The technique for identifying load static characteristics based on experimental data

Abstract

The urgency of the discussed issue is caused by the deficiency of the recordkeeping of power load actual parameters and characteristics for simulation, verification and analysis of power system regimes, since this information was updated more than twenty years ago. The attention to static characteristics is occurred due to their use in special software packages for dispatching operation control and electrical energy supply planning. Unless classical tasks of steady state regimes evaluation it turns to be possible to subsist an aperiodic steady-state stability limits, to analyze dynamic transitions, to confirm limits under calculations of emergency transfer capability, to calculate a complex load. The main aim of the study is to develop and improve the technique of polynomial load model derivation based on experimental data. The methods used in the study: Voltage, active power and reactive power instantaneous values are used as the master data. The successive approximation method and least-square method for the calculation of ill-conditioned linear equation systems are used as the methods of mathematical treatment for the polynomial load model derivation. Calculations are done by software package MathCAD. The results: The authors found out and evaluated mathematical methods of experimental data treatment for identifying load static characteristics. It is indicated that the static reactive power characteristic should be represented by the quadratic polynomial model while static active power characteristic should be represented by linear dependence. Polynomial coefficients of the second order were obtained and can be used for load simulation when calculating electric mode.

Keywords

• static characteristics of load
• current
• active power
• reactive power
• substation
• power system