TRANSDUCTOR DESIGN FOR CONTROL AND MEASUREMENT IN HVDC SYSTEM

In the control and protection of HVDC converters and lines, devices are required for obtaining signal proportional to the current of the main de circuits. Measurement of direct current are required for the current regulator and one of the input$ to the Constant Extinction Angle ( CEA ) control of the inverter [1] . For both these purposes very fast response is necessary. A small current proportional to the current in the main circuit and isolated from it can be obtained by means of a de current transformer ( transductor ) , consists of two saturable reactors.Transductors are usually more suitable than shunts for measring large currents, because these currents generate excessive power in a shunt if the voltage cross it is large enough to be meaured with reasonable accuracy. A Prototype transductor was built according to above outcomes. Then the results are investigated by means of simulation and experimentation of system.