Drive apparatus for vibrating-type compressor

• US 6,456,508 B1
• Filed: 12/18/2000
• Issued: 09/24/2002
• Est. Priority Date: 12/20/1999
• Status: Expired due to Fees

• Current Assignee: Sawafuji Electric Company Limited
• Original Assignee: Sawafuji Electric Company Limited
• Inventors: Namai, Masao, Akazawa, Naoki
• Primary Examiner(s): Patel, Rajnikant B.
• Application Number:
  US09/739,310
• Time in Patent Office: 645 Days
• Field of Search: 363/17, 363/56, 363/16, 363/19, 363/25, 363/26, 363/131, 363/127, 363/132, 363/37, 363/39, 318/116, 318/801, 318/807, 318/803, 417/45, 417/44, 417/11, 417/416
• US Class Current: 363/17
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02M 1/0006 Arrangements for supplying an adequate voltage to the control circuit of converters
• CPC Class Codes: H02M 1/10 Arrangements incorporating converting means for enabling loads to be operated at will from different kinds of power supplies, e.g. from ac or dc
• CPC Class Codes: H02M 7/53803 with automatic control of output voltage or current

Abstract

A drive apparatus for a vibrating-type compressor includes a DC power source as well as an inverter including switching elements. The inverter is adapted to convert direct time to alternating current through alternating switching of the switching elements. An inverter control unit is provided for controlling the alternating current supplied from the inverter to the vibrating type compressor. A DC power supply comprises a first power supply including a DC/DC converter. A second power supply is provided including an AC/DC converter. A diode OR circuit is connected to the first and second power supplies. A further circuit is provided which, upon detection of a voltage output from the second power supply, operates to stop the output of the first power supply via a DC/DC converter control unit for controlling the DC/DC converter.

Claims

1. A drive apparatus for a vibrating-type compressor, the drive apparatus comprising:

a DC power source;

an inverter including switching elements and adapted to convert direct current to alternating current through alternating switching of the switching elements; and

an inverter control unit for controlling the alternating current supplied from the inverter to the vibrating-type compressor, wherein the DC power source comprises;

a first power supply including a battery and a DC/DC converter for converting direct current from the battery to direct current of a different voltage;

a second power supply including a commercial AC power source and an AC/DC converter for converting alternating current from the commercial AC power source to direct current;

a diode OR circuit to which are connected the first and second power supplies; and

a circuit which, upon detection of a voltage output from the second power supply, operates to stop the output of the first power supply via a DC/DC converter control unit for controlling the DC/DC converter.

2. A drive apparatus for a vibrating-type compressor according to claim 1, wherein

one of two output terminals of the first power supply and one of two output terminals of the second power supply are grounded;

the grounded terminals are connected to one end of a first switching element of the inverter, while the other end of the first switching element is connected in series to one end of a second switching element;

a voltage output from the OR circuit is supplied to the other end of the second switching element;

a current detection resistor is connected in series to one of the two switching elements; and

the connection point between the two switching elements is connected to one end of the vibrating-type compressor via a capacitor, and the one end of the first switching element is connected to the other end of the vibrating-type compressor, thereby enabling the other end of the vibrating-type compressor to be grounded.

3. A drive apparatus for a vibrating-type compressor according to claim 1, wherein the inverter control unit controls, within a phase angle range of 100°

to 140°

, the on period within each switching cycle of the alternating switching operation of the switching elements.

4. A drive apparatus for a vibrating-type compressor according to claim 1, further comprising a constant voltage generation circuit for supplying a constant voltage for control use to the inverter control unit and the DC/DC converter control unit;

and an AC/DC changeover unit which supplies direct current from the battery to the constant voltage generation circuit and supplies output from the AC/DC converter to the constant voltage generation circuit when the drive apparatus is connected to the commercial AC power source.

5. A drive apparatus for a vibrating-type compressor according to claim 4, further comprising a voltage drop detection unit for detecting a fact that voltage output from the AC/DC changeover unit has dropped below a reference value and turning off the output of the constant voltage generation circuit to thereby shut off at least the AC output of the inverter, wherein the detection unit judges a voltage type of a connected commercial power source or battery, and judges whether the detected voltage has dropped in consideration of the voltage type.

6. A drive apparatus for a vibrating-type compressor according to claim 4, wherein a light-emitting diode for displaying the operation state of the drive apparatus is inserted into a main current path between the AC/DC changeover unit and the constant voltage generation circuit.

7. A drive apparatus for a vibrating-type compressor according to claim 4, wherein the output voltage of the AC/DC converter is set not to overlap a range of the battery voltage, and the AC/DC changeover unit connects the output of the AC/DC converter and the battery by use of a diode OR connection.

8. A drive apparatus for a vibrating-type compressor according to claim 2, wherein a DC fan motor is connected between the opposite terminals of the capacitor.

9. A drive apparatus for a vibrating-type compressor according to claim 1, wherein the inverter control unit detects and holds a first peak of current flowing during a half cycle of an AC output, detects a timing at which the current again reaches the level the held peak, and controls the timing of the alternative switching of the switching elements of the inverter to thereby variably control the output frequency of the inverter.

10. A drive apparatus for a vibrating-type compressor according to claim 3, wherein the on phase period of 100°

to 140°

is varied on the basis of a detected ambient temperature of the vibrating-type compressor.

20. A drive apparatus for a vibrating-type compressor according to claim 4, wherein the DC power source further comprises a voltage drop detection unit for detecting a fact that voltage output from the AC/DC changeover unit has dropped below a reference value and turning off the output of the constant voltage generation circuit to thereby shut off at least the AC output of the inverter, wherein the detection unit judges a voltage type of a connected commercial power source or battery, and judges whether the detected voltage has dropped in consideration of the voltage type.

11. A drive apparatus for a vibrating-type compressor, the drive apparatus comprising:

a DC power source;

an inverter including switching elements and adapted to convert direct current to alternating current through alternating switching of the switching elements; and

an inverter control unit for controlling the alternating current supplied from the inverter to the vibrating-type compressor, wherein

the inverter control unit controls, within a phase angle range of 100°

to 140°

, the on period within each switching cycle of the alternating switching operation of the switching elements the switching elements being turned off together for each period between each of the on periods.

12. A drive apparatus for a vibrating-type compressor according to claim 11, wherein the on phase period of 100°

to 140°

is varied on the basis of a detected ambient temperature of the vibrating-type compressor.

13. A drive apparatus for a vibrating-type compressor according to claim 11, wherein the inverter control unit detects and holds a first peak of current flowing during a half cycle of an AC output, detects a timing at which the current again reaches the level of the held peak, and controls the timing of the alternative switching of the switching elements of the inverter to thereby variably control the output frequency of the inverter.

14. A drive apparatus for a vibrating-type compressor according to claim 13, further comprises a circuit for stopping the operation of the inverter when a value obtained through integration of instantaneous values the current exceeds a reference value.

15. A drive apparatus for a vibrating-type compressor according to claim 11, wherein the DC power supply is configured to supply direct current selectively from a first power supply including a DC/DC converter for converting direct current from a battery to direct current of a different voltage, and a second power supply including an AC/DC converter for converting alternating current from a commercial AC power source to direct current;

and the DC power supply includes a constant voltage generation circuit for supplying a constant voltage for control use to the inverter control unit and the DC/DC converter control unit, and an AC/DC changeover unit which supplies direct current from the battery to the constant voltage generation circuit and supplies output from the AC/DC converter to the constant voltage generation circuit when the drive apparatus is connected to the commercial AC power source.

16. A drive apparatus and compressor, comprising:

vibrating-type compressor;

an inverter including switching elements and adapted to convert direct current to alternating current through alternating switching of the switching elements;

an in inverter control unit for controlling the alternating current supplied from the inverter to the vibrating-type compressor; and

a DC power source connected to the inverter, the DC power source including a first power supply with a battery and a DC/DC converter for converting direct current from the battery to direct current of a different voltage, a second power supply associated with an AC power source and an AC/DC converter for converting alternating current from the AC power source to direct current, a diode OR Circuit to which are connected the first and second power supplies and a circuit which operates to stop the output of the first power supply via a DC/DC converter control unit for controlling the DC/DC converter upon detection of a voltage output from the second power supply.

17. A drive apparatus and compressor according to claim 16, wherein

one of two output terminals of the first power supply and one of two output terminals of the second power supply are grounded;

the grounded terminals are connected to one end of a first switching element of the inverter, while the other end of the first switching element is connected in series to one end of a second switching element;

a voltage output from the OR circuit is supplied to the other end of the second switching element;

a current detection resistor is connected in series to one of the two switching elements; and

the connection point between the two switching elements is connected to one end of the vibrating-type compressor via a capacitor, and the one end of the first switching element is connected to the other end of the vibrating-type compressor, thereby enabling the other end of the vibrating type compressor to be grounded.

18. A drive apparatus and compressor according to claim 16, wherein the inverter control unit controls, within a phase angle range of 100°

to 140°

, the on period within each switching cycle of the alternating switching operation of the switching elements.

19. A drive apparatus for a vibrating-type compressor according to claim 16, wherein the DC power source further comprises a constant voltage generation circuit for supplying a constant voltage for control use to the inverter control unit and the DC/DC converter control unit and an AC/DC changeover unit which supplies direct current from the battery to the constant voltage generation circuit and supplies output from the AC/DC converter to the constant voltage generation circuit when the drive apparatus is connected to the commercial AC power source.