Short-circuit calculations and steady-state theoryMcGraw-Hill Book Company, Incorporated, 1928 - Electric circuits |
Common terms and phrases
100 per cent active and reactive amperes angle assumed calculated cent cent cent cent terminal voltage chart for constant circles circuit constants connection copper loss cosh determined equal equivalent Evans and Sels excitation voltage exciting current field current flux given gives harmonics Hence hyperbolic hyperbolic angle hyperbolic functions I₁ induction motor lagging leakage impedances leakage reactance line voltages machine magnetomotive force negative-sequence currents obtained ohms operating point phase positive positive-sequence power factor primary ratio reactive power receiver chart receiver voltage receiving transformers resistance rotor salient-pole secondary Sels charts sending chart sending end sending voltage short circuit short-circuit currents shown in Fig single-phase sinh solution station stator symmetrical synchronous condensers tanh third-harmonic current three-phase torque Trans transmission line V₁ V₂ values vector diagram voltage and current voltages to neutral volts winding Y-connected Z₁ Z₂ zero
Popular passages
Page 189 - Quantities sinh jy = j sin y ; cosh jy = cos y ; tanh jy = j tan y. sinh (x + jy) = sinh x cos y + j cosh x sin y.
Page 225 - Observation of Harmonics in Current and in Voltage Wave Shapes of Transformers.
Page 12 - This is a linear differential equation of the first order with constant coefficients, the solution of which is well known.
Page 193 - Tables of Complex Hyperbolic and Circular Functions," Harvard University Press, Cambridge, Mass., 1927.
Page 19 - ... assembly of a type used in destroyers, and with a high pound price. At the other end of the series was a heavy assembly with a low pound price. Considering the effect of weight on the rest of the turbine structure, an intermediate design was selected. Estimates of the gear assembly were also supplied by the General Electric Company and the Westinghouse Electric and Manufacturing Company. The Electric Coupling The problem of providing a coupling between the generator and the gear box, to serve...
Page 37 - In an n-winding transformer, therefore, the true leakage reactance of one of the windings may, in general, have n — 1 values, namely, a distinct value for each of the other windings with respect to which the leakage reactance is determined. Of course, there is a possibility that two or more of these values may coincide, due, for instance, to symmetrical arrangement of the windings. It is convenient to introduce symbols for the true leakage impedances and reactances as follows: ZK» = Ri + jXim...
Page 18 - Hence, the effective value of a complex wave is equal to the square root of the sum of the squares of the effective values of the components.
Page 318 - The magnetomotive force is not constant over the pole but varies according to the sine law. Since it is not constant, it is necessary to determine its average value over the pole shoe in order to find its effect in modifying the field. The portion of the magnetomotive force which is effective is shaded in the sketch.
Page 29 - Solution of electric power transmission problems in the laboratory by miniature circuits.
Page 231 - The transformer core is in this respect nothing but a frequency converter, and the harmonics add to what may be called the apparent core loss, or to the fundamental input to the core, while, in reality, a part of this power is expended as copper loss by harmonic currents.