Periodic external disturbance suppression control device

• US 10,331,094 B2
• Filed: 01/30/2015
• Issued: 06/25/2019
• Est. Priority Date: 01/30/2014
• Status: Active Grant

• Current Assignee: Meidensha Corporation
• Original Assignee: Meidensha Corporation
• Inventors: Tadano, Yugo
• Primary Examiner(s): Mitchell, Jason D
• Application Number:
  US15/114,659
• Publication Number:
  US 20160349717A1
• Time in Patent Office: 1,607 Days
• Field of Search: 700 47
• CPC Class Codes: G05B 13/0265 the criterion being a learning criterion
• CPC Class Codes: G05B 13/045 using a perturbation signal
• CPC Class Codes: G05B 5/01 electric
• CPC Class Codes: H02J 3/01 Arrangements for reducing harmonics or ripples
• CPC Class Codes: Y02E 40/40 Arrangements for reducing harmonics

Abstract

A periodic disturbance suppressing control apparatus is designed to estimate and correct an inverse model of a transfer characteristic of a real system successively even in case of large condition change in the real system, and to realize a stable control system.

A periodic disturbance of an object to be suppressed is outputted as a sensed periodic disturbance ISdn, ISqn of a direct current component. A difference between a signal obtained by multiplication of the sensed periodic disturbance ISdn, ISqn with a multiplier using a reciprocal Qn of a transfer characteristic, and a signal obtained by adding only a detection delay to a periodic disturbance suppressing command I*dn, I*qn, to estimate the periodic disturbance dI^dn, dI^qn. Thee periodic disturbance suppressing command is calculated by calculating a deviation between the estimated periodic disturbance dI^dn, dI^qn. A learning control section 29 corrects the reciprocal Qn of the transfer characteristic in accordance with a quantity obtained by diving a difference of the periodic disturbance suppressing command I*dn, I*qn during one sample interval by a difference of the sensed periodic disturbance during the one sample interval.

Claims

1. A periodic disturbance suppressing control apparatus comprising:

an input device configured to sense a controlled object in a form of a current;

a controller configured to produce a periodic disturbance suppressing command in accordance with the current of the controlled object; and

an output device configured to suppress the periodic disturbance of the controlled object in accordance with the periodic disturbance suppressing command;

the controller configured to;

sense a periodic disturbance of the controlled object as a sensed periodic disturbance in a form of a direct current component;

determine an estimated periodic disturbance by calculating a difference between a first signal and a second signal, the first signal obtained by multiplication of the sensed periodic disturbance by a reciprocal of a transfer characteristic, the transfer characteristic being from the periodic disturbance suppressing command to the sensed periodic disturbance, the second signal obtained by adding only a detection delay to the periodic disturbance suppressing command;

produce the periodic disturbance suppressing command from the estimated periodic disturbance; and

correct the reciprocal of the transfer characteristic in accordance with a quantity determined by dividing a variation of the periodic disturbance suppressing command by a variation of the sensed periodic disturbance.

2. The periodic disturbance suppressing control apparatus as recited in claim 1, wherein the periodic disturbance suppressing control apparatus is arranged to suppress the periodic disturbance by superposing the periodic disturbance suppressing command on a command of a power conversion device connected with a system bus of a power source.

3. The periodic disturbance suppressing control apparatus as recited in claim 1, wherein the controller is configured to use average values during an interval of a control period of a periodic disturbance observer, as the sensed periodic disturbance and the period disturbance suppressing command.

4. The periodic disturbance suppressing control apparatus as recited in claim 3, wherein the controller is configured to stop a learning control and output the reciprocal of the transfer characteristic just before stoppage when the difference during a one sample interval in an average value of the sensed periodic disturbance is lower than or equal to a threshold value.

5. The periodic disturbance suppressing control apparatus as recited in claim 1, wherein the controller includes a filter suppressing abrupt change in the reciprocal of the transfer characteristic.

6. The periodic disturbance suppressing control apparatus as recited in claim 1, wherein there is provided a limiter to limit an amplitude of the periodic disturbance suppressing command when the amplitude of the periodic disturbance suppressing command is greater than a limit value.

7. The periodic disturbance suppressing control apparatus as recited in claim 1, wherein a plurality of the periodic disturbance suppressing control apparatus are arranged in parallel and configured to suppress periodic disturbances of a plurality of orders.

8. The periodic disturbance suppressing control apparatus as recited in claim 1, wherein the controller is configured to stop a learning control and output the reciprocal of the transfer characteristic just before stoppage when the difference during a one sample interval of the sensed periodic disturbance is smaller than or equal to a threshold value.

9. The periodic disturbance suppressing control apparatus as claimed in claim 1, wherein the controller is configured to set the variation of the sensed periodic disturbance equal to a difference between a previous value of the sensed periodic disturbance determined from a previous sample of data collected in a previous cycle of the correcting the reciprocal of the transfer characteristic performed periodically and a current value of the sensed periodic disturbance determined from a current sample of data collected in a current cycle next to the previous cycle of the correcting the reciprocal of the transfer characteristic, and to set the variation of the periodic disturbance suppressing command equal to a difference between a previous value of the periodic disturbance suppressing command determined from the previous sample in the previous cycle and a current value of the periodic disturbance suppressing command determined from the current sample in the current cycle.

10. The periodic disturbance suppressing control apparatus as claimed in claim 9, wherein the controller is configured to use, as the previous value of the sensed periodic disturbance, a previous average value of the sensed periodic disturbance determined by averaging values of the sensed periodic disturbance sampled during the previous cycle of the correcting the reciprocal of the transfer characteristic, to use, as the current value of the sensed periodic disturbance, a current average value of the sensed periodic disturbance determined by averaging values of the sensed periodic disturbance sampled during the current cycle next to the previous cycle, to use, as the previous value of the periodic disturbance suppressing command, a previous average value of the periodic disturbance suppressing command determined by averaging values of the periodic disturbance suppressing command sampled during the previous cycle of the correcting the reciprocal of the transfer characteristic and to use as the current value of the periodic disturbance suppressing command, a current average value of the periodic disturbance suppressing command determined by averaging values of the periodic disturbance suppressing command sampled during the current cycle of the correcting the reciprocal of the transfer characteristic.

11. The periodic disturbance suppressing control apparatus as recited in claim 1, wherein the output device includes a power conversion device adapted to be connected with a system bus of a power source, and the input device includes a current sensor configured to sense the controlled object which is a system current flowing through the system bus.

12. The periodic disturbance suppressing control apparatus as recited in claim 11, wherein the power conversion device includes an active filter, and the controller is arranged to control the active filter.

13. A periodic disturbance suppressing control process comprising:

sensing a controlled object in a form of a current;

sensing a periodic disturbance of the controlled object as a sensed periodic disturbance in a form of a direct current component;

determining an estimated periodic disturbance by calculating a difference between a first signal and a second signal, the first signal obtained by multiplication of the sensed periodic disturbance by a reciprocal of a transfer characteristic, the transfer characteristic being from a periodic disturbance suppressing command to the sensed periodic disturbance, the second signal obtained by adding only a detection delay to the periodic disturbance suppressing command;

producing the periodic disturbance suppressing command from the estimated periodic disturbance; and

correcting the reciprocal of the transfer characteristic in accordance with a quantity determined by dividing a variation of the periodic disturbance suppressing command by a variation of the sensed periodic disturbance; and

controlling a power conversion device in accordance with the periodic disturbance suppressing command to suppress the periodic disturbance of the controlled object.

14. The periodic disturbance suppressing control process as claimed in claim 13, wherein the variation of the sensed periodic disturbance is a difference between a previous value of the sensed periodic disturbance determined in a previous cycle of the correcting the reciprocal of the transfer characteristic performed periodically and a current value of the sensed periodic disturbance determined in a current cycle next to the previous cycle of the correcting the reciprocal of the transfer characteristic, and

the variation of the periodic disturbance suppressing command is a difference between a previous value of the periodic disturbance suppressing command determined in the previous cycle and a current value of the periodic disturbance suppressing command determined in the current cycle.

15. The periodic disturbance suppressing control process as claimed in claim 14, wherein the previous value of the sensed periodic disturbance is a previous average value of the sensed periodic disturbance determined by averaging values of the sensed periodic disturbance sampled during the previous cycle of the correcting the reciprocal of the transfer characteristic performed periodically, the current value of the sensed periodic disturbance is a current average value of the sensed periodic disturbance determined by averaging values of the sensed periodic disturbance sampled during the current cycle next to the previous cycle, the previous value of the periodic disturbance suppressing command is a previous average value of the periodic disturbance suppressing command determined by averaging values of the periodic disturbance suppressing command sampled during the previous cycle of the correcting the reciprocal of the transfer characteristic and the current value of the period disturbance suppressing command is a current average value of the periodic disturbance suppressing command determined by averaging values of the periodic disturbance suppressing command sampled during the current cycle.

16. The periodic disturbance suppressing control process as claimed in claim 13, further comprising stopping a learning control and outputting a most recent value of the reciprocal of the transfer characteristic just before stoppage when the variation of the sensed periodic disturbance is smaller than or equal to a predetermined threshold value.

17. A periodic disturbance suppressing control apparatus comprising:

an input device including a current sensor configured to sense a controlled object in a form of a system current at a connection point of a system bus of a power source;

a controller configured to produce a periodic disturbance suppressing command in accordance with the system current of the controlled object; and

an output device including a power conversion device adapted to be connected with the system bus of the power source at the connection point, and to suppress a periodic disturbance of the system current in accordance with the periodic disturbance suppressing command;

the controller being configured to;

sense a periodic disturbance of the controlled object as a sensed periodic disturbance in a form of a direct current component;

determine an estimated periodic disturbance by calculating a difference between a first signal and a second signal, the first signal obtained by multiplication of the sensed periodic disturbance by a reciprocal of a transfer characteristic, the transfer characteristic being from the periodic disturbance suppressing command to the sensed periodic disturbance, the second signal obtained by adding a detection delay to the periodic disturbance suppressing command;

produce the periodic disturbance suppressing command from the estimated periodic disturbance; and

correct the reciprocal of the transfer characteristic in accordance with a quantity which is a quotient determined by dividing a variation of the periodic disturbance suppressing command by a variation of the sensed periodic disturbance.

18. The periodic disturbance suppressing control apparatus as claimed in claim 17, wherein the controller is configured to set the variation of the sensed periodic disturbance equal to a difference between a previous value of the sensed periodic disturbance determined from a previous sample of data collected in a previous cycle of the correcting the reciprocal of the transfer characteristic performed periodically and a current value of the sensed periodic disturbance determined from a current sample of data collected in a current cycle next to the previous cycle of the correcting the reciprocal of the transfer characteristic, and to set the variation of the periodic disturbance suppressing command equal to a difference between a previous value of the periodic disturbance suppressing command determined from the previous sample in the previous cycle and a current value of the periodic disturbance suppressing command determined from the current sample in the current cycle.