Electromagnetic Compatibility in Underground Mining

Part 1 General principles, concepts and terms: the technological environment - environmental protection; hazards and interferences induced by the use of electric mining equipments; the electromagnetic field; electromagnetic interferences - electromagnetic compatibility; the causes, nature and propagation of industrial electromagnetic interferences; general principles of electromagnetic interference measurement. Part 2 Electromagnetic interactions due to alternating current power network: types and range of interaction; theoretical principles of calculating the electromotive force of electromagnetic induction; principles of calculating the included voltages in auxiliary cores of mining power cables; values of voltages induced in the pilot (auxiliary) cores of power cables and flexible mining cables; the influence of screens used in power cables and flexible mining cables; the influence of the operation of thyristor convertors on interference in high-voltage power networks; examples of the results of measurements of electromagnetic interference in the underground low-voltage networks and their immediate vicinity. Part 3 Sources and propagation of electromagnetic interference in eletric traction networks: preliminary remarks; rectifier stations as sources of electromagnetic interference; electric locomotives as a source of interference; transmission of interference by contact lines; the storage-battery locomotive as a source of radio noise; the electric field of a contact wire in a heading; examples of the electric interaction of a contact line; the mutual impedance of earth return circuits; the influence of rails on the mutual impedance of earth return circuits in headings; the magnetic interaction between a traction (contact) line and the earth return circuit; the magnetic interaction between a contact line and a symmetrical line. Part 4 Electromagnetic interference in mine communications networks: communication and dispatching systems in underground mines; telephone communication; radio-telephone communication; wire teletransmission lines - types of cables used and principal parameters; circuit resistance and its asymmetry, and cable circuit insulation resistance; circuit resistance; circuit insulation resistance; attenuation and capacity asymmetry of a circuit; effective attenuation of circuits; cross-talk attenuation; asymmetry of circuit capacity; psophomatric voltages and their measurement in underground telephone networks and some requirements; internal interference in telephone communicaiton - cross-talk in call signals; the influence of dispatching alarm and warning systems on the level of the interference voltage in telecommunication lines; the influence of an electric mine traciton system on hte level of interference in telephone lines; interference produced by oepration of radiotelephones; the influence of electric trction systems on the level of the interference voltage in radio-telephone loop antennas. (Part contents)