The smart grid has caught great attentions in recent years, which is poised to transform a centralized, producer-controlled network to a decentralized, consumer- interactive network that＇s supported by fine-grained m...The smart grid has caught great attentions in recent years, which is poised to transform a centralized, producer-controlled network to a decentralized, consumer- interactive network that＇s supported by fine-grained monitoring. Large-scale WSNs （Wireless Sensor Networks） have been considered one of the very promising technologies to support the implementation of smart grid. WSNs are applied in almost every aspect of smart grid, including power generation, power transmission, power distribution, power utilization and power dispatch, and the data query processing of ＇WSNs in power grid＇ become an hotspot issue due to the amount of data of power grid is very large and the requirement of response time is very high. To meet the demands, top-k query processing is a good choice, which performs the cooperative query by aggregating the database objects＇ degree of match for each different query predicate and returning the best k matching objects. In this paper, a framework that can effectively apply top-k query to wireless sensor network in smart grid is proposed, which is based on the cluster-topology sensor network. In the new method, local indices are used to optimize the necessary query routing and process intermediate results inside the cluster to cut down the data traffic, and the hierarchical join query is executed based on the local results.Besides, top-k query results are verified by the clean-up process, and two schemes are taken to deal with the problem of node＇s dynamicity, which further reduce communication cost. Case studies and experimental results show that our algorithm has outperformed the current existing one with higher quality results and better efficiently.展开更多
The smart grid is the next generation of power and distribution systems. The integration of advanced network, communications, and computing techniques allows for the enhancement of efficiency and reliability. The smar...The smart grid is the next generation of power and distribution systems. The integration of advanced network, communications, and computing techniques allows for the enhancement of efficiency and reliability. The smart grid interconnects the flow of information via the power line, intelligent metering, renewable and distributed energy systems, and a monitoring and controlling infrastructure. For all the advantages that these components come with, they remain at risk to a spectrum of physical and digital attacks. This paper will focus on digital vulnerabilities within the smart grid and how they may be exploited to form full fledged attacks on the system. A number of countermeasures and solutions from the literature will also be reported, to give an overview of the options for dealing with such problems. This paper serves as a triggering point for future research into smart grid cyber security.展开更多
The violently penetration of renewables in power supply network leads to situations, by which the offer exceeds the demand. Therefore, it is necessary to include a system for processes＇ management. SmartGrid is a pla...The violently penetration of renewables in power supply network leads to situations, by which the offer exceeds the demand. Therefore, it is necessary to include a system for processes＇ management. SmartGrid is a platform over the power supply network. It is represented with its network and services, which also have to be managed. The paper aims to show the second stage of SmartGrid management modeling. It meets heterogeneous requirements of the actors--subscriber without photovoltaics, subscriber with photovoltaics, service provider, network operator, and network elements operator--to service and network management and is oriented to functional areas, covering the life cycle of power supply service： Design, Planning, Installation, Provision, Configuration, Maintenance, Performance, Accounting, Buying Up, Security and Subscriber Control. Functional models for existing networks--telecommunications--are used and they are adapted to power supply. The results are illustrated with three functional areas for service management： Accounting, Buying Up, and Performance. The synthesis of network management functions and network element management functions are similar.展开更多
Meter Data Collection Building Area Network(MDCBAN) deployed in high rises is playing an increasingly important role in wireless multi-hop smart grid meter data collection. Recently, increasingly numerous application ...Meter Data Collection Building Area Network(MDCBAN) deployed in high rises is playing an increasingly important role in wireless multi-hop smart grid meter data collection. Recently, increasingly numerous application layer data traffic makes MDCBAN be facing serious communication pressure. In addition, large density of meter data collection devices scattered in the limited geographical space of high rises results in obvious communication interference. To solve these problems, a traffic scheduling mechanism based on interference avoidance for meter data collection in MDCBAN is proposed. Firstly, the characteristics of network topology are analyzed and the corresponding traffic distribution model is proposed. Next, a wireless multi-channel selection scheme for different Floor Gateways and a single-channel time unit assignment scheme for data collection devices in the same Floor Network are proposed to avoid interference. At last, a data balanced traffic scheduling algorithm is proposed. Simulation results show that balanced traffic distribution and highly efficient and reliable data transmission can be achieved on the basis of effective interference avoidance between data collection devices.展开更多
The new reality of smart distribution systems with use of generation sources of small and medium sizes brings new challenges for the operation of these systems. The complexity and the large number of nodes requires us...The new reality of smart distribution systems with use of generation sources of small and medium sizes brings new challenges for the operation of these systems. The complexity and the large number of nodes requires use of methods which can reduce the processing time of algorithms such as power flow, allowing its use in real time. This paper presents a known methodology for calculating the power flow in three phases using backward/forward sweep method, and also considering other network elements such as voltage regulators, shunt capacitors and sources of dispersed generation of types PV （active power and voltage） and PQ （active and reactive power）. After that, new elements are introduced that allow the parallelization of this algorithm and an adequate distribution of work between the available processors. The algorithm was implemented using a multi-tiered architecture; the processing times were measured in many network configurations and compared with the same algorithm in the serial version.展开更多
The purpose of this article is to present an additional overloading assessment scheme to the current protection scheme, which can be applied in the low voltage distribution network to prevent overloading of network as...The purpose of this article is to present an additional overloading assessment scheme to the current protection scheme, which can be applied in the low voltage distribution network to prevent overloading of network assets. As higher penetration of distributed generators is envisioned among distribution networks, the network operators will have an challenging task in the future to maintain the reliability and quality of supply. The distribution networks are going to be challenged simultaneously by increasing penetration of distributed generators and by increasing loading （inter alia heat pumps, air conditioners or electric vehicles）, which will change the operational perspective of the future distribution networks. Presented simulation results show that the increasing penetration of those appliances can jeopardize the functionality of current protection scheme in distribution networks. Therefore, an additional scheme for assessment of network overloading applicable at low voltage distribution networks is proposed and the application of this scheme, supported by smart metering infrastructure, is demonstrated in a case study. The proposed overloading assessment scheme should help the network operators to increase the flexibility of distribution networks, their hosting capacity, safety and reliability.展开更多
SG （smart grids） is an intelligent power grid in which the diverse nodes should communicate different types of information which have different communication requirements with CS （control stations）. There exist se...SG （smart grids） is an intelligent power grid in which the diverse nodes should communicate different types of information which have different communication requirements with CS （control stations）. There exist several RATs （radio access technologies）, with diversification in quality of service character which respect to the SG nodes communication requirements. On the other side, spectrum is becoming a rare source and its demands request is increasing exponentially. Therefore, resource allocation to support different types of SG nodes should be elaborated so that the resource efficiency is maximized while the SG communication requirements are respected. Using a CF （cost function） based on the SG node requirements and RATs characteristics to find the desirability value of every RATs for a certain node type accomplish this goal in combination with prioritizing the different SG nodes types based on SG goals by creating a priority table for RATs and different SG node types. The main node communication requirements are formulized to be used in the CF in this paper. The numerical results show that the proposed method defines the desirability value of each RAT for a certain SG node type that helps to make a priority table by using the SG node prioritization table.展开更多
The topology of in-home power line communication(PLC) networks varies frequently, which makes traditional routing algorithms failure. To solve this problem, an end-to-end transmission time for remaining path(TTRP) met...The topology of in-home power line communication(PLC) networks varies frequently, which makes traditional routing algorithms failure. To solve this problem, an end-to-end transmission time for remaining path(TTRP) metric-based opportunistic routing(TTRPOR) is proposed. Since a local broadcasting scheme is adopted, the algorithm can find the optimal path for forwarding packets in a dynamic PLC network. The closed-form of the outage probability for a PLC channel is derived to estimate the TTRP. It is proved that the average throughput can achieve maximum as the metric TTRP is utilized to sort candidate forwarding nodes.Numerical results show that the end-to-end throughput of networks with TTRPOR, outperforms that of the network adopting DSR and EXOR, especially for the case of varying-topology in-home PLC networks.展开更多
文摘The smart grid has caught great attentions in recent years, which is poised to transform a centralized, producer-controlled network to a decentralized, consumer- interactive network that＇s supported by fine-grained monitoring. Large-scale WSNs （Wireless Sensor Networks） have been considered one of the very promising technologies to support the implementation of smart grid. WSNs are applied in almost every aspect of smart grid, including power generation, power transmission, power distribution, power utilization and power dispatch, and the data query processing of ＇WSNs in power grid＇ become an hotspot issue due to the amount of data of power grid is very large and the requirement of response time is very high. To meet the demands, top-k query processing is a good choice, which performs the cooperative query by aggregating the database objects＇ degree of match for each different query predicate and returning the best k matching objects. In this paper, a framework that can effectively apply top-k query to wireless sensor network in smart grid is proposed, which is based on the cluster-topology sensor network. In the new method, local indices are used to optimize the necessary query routing and process intermediate results inside the cluster to cut down the data traffic, and the hierarchical join query is executed based on the local results.Besides, top-k query results are verified by the clean-up process, and two schemes are taken to deal with the problem of node＇s dynamicity, which further reduce communication cost. Case studies and experimental results show that our algorithm has outperformed the current existing one with higher quality results and better efficiently.
文摘The smart grid is the next generation of power and distribution systems. The integration of advanced network, communications, and computing techniques allows for the enhancement of efficiency and reliability. The smart grid interconnects the flow of information via the power line, intelligent metering, renewable and distributed energy systems, and a monitoring and controlling infrastructure. For all the advantages that these components come with, they remain at risk to a spectrum of physical and digital attacks. This paper will focus on digital vulnerabilities within the smart grid and how they may be exploited to form full fledged attacks on the system. A number of countermeasures and solutions from the literature will also be reported, to give an overview of the options for dealing with such problems. This paper serves as a triggering point for future research into smart grid cyber security.
文摘The violently penetration of renewables in power supply network leads to situations, by which the offer exceeds the demand. Therefore, it is necessary to include a system for processes＇ management. SmartGrid is a platform over the power supply network. It is represented with its network and services, which also have to be managed. The paper aims to show the second stage of SmartGrid management modeling. It meets heterogeneous requirements of the actors--subscriber without photovoltaics, subscriber with photovoltaics, service provider, network operator, and network elements operator--to service and network management and is oriented to functional areas, covering the life cycle of power supply service： Design, Planning, Installation, Provision, Configuration, Maintenance, Performance, Accounting, Buying Up, Security and Subscriber Control. Functional models for existing networks--telecommunications--are used and they are adapted to power supply. The results are illustrated with three functional areas for service management： Accounting, Buying Up, and Performance. The synthesis of network management functions and network element management functions are similar.
基金supported by the National Science and Technology Support Program of China (2015BAG10B01)the National Science Foundation of China under Grant No. 61232016, No.U1405254the PAPD fund
文摘Meter Data Collection Building Area Network(MDCBAN) deployed in high rises is playing an increasingly important role in wireless multi-hop smart grid meter data collection. Recently, increasingly numerous application layer data traffic makes MDCBAN be facing serious communication pressure. In addition, large density of meter data collection devices scattered in the limited geographical space of high rises results in obvious communication interference. To solve these problems, a traffic scheduling mechanism based on interference avoidance for meter data collection in MDCBAN is proposed. Firstly, the characteristics of network topology are analyzed and the corresponding traffic distribution model is proposed. Next, a wireless multi-channel selection scheme for different Floor Gateways and a single-channel time unit assignment scheme for data collection devices in the same Floor Network are proposed to avoid interference. At last, a data balanced traffic scheduling algorithm is proposed. Simulation results show that balanced traffic distribution and highly efficient and reliable data transmission can be achieved on the basis of effective interference avoidance between data collection devices.
文摘The new reality of smart distribution systems with use of generation sources of small and medium sizes brings new challenges for the operation of these systems. The complexity and the large number of nodes requires use of methods which can reduce the processing time of algorithms such as power flow, allowing its use in real time. This paper presents a known methodology for calculating the power flow in three phases using backward/forward sweep method, and also considering other network elements such as voltage regulators, shunt capacitors and sources of dispersed generation of types PV （active power and voltage） and PQ （active and reactive power）. After that, new elements are introduced that allow the parallelization of this algorithm and an adequate distribution of work between the available processors. The algorithm was implemented using a multi-tiered architecture; the processing times were measured in many network configurations and compared with the same algorithm in the serial version.
文摘The purpose of this article is to present an additional overloading assessment scheme to the current protection scheme, which can be applied in the low voltage distribution network to prevent overloading of network assets. As higher penetration of distributed generators is envisioned among distribution networks, the network operators will have an challenging task in the future to maintain the reliability and quality of supply. The distribution networks are going to be challenged simultaneously by increasing penetration of distributed generators and by increasing loading （inter alia heat pumps, air conditioners or electric vehicles）, which will change the operational perspective of the future distribution networks. Presented simulation results show that the increasing penetration of those appliances can jeopardize the functionality of current protection scheme in distribution networks. Therefore, an additional scheme for assessment of network overloading applicable at low voltage distribution networks is proposed and the application of this scheme, supported by smart metering infrastructure, is demonstrated in a case study. The proposed overloading assessment scheme should help the network operators to increase the flexibility of distribution networks, their hosting capacity, safety and reliability.
文摘SG （smart grids） is an intelligent power grid in which the diverse nodes should communicate different types of information which have different communication requirements with CS （control stations）. There exist several RATs （radio access technologies）, with diversification in quality of service character which respect to the SG nodes communication requirements. On the other side, spectrum is becoming a rare source and its demands request is increasing exponentially. Therefore, resource allocation to support different types of SG nodes should be elaborated so that the resource efficiency is maximized while the SG communication requirements are respected. Using a CF （cost function） based on the SG node requirements and RATs characteristics to find the desirability value of every RATs for a certain node type accomplish this goal in combination with prioritizing the different SG nodes types based on SG goals by creating a priority table for RATs and different SG node types. The main node communication requirements are formulized to be used in the CF in this paper. The numerical results show that the proposed method defines the desirability value of each RAT for a certain SG node type that helps to make a priority table by using the SG node prioritization table.
基金supported in part by Open Research Fund of National Key Laboratory of Electromagnetic EnvironmentChina Research Institute of Radiowave Propagation (Grant No. 201500013)+3 种基金Open Research Fund of National Mobile Communications Research LaboratoryJiangsu Provincial Science Foundation Project (Grant No. BK20150786)Southeast University (Grant No. 2013D02)National Natural Science Foundation of China (Grants Nos. 61501238, 61271230, 61472190)
文摘The topology of in-home power line communication(PLC) networks varies frequently, which makes traditional routing algorithms failure. To solve this problem, an end-to-end transmission time for remaining path(TTRP) metric-based opportunistic routing(TTRPOR) is proposed. Since a local broadcasting scheme is adopted, the algorithm can find the optimal path for forwarding packets in a dynamic PLC network. The closed-form of the outage probability for a PLC channel is derived to estimate the TTRP. It is proved that the average throughput can achieve maximum as the metric TTRP is utilized to sort candidate forwarding nodes.Numerical results show that the end-to-end throughput of networks with TTRPOR, outperforms that of the network adopting DSR and EXOR, especially for the case of varying-topology in-home PLC networks.
