What the 1996 outages did for oversight

The power failures of the summer of 1996 stimulated development of planning and operating standards by the North American Electric Reliability Council (NERC), Princeton, N.J., which oversees the regional coordinating councils. The standards may require hefty investments by generation and transmission owners. Mandatory compliance procedures are being developed, with penalties for noncompliance.

The Planning Standards emphasize the design and operation of control and protection, system monitoring, and power plant testing for validating simulation models and data. One example is a requirement that synchronous generators connected to the transmission network operate in a voltage-control mode.

Overall, the NERC Operating Standards specify best engineering practice in many areas affecting the dynamic performance and reliability of power systems. A key part of the Operating Standards concerns the development of ancillary service mechanisms affecting system reliability. Deregulation and restructuring include unbundling of power system "services" such as generation reserve, generation control for load following and frequency regulation, reactive power supply, and the capability to restart a plant after a blackout without the aid of off-side power.

Interconnection agreements between generation and transmission companies, for example, may specify reactive power interchange between, say, 0.98 power factor leading and lagging. If the network required production or absorption of reactive power outside this range, the transmission company would pay the generation company for the service. It would also have a big incentive to install reactive power compensation equipment (shunt capacitor banks and shunt reactors) at effective locations to keep the generation company interchange close to a unity power factor.

Reliability would be enhanced because the generators would have substantial reactive power reserves for emergencies. —C.W.T.