Method of digital flux reconstruction with DC elimination
US4698577A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 16, 1986 |
| Grant date | Oct 6, 1987 |
| Priority date | — |
| Expiry date | Jan 16, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P21/34
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for developing current control signals from motor terminal voltage in the control of alternating current electric motors which utilize electric current control signals oriented to the phase of a flux component in a rotating field for applying current so as to control the flux and torque in the motor. The method includes developing flux signals from measurement of motor terminal voltage and integrating those signals to develop corresponding flux signals. In one form, the method eliminates DC components occuring in the resultant flux signals by locating local maxima and minima of the resultant flux signal and correcting the value of the flux integrator so as to provide maxima and minima flux signals having equal absolute values. The method also includes establishing an initial flux in the motor prior to startup which is oriented in a predetermined manner such that initial current applied to the motor can be applied so as to immediately develop torque, if required. The method further provides for initializing the flux integrators and associated logic such that discontinuities attributable to events such as frequency reversals are avoided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.