Online Identification Method of System Frequency Response Model Parameters Based on PMU Measurements

As the proportion of new energy output continues to rise, the risk of frequency stability operation in the power grid has heightened, necessitating stricter standards for real-time assessment of transient frequency stability margins. Choosing appropriate system frequency response (SFR) model parameters is crucial for evaluating transient frequency stability margin. At present, the monitoring coverage of conventional units on the source side is comprehensive and the modeling level is high, but due to the large number, variety, and scattered distribution of load equipment, it is difficult to obtain the operating conditions and model structure accurately. Therefore, an online identification method of system frequency response model parameters based on PMU measurement is proposed in this paper. By combining phase measurement unit (PMU) measurements after large disturbances and based on SFR model, SFR model parameter identification considering load dynamic characteristics is carried out to improve the accuracy of transient frequency stability assessment. The simulation analysis confirmed the efficacy of the SFR parameter identification approach, utilizing PMU data from DC blocked events, the model calculation results obtained by identifying parameters are closer to the actual values measured by PMU compared to typical parameters.