@article{lu_wang_ma_2013, title={An Empirical Study of Communication Infrastructures Towards the Smart Grid: Design, Implementation, and Evaluation}, volume={4}, ISSN={["1949-3061"]}, DOI={10.1109/tsg.2012.2225453}, abstractNote={The smart grid features ubiquitous interconnections of power equipments to enable two-way flows of electricity and information for various intelligent power management applications, such as accurate relay protection and timely demand response. To fulfill such pervasive equipment interconnects, a full-fledged communication infrastructure is of great importance in the smart grid. There have been extensive works on disparate layouts of communication infrastructures in the smart grid by surveying feasible wired or wireless communication technologies, such as power line communications and cellular networks. Nevertheless, towards an operable, cost-efficient and backward-compatible communication solution, more comprehensive and practical understandings are still urgently needed regarding communication requirements, applicable protocols, and system performance. Through such comprehensive understandings, we are prone to answer a fundamental question, how to design, implement and integrate communication infrastructures with power systems. In this paper, we address this issue in a case study of a smart grid demonstration project, the Future Renewable Electric Energy Delivery and Management (FREEDM) systems. By investigating communication scenarios, we first clarify communication requirements implied in FREEDM use cases. Then, we adopt a predominant protocol framework, Distributed Network Protocol 3.0 over TCP/IP (DNP3 over TCP/IP), to practically establish connections between electric devices for data exchanges in a small-scale FREEDM system setting, Green Hub. Within the real-setting testbed, we measure the message delivery performance of the DNP3-based communication infrastructure. Our results reveal that diverse timing requirements of message deliveries are arguably primary concerns in a way that dominates viabilities of protocols or schemes in the communication infrastructure of the smart grid. Accordingly, although DNP3 over TCP/IP is widely considered as a smart grid communication solution, it cannot satisfy communication requirements in some time-critical scenarios, such as relay protections, which claim a further optimization on the protocol efficiency of DNP3.}, number={1}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Lu, Xiang and Wang, Wenye and Ma, Jianfeng}, year={2013}, month={Mar}, pages={170–183} }
 @inproceedings{wang_lu_wang_huang_2012, title={Development of distributed grid intelligence platform for solid state transformer}, DOI={10.1109/smartgridcomm.2012.6486031}, abstractNote={This paper introduces the development of a platform intended as a distributed controller for grid intelligence (DGI) system at FREEDM Systems Center. This platform serves as both a hard real-time local converter controller and a communication node for distributed deployment of energy management schemes. One of the converter devices it controls is the solid state transformer (SST), one of the key elements to interface renewable energy sources into distribution system in FREEDM Center. Both the hardware design and software structure for SST control are presented in this paper. For the communication part, the Distributed Network Protocol (DNP) 3.0 is adopted to congregate multiple SSTs to balance local generation and demands in a coordinated manner. Experiment results are presented to show that this distributed platform has good performance.}, booktitle={2012 IEEE Third International Conference on Smart Grid Communications (SmartGridComm)}, author={Wang, F. and Lu, X. and Wang, Wenye and Huang, A.}, year={2012}, pages={481–485} }
 @inproceedings{lu_lu_wang_ma_2011, title={On network performance evaluation toward the smart grid: A case study of DNP3 over TCP/IP}, DOI={10.1109/glocom.2011.6134406}, abstractNote={The smart grid is the next-generation power system that incorporates power infrastructures with information technologies. In the smart grid, power devices are interconnected to support a variety of intelligent mechanisms, such as relay protection and demand response. To enable such mechanisms, messages must be delivered in a timely manner via network protocols. A cost-efficient and backward-compatible way for smart grid protocol design is to migrate current protocols in supervisory control and data acquisition (SCADA) systems to the smart grid. However, an open question is whether the performance of SCADA protocols can meet the timing requirements of smart grid applications. To address this issue, we establish a micro smart grid, Green Hub, to measure the delay performance of a predominant SCADA protocol, distributed network protocol 3.0 (DNP3) over TCP/IP. Our results show that although DNP3 over TCP/IP is widely considered as a smart grid communication protocol, it cannot be used in applications with delay constraints smaller than 16ms in Green Hub, such as relay protection. In addition, since DNP3 provides reliability mechanisms similar to TCP, we identify that such an overlapped design induces 50%-80% of the processing delay in embedded power devices. Our results indicate that DNP3 over TCP/IP can be further optimized in terms of delay efficiency, and a lightweight communication protocol is essential for time-critical smart grid applications.}, booktitle={2011 ieee global telecommunications conference (globecom 2011)}, author={Lu, X. and Lu, Z. and Wang, Wenye and Ma, J. F.}, year={2011} }
 @inproceedings{lu_lu_wang_wang_2010, title={Review and evaluation of security threats on the communication networks in the smart grid}, DOI={10.1109/milcom.2010.5679551}, abstractNote={The smart grid, generally referred to as the next-generation power electric system, relies on robust communication networks to provide efficient, secure, and reliable information delivery. Thus, the network security is of critical importance in the smart grid. In this paper, we aim at classifying and evaluating the security threats on the communication networks in the smart grid. Based on a top-down analysis, we categorize the goals of potential attacks against the smart grid communication networks into three types: network availability, data integrity and information privacy. We then qualitatively analyze both the impact and feasibility of the three types of attacks. Moreover, since network availability is the top priority in the security objectives for the smart grid, we use experiments to quantitatively evaluate the impact of denial-of-service (DoS) attacks on a power substation network. Our work provides initial experimental data of DoS attacks against a power network and shows that the network performance degrades dramatically only when the DoS attack intensity approaches to the maximum.}, booktitle={Military communications conference, 2010 (milcom 2010)}, author={Lu, Z. and Lu, X. A. and Wang, Wenye and Wang, C.}, year={2010}, pages={1830–1835} }