The Mechanism Of Fault Management In Smart Grid Communication Network

Smart grid communication network is coupled tightly with the electric power system. It has carried the information data of energy scheduling and power distribution control. The smart grid communication network has ensured the operation of different power services. The fault management is responsible for management of fault comprehensively. The research about fault management is fault identification timely, fault analysis scientifically, fault solution quickly, in order to enhance the quality of service efficiently. The fault management in combination with the smart grid communication, not only can provide the two-way services which are the future demands with more reliability and security, but also can promote the network stability and level of operation and maintenance, in order to fully support the smart grid services. Therefore, the network fault management has a significant research value.The network fault management is one of the core contents of the network management. In a general way, it has included a series of processes, such as fault detection, fault location, fault isolation, fault tolerance and fault recovery. The existing methods about network fault management are mostly followed the traditional network management models, lacking of considering for the characteristics of electric power communication. The present problems are mainly embodied in three aspects as follow:1) In the process of fault location, there is a ignoring the fault influence on the service of power schedule and control. As leaked faults may have the more impact on the power service, the risk is out of control in algorithm of location. Furthermore, the power service is likely to face the high risk because of high false positive rate.2) There is the remarkable feature that the fault is easier to propagate in the coupled network which is made of the power network and communication network. In the process of fault isolation, there is lack of effective control mechanism to deal with the fault propagation to avoid the large-scale outage.3) The future requirements are the trusted capability and efficient mechanism with fault tolerance in the communication network, in order to build the strong, resilient, economic smart gird communication network. However, the related research work has not well developed at present. Oriented the future requirements and aimed to a remarkable feature, this paper has discussed the fault management for the smart gird communication, and especially has stressed on the fault location, fault control and fault tolerance. The main contributions are fourfold just as follow:(1) For the fault location in backbone transmission network, this paper has proposed an algorithm which considers impact analysis. At first, the bipartite graph model is presented, which actually reflects a relationship between alarms and faults. Then, Bayes formula and regularization are applied to calculate the fault impact value. Later on, by using reliable parameters, a minimum loss of credible parameter algorithm is designed with the reasonable explanation of the symptoms based on the existing the located algorithm. The proposed algorithm can put the violation risk under control and guarantee the power service safety. Finally, numerical results show that the proposed algorithm is effective. Comparing with other algorithms, the algorithm shows more advantages. These advantages of the algorithm are that a fault impact is under control, and it gives a reasonable explanation for the observed symptoms. Moreover, the algorithm has less false detection rate to adapt to the smart grid communication network requirement.(2) For the fault propagation and control in the coupled network, which is made of the power network and communication network, a configuration algorithm for alleviating cascade is proposed from the communication perspective. Firstly, we model the interdependent network. Based on this model, the necessary condition of the fault propagation is deduced by means of fault pair. Subsequently, based on the necessary condition is broken, a heuristic double cover and double redundancy configuration algorithm is proposed. The simulation shows that this redundancy configuration algorithm can isolate the fault effectively in the communication network, and can alleviate the fault propagation in the coupled network.(3) In the condition in which wireless sensor network is used to monitor overhead power line for power distribution and utilization, this paper proposed a fault tolerance mechanism which is based on the combination model with fault tolerant ability to combat the poor tolerance in the linear network. Firstly, two salient network features are identified. Based on the two features, a combination network model with fault tolerance is proposed. Then, the working mechanism of proposed model is presented. Finally, for the diffident fault types, such as a fault, multiple discontinuous faults and multiple continuous faults, a lower bound is presented by analyzing the combination network tolerance model. Simulation results show that in contrast to the other models, a combination network model is more suitable for the condition in which a power transmission line a is monitored in the open air.(4) For the scenario of surveillance transmission line by wireless sensor network, this paper has concentrated on the redundancy for the fault tolerance to deals with the different delays in the various application. A based on the hybrid network model WSN gateway tolerance mechanism is proposed. Firstly, based on the cellular for the directed transmission, followed on the fault tolerance n-x principle, the paper identifies how many backup nodes and cellular modules are enough by means of optimization. Next, different poles or towers have different fault frequencies. Then, we regard frequencies as a prior knowledge and determine the exactly the placement for the relays and cellular modules by the proposed based prior backup placement algorithm leveraging the frequency of fault as a prior. The adaptive fault adjustment algorithm is proposed to tolerate the fault in gateways of the wireless sensor network.The simulation experiments show that the proposed fault tolerance mechanism can solve the WSN gateway backup problem, improve the ability of fault tolerance. The fault tolerance mechanism is more applicable to the delay sensitive applications in the scenario of monitoring the power line.