Digital current regulator
US5319295A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 26, 1991 |
| Grant date | Jun 7, 1994 |
| Priority date | — |
| Expiry date | Nov 26, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/53873
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A digital current regulator for controlling the operation of an inductance device such as an AC motor. A plurality of independently controllable insulated gate bipolar transistors are selectively enabled to vary the instantaneous phase and magnitude of current applied to an AC motor. To minimize induced back EMFs during current switching operations, a number of safeguards are utilized. Switching between adjacent states only is provided to minimize the magnitude of instantaneous current changes. A "ready blocking" function limits the maximum switching frequency to avoid significantly derating the switching device capabilities, while a "time out" feature assures system operation above at least a minimum switching frequency to further minimize the magnitude of instantaneous current changes. A time hysteresis function is provided to avoid switching device response to false feedback control signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.