Method and apparatus for controlling power converter

• US 4,870,556 A
• Filed: 01/12/1987
• Issued: 09/26/1989
• Est. Priority Date: 01/11/1986
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Inaba, Hiromi, Hombu, Mitsuyuki, Mitsui, Nobuo, Tobita, Toshimitsu, Kurosawa, Toshiaki, Shima, Seiya
• Primary Examiner(s): Salce, Patrick R.
• Assistant Examiner(s): Peckman, K.
• Application Number:
  US07/002,283
• Time in Patent Office: 988 Days
• Field of Search: 363/35, 363/37, 363/41, 363/51
• US Class Current: 363/41
• CPC Class Codes: H02M 5/4585 having a rectifier with controlled elements
• CPC Class Codes: H02M 7/53873 with digital control

Abstract

Control signals for operating power converter switching elements are created using one-chip microcomputers. Pulse patterns required to supply the control signals and their generating timings are previously created and scheduled in pairs. When the times when the control signals are to be supplied to the switching elements have actually come, those control signals are successively output.

Claims

1. A method for controlling a power converter in which a control signal is applied to the power converter to operate the power converter, comprising the steps of:

storing a pair of information including first information for turning on or off at least one element constituting the power converter and second information relating to a time for enabling said first information independently of a prior turn on or turn off of the at least one element; and

enabling said first information when a time of a timer is coincident with said time of said second information for enabling said first information and applying a control signal for turning on or off said at least one element of said power converter in accordance therewith.

2. A method for controlling a power converter according to claim 1, wherein said storing step stores said pair of information at least one time for each predetermined time interval.

3. A method for controlling a power converter according to claim 2, wherein said storing step stores said paired information of said information for turning on or off and said time for enabling said information a plurality of times for each said predetermined time interval.

4. A method for controlling a power converter according to claim 2, wherein said predetermined time interval is initiated synchronously with a timer interruption.

5. A method for controlling a power converter according to claim 2, wherein said predetermined time interval is a variable time interval.

6. A method for controlling a power converter according to claim 1, wherein said power converter includes a plurality of elements and said storing step stores said pair of information in connection with each of said elements.

7. A method for controlling a power converter according to claim 1, wherein said storing step stores said pair of information so that a width of a pulse representing a period of turn on or turn off of said at least one element is minimized.

8. A method for controlling a power converter in which at least one control signal is applied to the power converter to operate the power converter, comprising the steps of:

calculating first information for turning on or off at least one element constituting the power converter and second information relating to a time for enabling said first information;

storing a pair of information including said first and second information independently of a prior turn on or off of the at least one element; and

enabling said first information when a time of a timer is coincident with said time of said second information for enabling said first information and applying a control signal to said element of said power converter.

9. A method for controlling a power converter according to claim 8, wherein said storing and calculating steps are executed every predetermined time interval, respectively.

10. A method for controlling a power converter according to claim 9, wherein said predetermined time interval in said storing step is initiated by one timer interruption, and said predetermined time interval in said calculation step is initiated by another timer interruption occurring prior to said one timer interruption.

11. A method for controlling a power converter according to claim 8, wherein said storing step stores said pair of information for turning on and so that a width of a pulse representing a period of turn on or turn off of said at least one element is minimized.

12. An apparatus for controlling a power converter in which at least one control signal is applied to the power converter to operate the power converter, comprising:

memory means for storing a pair of information including a first information for turning on or off at least one element constituting the power converter and a second information relating to a time for enabling said first information independently of a prior turn on or turn off of said at least one element;

a timer for outputting a time; and

means for enabling said first information when the time of said timer is coincident with said time of said second information for enabling said first information and for applying a control signal for turning on or turning off said at least one element of said power converter in accordance therewith.

13. An apparatus for controlling a power converter according to claim 12, wherein said memory means is an associative memory.

14. An apparatus for controlling a power converter according to claim 12, wherein said power converter is an A.C.-D.C. converter.

15. An apparatus for controlling a power converter according to claim 14, further comprising means for executing an interruption in synchronism with an A.C. side input power supply.

16. An apparatus for controlling a power converter according to claim 12, wherein said power converter is a D.C.-A.C. converter.

17. An apparatus for controlling a power converter according to claim 16, wherein said D.C.-A.C. converter is a current type converter.

18. An apparatus for controlling a power converter according to claim 17, further comprising means for calculating a total phase by adding an integrated value of a frequency instruction and a phase instruction and calculating, said pair of information in connection with each of said at least one element constituting said power converter in accordance with a peak value of at least two phase voltages of a polyphase A.C.

19. An apparatus for controlling a power converter according to claim 18, further comprising means for dividing electrical angle of 360°

into a plurality of modes to enable calculation for each of said modes.

20. An apparatus for controlling a power converter according to claim 12, wherein said memory means stores said pair of information so that a width of a pulse representing a period of turn on or turn off of said at least one element is minimized.

21. An apparatus for controlling a power converter according to claim 12, further comprising means for calculating said pair of information in connection with said at least one element.

22. An apparatus for controlling a power converter according to claim 21, wherein said means for calculating enables calculation of said pair of information in accordance with at least one of a frequency instruction, phase instruction, and a voltage.

23. An apparatus for controlling a power converter according to claim 12, further comprising motor means coupled to an output of said power converter.

24. An apparatus for controlling a power converter according to claim 23, further comprising an elevator coupled to said motor means for being driven thereby.

25. An apparatus for controlling a power converter according to claim 23, wherein said motor means includes an induction motor.

26. An apparatus for controlling a power converter according to claim 25, further comprising an elevator coupled to said induction motor for being driven thereby.