Westinghouse Electric

About: Westinghouse Electric is a company organization based out in Cranberry Township, Pennsylvania, United States. It is known for research contribution in the topics: Brake & Circuit breaker. The organization has 27959 authors who have published 38036 publications receiving 523387 citations.

A New Approach to the Calculation or the Lightning Perrormance or Transmission Lines III-A Simplified Method: Stroke to Tower

Abstract: 1. Simplified methods of calculating the voltage across the insulator string are presented based on field-theory concepts for a stroke to the tower with zero towerfooting resistance. 2. The voltage across the insulator string is composed of two components: (a). that produced by the rent and the charge fed into the tower and ground wires, and (b). that produced by the charge above the tower. 3. To calculate the voltage produced by the current and charge fed into the tower and ground wires, conventional traveling-wave theory and methods can be used provided the proper value of surge impedances are used. 4. Equations, based on field theory, are presented to calculate the ground wire and tower surge impedances and the conductor-to-ground mutual impedances. 5. The development of travelingwave theory directly from field theory places traveling-wave theory on a more rigorous basis. 6. To calculate the voltage produced by the charge above the tower, approximate simplified equations are given for a given stroke mechanism. These can be modified for other assumptions. 7. From examples and calculations given in this paper it is possible to gain some insight on the effect of tower geometry, number of ground wires, and position of the conductor on the voltage across the insulator string. Voltages were calculateed across the top and bottom insulator strings of the single-groundwire AEP-OVEC 345-kv tower, across the top insulator string of the two-groundwire AEP-OVEC 345-kv tower, and across the insulator string on the PW&P 220-kv tower.

Design, fabrication, and analysis of 17-18-percent efficient surface-passivated silicon solar cells

Abstract: A simple analytical model has been developed which provides useful guidelines for fabricating high-efficiency silicon solar cells. Consistent with the model calculations, both surfaces of n+-p-p+solar cells were passivated by a thin layer of thermally grown SiO 2 . Oxide passivation resulted in 17.2-percent efficient solar cells on 4 Ω . cm base material. Passivated cells show about 3 mA/cm2increases in J SC , ∼20 mV improvement in V OC , and ∼2-percent increase in absolute cell efficiency compared to the counterpart 15.2-percent efficient unpassivated cells. The majority of improvement in V OC came from the emitter surface passivation, while both front- and back-surface passivation contributed to the increase in J SC . The emitter region should not be regarded as a "dead layer" because emitter surface passivation can increase the quantum efficiency at short wavelengths from 40 percent to greater than 75 percent.