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Guozhen, China

Ding T.,Tsinghua University | Guo Q.,Tsinghua University | Bo R.,Midwest ISO | Sun H.,Tsinghua University | And 3 more authors.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2014

To achieve a fast approach to the dynamic reactive power optimization model, a mixed integer nonlinear programming model was set up, with consideration of the discrete reactive power equipment operation limit and power grid security constraints, to minimize the transmission losses. Furthermore, a method called heuristic search and variable correction was proposed that for the first stage, the discrete variables are relaxed into continuous ones, which leads to an optimization model with equilibrium constraints. According to the optimal value of relaxed model, a mixed integer quadratic programming model is formulated to minimize the objective of approximation variance, satisfied the discrete switching operation constraints in primary model. For the second stage, the continuous variables are redressed with respect to the determined discrete variables. The impact of adjustment step and operation limit on the optimal solution was fully studied in IEEE 14-bus test system. Besides, the result of IEEE 30, 57, 118 test systems show that an optimal solution can fast be obtained by proposed method, and the precision satisfies the actual engineering, which can also employ the parallel technology. © 2014 Chinese Society for Electrical Engineering.

Ding T.,Tsinghua University | Sun H.,Tsinghua University | Bo R.,Midwest ISO | Yao Z.,Baoji Power Supply Bureau
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2015

Due to the physical limitations of the generator, the vibrations in a shaft bearing may be amplified at a certain operation regimes, the prohibited zones are needed which leads to a disjoint power generation instead of continuous output. Besides, the reservation for each generator should also be considered to face with the stochastic integrated generation of large-scale wind power into power grid, which actually reduces the total reservation of the grid. Therefore, the economic dispatch with the multiple objective of minimized cost and maximized wind power integration, as well as the prohibited zones, was set up, and a standard mixed integer quadratic programming was formulated. Furthermore, the test system with six, fifteen and multiple generators were simulated respectively. The results show that the proposed method can be applied to the real-time system. ©2015 Chin. Soc. for Elec. Eng.

Ding T.,Tsinghua University | Guo Q.,Tsinghua University | Sun H.,Tsinghua University | Bo R.,Midwest ISO | Yao Z.,Baoji Power Supply Bureau
Qinghua Daxue Xuebao/Journal of Tsinghua University | Year: 2013

Vibrations in a shaft bearing can be amplified in other seemly unconnected regions due to the generators' physical limitations. Therefore, the traditional economic dispatch model should include prohibited zones. By ignoring the network losses, the problem can be transformed into a mixed integer quadratic programming (MIQP) and solved using the branch and bound method. If the losses are considered, the problem can be represented with a quadratic generation term according to the B-coefficient method, with the nonlinear non-convex model set up using polynomial interpolation. Taking the optimal value of the MIQP model as the starting point, this model can then be solved using the interior point method. The method was tested with 6 and 15 generator systems and compared with 10 existing methods. The results show the effectiveness and efficiency of this method. Finally, the time complexity was analyzed with a 200 generator system.

Chen L.,Baoji Power Supply Bureau | Lei M.,Shanghai Huadong Electrical Group Electrical Co. | Tang X.,Shanghai Huadong Electrical Group Electrical Co.
Gaoya Dianqi/High Voltage Apparatus | Year: 2013

Because the gas-insulated transmission line (GIL) is very long so the design is generally divided into a plurality of inflatable units. Each line inflatable unit is composed of a plurality of manufacturing units and generally contains an telescopic joint. In order to ensure the line inflatable unit only to move along the axial direction and not move radially during the normal operation, the installation modes of each line inflatable unit should be one point fixed and other points can move freely. And how to properly design the position of fixed fulcrum and to calculate the intensity of support bracket is also discussed in this paper.

Liu Y.,Xian University of Science and Technology | Fu Z.-X.,Xian University of Science and Technology | Nan F.-D.,Xian University of Science and Technology | Lu N.,Baoji Power Supply Bureau | Ma C.,Xian University of Science and Technology
Gaoya Dianqi/High Voltage Apparatus | Year: 2013

A capacitance-adjustable arc suppression coil is designed based on TMS320F2812 regulated controlled-silicon switching capacitors for the 2.2 kV·A/220 V capacity-adjustable arc suppression coil and 2 kvar capacitance regulating cabinet, and experimental verification is carried out in laboratory. The working principle and the hardware and software design scheme of the coil are illustrated. The result suggests that the capacitance-adjustable automatically tracking arc-suppression compensation device can realize on-line measurement of capacitive current of power grid. Its functions, such as automatic recognition of operating condition of power gird and complete compensation for earthing capacitive current, fulfill the qualifications for automatic compensation of power grid capacitive current. Furthermore, a 2 kvar capacitance regulating cabinet is designed based on bidirectional controlled-silicon switching capacitor. Moreover, a human-computer interface for displaying real-time parameters of LCD128 × 64 module is designed. The real compensation currents of the arc suppression coil at all levels are obtained experimentally, and are compared with the theoretical ones with an error analysis. The proposed arc-suppression compensation device has the merits of rapid tuning, wide range, high reliability and no harmonic pollution.

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