The new Midland Metro chose ups protection to secure its power supply. Electrical Contractor jumps on board.
Midland Metro rolled into service in June with a PowerLan unit, from Chloride Power Protection, sited at every one of the 23 stations along its 20 km route. Linking Wolverhampton to Birmingham, the Midland Metro employs ups to ensure a power supply to security and communications facilities in the event of a mains failure.

The Metro Line One uses the former Great Western Railway route from Birmingham Snow Hill to Wolverhampton St George's. The final 2 km of the line at Wolverhampton share road space with motor vehicles, the tracks being flush with the road surface. Three more lines will be added at a later stage.

Providing passenger information, maintaining communications and ensuring safety at every station is essential and to this end, each station is equipped with a pa system, cctv, electronic information boards and emergency telephones. All these services, together with on-board emergency alarms and communications, have ups support and are remotely controlled from a centre at Wednesbury Parkway. The ups also support the data for signalling and transmission systems.

Power and transmission equipment for these facilities, together with the PowerLan ups units, are installed in trackside cabinets located at each station. The specification for the project was for each ups to provide 30 minutes autonomy. However, in the period since their installation, the PowerLans have demonstrated under trial conditions a capability to provide as much as two hours autonomy in emergency mode. Each PowerLan installation comprises the ups and a separate battery unit. Both are relatively compact units and are capable of withstanding the arduous conditions that can be experienced when placed in an external location.

At Midland Metro, the ups are linked to a SCADA system that allows the control centre to monitor the performance of the ups, and other equipment, at all times.

As most stations on the line are unattended, it is necessary to provide up-to-the-minute travel information and emergency communications facilities for passengers. CCTV is also an essential for passenger safety and as a deterrent against vandalism. Any interruption of the mains supply at a station would sever communications with the Wednesbury control centre and this cannot happen. The benefit of the ups is twofold. It makes sure essential equipment continues to function and personnel at the control centre are alerted to the power failure and can react to the problem.

What's new in power quality

Advance Galatrek unveils the second generation PowerRak. It provides a customised ups system, housed in a 19” rack. AC packages are available in the 700 VA to 4 kVA output range. Socomec UPS presents the three-phase Digys ups. It is available in sizes from 10-60 kVA and incorporates a processor that executes operations at seven times the speed of standard processors. Liebert adds to the UPStation GXT ups range. New 6 and 10 kVA versions have been introduced to offer high levels of protection to expanding networking environments.

Best Power launches the double-conversion Axxium ups, a rack mounted version of its server-sized Best 610 ups. Three models include 1000, 2000 and 3000 VA.

IMV UK has launched a ups that uses a technique called power mirroring to achieve low distortion on both input and output. The unit is called Image and is available in models from 10 to 40 kVA. MGE UPS Systems has launched the Pulsar EX Plus range of ups. It offers protection from 1000-4000 VA, with extended autonomy achieved with optional battery cabinets. These can be mixed and matched for optimum protection

Powerware Systems introduces the Powerware Prime 20 and 30 kVA, a three-phase double conversion on-line ups. It is designed for power protection of server frames, telecommunications and industrial applications.

Rhopoint Systems introduces the Power Recorder, a cost effective power monitoring system that can measure power quality, consumption and harmonics simultaneously. Chloride Power Protection introduces the Synthesis 3Twin Series of ups. It provides protection for loads from 10-30 kVA and offers two types of circuit architecture.

Uninterruptible Power Supplies offers the PowerWAVE ups. It gives flexibility and cost efficiency for n+1 parallel redundancy and is available in ratings from 7·5 to 60 kVA. AVK SEG introduces Powercon DVR, a synchronous machine and matching reactor which sits across the supply eliminating power sags. The rotary system sustains output voltage and so stabilising the power.