On the Parameter Estimation of Linear Models of Aggregate Power System Loads

This paper addressed some theoretical and practical issues relevant to the problem of power system load modeling and identification. An identification method is developed in the theoretical framework of stochastic system identification. The identification method presented in this paper belongs to the family of output error models and is based on well-established equations describing load recovery mechanisms having a commonly recognized physical appeal. Numerical experiments with artificially created data are first performed on the proposed technique and the estimates obtained proved to be reliable and accurate. The proposed method is then tested using actual field measurements taken at a paper mill, and the corresponding results are used to validate a commonly used linear model of aggregate power system load. The results reported in this paper indicate that the existing load models satisfactorily describe the actual behavior of the physical load and can be reliably estimated using the identification techniques presented herein. Keywords— Parameter estimation, power system load modeling, system identification, linear dynamic systems, output error method.