Cyber Defense Budget Assessment in Smart Grid Based on Reliability Evaluation Considering Practical Data of HV Substation

Abstract

Communication and control in the smart grid without any disturbance is the primary task of High Voltage (HV) substation. The nature of electrical network obliges constructing and operating the functions of substations in remote areas far from urban centers. This can cause increasing of concerns about their security. Thus, HV substation designers have focused on defensive algorithms for decreasing these concerns. This paper deals with four cyber defense approaches, including hardware, software, communication shielded cable, and optimized cable route. The defense budget has been estimated via Fuzzy Analytic Hierarchy Process (FAHP) as a function of hardware, software, and communication shielded cable and optimized cable route. Knowledge and experience of experts help to extract mathematical relations between these four approaches. These relations are the base of optimization of attack and defense budget. In the proposed algorithm, "loss of load expectation (LOLE)" as a reliability index is utilized to optimize cyber defense budget of each part of studying network (one supervisory control and data acquisition (SCADA) center and nine HV substations). By comparing the LOLE with a permitted design threshold value, optimal budget of each item is determined. The accuracy of proposed methods has been validated by implementing to a case study real network.