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Liu Y.,Tongji University | Lin J.,Tongji University | Guo L.,Tianjin Electrical Power Dispatch Center | Cai N.,Tianjin Electrical Power Design Institute | And 4 more authors.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2015

To focus on the drawbacks of existing robust state estimation methods and algorithms, a novel robust state estimation algorithm based on adaptive kernel density estimation was hereby proposed. The new robust state estimation model based on adaptive kernel density estimation theory was firstly presented. In order to determine the bandwidth of adaptive kernel density, the approximative expression of optimal kernel bandwidths is deduced using mean integral square error of probability density estimation, and the characteristic of the state variable components having stronger correlation with the local direct measurements than with all un-direct measurements; and the constraints of kernel bandwidths for state variable components, including initial constraint, modified constraint and standard deviation constraint, are further designed, for insuring measurement redundancy and system observability and overcoming the issue of misidentification and unidentification of bad data; based on the above expression and constraints, the composite determination method of kernel bandwidths is finally made. Successful application of practice power system of the algorithm illustrate that: the new state estimation model, the expression of approximative optimal kernel bandwidths, constraints of kernel bandwidths and its composite determination method are all effective and reasonable. © 2015 Chinese Society for Electrical Engineering.

Lu P.,Hohai University | Zhao J.,Hohai University | Li D.,Anhui Electrical Power Dispatch and Control Center | Lin C.,Beijing Kedong Electrical Control System Co.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2016

The cyber physical system (CPS) paves a new way for real time dispatch of island microgrid. A framework of island microgrid cyber physical system was provided in this work. According to the framework, a real time dispatch model for active power control was established, and a consensus-based collaborative algorithm was proposed. The algorithm consists of two control stages: the consensus term and the adjustment term. First order consensus algorithm with self-designed weights is adopted in the consensus term, which is responsible for information synchronization of neighbor units. The coefficient matrix with self-designed weights assists to improve the status of controllable units, so as to enhance the optimization speed. According to the actual operation situation of physical devices, the adjustment term serves as a feedback to do real-time correction, in order to make the results satisfy all constraints. Simulation results were presented to demonstrate the effectiveness and robustness of the proposed algorithm. © 2016 Chin. Soc. for Elec. Eng.

Zhao J.,Hohai University | Liu X.,Hohai University | Lin C.,Beijing Kedong Electrical Control System Co. | Wei W.,Beijing Kedong Electrical Control System Co.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2016

The extensive penetration of open-phase running distributed generators (DGs) such as photovoltaic generators to distribution systems may lead to a serious three-phase unbalanced condition, which is an intrinsic characteristic of distribution systems. The effect of the traditional reactive power optimization method is poor without considering the unbalanced problem. A three-phase unbalanced reactive power optimization model for active distribution networks is presented. The model with the objective of minimizing both the negative sequence system voltages and network losses considers continuous and discrete variables e.g. the under-load tap changers, capacitors banks and static var compensator. The reactive power optimization problem is formulated in rectangular coordinates as a mixed-integer quadratic programming with the quadratic constraint problem. It is solved by the branch-and-bound method and the original problem is divided into a lot of sub-problems without discrete variables, which are solved to get the control strategy of devices. The simulation results of the modified IEEE 33-bus three-phase test system show that the proposed model and method are effective. © 2016 Automation of Electric Power Systems Press.

Lin C.,Beijing Kedong Electrical Control System Co. | Gao F.,Beijing Kedong Electrical Control System Co. | Wang G.,Beijing Kedong Electrical Control System Co. | Wei W.,Beijing Kedong Electrical Control System Co. | Yang X.,Beijing Kedong Electrical Control System Co.
Dianwang Jishu/Power System Technology | Year: 2015

Aimed at the disadvantages of existing Substation Operator Training Systems (SOTS), this paper presents a system design of immersive SOTS, and has developed the core technologies, such as 3D virtual reality engine technology, multi-channel video output technology, virtual human drive technology, Kinect somatosensory interaction and walkthrough technology, etc. Immersive SOTS provides immersive substation virtual reality environment in the respects of auditory and visual senses and interactive mode for substation operators. Among them, the multi-channel video output technology is achieved with innovative methods to convert the underlying computer graphics data. The virtual human driven interactive technology uses dynamic time warping (DTW) algorithm, making up for the disadvantages in Microsoft Kinect skeletal tracking SDK system which cannot recognize people gesture. With the scene roaming technology based on somatosensory interaction, the effect of controlling virtual character roaming and steering in simulation scene is achieved. This system enhances user's experience and increases user's training interest, effectively improving the quality of training with strong practicality. In the study, repeated testing was performed to identify the scope and Kinect motion recognition rate, and a large number of experimental data were accumulated for later researchers' reference that how to avoid simulation system design errors. ©, 2015, Power System Technology Press. All right reserved.

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