The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
A novel fast method based on phasor measurement units (PMU) measurements for transient stability prediction is presented in this paper. The method simulates various faults of a system off-line and records all rotor angle trajectories. Then a characteristic trajectory set is obtained for each generator using hierarchical cluster algorithm (HCA) and a perturbed trajectory standard pattern database (PTSPD)...
The impact of different types of line faults on the turbine-generator (T-G) shaft torsional dynamics in AC/DC power system, including three-phase to ground fault, one-phase to ground fault on sending end bus and receiving end bus are analyzed by PSCAD/EMTDC time-domain simulation. The simulation results shows that three-phase to ground fault on the sending end bus will cause shock electromagnetic...
Low-frequency power oscillation issues are both serious in Yunnan power grid and Southern China power grid, the two "west to east" complex and long chain configuration networks. Based on the significant data provided by the real-time monitoring system in Yunnan power grid, low-frequency issue is analyzed by Prony method, frequency, amplitude, angle and the damping ratio of system are obtained...
Low-frequency power oscillation issues are both serious in Yunnan power grid and Southern China power grid, the two ldquowest to eastrdquo complex and long chain configuration networks. Based on the significant data provided by the real-time monitoring system in Yunnan power grid, low-frequency issue is analyzed by Prony method, frequency, amplitude, angle and the damping ratio of system are obtained...
This paper describes the comparison of the micro-grid method and a 3D FEM for predicting the medium field in perpendicular recording systems. The microgrid method uses Fourier series expansion to simulate the three dimensional (3D) field emanated from the perpendicular medium under the air bearing surface (ABS) of the read sensor. The proposed method can account for the effect of the recorded transitions...
The advancement in micro and nano-scale technologies demands in depth understanding of magnetic behaviors. For example, as the ever increasing need for high capacity data storage continuously pushes the boundaries of magnetic recording technology to the physical limits, detailed analysis of the magnetic properties becomes necessary. It is expected that finite element micromagnetics can predict the...
This paper presents a dynamic magnetic field prediction for perpendicular writer heads in magnetic recording systems. The dynamic model considered the effect of time dependence and velocity of soft underlayer when compared with a static model. The effects of the spin speed of the disk platters, and rise time of the recording signals are investigated. The results showed that the write field performance...
A numerical model has been developed to analyze and optimize the run-time performance of a disk drive spindle motor. A field-circuit coupled time-stepping finite element method is used for the analysis of the motor optimal performances with limits of supply voltage, current and power consumption during the spin-up time of the drive. Results of investigations with one and two disks are presented
In this paper, an effective method for predicting cogging torque developed in high precision permanent magnet motors used in data storage devices is presented. The torque component due to transition of magnet polarity over slot opening is studied in details, numerically and analytically, to gain in depth understanding of the torque development mechanism. The resultant cogging torque has good agreement...
This paper presents an analytical solution of the write field distribution for perpendicular recording with effect of the soft underlayer taken into consideration. The solution is based on vector magnetic potential, and the analytical solutions obtained are in good agreement with numerical simulations. It is useful in the design phase of the perpendicular recording heads to investigate the characteristics...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.