Sensitivity analysis of smart grids reliability due to indirect cyber-power interdependencies under various DG technologies, DG penetrations, and operation times

The proposed risk assessment methodology is applied to an actual distribution grid. The several sensitivity studies are performed to gain insight into how the penetration level of DG units under various DG technology scenarios can affect the ICPIs impacts on the risk level of smart grid. The test results show that regardless of the DG technology scenario, the ICPIs impacts of protection system vulnerabilities gradually increase while the DG penetration increases. On the contrary, the ICPIs impacts which are corresponding to the monitoring system monotonically decrease as a function of DG penetrations, and it saturates when the penetration exceeds a certain level. The test result infers that the ICPIs impacts on the risk level of smart grid are more dramatically emphasized when the extended study duration is analyzed. In fact, the ICPIs impacts increase as a function of system age, because the failure in monitoring system may accelerate the aging failures, and particularly when the system is subject to wear out period, the ICPIs impacts on the system reliability should be more concerned.