The Next Generation: SLIMLINE Telecom power supply systems
The average German household has 10 devices on line at any time. In modern society, everyone normally has access online for communications or business purposes at all times. Being ‘Always In Touch’ means always having Internet access, with broadband networks spreading globally using wireless technology (LTE, in future 5G).
The telecommunications systems required need power supplies that are always operational and reliable.
For decades, BENNING has been supplying mobile phone and landline operators worldwide with battery-backup AC/DC power supplies and has invested particularly in developing highly efficient power supplies for reliable, energy-saving operations. POWER News talked with Stefan Kleefeld, BENNING’s product manager, about the next generation of intelligent power supplies.
PN: Mr Kleefeld, BENNING is seen as one of today’s leading suppliers of high efficiency power supplies for operating IT, communications and industrial technology systems reliably. What are the main things the market wants from the new development of the SLIMLINE Series for the telecommunications sector?
Kleefeld: BENNING develops feature rich power supply solutions to give network operators precisely what they need. Current ‘must-haves’ include maximum operating reliability, maximum energy efficiency and maximum available ‘user space’. Features such as flexibility and modularity are also highly important. These form the basis for a significant reduction in installation and assembly times and simpler and more efficient maintenance in subsequent operation. BENNING meets these requirements with its modular concept in our new SLIMLINE telecoms power supply. At the same time, we are cutting the time and costs required to install or maintain power supplies at communications sites regardless of whether they are new ones or existing conversions.
PN: You said the equipment was developed specifically for use in the telecommunications market. What are the fields in which the new system is normally used?
Kleefeld: Kleefeld: Our new SLIMLINE range covers the whole spectrum of mobile phone applications, from switching centres (mobile switching centres or MSCs) through base station controllers (BSCs) right up to the individual base transceiver stations (BTS). So our power supply systems protect all the transmission technology involved (LTE, 4G, VOIP, TV, Server, etc) against any mains supply deviation .
PN: Could you tell us something about power density?
Kleefeld: To build complete power supply systems, individual modules are available with a power output of 2000 W. Compared with our previous SLIMLINE SE models, we have succeeded in increasing power density by 50%. Our 19“ 1HU equipment rack can accommodate either six rectifier modules or five 48 V rectifier modules at 2000 W and one MCU module, giving a power of 10 kW or 12 kW per 1U of rack space.
PN: What other advantages does your new SLIMLINE telecom power supply offer – in terms of flexibility in particular?
Kleefeld: Thanks to their hot plug technology, all modules can be replaced without interruption to the clients load. The equipment racks with their corresponding number of rectifier modules, and the battery and user distribution systems allocated, create a complete modular SLIMLINE power supply system ensuring maximum flexibility.
There are also add-on battery and load distribution systems available at different power ratings. The distribution systems are also designed as 19” plug-in units and comprise one or three height units, depending on power output.
PN: Can the new SLIMLINE be fully flexible, bearing in mind there may be very different performance criteria with very special requirements?
Kleefeld: Yes, we have solutions to meet every need. Our SLIMLINE PSU 4000 power supply system, which is the smallest in power terms, has up to two 48 V/2000 W rectifier modules and one MCU, plus the battery and load distribution system, all in a single 19“ 1HU equipment rack.
For the mid-performance range – which includes, for example, mobile phone base stations – system performances of 10 kW (with an MCU module) or 12 kW can be achieved within a single height unit using just one 1U rack, fully equipped with rectifiers. Connecting a second rectifier rack in parallel can increase power to 22 kW – including an MCU module. Special battery and user distribution systems are available for all power ranges, ensuring flexible and compact space-saving systems.
Even higher power outputs, which central hubs and distribution stations need for example, can be produced by connecting a number of equipment racks in parallel. In this way, output power ratings of up to 400 kW are possible. Such systems are then installed in the special BENNING UC cabinets, which can also accommodate batteries and distribution.
PN: You mentioned the term ‘MCU’ a number of times. What does this module do?
Kleefeld: For the comprehensive control and monitoring functions for these systems, we provide our remote monitoring system MCU (monitoring control unit). For low-power units, this is usually installed as a module in the rectifier equipment rack; for higher-power systems, it can be installed in the power supply cabinet door.
PN: As you said earlier, high-energy efficiency is one of the ‘must haves’. What are the advantages of the new range compared with the previous one specifically?
Kleefeld: Our new series of highly efficient rectifiers reduces AC-DC conversion losses by up to 30%, reducing the actual rectifier physical size by approximately 50% at the same time. What is particularly impressive is that the SLIMLINE range operates at > 97% efficiency in the 50–90% load range.
This means major savings in most facilities telecommunications that service providers use in the field. We have an optional active power management system that determines what the load is at any time and connects or disconnects the rectifier modules accordingly, this will always ensure the maximum system efficiency without compromise to redundancy.
PN: We see the MCU is not redundant. What happens if it fails?
Kleefeld: It is true that the MCU monitors a system and controls it appropriately – for power management, for example; but the system is in fact designed in such a way that the power supply continues to operatereliably even if the MCU fails. The rectifiers continue to supply the system and batteries so that performance remains at 100%. So, failure of the MCU is not critical to the process – and there is no need for the MCU to be redundant. Quite the opposite, in fact: it would merely take up more space and cost more. If it does fail, of course, a signal is sent so we can plan to replace the MCU as soon as possible.
PN: With the rectifiers, you have managed to double the power density for each individual things looking with the MCU unit installed in the racks?
Kleefeld: If you look closer at the MCU module, you will notice that no less than five components are integrated in just one sixth of the 19“ width, which were still separate in the previous model and took up extra space, e.g. an SMNP adapter and the Modbus, which can be connected both via the RS 485 interface or via the network. A modem connection, which is supplied via an RS 232 interface, and the 12 V power supply has also been added. The system configuration can be set up via the colour display or,if a mobile device or a computer is available, then it can be configured easily via a network connection and the Internet browser also. No additional software is required.
PN: You said the system is modular in terms of both rectifier systems and distribution. How will you cope with future power upgrades?
Kleefeld: The system is easily scalable, of course and can grow in line with customer requirements – from 2–400 kW. Through being highly modular, we will be able to plan, configure and deliver customer-specific systems in a matter of weeks from 2018.
PN: If we look at the economics, operating costs should be considered, as well as energy efficiency. What opportunities does the new generation offer for making savings?
Kleefeld: The rectifier modules are identical and mutually compatible, so they can be easily exchanged in all available systems. The advantage for our customers is simple stockkeeping and logistics because only one type of module needs to be kept for all the systems. The bright, high-contrast display of the MCU is also programmed as a signalling unit. If any problem occurs, it lights up all in red and is highly visible from a distance.
PN: The next generation of mobile phone networks is already on the drawing board. 5G mobile phone networks with up to 10 GB/sec offering approximately one hundred times the data rates of the current 4G-LTE networks. What does this technology mean for the existing infrastructure and what challenges does this mean to power supply manufacturers like BENNING in the future?
Kleefeld: As 5G will probably use frequencies between 300 MHz and 300 GHz, the short wavelength means it can carry significantly more data; but it also reduces the operating range. This means that instead of having a few dozen transmitter masts in anurban area, we might need to install and connect hundreds of small transmitter cells. So, on the one hand, we need to supply power reliably to hundreds of small transmitter cells needing power supply systems with low ratings; on the other hand, communication hubs will provide high-speed connections between individual mobile phone stations and providers’ core networks. If these break down, whole regions may crash, so these hubs must be particularly protected against mains failures.
At the same time, if we look at what is happening in the Internet of Things, it is clear that process reliability, for example, in relation to Industry 4.0, will depend on reliable data communications much more than today. So, a modular scalable DC power supply can provide the basis for covering these widely ranging performance requirements within the overall infrastructure. With our SLIMLINE power supply system for indoor and outdoor operations, BENNING is already offering a flexibly scalable system, which can currently be used to upgrade LTE mobile phone stations, hubs and distribution points. As it is equipped with the MCU monitoring and controlling unit, this power supply system is already meeting tomorrow’s communications challenges today.
PN: You mentioned the large number of widely distributed transmission cells and the resulting new or upgraded communications hubs. How will these affect network operators’ operating costs as a whole?
Kleefeld: As it will take 1000 times less energy to send each transmission and so the operating cost per megabyte will fall. Within total operating costs (total cost of ownership), maintenance and service costs will account for a much greater percentage. Multiplying the transmission cells required means operators’ service and maintenance costs will soar if no quick and simple service options are available. Integrated service functionalities could be used to extend the maintenance cycle.
PN: Mr Kleefeld, many thanks for this informative interview. We look forward to further innovative developments from your engineers.