Variable-voltage variable-frequency elevator control apparatus
US4503940A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 3, 1984 |
| Grant date | Mar 12, 1985 |
| Priority date | — |
| Expiry date | Feb 3, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P3/18
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A variable-voltage variable-frequency elevator control apparatus is disclosed in which a circuit for the consumption of regenerated power produced during regenerative braking is provided on the DC side of the apparatus rather than on the AC side. During regenerative braking with an emergency generating unit in operation, regenerated power is consumed by the consumption circuit on the DC side of the circuit and is prevented from being returned to the emergency generating unit. This prevents the production of voltage notches commonly produced during regenerative braking by thyristor commutation in conventional circuits. Because no voltage notches are produced, a reduction in the size of the emergency generating unit can be achieved. In addition, since it consumes DC power rather than 3-phase AC power, the consumption circuit requires fewer elements than in conventional control apparatuses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.