Method and system for controlling chopper
US4801855A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 1987 |
| Grant date | Jan 31, 1989 |
| Priority date | — |
| Expiry date | Jun 18, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/93
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
The magnitude of current change for the change of input voltage or for the change of speed of rotation of the shunt motor is utilized, i.e., the shunt characteristics are utilized, and the voltage applied to the motor is limited so that the armature current decreases by an amount that corresponds to the increase in the armature voltage when slipping and to the decrease in the armature voltage when sliding have taken place, thereby to obtain improved adhesion characteristics. For this purpose according to the invention, an electromotive force of the motor is calculated from a motor speed detected by a detector and from a field current of the motor, a voltage drop caused by the motor resistance and the motor current is calculated, a motor voltage is calculated by adding the thus calculated voltage drop to the electromotive force of the motor, and the voltage applied to the motor is limited depending upon the calculated motor voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.