Inverter control apparatus

• US 20010036093A1
• Filed: 05/24/2001
• Published: 11/01/2001
• Est. Priority Date: 11/29/1999
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Suzuki, Hiroaki, Tanikawa, Makoto, Kawasaki, Isao, Iwasaki, Yoshihiro, Ishigami, Takahiro, Kikkawa, Yoshihiko, Tanifuji, Hitoshi, Minejima, Ichiro
• Granted Patent: US 6,687,139 B2
• Time in Patent Office: Days
• US Class Current: 363/37
• CPC Class Codes: B60H 1/00428 electric
• CPC Class Codes: B60H 1/3222 characterised by the compressor driving arrangements, e.g. clutches, transmissions or multiple drives B60H1/3208, B60H1/3226 take precedence
• CPC Class Codes: H02M 1/0022 the disturbance parameters being input voltage fluctuations
• CPC Class Codes: H02M 7/53871 with automatic control of output voltage or current
• CPC Class Codes: H02M 7/53873 with digital control
• CPC Class Codes: H02P 27/08 with pulse width modulation
• CPC Class Codes: Y02T 10/88 Optimized components or subsystems, e.g. lighting, actively controlled glasses

Abstract

Provided are, a converter section (30) which converts a commercial AC voltage (V_AC) into a DC voltage (V_DC); an inverter section (60) which converts the DC voltage (V_DC) into an output AC voltage (V_OUT) of a predetermined frequency by a pulse-width modulation system based on an assigned PWM width, and supplies the output AC voltage (V_OUT) to a compressor motor (70). Further, an instantaneous DC voltage detecting section (50) detects an instantaneous DC voltage (V_DCS); and an arithmetic processing section (100) corrects the PWM width so as to maintain the output AC voltage (V_OUT) at a desired value following the variation in the instantaneous DC voltage (V_DCS). It is possible to operate a compressor motor (70) in an optimum state of load characteristics and efficiency.

Claims

1. An inverter control apparatus comprising:

a converting unit which converts a commercial AC voltage into a DC voltage;

an inverting unit which converts the DC voltage into an output AC voltage of a predetermined frequency by a pulse-width modulation system based on an assigned pulse width, and supplies the output AC voltage to an AC load;

an instantaneous DC voltage detecting unit which detects an instantaneous value of the DC voltage; and

a correcting unit which corrects the pulse width so as to maintain the output AC voltage at a desired value following the variation in a result of a detection by the instantaneous DC voltage detecting unit.

2. The inverter control apparatus according to

claim 1

,

wherein the correcting unit corrects the pulse width based on a result of multiplying a ratio of a preset reference voltage to a detection result of the instantaneous DC voltage detecting unit, and a target voltage as a target value of the output AC voltage.

3. The inverter control apparatus according to

claim 2

, further comprising a setting changing unit which changes a setting of the reference voltage according to the commercial AC voltage.

4. The inverter control apparatus according to

claim 2

,

wherein the correcting unit corrects the pulse width by calculating the ratio for every one period of a modulation carrier in the pulse-width modulation system.

5. The inverter control apparatus according to

claim 2

,

wherein the correcting unit corrects the pulse width by calculating the ratio for every n periods (=equal to or above 2) of a modulation carrier in the pulse-width modulation system.

6. The inverter control apparatus according to

claim 1

,

wherein the instantaneous DC voltage detecting unit directly detects the DC voltage by a non-insulating circuit that has been grounded to be in a potential common to that of the correcting unit.