Linear compressor driving device, medium and information assembly

• US 6,501,240 B2
• Filed: 11/30/2000
• Issued: 12/31/2002
• Est. Priority Date: 11/30/1999
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ueda, Mitsuo, Nakata, Hideki, Hasegawa, Hiroshi, Yoshioka, Kaneharu
• Primary Examiner(s): Ramirez, Nestor
• Assistant Examiner(s): JONES, JUDSON
• Application Number:
  US09/727,020
• Publication Number:
  US 20010005320A1
• Time in Patent Office: 761 Days
• Field of Search: 318/119, 318/126, 318/127, 318/128, 318/135, 318/811, 318/812, 310/12, 310/15, 310/17, 363/37, 363/41, 363/97, 363/98, 363/40, 363/95
• US Class Current: 318/135
• CPC Class Codes: F04B 35/045 using solenoids
• CPC Class Codes: F04B 49/065 and making use of computers

Abstract

A linear compressor driving device for linear compressor driving a piston in a cylinder by means of a linear motor to generate a compressed gas, has an inverter for outputting an alternating current to be supplied to the linear motor; current detecting means for detecting an output current from the inverter; voltage detecting means for detecting an output voltage from the inverter; current amplitude value determining means for determining a current amplitude value of the output current; output power calculating means for calculating an output power from the inverter based on the detected output current and the detected output voltage; frequency determining means for determining a frequency of the output current such that the output power is maximum; and inverter controller for controlling the inverter based on the determined current amplitude value and the determined frequency.

Claims

1. A linear compressor driving device for linear compressor driving a piston in a cylinder by means of a linear motor to generate a compressed gas, comprising:

an inverter for outputting an alternating current to be supplied to said linear motor;

current detecting means of detecting an output current from said inverter;

voltage detecting means of detecting an output voltage from said inverter;

current amplitude value determining means of determining a current amplitude value of said output current;

output power calculating means of calculating an output power from said inverter based on said detected output current and said detected output voltage;

frequency determining means of determining a frequency of said output current such that said output power is maximum; and

inverter controller for controlling said inverter based on said determined current amplitude value and said determined frequency.

2. The linear compressor driving device according to claim 1,

wherein said voltage detecting means has:

DC voltage detecting means of detecting a DC voltage input to said inverter; and

output voltage calculating means of calculating the output voltage from said inverter based on a control signal transmitted from said inverter controller to said inverter and on said detected DC voltage.

3. The linear compressor driving device according to claim 1 or 2,

wherein said frequency determining means has two variables including a frequency control period and a frequency variation to compare said output power obtained through an operation with a frequency determined during said frequency control period before last with said output power obtained through an operation with a frequency determined during the last frequency control period, in order to determine a present frequency

(1) by varying said frequency in the same direction as that during said last frequency control period, by an amount corresponding to said frequency variation if said output power has increased, and

(2) by varying said frequency in a direction opposite to that during said last frequency control period, by said amount corresponding to said frequency variation if said output power has decreased.

4. The linear compressor driving device according to claim 3, wherein said frequency determining means varies said frequency in said same direction a predetermined number of times or more, and maintains the frequency determined during said last frequency control period if said output power has varied by a predetermined amount or more.

5. The linear compressor driving device according to claim 3, wherein said frequency determining means changes said frequency control period based on a variation in said output power.

6. The linear compressor driving device according to claim 3, wherein said frequency determining means changes said frequency variation based on a variation in said output power.

7. The linear compressor driving device according to claim 1, wherein said frequency determining means maintains said determined frequency if said determined current amplitude value has varied.

8. The linear compressor driving device according to claim 1, wherein said current amplitude value determining means maintains said determined current amplitude value if said output power has varied by a predetermined amount.

9. The linear compressor driving device according to claim 1, wherein said linear compressor is used as part of a refrigerating cycle apparatus, and said current amplitude value determining means determines said current amplitude value based on an ambient temperature of said refrigerating cycle apparatus and a corresponding set temperature.

10. The linear compressor driving device according to claim 9, wherein said current amplitude value determining means determines said current amplitude value so as to reduce a difference between said ambient temperature and said set temperature.

11. The linear compressor driving device according to claim 9, wherein said current amplitude value determining means determines said current amplitude value in a manner such that said calculated output power equals a set power to be input to said linear compressor, the power being set based on said ambient temperature and said set temperature.

12. The linear compressor driving device according to claim 1, wherein said current amplitude value determining means gradually increases said current amplitude value when said linear compressor is actuated.

13. The linear compressor driving device according to claim 1, wherein said current amplitude value determining means gradually reduces said current amplitude value when said linear compressor is stopped.

15. A medium which can be processed by a computer to carry programs and/or data for causing the computer to execute all or some of functions of all or some of the means of the present invention according to any one of claims 1, 2, 7, 8, 9, 12 ,13 and 14.

16. An information assembly comprising programs and/or data for causing a computer to execute all or some of functions of all or some of the means of the present invention according to any one of claims 1, 2, 7, 8, 9, 12, 13 and 14.

14. A linear compressor driving device for linear compressor driving a piston in a cylinder by means of a linear motor to generate a compressed gas, comprising:

an inverter for outputting an alternating current to be supplied to said linear motor;

input current detecting means of detecting an input current to said inverter;

current amplitude value determining means of determining a current amplitude value of an output current of said inverter;

input power calculating means of calculating an input power to said inverter based on (1) said detected input current an (2) a predetermined or detected input voltage to said inverter;

frequency determining means of determining a frequency of the output current of said inverter such that said input power is maximum; and

inverter controller for controlling said inverter based on said determined current amplitude value and said determined frequency.

17. A method for controlling linear compressor driving device powered by an alternating current supply, comprising the steps of:

(a) measuring the power provided by the alternating current supply to the linear compressor driving device;

(b) adjusting the current to the linear compressor driving device to a predetermined amplitude level;

(c) adjustably controlling variation in frequency of the current to the linear compressor driving device, while maintaining the predetermined amplitude level constant; and

(d) adjusting the frequency of step (c) so that the power measured in step (a) is a maximum.

18. The method of claim 17 in which step (b) includes determining the predetermined amplitude level based on a temperature setting of an apparatus being driven by the linear compressor driving device.