Case study: HF powers ahead

A US electrical power agency that spans eight states in the Pacific Northwest has chosen Barrett HF equipment for its independent emergency radio communication system.

The Bonneville Power Administration (BPA) is a federal, self-funded, non-profit agency based in the United States’ Pacific Northwest that markets wholesale electrical power from 31 federal hydro projects in the Columbia River Basin, plus one non-federal nuclear plant and several other small non-federal power plants. Its service territory includes Idaho, Oregon, Washington, western Montana and small parts of eastern Montana, California, Nevada, Utah and Wyoming and supplies about one third of the electric power used in the Northwest.

BPA operates and maintains its extensive high-voltage transmission system (about 24,000 kilometres) in some of the most rugged and difficult to access territory in the continental United States. The territory is also subject to a number of significant natural risks including earthquakes, tsunamis, volcanic eruptions, severe winter weather and flooding, which can cause long-term power outages throughout the region. In addition, other potential threats to the system have been identified, including sabotage, accidents and terrorism.

In this environment, reliable voice communications are essential for the safe operation and maintenance of the system.

In the early years of BPA’s 75 years of operation, an extensive HF system was used, but in recent years cellular telephones and an extensive microwave/fibre backhaul-supported VHF system have provided the BPA’s communication needs. But because BPA’s voice and data administrative communications systems are highly dependent on connective infrastructure and line-of-sight radio communications, they are also subject to gaps in areas of coverage and to potentially widespread degradation of the service during significant disruptive events.

Recognising these gaps, BPA’s transmission services emergency manager, Nelson King, has been working on obtaining management approval to develop and implement an emergency high frequency (HF) radio communication system. The system developed incorporates Barrett Automatic Link Establishment (ALE), a common HF option that provides a reliable and rapid method for calling and connecting during continually changing environmental and radio conditions. The system is user-friendly and allows HF operation with minimal user training.

In 2011, Region X of the Federal Emergency Management Agency worked with Barrett Communications and system integrator NVIS Communications of Morgan Hill, California, to evaluate the Barrett HF equipment for National Telecommunications and Information Administration (NTIA) certification. The subsequent NTIA approval and the positive results of this evaluation facilitated BPA’s management to approve and implement an emergency HF project for their transmission service.

First phase completed

David Rudawitz, a project manager and HF communications expert working for Nelson King, was tasked with moving this project from initial scoping to commissioning. He conducted a detailed analysis of HF products and vendors in the US market and, after completion of his competitive analysis, Barrett Communications was selected. In addition to cost and performance criteria, NTIA certification was also a key element in vendor selection. NVIS Communications was awarded the contract as the system integrator.

The emergency HF system was envisioned to consist of Barrett 2050 HF transceivers in base station configurations, at all power dispatch centres, operations and maintenance headquarters, and each transmission line maintenance headquarters, a total of 31 locations. In addition, Barrett 2050 transceivers in mobile vehicle configurations were also planned for each operations and maintenance headquarters and each transmission line crew; a total of 30 units. The system was also planned to include several Barrett 2060 telephone interconnects, for automatic bidirectional telephone connection into the HF system, and Barrett 2090 HF Manpack transceivers were also identified for the Transmission Vancouver Emergency Coordination Centre (VECC) and each regional office.

Due to the size of the BPA service territory, Near Vertical Incident Skywave (NVIS) antenna configurations were determined to be the best antenna configuration. A NVIS configuration focuses the radio transmissions into an omnidirectional coverage area providing highly reliable operations out to about 500 miles. After extensive testing of various antenna types, BPA selected the Barrett 912 multiwire broadband for the base station installations and the Barrett 2019 automatic tuning antennas with the NVIS kit for the mobile vehicle installations.

Field testing by BPA telecommunications engineering staff and NVIS Communications was conducted to evaluate each proposed radio site and develop installation specifications. Field tests were conducted with the Barrett 2050 mobile vehicle and Barrett 2090 HF Manpack transceiver using several antennas including the 912, 2019 and rapid-deployment broadband antenna. Each site was different, although almost all had the common issue of being located at very large, high-voltage (230 to 500 kV) substations. Initially, there was the concern of significant radio interference from the substation equipment and transmission lines. Of major concern was the station located in Dalles, Oregon, which operates the one million volt Celilo DC Converter, operating both in rectifier (AC to DC) and inverter (DC to AC) modes. Extensive field testing confirmed that the Barrett 912 antenna, in an NVIS configuration along with the meticulous maintenance performed by BPA personnel, reduced this interference to negligible levels.

The integration of the emergency HF system with the existing Power Dispatch Centre’s Avtec communications control units was accomplished by using the Barrett 2060 telephone interconnect. This allowed the HF system to operate as though it were an additional telephone line patch into the Avtec system, thereby making it compatible with the BPA VHF radio system.

Due to the engineering effort and cost, the project is being implemented in phases, with the initial phase (13 base and mobile radios, the dispatch centre base radios and the VECC) completed in June 2013. BPA is also investigating movable, mobile radio configurations using existing trailer hitches. This will enable a mobile radio to be shared amongst several vehicles with a simple procedure to move between vehicles. Further plans include the addition of data transmission capabilities and the possible expansion of the system to include BPA business partners and customers.

This comprehensive HF system is providing BPA with a reliable, infrastructure-independent, emergency communication system that will maintain voice communications under the most demanding and disruptive situations. BPA is currently unique within the US power industry with the deployment of this capability.