooling, monitoring and optimisation. We also offer hybrid solutions with active/dynamic DG control that can work with solar as well as wind energy,” informs Venkat Rao. Emerson also has solar UPS systems and inverters for telecom towers.
Emerson’s power modules use an intelligent inverter management (IIM) system to maximise energy yields by controlling the active and standby status of each inverter module. In case an inverter module trips, the system automatically reconfigures itself to continue generating power. For critical applications, built-in redundancy can be incorporated within the system to maintain maximum output.
“Nowadays, instead of UPS systems, the telecom industry is switching over to telecom inverters, where the DC is generally available through the rectifier. For higher kVA UPS systems, the telecom operator generally insists on UPS systems in the 3+1 configuration instead of 1+1 configuration. This way, the cost is reduced,” explains RK Bansal.
The typical loads in telecom applications require a high level of protection because they are more sensitive to electrical disturbances, over voltage and all possible interference from a mains network. “The UPS system must, therefore, respond to the increasing demands of the loads while avoiding the propagation of electrical disturbances from (and to) the network. Compact UPS systems, designed to fit into small cabinet racks, provide functional and centralised protection to all the peripheral devices,” says Jerome Rodriguez.
As more and more networks are being rolled out, the cost of operating the network is one of the most significant challenges for telecom players in emerging markets. Each location may have different grid power availability and telcos need to provide for contingencies with backups. Voltage fluctuations and phase missing are other commonly encountered power quality problems. UPS players are, therefore, offering products with upgraded energy conversion, storage and control technologies to meet these challenges.
Cost of installation and maintenance
Telecom companies not only demand tailor made solutions, they also look for cost effective options. UPS brands are, therefore, making conscious efforts to keep costs low. “The cost of installing and maintaining UPS systems ranges from 1-3 per cent of CAPEX in the first year and 3-5 per cent every subsequent year. However, the cost also depends largely on the applications installed and conditions at the site,” says Venkat Rao.
Delta’s UPS systems, particularly the Ultron DPS and Modulon NH Plus series, are easy to deploy, install, and redeploy if required, as they have modular architecture. Modular UPS systems also require a low initial investment, as the UPS can be ‘scaled’ when the need for power increases. All these systems are cost effective. “Due to extremely high energy efficiency even at part loads from 15 per cent onwards, Delta UPS systems have very low operating expenses, thereby leading to high savings in energy consumption. A wide input voltage range ensures the operation of the UPS system on the mains without discharging the batteries, thereby extending the life of batteries and reducing battery replacement costs. Delta’s Ultron DPS UPS systems have active power factor correction, which reduces the cost of installation by reducing the requirement of DG sizing and AC panels,” he adds.
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