TRANSFORMED AUTOMATIC-GENERATION CONTROL

A new formulation of the principles of Automatic Generation Control (A GC) is presented. Current AGC practice requires estimates of governor caused MW response to frequency deviation from nominal. The frequency bias for the AGC area control loop is an estimate of response for all on-line units within a given area, while the frequency bias for the AG C unit control loop and plant coordinated control loop is an estimate of the response of a given unit. If these estimates (biases) do not re present the actual response in real-time, AGC will create over (or und er) shoot of governor nominal frequency setpoints and corresponding fr equency deviation from nominal. Transformed AGC eliminates the need fo r bias settings, directly controlling the nominal frequency setpoint o f each unit, The AGC process causes the area obligation (area load plu s area net interchange schedule) to be divided up among the on-line un its by any appropriate dispatch scheme and the resulting unit allocati ons become the targets for individual unit closed loop control. Units with setpoint capability receive the target directly while AGC control s the setpoint of the other units (rather than the measured megawatt o utput) to the target values.