Applied Mechanics and Materials Vols. 284-287

Abstract: This study investigates the RFID based innovative power meter system. The system architecture and business process are improved by adopting standard complied design approach. Open Standards contributes more flexibility, more interoperability, less time consuming to our innovative system developing and play a key role for well emerging and running into global ICT infrastructures. Then a protocol framework to address security issue is provided and it make password based authentication scheme workable to enhance the security strength. RSA based digital signature methods are introduced to achieves a two-way authentication from tag to reader. Proposed protocol framework suits for power meter practical service process and offers potential to upgrade the cryptography methods for future hardware progress. It could be used as the foundation for inducing advanced technique while inspecting the information security requirements need. Our study is helpful for future power resource management system deploying and it is also valuable to address the security problem for mobile reader like RFID innovation system.

Abstract: The purpose of this paper is to contribute the database to users of wind power in Taiwan. The study analyzes 12 stations in Taiwan. The data were collected during the period 2001-2010. The Weibull distribution method was used to analyze wind characteristics and wind energy potential in the different site and height as well. The results show that the wind speed at the height 100 m and roughness length 0.1 m in Taiwan between 1.7 m/s and 4.3 m/s, and the power density from 5 W/m2 to 75 W/m2. Taipei is the windy place, while Taichung is the less. The direction of the wind most commonly comes from north-east. The wind energy varies depend on season, strong wind in spring and winter, while weak wind in autumn and summer. The results obtained contribute to a global vision of the wind energy potential and the windy areas in Taiwan.

Abstract: An accurate forecasting method for wind power generation of the wind energy conversion system (WECS) can help the power system’s operator to reduce the risk of unreliability of electricity supply. This paper proposed a radial basis function (RBF) neural network method to forecast the wind power generation of WECS. To demonstrate the effectiveness of the proposed method, the method is tested on the practical information of wind power generation of a WECS. The good agreements between the realistic values and forecasting values are obtained; the numerical results show that the proposed forecasting method is accurate and reliable.

Abstract: Increase in the efficiency of a small vertical-axis wind turbine (VAWT) elevates its potential that compares with a horizontal-axis wind turbine (HAWT). The efficiency does not only depend on the power coefficient of the wind rotor but also on the efficiency of the generator. A permanent magnet synchronous generator having two windings keeps high efficiency in both of low rotor speed regime and high rotor speed regime. To maximize the electricity output of the VAWT, this study directly coupled a generator having 1kW winding and 3kW winding with a straight wing vertical-axis wind rotor as a 4kW VAWT. Meanwhile, system integration and control systems of the wind power system were developed to make sure the operation and the safety of the VAWT. The average efficiency of the wind power system is 0.32 through field tests. The results demonstrated that the small VAWT has the same potential in comparison with two small HAWTs via using the electrical generator having two windings.

Abstract: This paper presents the emergency generator planning and operation strategy of Taipei Mass Rapid Transit (TMRT). To execute the planning and operation of the emergency power system, the system configuration is described first. Also, the line charging capacitance of distribution cables is obtained by using the line constant program under various cable characteristics and lengths. The proper mathematical models and suitable parameters of the diesel generator, excitation system, governor system and load are investigated and applied in the computer simulation. Besides, a load shedding scheme is designed to trip the predetermined loads to avoid generators from tripping due to system overload. Finally, the dynamic system responses under various vital load scenarios are simulated to ensure the abilities of the generator during the emergency conditions by executing the transient stability analysis.

Abstract: The objective of this paper is to integrate five traditional criteria of the Dissolved Gases Analysis published in different standards into a more reliable approach of the fault diagnosis of power transformer for maintenance personnel of Taiwan Power Company(TPC). This paper employs Fuzzy Inference System(FIS) to develop two factors as a integrated fault diagnosis for power transformer. One is the identifiable factor which interprets the fault type, the other is the fault factor which asseses the operating condition of transformer. The result of diagnosis can be observed by web browser on TPC intranet. The designed synthetic method has been verified by TPC historical transformers gas records and shows its effectiveness in transformers diagnosis.

Abstract: As electricity demands and power transactions continuously increase, it becomes vulnerable to voltage instability for power systems, generally incurred by over-utilized facilities or any contingency. The transmission system loading margin (LM) enhancement problem with Static Synchronous Compensator (STATCOM) installation can be formulated as a mixed discrete-continuous nonlinear optimization problem (MDCP); due to the complexity of the MDCP, the computing burden might be very heavy. In the paper, the proposed ordinal optimization (OO) based STATCOM installation method is applied to the MDCP to solve for good enough solutions rather than the best solution, so as to largely reduce the computation burden. In the method, the crude method is first used to solve the MDCP and, based on OO theory, the exact method is then used to determine the good enough solutions. Finally, the good enough solution, as uses the fewest STATCOM device units for installation and makes the power system able to provide the required LM, is recommended for network reinforcement.

Abstract: This paper presents a method for parameter estimation of composite load model using a hybrid searching algorithm, which is performed by the combination of particle swarm optimization (PSO) and complex method. The method intends to enhance the ability of local searching around the solutions, also taking the advantage of global searching by PSO. The load model of interest, in this paper, is composed of a static model and the third order induction motor model, for power system stability analysis. The origin of the hybrid method is to further apply the complex method as a local search for better solutions, with the selected particles from the PSO procedure performed at PSO iteration.

Abstract: High voltage Gas Insulated Switchgear (GIS) is prone to metallic particles. The particle void can reduce the dielectric strength of the insulation material of SF6 gas. This paper discusses the developed particle detector for GIS using a new approach by using image processing to reduce flashover phenomena occurring on energized GIS. The particle detector consists of borescope, laptop and a detection program. The program was coded using MATLAB using image processing algorithm. The in-lab test was conducted on the simulated GIS to see the effectiveness of the particle detector to detect small particles inside the narrow GIS enclosure. In real world application, the borescope will be inserted through GIS access hole before filling the enclosure with SF6 gas. This new approach is proposed to be conducted during the erection and commissioning of new GIS. This new approach looks promising because it can reduce flashover phenomena caused by existence of metallic particle and also reduces Greenhouse gas emission to the air.

Abstract: Ageing is the major problem to the life span of high voltage insulation. Thus, continuous assessment method had gained an interest recently due to the economic concern. The measurement and evaluation of the dielectric response is one of the methods to diagnose transformer insulation condition. Dielectric diagnosis through polarization and depolarization current (PDC) measurement used dielectric response in time domain to assess the insulator. This paper presents the PDC data analysis system developed using LabVIEW software. The developed user-friendly system will enable user to run the recorded PDC data to evaluate the performance of the insulator in term of its conductivity and response function. The analysis result on PDC data recorded from field run using this system also been presented in this paper. Based on the obtained result, the system developed has been successfully helping user to do analysis on PDC data by giving the PDC pattern, conductivity value and response function of the insulator tested.