Impact analysis of cyber system in microgrids: Perspective from economy and reliability

Abstract With the increasing requirements of power supply quality and operation economy of the microgrid in smart grid field, real-time energy scheduling methods that highly rely on the cyber system are inevitable supports for the optimal operation of microgrids. As a typical cyber-physical system, the disturbance and failure on the cyber side may make the performance of microgrids deviate from the expected ones. To quantify the degree to which these cyber contingencies influence the microgrid system, we propose a novel quantification and analytical framework. In this framework, the cyber system of a centrally controlled microgrid is abstracted consisting of information conversion, transmission and routing forward, as well as fusion and calculation. On this basis, the general information flow is modeled through information mapping between measured state and control command. Furthermore, an equivalent model for a cyber-physical microgrid system is formulated by integrating information mapping model into the state transition of physical microgrid. With this equivalent model, a unified impact analytical procedure is presented to accurately quantify the physical impact of multi-cyber-contingencies in both economy and reliability aspects. Numerical simulations on a microgrid validate the reasonableness and effectiveness of the proposed method.