The influence of model mismatch to power system calculation, part II: on the stability calculation

Secure and reliable operation of power system is significant for nation's economy development and society stability. To ascertain this, analysis and calculation plays an important role. Power system calculations can be classified into three categories in time domain: for the past, for the present and for the future respectively. And the calculations for the future seem to be more significant to support power system operation and make production arrangement. However, almost all the calculations of power system are based on the mathematic models established from the physical system; and the models may have various errors and mismatch the actual system, especially for the calculations facing the future. The mismatch between calculation model and actual system influences the analysis result and the operation of power system. Aimed at the possible mismatch between calculation model and actual power system, this paper analyzes the influences of bus operating mode, transmission line operating mode, load distribution and quantity respectively on power system transient stability. The results show that the mismatch of grid structure can influence power system stability more greatly than loads do. As the mismatch between calculation model and actual system always exists, this paper also suggests that power system analysis should depend more on measurements rather than calculation model