Method and system for starting a motor-commutated SCR inverter
US4565957A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1983 |
| Grant date | Jan 21, 1986 |
| Priority date | — |
| Expiry date | Jun 30, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P1/50
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Highly reliable and consistent starting is achieved by first initializing the rotor position, namely establishing the rotor in a known starting position. This is accomplished by gating on two pairs of SCRs in sequence and supplying current pulses through the gated SCRs to the stator of the motor to rotate the rotor to a first position and then to a second position, the rotor coming to a complete stop in each of those positions. The rotor aligns itself with the magnetic field created by the stator in each position and any ambiguity in the rotor position is eliminated. Thereafter, the inverter is operated asynchronously in a second mode with predetermined pairs of the inverter SCRs being sequentially gated into conduction at an increasing frequency to current pulse energize the motor to effect step-by-step rotation of the rotor at a faster and faster rate, the motor current being reduced to zero at the termination of each energizing pulse to force commutate the conducting pair of SCRs. After the motor has reached a preset speed, operation in a third mode occurs and the inverter is synchronized with the motor, gating of the SCRs being controlled by the motor voltage in order that the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.