This paper propose the safety design of automatic train control system which is used for controlling and monitoring train speed not to excess a permitted speed. Safety activities are shown for the computerized system to achieve a required safety requirement. The safety activities are composed of system dynamic modelling to identify potential hazards contained in the target system, to analyze sub system faults to provoke the hazards. Risks analysis are carried out to estimate losses caused from the hazards to allocate safety requirement. We Proposed design solutions for sub system to meet safety requirement.

In this paper, designs of an Interior Permanent Magnet Synchronous Motor (IPMSM) and its motor driver for 42V automotive air condition system are introduced. The characteristics of the IPMSM are predicted by using d-q equivalent circuit having the parameters, such as current phase angle, d-q axis inductances, core loss resistance, etc. The experimental and analysis results of the prototype are compared to show validity of the analysis method, and to give analyzed characteristics in detail. As the result, an improved IPMSM is designed to widen the operating speed limit of prototype; a cost effective AC drive are considered at the same time.

Recently, high-speed centrifugal turbo-compressors have been under intensive research and development. Since, compared to conventional compressors, high-speed centrifugal compressors hive numerous qualities such as simple structure, light weight small size, and high efficiency, etc. In cope with such industrial demands, a high-speed brushless DC motor for a 50-kW, 70-krpm turbo-compressor was developed based on a 2-D analytical method, of which design was verified using the FE analysis. A prototype machine was also fabricated and tested to confirm the analytical design. Preliminarily obtained experimental data using the prototype mac]line shows the validity of the analytical approach.

Equations have been derived for computing electromagnetic forces by using the Continuum Design Sensitivity Analysis based on the Continuum Mechanics and the Virtual Work Principle. The resultant expressions have similar terms relating to the Korteweg-Holmholz force density, Maxwell Stress Tensor and Magnetic Charge Method but numerical implementation of the proposed scheme leads to efficient calculation and improved accuracy. In addition, the method can be easily applied to computing the magnetic force distribution as well as the global force. Results show the aforementioned advantages in comparison with the conventional methods.

PV system's islanding occurs when the uitilty grid is removed but local sources continue to operate and provide power to local loads. Islanding is one of the serious problems in an electric power system connected with dispersed power sources. Also, this can present safety hazards and the possibility of damage to other electric equipments. If the real and reactive power of RLC load and PV system are closely matched, islanding detection by passive methods becomes difficult. This paper shows the simulation and comparision for the previous active methods and novel islanding detection method using frequency drift is proposed for grid-connected PV system.

As the cost of photovoltaic(PV) generation systems continues to decrease, utility interactive systems are becoming more economically viable. Furthermore, increases in consumer awareness correspond to a willingness to pay a premium price for clean electrical energy generated using renewable energy resources. Especially, PV generation systems, in particular, is undergoing a rapid expansion-showing an industrial growth of approximately 40$\%$ per year in the worldwide, as PV cell and systems technology improve new markets become increasingly accessible. This has resulted in an increased demand for the simulation scheme and operational technologies of utility interactive PV devices and systems. The simulation schemes that can be applied to the utility interactive PV generation systems readily and cheaply under various conditions considering the sort of solar cell, the capacity of systems and the converter system as well are strongly expected and emphasized among researchers. So far, authors have been introducing the simulation method of PV generation systems with several papers. In this paper, authors introduce the simulation way of PV generation systems using EMTP type simulators; EMTP/ATP, EMTDC/PSCAD, RTDS, with each examples. And, by connecting the voltage amplifier to the RTDS a novel simulation method which is extremely close to the real condition of PV generation system is also introduced.