Power switching device operating time prediction equipment and method

• US 9,966,753 B2
• Filed: 02/02/2011
• Issued: 05/08/2018
• Est. Priority Date: 02/02/2011
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Kobayashi, Shoichi, Tsutada, Hiroyuki, Shikai, Masahiro, Mori, Tomohito
• Primary Examiner(s): Quigley, Kyle R
• Application Number:
  US13/978,644
• Publication Number:
  US 20130297255A1
• Time in Patent Office: 2,652 Days
• CPC Class Codes: H01H 2009/566 with self learning, e.g. measured delay is used in later actuations
• CPC Class Codes: H01H 33/593 for ensuring operation of the switch at a predetermined point of the ac cycle for multipolar switches H01H9/563
• CPC Class Codes: H01H 9/56 for ensuring operation of the switch at a predetermined point in the ac cycle
• CPC Class Codes: H02H 1/0092 concerning the data processing means, e.g. expert systems, neural networks

Abstract

An apparatus for predicting an operating time in a power device includes an operating characteristic parameter estimating unit, and only the operation historical data in the vicinity of a current operation environmental condition is extracted and input by a vicinity operation historical data extracting unit.

Claims

1. A system for predicting an operating time in a power switching device and controlling an operating time of an opening or closing operation of the power switching device, the system comprising:

the power switching device;

an operation environmental condition measuring unit including a plurality of sensors that measure a current operation environmental condition including at least one of an ambient temperature, a control voltage, and an operating pressure of the power switching device; and

a controller that controls the operating time of the opening or closing operation of the power switching device based on corrected next operating times, the controller being programmed to perform as

an operating time measuring unit that measures an operating time of the power switching device on the basis of an opening/closing command signal of the power switching device, and a main circuit current or an operation stroke of the power switching device,

an operation history retaining unit that stores historical data of the operating time measured by the operating time measuring unit and the operation environmental condition measured by the operation environmental condition measuring unit in a manner associated with each other,

a vicinity operation historical data extracting unit that extracts, from among the historical data stored in the operation history retaining unit, only vicinity historical data, which is the historical data having an operation environmental condition within a predetermined range of a current operation environmental condition,

an operating characteristic parameter estimating unit that estimates an operating characteristic parameter of the power switching device by functional approximation of the vicinity historical data extracted by the vicinity operation historical data extracting unit,

an operating time predicting unit that predicts next operating times of the power switching device on the basis of an estimated value of the operating characteristic parameter estimated by the operating characteristic parameter estimating unit, and the current operation environmental condition of the power switching device,

a variable feedback correcting unit that, with respect to N different parameter candidates being candidates for a reference parameter, where N is an integer value larger than 1, calculates each of N feedback candidate amounts based on a corresponding one of the N parameter candidates, and produces N sets of candidate corrected operating times based on the N feedback candidate amounts, the variable feedback correcting unit further calculating, for each of the N sets of candidate corrected operating times, an evaluation value that is a sum or product of a standard deviation of the candidate correcting operating times and an average of the candidate corrected operating times, and selecting, as the reference parameter, one of the N parameter candidates corresponding to the smallest evaluation value, and the variable feedback correcting unit further calculating a plurality of first errors between historical data of the next operating times and historical data of actual operating times measured by the operating time measuring unit, calculating a feedback correction amount based on n first errors obtained from the plurality of first errors where n is an integer value of a reference parameter, and thereafter corrects the next operating times by adding the feedback correction amount to the next operating times to thereby produce the corrected next operating times, and

a learning completion determining unit that outputs an operation start signal when second errors between the actual operating times and the corrected next operating times are detected as being less than a threshold value prescribed in advance for a predetermined number of times.

2. The system according to claim 1, wherein the feedback correction amount is calculated as an average value of the n first errors.

3. A system for predicting an operating time in a power switching device and controlling an operating time of an opening or closing operation of the power switching device, the system comprising:

the power switching device;

an operation environmental condition measuring unit including a plurality of sensors that measure a current operation environment condition of the power switching device; and

a controller that controls the operating time of the opening or closing operation of the power switching device based on corrected next operating times, the controller being programmed to perform as

an operating time measuring unit that measures an operating time of the power switching device on the basis of an opening/closing command signal of the power switching device, and a main circuit current or an operation stroke of the power switching device,

an operation history retaining unit that stores historical data of the operating time measured by the operating time measuring unit and the operation environmental condition measured by the operation environmental condition measuring unit in a manner associated with each other,

an operating characteristic parameter estimating unit that estimates an operating characteristic parameter of the power switching device by functional approximation of the historical data stored in the operation history retaining unit,

an operating time predicting unit that predicts next operating times of the power switching device on the basis of an estimated value of the operating characteristic parameter estimated by the operating characteristic parameter estimating unit, and the current operation environmental condition of the power switching device,

a variable feedback correcting unit that, with respect to N different parameter candidates being candidates for a reference parameter where N is an integer value larger than 1, calculates each of N feedback candidate amounts based on a corresponding one of the N parameter candidates, and produces N sets of candidate corrected operating times based on the N feedback candidate amounts, the variable feedback correcting unit further calculating, for each of the N sets of candidate corrected operating times, an evaluation value that is a sum or product of a standard deviation of the candidate corrected operating times and an average of the candidate corrected operating times, and selecting, as the reference parameter, one of the N parameter candidates corresponding to the smallest evaluation value, and the variable feedback correcting unit further calculating a plurality of first errors between historical data of the next operating times and historical data of actual operating times measured by the operating time measuring unit, calculating a feedback correction amount based on n first errors obtained from the plurality of first errors where n is an integer value of the reference parameter, and thereafter correcting the next operating times by adding the feedback correction amount to the next operating times to thereby produce the corrected next operating times, and

a learning completion determining unit that outputs an operation start signal when second errors between the actual operating times and the corrected next operating times are detected as being less than a threshold value prescribed in advance for a predetermined number of times.

4. The system according to claim 3, wherein the feedback correction amount is calculated as an average value of the n first errors.

5. A method for predicting an operating time in a power switching device and controlling an operating time of an opening or closing operation of the power switching device, the method comprising:

measuring an operating time of the power switching device on the basis of an opening/closing command signal of the power switching device, and a main circuit current or an operation stroke of the power switching device;

measuring a current operation environmental condition including at least one of an ambient temperature, a control voltage, and an operating pressure of the power switching device;

storing historical data of the operating time measured by the operating time measuring and the operation environmental condition measured by the operation environmental condition measuring in a manner associated with each other;

extracting from the stored historical data, only vicinity historical data, which is the stored historical data having an operation environmental condition within a predetermined range of a current operation environmental condition;

estimating an operating characteristic parameter of the power switching device by functional approximation of the vicinity historical data extracted by the extracting;

predicting next operating times of the power switching device on the basis of an estimated value of the operating characteristic parameter estimated by the estimating, and the current operation environmental condition of the power switching device;

calculating a plurality of first errors between historical data of the next operating times and historical data of actual operating times measured by the operating time measuring;

calculating each of N feedback candidate amounts based on a corresponding one of N parameter candidates, each being a candidate for a reference parameter, where N is an integer value larger than 1;

producing N sets of candidate corrected operating times based on the N feedback candidate amounts;

calculating, for each of the N sets of candidate corrected operating times, an evaluation value that is a sum or product of a standard deviation of the candidate corrected operating times and an average of the candidate corrected operating times;

selecting, as the reference parameter, one of the N parameter candidates corresponding to the smallest evaluation value;

calculating a feedback correction amount based on n first errors obtained from the plurality of first errors where n is an integer value of the reference parameter;

correcting the next operating times by adding the feedback correction amount to the next operating times to thereby produce the corrected next operating times;

outputting an operation start signal when second errors between the actual operating times and the corrected next operating times are detected as being less than a threshold value prescribed in advance for a predetermined number of times;

controlling the operating time of the opening or closing operation of the power switching device based on the corrected next operating times and the operation start signal.

6. The method according to claim 5, wherein the feedback correction amount is calculated as an average value of the n first errors.