Calculation of power systems inertia and frequency response

Fundamental changes are taking place in the way that electricity is produced and consumed. These changes are raising concerns related to the deterioration of Inertial and Frequency responses. This paper presents a method to calculate the value of these responses using the data from system disturbances that result in sudden loss of generation. The method has very modest data and computational requirements and has a number of practical applications such as monitoring the deterioration of these responses over time. The method is illustrated by applying it to an actual generation loss incident on the Eastern Interconnection.

I. Introduction

Frequency Response (FR) and Inertia (M) on our interconnections are declining [1]–[4]. This trend is considered to be due to emerging new generation technologies, new load supply technologies, and new types of loads. As FR and M are of fundamental importance to the reliability of our interconnections, the North American Electric Reliability Corporation (NERC) has initiatives [1], [2] to study and monitor these parameters. Early last year the Federal Energy Regulatory Commission (FERC) also acted on this issue and revised the pro forma for large and small generator interconnection agreements to require these facility to have adequate frequency response capability. The effective monitoring of FR and M requires a power system simulation model which does not require large amounts of data, does not have large computing requirements, and can be applied to study several scenarios quickly to validate result correctness. This paper presents such a simulation model, and demonstrates it by applying it to the May 12, 2012 generation loss incident of 1711 MW on the Eastern Interconnection.