Advanced Materials Research Vols. 433-440

Abstract: It is commonly used to represent static frequency characteristics of a power system that coefficient K reflects the frequency excursion caused by load changes. As the parameter for dispatching branch to arrange measure or design equipment when frequency excursion occurs, K is of great importance to dispatching branch. However, the traditional methods can only get the range of coefficient K, but not the K corresponded to the specific disturbance. In this paper, curve fitting is used to obtain the trend of K-value by a finite number of measured points of coefficient of static frequency characteristics. And then, the predicted value is compared to the simulated result to judge whether it meets the permitted error. This is a breakthrough in the study of K-value.

Abstract: Solar photovoltaic (PV) grid-connected generation represents the direction of solar energy’s development and it is the most attractive technology of energy utilization in the 21st century. This paper is focused on the PV system and makes simulations for it. The result represents its characteristic.

Abstract: This new hybrid capacitance and micro-leverage amplifier actuator was based on modifying existing structure and mechanism. That overcame the drawback of small displacement of the capacitance actuator in virtual of the micro-leverage amplifier. The amplifier time of the single micro-leverage amplifier was 4.5. Connect the 1×9 array with nine electrostatic capacitance micro-actuators with the amplifier and form a polymer actuator. The actuator whole size was limited to 4×4 mm, the maximum output displacement was 42μm under 15V voltage input. The pull-in voltage of the actuator array was 19V.

Abstract: The effective control strategies of traffic signal can increase the passing-through traffic volume and decrease the total queue delay. Based on the prediction model of cellular automata, the corresponding non-analytical optimization procedure utilizing genetic algorithm is established for the traffic signal predictive control. The inductive predictive control for traffic signal is proposed which has certain practical importance. The simulation results demonstrate the advantages of proposed predictive control strategy over the conventional methods.

Abstract: This paper considers the repeated-executing characteristics of circuit simulators in practical situations, and raises according methods. These methods are incremental simulation and simulation-on-demand (SOD, just simulate the portion of circuit contributing to user-wanted outputs). A specialized relaxation-based algorithm, Backward-traversing Waveform Relaxation (BTWR), is adopted as the fundamental simulation algorithm. All proposed methods have been implemented and tested. Experimental results justify the values of proposed methods.

Abstract: In this paper, based on the analysis and discussion of multistage decimation structure, we have studied and analyzed some key technologies of the digital filter in digital down conversion. Meanwhile, we have analyzed and summarized the decimation filter modules as CIC, HB, FIR of the digital filter, and a multistage decimation filter design program is given in this paper. An optimum design method is proposed in this article, which greatly reduce the complexity of system design and memory usage and has upgrade the data rate operation with great extent.

Abstract: In this paper, power system electromagnetic and electromechanical transient hybrid real-time simulation technology is expounded in details, which has advantages of the electromagnetic transient simulation program and electromechanical ones. The more details needed to analyze the dynamic characteristics of power systems are provided by this hybrid simulation technology, and the scale of power system simulated is not limited in the hybrid simulation program. The hybrid simulation program is applied to analyze the power system subsynchronous oscillation problem occurred in a power plant with 4 turbine generators located in the northwestern China. According to the simulation results, it is clear that the stability of generators is threatened by the subsynchronous oscillations caused by capacitor series compensation in the transmission line connecting the power plant and the load center system. In meantime, the effectiveness of the countermeasure is validated simultaneously by the hybrid simulation results.

Abstract: In this paper, we proposed a new fuzzy support vector machine(called L2–FSVM here), which error part of object is L2–norm.Meanwhile we introduce a new method of generating fuzzy memberships so as to reduce to effects of outliers. The experimental results demonstrate that the L2-FSVM method provides improved ability to reduce to effects of outliers in comparison with traditional SVMs and FSVMs, and claim that L2–FSVM is the best way to solve the binary classification in the three methods stated above.

Abstract: OntoUML is a conceptual modeling language which is built with a lightweight expansion of UML metamodel, but it doesn’t provide mechanism of consistency checking on conceptual model. The correctness of the syntax and semantics of the model still need artificial check. The paper introduced OntoUML briefly and put forward a scheme of consistency checking of OntoUML model based on description logics. By transforming into knowledge base of description logics, the detection of consistencies at the OntoUML model can be realized using existing mature reasoning system.

Abstract: This paper introduces modeling method for calculating nodes responses of transmission-line network directly in the time domain. Arising from classical telegrapher equations, the time-domain model of transmission line is gained. The transmission-line model, together with transmission-line nodes model, form the network model. Using the time-domain modeling method, transient responses for two given networks are gained. The injection experiments to cable networks are done to validate the calculating results. The consistency of calculating results with measure results indicates the model is feasible.