Contactless Rotor Ground Fault Detection Method for Brushless Synchronous Machines Based on an AC/DC Rotating Current...

Area of Science:

• Electrical Engineering
• Power Systems
• Machine Diagnostics

Background:

• Brushless synchronous machines (BSMs) offer advantages over conventional machines, including reduced maintenance and elimination of sparking.
• The absence of brushes and slip rings in BSMs complicates rotor-based electrical parameter measurement, particularly for detecting ground faults.
• Ground faults are the most prevalent electrical fault in rotating machinery, necessitating effective detection strategies.

Purpose of the Study:

• To propose and validate a novel ground fault detection method for brushless synchronous machines (BSMs).
• To address the challenges in detecting ground faults within the rotating components of BSMs.
• To develop a sensor-based system that operates without additional power sources, slip rings, or brushes.

Main Methods:

• Implementation of an inductive AC/DC rotating current sensor integrated into the machine's shaft.
• Monitoring the voltage induced in the sensor's stator, which occurs when a ground fault current flows through the rotor.
• Analysis of the frequency components within the induced voltage signal to identify ground fault occurrences.

Main Results:

• Successful detection of ground faults within the rotating parts of BSMs.
• The method effectively covers the entire rotor and distinguishes between AC and DC sides.
• Experimental validation using a prototype sensor connected to laboratory synchronous machines confirmed satisfactory performance.

Conclusions:

• The proposed inductive AC/DC rotating current sensor provides an effective solution for ground fault detection in BSMs.
• This method offers significant advantages over existing techniques by eliminating the need for auxiliary power, slip rings, and brushes.
• The experimental results demonstrate the reliability and practicality of the developed ground fault detection system for BSMs.