Balanced control waveform for reducing inverter harmonics
US4153930A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 1977 |
| Grant date | May 8, 1979 |
| Priority date | — |
| Expiry date | Oct 20, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/48
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A particular control waveform actuates the half-bridge switching elements of a three-phase power inverter in such a manner as to balance harmonic cancellation between waveform notching and low impedance filtering in obtaining a substantial sinusoidal output signal. The control waveform allows a small amount of lower order harmonics which inherently decreases the higher order harmonics generated by the notches in the control waveform so that a small filter, e.g., a five percent filter, can be used which eliminates the need for voltage regulation under various current loads and yet both the unregulated voltage fluxations and overall harmonic content of the output signal is well within acceptable tolerances for use by an electrical power utility or the like. At the same time, the control waveform employs a relatively low per cycle switching rate which minimizes the number of off-on transitions of each of the high-current, solid state switches in the inverter thereby retaining high inverter efficiency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.