Multiple Address Systems (MAS) play an important role in energy production and distribution operations, especially for large companies with many substations at great distances from a central control station. MAS use wireline and wireless systems to achieve two-way point-to-multipoint communications between substations and central control points to monitor and control unmanned substations.

The Southern Co. (Atlanta, Georgia, U.S.) has five power-producing subsidiaries operating in the southeastern United States: Georgia Power, Alabama Power, Mississippi Power, Gulf Power and Savanna Electric. All of these subsidiaries use MAS to monitor and operate their substations remotely. Substation data concerning transmission and distribution of power is transmitted to master sites where it is aggregated and rebroadcast to central control facilities. Southern Co. then makes decisions to ensure that each substation — and by extension the entire system — is running efficiently, helping to control costs.

However, radio frequency (RF) interference was causing problems with MAS wireless communications for many of these power providers, impairing the ability to send and receive critical information. The primary cause of this interference is paging towers used to transmit wireless “interactive messaging” (two-way text paging) services. Unfortunately for MAS users, the RF assigned to paging services is close to those MAS use. The number, proximity and very-high-power output of paging towers creates heavy interference with MAS signals.

AeroComm Inc. (Englewood Cliffs, New Jersey, U.S.) used its patented Ultra-Q active-band pass filter to solve the MAS interference problems for Georgia Power. The Ultra-Q filter uses proprietary technology to reject all off-channel interference, including next-channel interference. The filter adds no insertion loss and has the ability to add gain if needed. In addition, the software-driven Ultra-Q can be programmed in the field using a laptop and serial cable. All five Southern Co. subsidiaries now use the Ultra-Q filter.

The Ultra-Q also allows users to add gain to improve the signal being received at master stations. Southern Co. subsidiaries have installed more than 50 Ultra-Q filters at master stations throughout the southeast. Eliminating interference on their communication systems allows these power companies to continue to remotely monitor and control substations and to maintain a commitment to high-output efficiency.
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