Guard system for inverter apparatus
US4672525A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 1986 |
| Grant date | Jun 9, 1987 |
| Priority date | — |
| Expiry date | Jan 23, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/32
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An inverter using gate turn-off thyristors (GTOs) is controlled by means of pulse width modulation (PWM) to control the speed of an induction motor. If the current flowing through the induction motor becomes an overcurrent which can still be cut off by the GTOs, a gate off signal is supplied to respective GTOs to interrupt the overcurrent. If any one of arms respectively corresponding to phases is short-circuited, a gate on signal is supplied to all GTOs to distribute the short circuit current among the arms, and the main circuit is interrupted by a high-speed breaker. At this time, a simultaneous gate on signal is given priority. If the simultaneous gate on signal is present, a simultaneous gate off signal is disabled. Owing to this configuration, destruction of the GTOs due to consecutive guard operation can be prevented.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.