Performances And Quality Of Service Of PLC Networks For MV And LV Distribution Systems

With the deregulation of the energy markets, the present electricity distribution systems facing the future development, must improve the distribution automation and the quality and efficiency of power delivery. And it also should provide a platform to the power supply utilities for expanding the "electricity" product to special value-added services. All are based on the communication technology. So it demands a wide area network for covering all customers and equipments of distribution automation system. Power line becomes an alternative network solution, as it has full infrastructure from the provider to the home and is ready for use without any additional installation cost. In this thesis, we are interested in a wide-area PLC (Power Line Communication) network consisted of medium voltage level and low voltage level, to provide a communication infrastructure for monitoring and control of energy distribution and consumption. And the following problems are solved: transmitting a packet in a long distance and adapting the dynamic network topology change; managing the quality of service for meeting the applications' different network requirements basing on the master/slave mode; and reporting real-time event from slave side.This work has been carried out as a part of REMPLI (Real-time Energy Management via Power Line and Internet) European project and resulted in the definition of REMPLI PLC.We designed an efficient routing protocol to cope with dynamic electricity grid topology changes and to relay packets to reach the destination. This protocol is basing on the flooding principle and is called as Simple Frequency Network (SFN). Probabilistic analysis and simulations showed its advantages and satisfied the requirement of efficient routing and short transmission time, when compared to the source routing protocol.After the design of whole network architecture, we propose several logical channel for improving the bandwidth utilization and master/slave transmission mode for the applications structures. At first, a REMPLI PLC network composed of one master and several slaves has been evaluated. Then, a whole REMPLI network composed of MV and LV power line segments, connected by bridges has been investigated. From those analysis and simulation results, we can draw a conclusion that REMPLI PLC system can meet the requirements of most applications. Because in REMPLI project, the device data are not allowed to be stored outside the device itself in some countries, the slave node must get a response from the attached equipments (e.g. meters) directly after it receives a request from the master. The master must re-poll the slave node to get its response. And it leads to the request/response process is complex and is difficult to configure. We propose to relax the limitation and install the cache in the slave. Then the field level device data are stored inside the slave node such that a request can get its response immediately, even if the cached datum is not always the latest one. The performance evaluation has shown its high efficiency. We propose that the time for getting the data is provided by the slave. It solves the problem of the request/response process's configuration which is caused by forbidding the data to be stored in the slave. And we propose and implement a new dispatcher as a network layer mechanism that provides differentiated quality of service for the applications. For decreasing the calculating time, the dual-priority scheduling policy with the relaxation of deadline is proposed.The random access protocol is proposed in the one of the logical channel of REMPLI PLC system, for meeting the requirement of real-time event reporting. Two kind of random access protocol are modified to have capability of running SFN routing protocol: ALOHA-SFN and carrier sense-SFN. The simulation results show that they outperform master/slave periodic polling and the application requirement can be met.