New tie model for system operations

Over the past few years, electric utilities have witnessed an increased growth in the use of interconnections for power interchange and a greater reliance upon ties for normal operation of the system. Two new tie models have recently been developed. These models are part of a computer program which is currently being applied as an improved method for representing ties in system operations. How the need for such a model development, and several applications where utilities will find the models useful, are discussed.