System for converting variable frequency multiple phase alternating current into constant frequency multiple phase alternating current with neutral
US4931919A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 14, 1988 |
| Grant date | Jun 5, 1990 |
| Priority date | — |
| Expiry date | Jul 14, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A system for converting variable frequency multiple phase current into multiple phase current of constant frequency with a neutral having a multiple phase inverter with a neutral (N) is disclosed. A first input (34) is connected to the multiple phase inverter for receiving pulses of a positive polarity. A second input (36) is connected to the multiple phase inverter for receiving pulses of a negative polarity. A variable frequency multiple phase source (12, 14 and 16) of alternating current applies current to a multiple phase transformer (80, 142 and 180). Current from the transformer is applied to a full-wave rectifier (96) which has a first group of diodes (112) which applies the positive pulses to the input (34). A second group of diodes (116) applies the negative pulses to the input (36). The ripple frequency f.sub.r present on the inputs to the multiple phase inverter with neutral is twice the frequency present in the prior art which permits the capacitance of filter capacitors (74, 76) to be reduced to permit effective shunting of the undesired ripple frequency f.sub.r to the neutral which results in a weight savings and lessening of energy at the ripple frequency f.sub.r bei…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.