摘要:

Two main types of electromagnetic pump for liquid metals can be distinguished: conduction pumps, a.c. or d.c., in which a magnetic field is established across a tube containing liquid metal, and current is fed to the liquid through electrodes connected to the tube walls; and induction pumps, in which a travelling field induces the required current, as in the induction motor. The induction pump takes three main forms: annular linear (Alip), flat linear (Flip), and spiral (Sip).These are probably the most useful types of electromagnetic pump for liquid metal, and each is examined and compared in an attempt to predict their relative performance and their main design features.

DOI:10.1049/pi-a.1957.0021

出版商:IEE    

年代:1957

数据来源: IET

摘要:

A particular type of moving-coil regulator, of exceptional ingenuity, has found wide application over the last fifteen to twenty years, but it is believed that no rigorous analysis of it has previously been carried out. Besides being rigorous, it is thought that the theory here given also facilitates calculations on the performance of the regulator, and test results have shown that the theory is fully and closely supported by practical performance.

DOI:10.1049/pi-a.1957.0023

出版商:IEE    

年代:1957

数据来源: IET

摘要:

It is well known that an induction motor with an asymmetrically connected secondary circuit will run at a fractional slip rather greater than 0.5 but that the asynchronous performance is not wholly satisfactory. The defects arise chiefly, though not entirely, from a rotor field component which rotates with a small angular velocity (1–2s)ω, and is responsible for reflecting undesirable low-frequency currents into the primary supply system. These disadvantages are avoided by superimposing a stationary magnetic field which fixes the (1–2s)ω field in space and thus compels the rotor to run ats=0.5, i.e. at exactly half speed. Further, the power factor can be controlled by altering the d.c. excitation in the usual way, and good efficiencies can be achieved. Test results are quoted for three different types of rotor and compared with a first-order theory which provides suggestions for improved rotor design and further developments.

DOI:10.1049/pi-a.1957.0025

出版商:IEE    

年代:1957

数据来源: IET