Electrical motor coil short detection and protection

US10439388B2 · kind B2 · utility

Assignee

• Eaton Intelligent Power Limited · IE

Inventors

• Bharath Suda · Munich, DE
• James David · Portage, US

Key dates

• Filing date: Mar 3, 2017
• Grant date: Oct 8, 2019
• Expiry date: Mar 3, 2037

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R27/02
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A fault detection method for a multi-phase motor system applies a first duty cycle to first phase coil windings and applies a second duty cycle to second phase coil windings. The second duty cycle differs from the first duty cycle by a first difference value D1. A first current I1 is measured. A third duty cycle is applied to third phase coil windings and a fourth duty cycle is applied to the second phase coil windings. The fourth duty cycle differs from the third duty cycle by a second difference value D2. A second current I2 is measured. Line-to-line resistances R1, R2 are calculated using the difference values D1, D2, the measured currents 11, I2, and a measured DC voltage VDC. After determining a resistance difference ΔR between the line-to-line resistances R1, R2, a comparison to a first non-zero threshold T1 indicates a fault.