《电路》（英文版）12-1 Three-phase voltages

A A--connection three-phase sources a, b, c--line ter min als

The readings of three watt-meters Ax =v an+lnx vBx=vbn+lnx vc=von+v Nx (UANia tUBvibB+Uvicdt+l(uN(ia tibB +ic)dt T Jo aNaA foBNLbB +Uvic)dt The sum of the average powers taking by the three-phase loads

Let us add and subtract on the right side of I2 we have

the short-circuit input impedance I12=0 the short-circuit forward current gain I1V2=0 Let 1=0 he open-circuit reverse voltage gain I1=0 the open-circuit output admittance

13-6 Interconnection of two-ports 1. Series connection

13-8nic(Negative-impedance- converter(负阻抗变换器))

S14-2 Exponential Fourier series f(t)=+ cosot+a2 cos 2ot+.] sinot+ b2 sin

14-4 Line spectrum A plot showing each of harmonic amplitudes in the wave is called the line spectrum

14-6 Effective values and power The effective or rms value of the function f(t) is