Abstract: The invention concerns the analog simulation of the parameters and the operating characteristics of three-phase rotating machines. The system comprises a unit for transforming the three-phase armature currents of a machine into equivalent diphase currents and a further unit for transforming the diphase currents into currents so-called of direct and quadrature axes. A generator and control circuit simulates the parameters and operating characteristics of the machine in function of those currents of direct and quadrature axes, and feeds another circuit for generating diphase voltages. These diphase voltages are then transformed into three-phase voltages from which the dynamic characteristics of the machine are generated.

Abstract: A system for extracting and converting into complex power the electrical energy conveyed through a high voltage direct current (HVDC) transmission line, the system being serially mounted along that transmission line. The system comprises converter bridges to convert the transmission line high voltage into AC active power and a unit, connected to the line, for generating reactive power and feeding the latter through both the converter bridges and the load mounted across the system output. Moreover, there is provided a device for controlling the rate of extraction and conversion of the HVDC energy in function of the active power supplied by the generating unit. This control device ensures that the load requirements in active power are entirely supplied by the converter bridges alone. A voltage regulator is associated to the generating unit for the purpose of keeping constant the output voltages of that generating unit, thereby causing a nul output active power from the unit, in steady state.