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US 2011/0255198 A1Published application
Motor drive ground fault detection
AssigneeHamilton Sundstrand Corporation
InventorsSastry V. Vedula, James J. Wrobel, Neal D. Clements
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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.
Claims15
A method for detecting a ground fault in an AC electrical system comprising:
- detecting an AC input voltage of all phases of an inverter;
- computing a combined Root Mean Square (RMS) voltage of all phases of said inverter;
- comparing the combined RMS voltage to a threshold;
- and
- performing a specified action when the combined RMS voltage exceeds the threshold.
2 more elements
A computer readable medium containing instructions for performing the steps of:
- detecting an AC input of all phases of an inverter;
- computing a combined root mean square (RMS) voltage of all phases of said inverter;
- comparing the combined RMS voltage to a threshold;
- and
- performing a specified action when the combined RMS voltage exceeds the threshold.
2 more elements
An electrical system comprising:
- a ground fault detection device for detecting phase to ground fault conditions, said ground fault detection device comprising a voltage sensor connected to an AC input of each phase of an inverter;
- a voltage summer capable of summing a Root Mean Square (RMS) voltage of all phases of the inverter;
- a voltage comparator for comparing a summed RMS voltage against a threshold;
- and
- a ground fault detected signal transmitter for transmitting a ground fault detected signal when the summed RMS voltage exceeds the threshold.
2 more elements
Dependencies are inferred from the claim text.