High Voltage Three Phase Load Banks
Cressall installs a new 3 phase load bank for testing the Royal Navy’s latest aircraft carriers
As part of the testing regime for the new Royal Navy aircraft carriers Cressall have supplied a 17.225MW three-phase load bank to load test the 11kV distribution system. The distribution system has 6 x 11kV generators of differing capacities to cater for the main load as well as back up and emergency functions. The resistor was graded using 375kW steps and with the other system parts will be used to test the generators to the agreed performance levels.
The resistor was supplied as a naturally cooled system mounted on the dockside to minimise noise levels and save on auxiliary power requirements when running as the energy used to operate conventional forced cooled systems would be significant.
Actual load steps: 375kW, 750kW, 1400kW, 2100kW and 3 x 4200kW, each one 11kV 3 phase.
The silent load bank
This 84MW three phase load bank — the largest ever produced by Cressall — is installed at the Rolls-Royce development facility in Montreal, for testing gas turbines. The 60-metre long load bank is cooled entirely by convection and so is silent in use, an important consideration in this suburban location. It is suitable for both 13.8 kV/60 Hz and 11kV/50 Hz, allowing turbines for markets outside North America to be developed and tested alongside domestic products.
As well as protecting the nearby residential area from intrusive noise, the use of convection cooling instead of fans means that there are no motors to freeze up during the harsh Canadian winter.
This design of load bank is virtually maintenance free and requires very little auxiliary power when compared to force cooled designs.