AC pre-charge circuit

US8953296B2 · kind B2 · utility

Assignee

• Rockwell Automation Technologies, Inc. · US

Inventors

• Bruce W. Weiss · Milwaukee, US
• Doyle F. Busse · Sparta, US
• Jeremy J. Keegan · Kewaskum, US
• Lixiang Wei · Whitefish Bay, US
• Michael Loth · Germantown, US
• Rangarajan M. Tallam · Germantown, US
• Yogesh Patel · Grafton, US

Key dates

• Filing date: Jul 13, 2012
• Grant date: Feb 10, 2015
• Expiry date: Nov 30, 2032

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02H11/005
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

AC pre-charging techniques are provided for pre-charging the DC bus on a motor drive. AC pre-charging techniques involve pre-charge circuitry including a manual switch, an automatic switch, and pre-charge control circuitry to switch the automatic switch between pre-charge and pre-charge bypass modes in response to an initialized pre-charge operation, input voltage sags, etc. In some embodiments, the pre-charge operation may be initialized by switching the manual switch closed. In some embodiments, the pre-charge operation may also be initialized by a detected voltage sag on the DC bus. The pre-charge circuitry may also be configured to disconnect a motor drive from the AC power supply under certain fault conditions.