Current limiting strategy
US7026776B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 2005 |
| Grant date | Apr 11, 2006 |
| Priority date | — |
| Expiry date | Jun 30, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P25/024
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention provides a method for controlling current in a direct current motor having a back emf constant (ke), which may be a function of field current if the direct current motor is a field wound machine, and motor resistance (Rs) in all 4 quadrants of operation. The method includes the step of rotating a motor shaft of the direct current motor with a controller by applying a first voltage across the direct current motor's terminals. The first voltage corresponds to a first value of current passing through the armature windings of the direct current motor. The method also includes the step of determining a maximum value of current to pass through the armature windings of the direct current motor. The maximum value of current is selected to prevent undesirable over current conditions, such as thermal overload as one example. The method also includes the step of receiving a signal corresponding to a desired motor speed (ω*) with the controller during the rotating step. The method also includes the step of first computing a second voltage to replace the first voltage from the controller after the receiving and determining steps and in view of the estimates of the back emf constan…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.