As Superstorm Sandy approached the East Coast in October 2012, grid operators at PJM Interconnection braced for the severe tests of people and equipment that often come with extreme weather. But, thanks to the recently commissioned Advanced Control Center (AC2), the PJM operators had a powerful new tool for maintaining uninterrupted control over vital grid functions.
PJM, a regional transmission organization (RTO), now has more than a year of experience with the state-of-the-art technology systems developed as part of the AC2 program. Those systems run the power grid and administer wholesale electricity markets in 13 states and the District of Columbia in the eastern and central United States, comprising a large part of the Eastern Interconnection.
During the past year in which AC2 has demonstrated a record of 100% availability for reliability tools, the RTO has managed the grid successfully through several challenges, especially those weather-related, including a summer of searing temperatures, the derecho windstorm of the summer of 2012 — with straight-line winds 200 miles (322 km) wide and 600 miles (966 km) long — and Hurricane Sandy and its aftermath. The new AC2 technology systems enabled PJM grid operators to respond even more effectively than it had in the past.
Dual Control Centers
Commissioned on Nov. 8, 2011, AC2 features two fully functional control centers and data centers located at distant sites. Both sites are staffed 24/7 and simultaneously share responsibilities for operating the transmission system and PJM-administered wholesale electricity markets. Either site can run the RTO’s entire system independently should the other become inoperable.
As part of the more than five-year (800-person-year) development process, PJM closely examined the data-gathering efforts and decision-making techniques needed to preserve grid reliability. Measuring the time it takes operators to read alarms, process information and assess the work flow, the RTO developed visual displays that increase situational awareness, thereby improving the accuracy and certainty of the dispatchers’ actions.
By coupling intelligent alarm processing systems in the control rooms with advanced technologies, system operators can rapidly interpret patterns and spot potential grid weaknesses more quickly and with greater assurance. These technologies not only respond to ever-changing system conditions but also learn from operational events under selected conditions to help the operators keep electricity supply and demand in balance so the lights stay on.
PJM is the only grid operator in North America — and one of two around the world — to have two primary control centers. This configuration of dual primary capability reduces the risk to the region PJM serves, its people and the economy by helping to ensure uninterrupted operation of the electric system and markets.
As part of the program, each of the RTO’s control rooms was designed and updated to provide the same technology, work flows and human-factor engineering tools, permitting flexibility in staffing assignments between centers. New computer systems and applications were developed and installed as part of AC2. In addition, new and expansive video walls were developed and installed to make more operational data available for review in real time. A new video wall was built specifically for reliability engineers, and video teleconferencing is available for all consoles between the dual sites.