The state-of-the-art query techniques in power grid monitoring systems focus on querying history data, which typically introduces an unwanted lag when the systems try to discover emergency situations. The monitoring d...The state-of-the-art query techniques in power grid monitoring systems focus on querying history data, which typically introduces an unwanted lag when the systems try to discover emergency situations. The monitoring data of large-scale smart grids are massive, dynamic and highly dimensional, so global query, the method widely adopted in continuous queries in Wireless Sensor Networks(WSN), is rendered not suitable for its high energy consumption. The situation is even worse with increasing application complexity. We propose an energy-efficient query technique for large-scale smart grids based on variable regions. This method can query an arbitrary region based on variable physical windows, and optimizes data retrieve paths by a key nodes selection strategy. According to the characteristics of sensing data, we introduce an efficient filter into the each query subtree to keep non-skyline data from being retrieved. Experimental results show that our method can efficiently return the overview situation of any query region. Compared to TAG and ESA, the average query efficiency of our approach is improved by 79% and 46%, respectively; the total energy consumption of regional query is decreased by 82% and 50%, respectively.展开更多
This paper presents an in-depth evaluation of Wireless Sensor Networks. Wireless Sensor Networks have been highlighted as the major component that enables the development of modern infrastructures, such as the Smart G...This paper presents an in-depth evaluation of Wireless Sensor Networks. Wireless Sensor Networks have been highlighted as the major component that enables the development of modern infrastructures, such as the Smart Grid. As part of an on-going edification process on the subject matter, this paper brings to fore the many important functions and components of Wireless Sensor Networks, including application areas, functional architectures, physical topological design, communication protocols, routing schemes and Wireless Sensor Network hardware capabilities.展开更多
This paper concludes the case study work on the optical sensor, which is a new method for voltage and current measurement. Fiber Bragg gratings (FBG) have been developed and used for decades in the telecommunication i...This paper concludes the case study work on the optical sensor, which is a new method for voltage and current measurement. Fiber Bragg gratings (FBG) have been developed and used for decades in the telecommunication industry. In recent years, FBG sensors have found wide applications in monitoring strain, temperature, voltage and current across all industries. As the process of constructing a robust smart grid, thousands of miles of optical-fibers have been deployed along the power transmission lines for the purpose of power production communication. This paper focuses on using the power optical fiber as voltage/current sensors instead of those copper wired traditional current transformers. By using piezoelectric layers, the optical sensor is able to transform voltage/current magnitude into optical signal, as well as transmit the signal through the optical fiber. The application of using optical fiber will significantly reduce the cost of deploying traditional current transformers all around the power grid. Moreover, the optical sensor is more stable, more accurate and faster, with such characteristics, the smart grid monitoring system could be much better. The application of combining the optical composite low-voltage cable (OPLC) and the optical current sensor in the distribution network for smart distribution monitoring has been analyzed.展开更多
智能电网需要先进传感测量技术的支持。为此,针对智能电网中的电流测量需求,介绍了基于巨磁阻效应的高性能电流传感器,包括传感器系统结构、磁环、巨磁阻传感芯片、信号处理电路等的设计,以及对温度稳定性、电磁兼容性的设计。实验结果...智能电网需要先进传感测量技术的支持。为此,针对智能电网中的电流测量需求,介绍了基于巨磁阻效应的高性能电流传感器,包括传感器系统结构、磁环、巨磁阻传感芯片、信号处理电路等的设计,以及对温度稳定性、电磁兼容性的设计。实验结果表明,所设计的基于巨磁阻效应的高性能电流传感器在对电网中暂态电流、直流电流、泄漏电流、电晕电流的测量中表现出良好的性能,实现了对带宽直流到10 MHz、幅值1 m A至1.6 k A的电流的精确测量。相比其他电流测量装置,基于巨磁阻效应的高性能电流传感器具有体积小、灵敏度高、成本低、测量范围大、可集成度高等综合优势,适应了智能电网的测量需求。最后,提出了后续研究方向。展开更多
基金supported by the National Natural Science Foundation of China (NO. 61472072, 61528202, 61501105, 61472169)the Foundation of Science Public Welfare of Liaoning Province in China (NO. 2015003003)
文摘The state-of-the-art query techniques in power grid monitoring systems focus on querying history data, which typically introduces an unwanted lag when the systems try to discover emergency situations. The monitoring data of large-scale smart grids are massive, dynamic and highly dimensional, so global query, the method widely adopted in continuous queries in Wireless Sensor Networks(WSN), is rendered not suitable for its high energy consumption. The situation is even worse with increasing application complexity. We propose an energy-efficient query technique for large-scale smart grids based on variable regions. This method can query an arbitrary region based on variable physical windows, and optimizes data retrieve paths by a key nodes selection strategy. According to the characteristics of sensing data, we introduce an efficient filter into the each query subtree to keep non-skyline data from being retrieved. Experimental results show that our method can efficiently return the overview situation of any query region. Compared to TAG and ESA, the average query efficiency of our approach is improved by 79% and 46%, respectively; the total energy consumption of regional query is decreased by 82% and 50%, respectively.
文摘This paper presents an in-depth evaluation of Wireless Sensor Networks. Wireless Sensor Networks have been highlighted as the major component that enables the development of modern infrastructures, such as the Smart Grid. As part of an on-going edification process on the subject matter, this paper brings to fore the many important functions and components of Wireless Sensor Networks, including application areas, functional architectures, physical topological design, communication protocols, routing schemes and Wireless Sensor Network hardware capabilities.
文摘This paper concludes the case study work on the optical sensor, which is a new method for voltage and current measurement. Fiber Bragg gratings (FBG) have been developed and used for decades in the telecommunication industry. In recent years, FBG sensors have found wide applications in monitoring strain, temperature, voltage and current across all industries. As the process of constructing a robust smart grid, thousands of miles of optical-fibers have been deployed along the power transmission lines for the purpose of power production communication. This paper focuses on using the power optical fiber as voltage/current sensors instead of those copper wired traditional current transformers. By using piezoelectric layers, the optical sensor is able to transform voltage/current magnitude into optical signal, as well as transmit the signal through the optical fiber. The application of using optical fiber will significantly reduce the cost of deploying traditional current transformers all around the power grid. Moreover, the optical sensor is more stable, more accurate and faster, with such characteristics, the smart grid monitoring system could be much better. The application of combining the optical composite low-voltage cable (OPLC) and the optical current sensor in the distribution network for smart distribution monitoring has been analyzed.
文摘智能电网需要先进传感测量技术的支持。为此,针对智能电网中的电流测量需求,介绍了基于巨磁阻效应的高性能电流传感器,包括传感器系统结构、磁环、巨磁阻传感芯片、信号处理电路等的设计,以及对温度稳定性、电磁兼容性的设计。实验结果表明,所设计的基于巨磁阻效应的高性能电流传感器在对电网中暂态电流、直流电流、泄漏电流、电晕电流的测量中表现出良好的性能,实现了对带宽直流到10 MHz、幅值1 m A至1.6 k A的电流的精确测量。相比其他电流测量装置,基于巨磁阻效应的高性能电流传感器具有体积小、灵敏度高、成本低、测量范围大、可集成度高等综合优势,适应了智能电网的测量需求。最后,提出了后续研究方向。
