Quick release improvement for voltage inverters

Edited by the Engineeringtalk editorial team Apr 21, 2006

Quick release connectors on the cooling circuits of the medium voltage inverters significantly add to the functionality and ease of use of these advanced electrical systems.

The inclusion of Staubli quick release connectors on the cooling circuits of the medium voltage inverters produced by Converteam at Kidsgrove significantly adds to the functionality and ease of use of these advanced electrical systems.

Many control systems and electrical installations, particularly those containing advanced electronics, require dedicated cooling systems to maintain the designed operating temperature and ensure performance is to specification.

Cooling by forced air or liquid are options, demineralised water or an ethylene glycol mix often provide the cooling medium.

A liquid cooled solution brings advantages; it can often be half the size of the air cooled equivalent, cost less and is normally quieter in operation.

Converteam makes liquid cooled drives having supplied in total over 750MW of its Delta liquid cooled inverters.

The firm was originally part of English Electric, then GEC and subsequently Alstom; it now stands as an independently owned business alongside sister Converteam companies in Rugby and Glasgow, each developing electrical generation and power conversion products.

Current business levels are growing rapidly with increasing demand for its products from the burgeoning wind energy sector as well as buoyant sales to its more traditional markets of marine propulsion and process engineering.

Production volumes of some inverters are increasing tenfold.

Converteam includes in its original designs the use of Staubli SPT 12 or RMI 16 connectors on the cooling circuits depending on the cooling medium.

David Mayer, Mechanical Designer at Converteam, said: "We can rely on Staubli to suggest the most appropriate connector to use in each application, taking into account the cooling fluid, flow rate required and physical size constraints".

"The use of a quick release connector permits disconnection of the cooling circuit without the need to drain the system, a major advantage".

The SPT 12 is a compact, lightweight, 12mm nominal diameter, coupling manufactured from high strength aluminium.

The valve design provides optimal flow within a small outside diameter and, being flush-faced, no leakage occurs on disconnection.

The coupling can be supplied with a number of thread forms and seals.

Converteam uses this connector on demineralised water cooling circuits in inverters.

For ethylene glycol cooling circuits on rectifiers, Converteam uses an RMI 16 connector.

RMI couplings are suitable for applications where quick and easy connection of fluid lines is required.

The couplings can be specified with either single or double shut off valving providing an optimum flow with a low pressure drop.

When required, the plugs can be recessed for easy handling and storage, eliminating any risk of damage.

Staubli nickel plates the standard brass fitting for Converteam to reduce any galvanic effects of dissimilar metals in the system.

All cooling circuits are tested by Converteam, in situ, to a pressure of 6bar, twice the operating pressure; no failures of Staubli connectors have resulted.