DETERMINATION OF HEAT STATE OF NORMAL LOAD INDUCTION MOTORS BY A NO–LOAD TEST RUN

ABSTRACT

Determining the nominal thermal conditions of Induction Motors (IM) experimentally requires the appropriate equipment for loading the motor, expending the electrical energy and an enormous amount of time, The difficulties of these tests increase with the size of the motors and when it is necessary to perform the tests at the place of installation. This paper discusses the heating process of induction motors in a no–load test run under normal and over–voltage conditions. The method of prediction and recounting the results of a no–load test of IM on a full load run is proposed. The theoretical research of heat processes into IM is based on its thermal circuit and its electrical equivalent. Some of the parameters of the equivalent circuit were determined from the experiment. The influence of the technological uncertainties of manufacturing IM on their thermal parameters is also discussed.     

A NEW GA APPROACH FOR OPTIMAL CONTROL SETTING DETERMINATION OF UPFC IN POWER SYSTEM OPERATION

This paper presents a new, hybrid genetic algorithm (GA) approach to solve optimal power flow (OPF) in power system incorporating flexible AC transmission systems (FACTS). A versatile FACTS device, UPFC (unified power flow controller), is considered. In the solution process, GA, coupled with full AC power flow, selects the best regulation to minimize the total cost and keep the power flows within their security limits. The optimization process with GA is presented with case study examples using IEEE test system to demonstrate its applicability.The results are presented to show the feasibility and potential of this new approach.     

AN ACCURATE METHOD OF FAULT ANALYSIS FOR RESPONSE OF FAULTY DISTANT TRANSMISSION LINE

本文应用分布参数故障传输线复频域布参数节点导纳方程和另一种数值拉普拉斯反变换方法，对故障传输线首末端电压响应进行了分析，基于matlab的分析结果显示，与应用pade有理函数近似的拉普拉斯反变换方法相比较，该方法更易于分析，结果更准确。     

BOND GRAPH SIMULATION OF A CURRENT SOURCE INVERTER DRIVEN INDUCTION MOTOR (CSI–IM) SYSTEM

ABSTRACT

Based on the bond graph approach, the paper presents a developement of a dynamic model required for the simulation of a current–source–inverter (CSI) driven induction motor. The induction machine Is represented by the mutually perpendicular α–β model in a stationary reference frame, and is linked with the three phase current source inverter by a power conserving transformation which is taken as displacement modulated transformer structure In the bond graph model. A specific digital simulation program (COSMO–CAD) yields state space representation of the system from the bond graph structure with no reference to particular circuit configurations, representing various modes, during normal or abnormal operation. The acceptability of the simulation technique is shown by comparison of some results with those obtained from an available method of simulation.     

A FERROELECTRIC BASED PASSIVE RFID TAG FOR UHF (860–960 MHz) BAND

ABSTRACT

For a longer working distance between passive tags and the reader, the ferroelectric based technologies are proposed in UHF (860–960 MHz) band transponder. The small ferroelectric capacitor layout area with a stacked capacitor structure over circuit region and a large dielectric permittivity of 250 to 500 and small 1T1C cell array layout area with simple 2T2C based reference scheme allow small chip size. The low operation voltage of 1.5 V to 2.0 V without high voltage boosting scheme also contribute to small power consumption and low cost.