Evaluation of resistors for transient high-voltage applications

Applications for transient, high-voltage pulsed power technologies are on the increase. High-voltage resistors are an essential component of such systems, especially in the proof-of-concept and prototype testing. The authors have recently procured and tested certain resistor samples, supplied by Kanthal Globar and HVR Advanced Power Components. Results of a detailed evaluation of the HVR resistors are presented in this paper. Two types of HVR high-powered resistors have been tested to determine hold-off voltage, frequency variation and resistance to high voltage. The resistors were tested in a coaxial geometry driven by a two stage Marx generator. The voltage and current were measured by calibrated sensors. The high-voltage pulse resistance of each resistor is then determined on a pulse by pulse basis by dividing the maximum voltage by the maximum current in the time-domain. The two samples (HVR-10, HVR-12; washer type) were nominally 10 and 12 ohms with resistivity of 28 and 80 ohm-cm respectively. The variations in the low-voltage to pulsed high-voltage resistance were 9% for the HVR-10 and 18% for the HVR-12. With an average applied field of 65 kV/inch or 25.6 kV/cm, the resistors flashed in air, but not in pure SF/sub 6/ and N/sub 2//SF/sub 6/ mix. These resistors were found to be satisfactory for transient applications.