Inverter and air conditioner controlled by normal and defrost energization patterns
US5436547A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1993 |
| Grant date | Jul 25, 1995 |
| Priority date | — |
| Expiry date | Dec 17, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B30/70
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An inverter controlling an air conditioner including a brushless motor serving as a compressor motor. A microcomputer detects the rotational position of a rotor of the brushless motor from signals obtained by comparison of each of terminal voltages of the motor windings with a reference voltage in order to determine a commutation time. In a normal operation, the microcomputer forms, according to a normal energization signal forming pattern, energization signals corresponding to every commutation time at every occurrence of the commutation time, so that the motor windings are sequentially energized. When frost forms on an outdoor heat exchanger of a heat pump during a warming operation and a defrosting operation is necessary, the energization signals are formed according to a loss increasing energization signal forming pattern so that loss increasing energization signals for causing the rotor to produce counter torque are added to the respective energization signals formed according to the normal pattern. As a result, the brushless motor loss is increased and the brushless motor generates heat. The generated heat is used for defrosting the outdoor heat exchanger.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.