Reliability Evaluation Of Active Distribution Cyber Physical System

Massive renewable energy grid-connected and the increasing demand is driving the development of traditional distribution network to active distribution network,which makes the operation management of the distribution network has a deep dependence on the cyber system.Various factors that lead to the cyber failure also put impacts on the control and operation characteristics of the distribution network.Therefore,it is necesery for the distribution planning and analysis to study the refined modeling method of cyber system and the efficient reliability evaluation method of the distribution Cyber Physical System(CPS)by analysis of the influence mechanism of cyber system on the reliability.The main works of this paper are as follows:First,according to the development trend of the active distribution network and the communication modes and structures commonly applied in the present,a typical distribution cyber physical system is extracted.And combining with the characteristics of a variety of communication methods,a cyber validity model,covering fault,delay and error characteristics is established by analyzing the influence of cyber component faults on the transmission performance.Next,the fault isolation strategy,mesage interaction process and system emergency isolation method of active distribution CPS in the fault self-healing are deeply analyzed.And analysis method of the evolutionary process about cyber and physical system both faults is proposed,and the load loss quantization model of distribution network is established.Then,a distribution CPS reliability assessment method based on hybrid simulation method is proposed by combining sequential and nonsequential Monte Carlo simulation method.And the availability of this method is verified,the impact of the cyber component importance,access load rate,communication mode,network structure on the reliability is analyzed.Besides,in order to improve the efficiency of distribution CPS reliability evaluation,this paper puts forward a information physical combined active power distribution of the CPS reliability analytical calculation method based on fast calculation method of cyber link validity and the improved minimum path method,and the calculation method of the fault duration has made the improvement.In addition combined the validity and effectiveness of the proposed method is verified by a simulation system.