Variable speed drives are front line for fens flood defences21 March 2011

Variable speed drives are helping to protect 20,000 homes and Cambridgeshire farmland valued at over £3.6 billion, by effecting pump control at a new station at Wiggenhall St Germans, in Cambridgeshire.

The pumping station looks after the Middle Level District, an area of fens reclaimed during the l7th Century – much of it nowbelow sea level, due to peat shrinkage and soil erosion.

The original pumping station was built in 1934, but ageing equipment and a predicted requirement for higher capacity meant that a new station was needed.

The new station has six pumps instead of the previous four, each capable of raising 16.66m3/sec to a static head of 4.25m, giving a total capacity of 100m3/sec to handle extreme events.

The Middle Level Commissioners, operators of the station, engaged Atkins to design an electrical system for the new station, including the pump control drives, with an 11kV incomer and transformer to step down to 690V.

ABB supplied the drives – each a 1.2MW industrial drive, fitted as a chassis mount in three motor control centre (MCC) cabinets, and controlled via a SCADA system fed from level meters..

Andrew Heron, estimating engineer for MCC builder Technical Control Systems, explains that accurate flow control was essential to avoid over-pumping and allow navigation by boats.

"We got a lot of help from ABB throughout the project," says Heron. "We were not just given a kit of parts and left to get on with it. ABB gave us exceptional support."

Heron also says that the modules were easy to install. "This means they can also be swapped out very quickly for maintenance or to replace a failed drive," he asserts.

"Each ABB drive module is interchangeable and parts can also be swapped from one drive to another." And he notes that, if the drives suffer a borderline failure, they can still run at a reduced power of 800kW, allowing pumping to continue at a lower rate.

Brian Tinham

Related Companies
ABB Ltd

This material is protected by MA Business copyright
See Terms and Conditions.
One-off usage is permitted but bulk copying is not.
For multiple copies contact the sales team.