IEEE 776-2018 pdf free

IEEE 776-2018 pdf free.IEEE Recommended Practice for Inductive Coordination of Electric Supply and Communication Lines.
Inductive interference is defined as an ffect, arising from the characteristics and inductive relations of electric supply and telecommunication systems. The inductive interference is of such character and magnitude that it would prevent the telecommunication circuits from rendering service satisfactorily and economically if methods of inductive coordination were not applied. Induetive interference is produced by the simultaneous coexistence of three factors (see Figure 1):
a) An inductive influence.
b) A coupling mechanism between two electrical systems or circuits, one of which produces the influence.
c) A susceptibility of the second system or circuit to interference.
Whilc inductive intcrfcrcncc may occur at any time thc above conditions arc satisficd, thc majority of cascs and the principal concern of this recommended practice involve interference in telecommunication systems as a result of (heir proximity to electric power systems. Therefore, subsequent discussion is limited to that general case, although the principles and practices could apply to other cases as well.
4.1.1 InductIve Influence
inducrive influence is defined as those characteristics of an electric supply circuit that determine the character and intcnsity of the inductivc field that it produces. The voltagc and current present on an operating power system produce electric and magnetic fields in the vicinity of the system. The character and intensity of those fields determine the inductive influence. Character is related primarily to the frequencies present, while intensity is related to the magnitude of voltages and currents modified by line configuration, current distribution, and any shielding structures in the immediate vicinity, excluding the shield of a telecommunications cable.
NOTF.—Whcn buried or underground telecommunications cables arc located in the prosilnhty of buried or underground power cables thc cffeci. of electromagnetic interference (EMI) should bc carefully considered.4
4.1.2 Coupling
Coupling is defined as the transkr of energy from one system to another. For the inductive influence of a power system to affect another system or circuit, there has to be coupling bctween the two. The coupling mechanism consists of the mutual impedance between circuits in proximity to each other. This coupling has resistive, capacitive, and inductive components. Electric induction, via capacitive coupling, is often consequential when the exposed circuit is composed of unshielded conductors above ground. However, when the exposed circuit conductors are within a grounded metallic sheath or shield, capacitive coupling generally is considered negligible. Therefore, the coupling mechanism of primaiy concern will generally be the mutual inductance between an electric supply circuit or circuits and a telecommunications facility.IEEE 776 pdf download.