Abstract: A driver circuit for controlling a semiconductor power switch comprises a first power driver transistor and a second power driver transistor complementary to the first power driver transistor. Both power driver transistors have an output terminal connected to an input terminal of the semiconductor power switch. An input terminal of the second power driver transistor is connected to a half bridge circuit comprising a first pre-driver transistor and a second pre-driver transistor complementary to the first pre-driver transistor. Both first and second pre-driver transistors have an output terminal connected to the input terminal of the second power driver transistor. This provides fast switching times with low power consumption for the pre-driver transistors.

Abstract: A motor drive ground fault detection device operates by computing the total RMS voltage of all the phases, and comparing the total RMS voltage to a threshold to determine if a ground fault has occurred.

Abstract: A driver circuit for controlling a semiconductor power switch comprises a first power driver transistor and a second power driver transistor complementary to the first power driver transistor. Both power driver transistors have an output terminal connected to an input terminal of the semiconductor power switch. An input terminal of the second power driver transistor is connected to a half bridge circuit comprising a first pre-driver transistor and a second pre-driver transistor complementary to the first pre-driver transistor. Both first and second pre-driver transistors have an output terminal connected to the input terminal of the second power driver transistor. This provides fast switching times with low power consumption for the pre-driver transistors.

Abstract: A method of detecting partial corona discharge in a targeted circuit of an electrical apparatus, comprises the steps of: wrapping a Rogowski coil around a leg of the targeted circuit to produce a Rogowski coil signal that represents electrical current rate of change in the leg of the targeted circuit; coupling the Rogowski coil signal to a three-dimensional display device that may represent the dimension of time, the dimension of amplitude as a function of a time, and the dimension of duration of amplitude as a function of time in successive periods of that have a preselected duration; monitoring the display device to detect deviations of the duration of amplitude as a function of time from a normal waveform in the leg of the targeted circuit; and correlating ones of the detected deviations of the duration of amplitude as a function of time from a normal waveform that exceed a preselected deviation level as indicative of partial corona discharge within the targeted circuit.

Abstract: A motor drive ground fault detection device operates by computing the total RMS voltage of all the phases, and comparing the total RMS voltage to a threshold to determine if a ground fault has occurred.

Abstract: A method of detecting partial corona discharge in a targeted circuit of an electrical apparatus, comprises the steps of: wrapping a Rogowski coil around a leg of the targeted circuit to produce a Rogowski coil signal that represents electrical current rate of change in the leg of the targeted circuit; coupling the Rogowski coil signal to a three-dimensional display device that may represent the dimension of time, the dimension of amplitude as a function of a time, and the dimension of duration of amplitude as a function of time in successive periods of that have a preselected duration; monitoring the display device to detect deviations of the duration of amplitude as a function of time from a normal waveform in the leg of the targeted circuit; and correlating ones of the detected deviations of the duration of amplitude as a function of time from a normal waveform that exceed a preselected deviation level as indicative of partial corona discharge within the targeted circuit.

Abstract: A motor drive ground fault detection device operates by computing the total RMS voltage of all the phases, and comparing the total RMS voltage to a threshold to determine if a ground fault has occurred.

Abstract: An electrical switch structure which employs superconductive material. A magnetizable core is encompassed by a body of superconductive material. The body of superconductive material has a superconductive state and a normal resistive state and can be placed in either state. The magnetizable core is also encompassed by at least one electrically conductive winding through which electrical current flows to create a magnetic flux within the magnetizable core. When the body of superconductive material is in its superconductive state current is induced therein by the magnetic flux in the magnetizable core. Current flow in the body of superconductive creates a magnetic flux in the magnetizable core which cancels the magnetic flux which is created by current flow in the electrically conductive winding.