Papers by Keyword: Magnetic Saturation

Abstract: In order to make on-line monitoring on the temperature of high voltage switch circuit breakerand find outthermal fault in time. This paper puts forward a new method with radio frequency and magnetic saturation power supply technology to make on-line monitoring on the temperature of high voltage switch circuit breaker, it designs the high voltage switch circuit breaker contact temperature online monitoring device. The device mainly includes monolithic temperature collector and data receiver, they transmit data wirelessly, and this makes high temperature monitoring terminal and the data receiving terminal completely electrical isolated. Integrated temperature collector doesn’t need external power supply, it uses small CT saturation technology for continuous power. The experiment shows that the temperature error is ±2°C, it can meet online temperature monitoring requirements of high voltage switch circuit breaker contact.

Abstract: In this paper, the magnet arrangement for a manufactured Double Layer Interior Synchronous Permanent Magnet Motor (DLISPMM) for Electric Vehicle (EV) applications is investigated. In a first step, the manufactured motor is optimized for its nominal condition, by using a particular design of experiment (DOE) method. In a second step, a comparative analysis for the two types of DLISPMMs for a wide speed range operation is performed, by using a parametric Finite Element (FE) model, for calculation of the main machine characteristics, in conjunction with a convenient dynamic model, considering magnetic saturation, for implementation of field weakening control. The initial linear and the final, considering magnetic saturation, dynamic models are evaluated. Finally, the initial and final designs are compared in terms of the main operating characteristics for both nominal low speed and high speed field weakening operation.

Abstract: A Switched Reluctance Motor and Generator (SRMG) has a simple double salient pole structure that uses reluctance torque and does not use a permanent magnet, making the unit price low. This kind of structure makes it mechanically tough, have outstanding output characteristics making it used as traction purpose. However the noise, vibration and torque ripple is bigger than other motors and because it does not have any magnetic flux in the rotor, it is not useful in regenerating.[[ In this paper, novel regenerating method with separate excitation driving technique is presented. It is different from the existing regenerating brake that uses the remnant flux on a separate excitation type by using a parallel switching base to redirect portion of the flux path to excitation and the rest to generation. The proposed method makes it able to use a larger portion in generating, there is no limitation in the excitation current in order to generate and the control of the output is simple. Because the proposed method is based on the parallel switching technique the number of switch per phase does increase. However in motor mode the division of current goes down making it easier to go in generating mode. The proposed method is generated upper 50% regenerating power rate more than general method. In order to prove the possibility, a simulation of flux flow using FEM is applied. The proposed method is also verified by experiment result.

Abstract: Determine the electrical and mechanical coupling modeling and analysis method of power train system for electric driven vehicle. Mechanical vibration mathematical model, rotation DQ axis mathematical model of PMSM and electrical-mechanical coupling model of Power-train System for a new energy vehicle are given. Numerical solution and parameter sensitivity analysis has been done. Consider the impact of temperature change, iron core magnetic saturation, motor torque fluctuations and load torque fluctuation on the system.

Abstract: Radial weight and rotary torque load often demand large winding current in a bearingless switched reluctance motor (BSRM). This will tend to cause magnetic saturation. But traditional mathematic model can not fit for this saturated working state, which has formatted a sever limitation. With a BSRM model in Maxwell, its magnetic saturation characteristics were analyzed, and a critical criterion was computed. Then a novel mathematic model was established with Maxwell tensor method and confirmed by Finite element computing results. It could fit for both unsaturated and saturated working state, and also satisfy reversibility condition. These were both very useful for nonlinear decoupling with state feedback method and wide application in industry process. This proposed modeling and analyzing method could also provide useful references for motor’s optimization design and control algorithm research.

Abstract: In order to detect the overheating fault of high-voltage switch contacts in time, and enhance the reliability of power supply system, this paper presents a new method for temperature rise monitoring, it is realized by WSN (wireless sensor network) and electromagnetic coupling which is a power-gaining technology. Based on the above method and technology, the author designs an on-line system to monitor the temperature rise of high-voltage switch contacts and builds a WSN based on ZigBee protocol. The system includes integral temperature collectors and data receiver, and the data between two of them is transmitted wirelessly by using the opening frequency band of 2.4 G provided by wireless module. The integral temperature collector does not need external power for its power is provided directly from high-voltage bus by the principle of electromagnetic coupling. The extensive system tests show the measurement error of temperature is ± 1.5°C, which can meet the temperature measurement requirements of high-voltage switch contacts.

Abstract: Pulsed eddy current (PEC) technique has been successfully used for measuring wall thinning of carbon steel equipments without removal of the insulation. In field applications, the probe performance decreases in presence of ferromagnetic claddings. This paper presents a method based on saturation magnetization to solve this problem. The main principle of this method is to weaken the magnetic shielding effect of the cladding by magnetizing it to saturation. A U-shaped magnetizer is designed to realize this method. Contrast experiments are performed on a Q235 steel plate covered by a galvanized steel cladding. The experiment results show that the thickness measurement range and lift-off range are increased by applying this method to the common PEC probe.

Abstract: Aiming to obtain components with higher density, this work evaluated the technical and economical viabilities to replace the pre-alloyed Fe49Co2V by an elemental powder alloy of iron and cobalt (Fe-50Co). Using an elemental alloy could increase the density of the final material due to the driving force created by the chemical gradient between the powders. The results showed that is possible to achieve higher densities in an elemental powder Fe-50Co alloy sinterized at the same temperature and in shorter times than the Fe49Co2V alloy. The analysis of economical viability showed that the replacement of the alloys have advantages as the pre-alloyed powder price is higher than the elemental.