Rockwell Automation Technologies Incorporated

David W Kirschnik

Richard Lukaszewski

Lixiang Wei

Gary Leonard Skibinski

Brian Patrick Brown

Zhijun Liu

Carlos Daniel Rodriguez-Valdez

Russ J Kerkman

Rangarajan M Tallam

David Leggate

Richard A Lukaszewski

A method is provided for detection of a ground fault in a high resistance network in a voltage source power conversion circuit comprising a power converter that converts incoming AC power to DC power applied to a DC bus and an inverter that converts DC power from the DC bus to output AC power. The method includes detecting a midpoint-to-ground voltage between a low side of the DC bus and a ground potential and detecting the presence of a ground fault in a high resistance network based upon the detected midpoint-to-ground voltage.

System for detection of a ground fault in a high resistance ground network

The present techniques include methods and systems for detecting the grounding condition of an electrical system to automatically determine a suitable electrical drive configuration. The drive includes a test resistor which may be connected or disconnected from the drive to measure different drive voltages. The measured drive voltages are analyzed to determine a type of grounding configuration of the electrical system in which the drive is to be installed. Embodiments also include determining ground resistance condition such as a high resistance ground (HRG) fault or a ground resistance fault when the drive is in operation.

Ground scheme identification method

Control systems, methods and power conversion systems are presented for controlling common mode currents in power converters, in which feedback signals used in pulse width modulated inverter switching control are selectively adjusted to ensure minimum differences between the resulting common mode compensated feedback signals according to a common mode dwell time in each pulse width modulation period, with the common mode dwell time being adjusted according to modulation index.

Systems and methods for reducing AC drive common-mode currents

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Germantown, WI, United States of America

David W Kirschnik