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A risk assessment approach for the cascading failure of electric cyber-physical system (ECPS) considering multiple information factors is proposed. First, considering hardware, software and personnel factors existing in the information system, the reliability model of the control function of the information system is established. Second, the reliability model of the physical component considering the control function of the information system is established. Finally, the risk assessment approach for the cascading failure of ECPS is introduced, and the probability of the cascading failure and the expected energy not supplied are used as the risk indices. Test results on an improved RTS-79 system show the effectiveness and significance of the method for choosing the optimal power communication network topology and the measures to reduce the risk.

Deep integration of information and communication technology (ICT) brings insecure risk to power system operation. A risk assessment approach of power grid considering the reliability of information system was presented. The influence of information system on the action of protection was analyzed firstly. The reliability model of information system was established. Then the evaluation index, including risk of line overload and risk of bus voltage out of range, was established and calculated. A practical method was given to identify both the weakness of the grid and the equipment of information system that sensitive to the risk, helping operators make valid measures to reduce the risk level. The IEEE 118-bus system is taken as the test system. Risk assessment results indicate that the failure of the information system bring more risk to the system operation, service application software has the maximum sensitivity to the system risk variation, and prevention measures for operators can be obtained to decrease the risk level.

Based on the fact about self-regions in current power system, a new topology regions method is firstly proposed. Then a new comprehensive risk assessment method on electrical substation for dispatching operation is presented, in which the risk of bus system arrangement and equipment operation state within a substation and the overall topology of a substation during a whole power system are all considered. Finally, the correctness and effectiveness of this method are tested by the utilization in a real power system.

This paper presents a new risk assessment method for cascading failure caused by electric cyber-physical system (ECPS). The development of a trustworthy smart grid requires a deeper and more specific analysis of potential impacts resulting from failures of ECPS. A probability model is presented to calculate the reliability of ECPS which controls the security and stability control system. Cascading failure due to failures of ECPS is being investigated by risk assessment method in this paper. Two scenes including signal lost and signal transmission error which may lead to cascading failure in power system is considered. IEEE 118-bus system is used as a test system and the simulation results verifies the effectiveness of proposed failure model and risk assessment method.

Traditional risk assessment methods focus on the power network side while ignoring the impacts of the information system. A risk assessment approach for power system based on a comprehensive fault probabilistic model is proposed. The risk factors of the information system are considered in the model. Overload and voltage violation risk indices are adopted. The risk indices thus gained can be used to help operators and the planners to monitor the system, and make a more credible plan. The correctness of the proposed approach is validated by IEEE-118 bus test system.

In the power system, there probably exist some certain risks during the dispatching operation when it is determined by a fallacious recognition of system conditions. A risk assessment approach for dispatching operations is proposed. The risk of dispatching operations is defined as the overload or voltage violation induced after operations. A critical equipment search technique used for contingency searching is developed to enhance computational efficiency. The risk indices thus gained can be used to monitor the dispatching operations, and help operators to determine more credible operations or daily operation plan. The correctness and effectiveness of the proposed approach are validated by IEEE-118 bus test system and the Polish power system.