ABB And Great River Energy Celebrate 25 Years Of HVDC reliability
Control system upgrade is most recent investment for forward-looking utility
ABB, the leading power and automation technology company, joined Great River Energy (GRE) today in celebrating the Minnesota utility's milestone of twenty-five years operating one of the world's most reliable high voltage direct current (HVDC) transmission system.
The CU HVDC system — so called in reference to the original managing utilities — consists of a 435-mile transmission line and converters at each end. The system operates at a nominal +/-400 kV DC and delivers 1000 MW of power between Coal Creek Station in central North Dakota and Dickinson Converter Station located west of Minneapolis, Minnesota. The system was originally installed by ABB and the company has been an integral partner in subsequent upgrades.
"GRE prides itself on being proactive, and we've taken steps over the years to ensure the ongoing reliability of this increasingly important facility," says Karl Mortensen, GRE Supervisor, HVDC and System Engineering. The result has been over twenty five years of reliable HVDC service." The most recent example of GRE's focus on long-term performance was a control system upgrade completed in April of 2004.
"It was challenging," recalls ABB project manager Gunter Bergner. "The CU system is a bi-pole HVDC transmission system. We had to implement and test the control upgrade for one pole with the other pole in operation and then do the same for the other pole. Between those two tasks, we took advantage of a planned weekend bi-pole outage to upgrade the bi-pole system controls. We did as much work as possible prior to the outage, and we had the benefit of a very strong partnership with GRE, so the work was completed on time without any major snags."
Most upgrades of this kind take several weeks to implement for only one pole, but to take advantage of the general maintenance outage ABB and GRE had to complete the entire bipole upgrade in near record time of just four weeks. The new control system follows other upgrades to the converter controls and the system's voltage rating over the preceding four years, and positions GRE to continue its remarkable track record of reliability.
ABB (www.abb.us) is a leader in power and automation technologies that enable utility and industry customers to improve performance while lowering environmental impact. The ABB Group of companies operates in around 100 countries and employs about 102,000 people. The company's U.S. operations employ about 8,500 people in manufacturing and other facilities in 32 states.
Source: ABB