New Mobile Sub-Station Offers Big benefits to Power Companies
21.11.02

Long power outages for New Zealand consumers could become a thing of the past with the launch by Arthur D Riley & Co Ltd (ADR) of a new mobile substation developed in New Zealand specifically for New Zealand conditions.

The new mobile substation is an innovative combination of world-class technology from top international suppliers and New Zealand expertise pulled together by ADR, as a joint development between ADR and its first customer, the Northland-based lines company Top Energy.

The substation is ideal for lines companies with a predominantly rural base where most have a number of substations with only one power transformer.

This means that in an emergency situation such as breaker or transformer failure, or when maintenance becomes necessary, the substation could be out of action from hours to months, a situation that could stretch damage control contingencies too thin and affect customers.

While some of the technology and machinery in the substation has been sourced from recognised international experts in their areas, ADR estimates that about 60 percent of the total unit is built in New Zealand.

The trailer was constructed in Petone by MF King Industries Ltd, and the whole assembly undertaken in Hamilton by Power System Maintenance Ltd.

Key Points

• ADR’s mobile substations have been built mindful of Kyoto Protocol objectives. One is the use of Envirotemp insulating fluid oil, an exciting new product developed and proven in the United States and only recently released internationally.  It replaces the more than 5000 kgs of traditional transformer oil that would normally be used in a 7.5MVA transformer.

• Other environmentally friendly components are the new-age breakers, which use vacuum isolators and solid insulation instead of the oil or dangerous SF6 gas generally used.

• Unlike other mobile substations which require extensive and costly pre-preparation before they can be used, the ADR substation can typically be set up and operating within an hour of arriving at an unprepared site.

• Fault protection for the transformer as well as the feeders is all managed by one Cooper IXP420 relay.

• Station-class lightning and surge protection is fitted.

• Independent consultants have addressed safety and protection in detail throughout the project.

• The power transformer used on the mobile substation is a modern European design manufactured in China with a German Tapchanger.

• The substation is mounted on a specially designed trailer that is within New Zealand’s 13m x 2.5 m, 4.2 m high, 32 tonne dimension criteria.

• In service, special hydraulic legs extend to hold the trailer perfectly stable and level.    It also features a permanently mounted crane used for handling the unique cable connection spools, and a petrol-driven, hydraulic pump motor that powers the crane and the stabilising legs.

• New age moulded rubber bushings replace porcelain bushings on the transformer