Applied Mechanics and Materials Vols. 672-674

Abstract: A distribution network reconfiguration method with the considerations of time-varying weather conditions is proposed. The aim of distribution network reconfiguration is to minimize the outage risk. The effects of weather condition in evaluating the outage risk are considered. Finally, simulations on the 33-node test system validate the proposed method.

Abstract: With the increase of electricity consumption,the line-load tends to the limit,and easy to cause line overloads in the system. To solve this problem, a new algorithm to remove the line overloads is proposed in this paper. The algorithm greatly reduces the number of power flow calculation and improves the computational efficiency by using of the method of alternative routes for the sorting. Through the use of multipath search in the algorithm, the situation of regression is been avoided. Test has been performed with the IEEE 30 bus system. Results have been verified the effectiveness and feasibility of the proposed algorithm.

Abstract: Based on the mathematical model of the PWM converter, control strategy of the grid-side converter directed by the grid voltage and control strategy of the rotor-side converter directed by the stator flux were established combining the vector control theory. The method using the nonlinear simplex algorithm to optimize the PI control parameters of the DFIG unit was first proposed, optimization results proved that this method had good practicality and robustness.

Abstract: VxWorks operating system provides the technical foundation for the products development of DC protective measurement and control device for mass transit. According to technical requirements of products of DC protective measurement and control device for mass transit, this paper set up software and hardware implementation scheme and deeply analyzed the key technology such as task function division, message management, interrupt management and protection task realization.The successful application experience of this technology scheme has the guide meaning for the development of the similar products.

Abstract: To meet the new training requirement caused by the changing of grid management mode, a training simulation system that fits to the new mode is proposed in this paper. Based on the HLA platform, an integrated simulation framework which could coordinate different simulation modules is designed. Moreover, the key technologies of information exchanging mode, simulation time advance strategy, data filtering strategy and substation OM scene simulation are described, especially focused on the realization. At last, an application is presented, it indicates that the system is more realistic and more suitable for training the operation maintenance staff.

Abstract: A linear static state estimation on measured quantity transformation is proposed in this paper utilizing the high precision measurements of WAMS. Using transformation of measured quantity, the current measurements of WAMS are transformed into equivalent voltage measurement, and after simplification a constant real number information matrix is obtained, so the decoupling calculation of real part and imaginary part of nodal voltage is realized. The calculation has many advantages such as fast proposed algorithm, high estimation precision and better numerical stability. Finally, the algorithm is applied to the calculation of network loss in theory, the calculation accuracy of transmission loss is improved. The calculation results of IEEE 30-bus test system validate the effectiveness of the proposed method.

Abstract: The integration of distributed generator (DG) will bring a series of influence in distribution power system. With the trend of a large number of DG penetration, researches on the maximum integration capacity of DG become a hot research topic. A multi-objective optimization model with objective functions of the maximum DG output, network losses and voltage stability index are formulated. Particle swarm optimization (PSO) algorithm is adopted with variable inertia weight to calculate the maximum DG output. IEEE 33-bus test system with DG units is taken as one example to compute the maximum integration capacity. The results show that the proposed method is reasonable and effective.

Abstract: Distribution network can implement self-healing when real-time operation state can be mastered comprehensively and operation change tendency can be predicted. Firstly the evaluation index system of operation state was constructed from five aspects (safety, reliability, quality, economy and adaptability). Then, distribution network’s operation network evaluation model was established on the basis of attribute mathematics theory, which could transform this problem into calculation problem of operation state’s attribute measure. Analytic hierarchy process was used to determine the weights of indexes. Finally the process for evaluating operation state was given. The simulation results show that this model can get accurate operation state of distribution network.

Abstract: Operation number constraint of control means isn’t considered to traditional optimal power flow model, and at optimal solution all the control variables often be changed, which causes a tedious dispatching plan and is difficult to operate. In this paper, Optimal Power Flow (OPF) with constraints limiting the number of control actions was discussed, and 0-1 discrete variables of model was transformed to complementary constraint, then modern interior point algorithm was used for solving. Through simulation the relationship between generator number constraint on regulation of the active power output and optimization objective was explored, which could obtain best balance point on two, and close to conventional OPF optimization objective with reducing the number of regulation.

Abstract: At present, distributed integration setting calculation mode is widely used in power system. However, there are cross and overlap issues in protection relay model splicing process. Deeply researched in the characteristic of integrated relay splicing, according to power system network topology, an intelligent substation locating method based on the repulsion tension algorithm is applied in this paper. Finally, an example is used to verify the feasibility of the method.