Propulsion system for electrical vehicle
US4217529A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 1978 |
| Grant date | Aug 12, 1980 |
| Priority date | — |
| Expiry date | Sep 19, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/917
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A propulsion system for an electric vehicle in which a chopper is used to provide controlled DC power to a separately excited DC propulsion motor. In order to provide increased torque for comparatively short intervals to meet on-the-road requirements, the propulsion motor is provided with two sets of shunt field windings, and switch means are provided for connecting the windings in series or in parallel dependent upon the torque demands on the system. Normally the system is operated with the shunt field windings in series. To meet transient demands for increased torque, such as rapid acceleration from a stop light or improved gradability on hills, means are provided for detecting such increased torque demands and switching the field windings from series to parallel configuration thereby increasing the field flux and causing the motor to produce increased torque. The parallel connected field windings compensate for the demagnetizing effect of high armature currents without the need for a series field winding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.