Abstract: The Ageing mechanisms of electromagnetic relay were discussed. And the key ageing indicators were found out. Then, the test methods of ageing indicators were introduced. After that, a method to evaluate the lifetime for the coil of electromagnetic relay was proposed. Accelerated ageing test was conducted to the coils, and the key ageing indicators were collected periodically. According to those test data, the ageing condition and lifetime were evaluated. In the end of the paper, examples about assessing the ageing condition and lifetime were given separately.
Abstract: The Equivalent Turn Number of Coil (ETNC) is proposed for induction coil design. Simulation results show that the vibration on the induction coil’s structure. The optimized coil is composed by two symmetry parts on the condition of sinusoidal vibration. The effective value of output EMF of optimized coil increases 51.39% than uniform coil’s. In the experiment, the optimized and uniform coils are fabricated with 600 turns and comparatively studied in the same vibration-to-electrical generator. The test results show that the peak-to-peak value and effective value of output EMF of the optimized coil can increase up to 52.59% and 48.76%, respectively, compared with the uniform coil.
Abstract: The main role of the permanent magnet machine in the aviation frequency alternator is as the exciter. Its main function is not only to supply power for the generator controller but also supply the excitation current to exciter by supplying field winding of exciter with DC excitation voltage in the case without the emergency power. So we have to rectify 115V AC of permanent magnet machine output and make DC/DC conversion, so that the output is the suitable DC voltage. In the actual, it is very troublesome to make parameter tuning to rectifier module and DC/DC module, so this it is necessary to make model and simulation research. In this paper, we make module, simulation and parameter tuning for the rectifier and DC/DC transformation module in the MATLAB environment. From the simulation results, we can get that the model is correct, the parameters are appropriate.
Abstract: In the case of periodic load disturbance, the chaos oscillation phenomena may caused by power system to threaten the safety operation of the network. In order to solve this problem, this paper presents the strategy on tridiagonal structure matrix stability theory. Using the designed controller, the chaotic system operation state turn into a stable operation state, and system is stabilized an unstable nonzero equilibrium point.
Abstract: In recent years, the nonlinear load of the industry is increasing with the development of the power electronic technology. The harmonic distortion is getting more and more serious. So measurement, analysis, and restraining the harmonic of power system have become an important topic for the environmental management of the power system. This paper presented a novel method to analyze power harmonic using wavelet transform, and researched the technology how to detect and treat the harmonic in the power grid. The performance applying the wavelet method to detect harmonic from experimental signals was presented. The simulation results showed that wavelet transform can extract power harmonic in different frequency from the signal effectively.
Abstract: In this paper, the influence of superconducting fault current limiter (SFCL, flux-coupling type) on power system transient stability is studied in detail. The influence of SFCL to transient stability of power system is studied using a model of single generator infinite bus system, different transient stability calculation results gotten with and without SFCL and with model system in different fault conditions are compared. The results show that the SFCL can effectively reduce the transient swing amplitude of rotor and extend the critical clearance time, and the application of SFCL in the power system can help to enhance its transient stability.
Abstract: The demand of energy is increasing in today's society, to explore and utilize new energy sources is significant, especially as wind and solar energy can be reused. Today, the exploitation technology of solar-wind energy in countries is mature, however, there has always been weaknesses, eg: high development costs, low energy harvesting efficiency, poor control stability, such as the high cost of manufacturing solar panels and the limit of large power devices on the controller efficiency and power. In view of these difficulties above, this paper presents a method of resonant drive, all flow control to solved the problem of the controller's power and efficiency and improve the utilization ratio of battery board, and also reduce panels production cost indirectly. It is in line with national energy-saving emission reduction requirements. Finally, I used the technology to develop some stable products successfully, which are used in the field of communication base stations.
Abstract: This paper presented a novel high speed permanent magnet machine, which is used for electric drives and motion control systems. Compared to traditional high speed permanent magnet machines, the proposed structure can increase the cooling capacity and reduce the core loss, which can improve the reliability of the system and efficiency. Meanwhile, in order to protect the permanent magnet, the carbon fiber bandage with thin layer of conductive metal is used to cover the permanent magnet. The basic design principle for the proposed structure is described. To verify the proposed structure, finite element method (FEM) is adopted to get the characteristics of the proposed structure. Finally, the validity of the proposed structure was verified by the FEM analysis results.
Abstract: With the increasing demands of electric vehicles, many DC electrical energy meters for vehicle battery charger appear. In this paper, a verification device of DC electrical energy meter is developed that base on real-time pulse period compare method, which used PCI-6281 for data acquisition, used LabVIEW for data processing and human-computer interface. This article describes the working principle of the verification device and core technology. The practical application verify the device can use for calibration of DC electrical energy meter efficiently.
Abstract: In order to improve the performance requirements of voltage monitoring recorder, this article introduces the voltage monitoring recorder based on Atmega32 MCU system.According to the input voltage value choose high or low reference voltage to ensure the 10 conversion accuracy, realize the design of changeable range voltage monitoring recorder. The instrument has low cost, high reliability, high storage capacity.