Evaluation of Human Error Probabilities of Power Grid Dispatchers Based on Hybrid Risk Analysis Method

Abstract

In the power system, the dispatcher's inappropriate execution commands often have great impact on the safe operation and might lead to accidents. In order to further study the risk mechanism of human factors and calculate the human error probability (HEP), this paper proposes a hybrid risk analysis method called SD-SPAR (a System Dynamic Model for the Standardized Plant Analysis Risk (SPAR) Method), which combines the SPAR Human Reliability Analysis method with the System Dynamic (SD) approach to initialize a framework to model dynamic relationships between the Performance Shaping Factors (PSFs) and HEP. First of all, to reduce the uncertainty of grade division for the PSF stress and make the result of HEP more accurate, a physiological factor measurement method was adopted to calculate the dispatcher workload and help to divide the stress quantitatively. Second, based on the SD-SPAR method, the path dependence between the PSFs were summarized to reveal their influence on HEP and successful performance. Third, by analyzing the causality and feedback mechanism of the internal factors, the reasons accounting for incidents can be found to help analysts have a deeper understanding about the incidents, and to move forward improvement strategies to decrease the human error risk so as to achieve better task performance. This study can also be used to form the basis for the simulation of various control scenarios. It can help to explore better solutions to prevent and correct human error behaviors, and guarantee the safe operation of the power system.