阅读说明：本技术 基于多传感器的断路器机械特性在线监测方法及装置 (On-line monitoring method and device for mechanical characteristics of circuit breaker based on multiple sensors ) 是由 许挺 刘伟浩 陈炜 尤敏 陈巧勇 钱少锋 汤明 许杰 李颖浩 姜竞 王海荣 汪 于 2019-09-27 设计创作，主要内容包括：本发明涉及监测领域,尤其涉及基于多传感器的断路器机械特性在线监测方法及装置,包括：S1：通过位移传感器测量断路器总行程及运行时间；S2：采集断路器分合闸加速度振动信号,并获得断路器刚分和刚合点,实现断路器总行程、开距、超程、平均分闸速度、平均合闸速度的在线监测,并实现断路器触头超程状态的在线自动识别；S3：通过压力传感器获得断路器刚分和刚合点,实现断路器总行程、开距、超程、平均分闸速度、平均合闸速度的在线监测；并实现断路器触头超程状态的在线自动识别；S4：根据步骤S2和S3对断路器触头超程状态的在线自动识别结果,得到对断路器触头超程状态的最终判断结果,本发明最终目的是实现断路器机械特性在线监测。(The invention relates to the field of monitoring, in particular to a method and a device for monitoring mechanical characteristics of a circuit breaker on line based on multiple sensors, which comprises the following steps: s1: measuring the total stroke and the operation time of the circuit breaker by a displacement sensor; s2: collecting a breaker opening and closing acceleration vibration signal, obtaining a breaker just opening point and a breaker just closing point, realizing online monitoring of a total stroke, an opening distance, an over travel, an average opening speed and an average closing speed of the breaker, and realizing online automatic identification of an over travel state of a breaker contact; s3: the on-line monitoring of the total stroke, the opening distance, the over travel, the average opening speed and the average closing speed of the circuit breaker is realized by acquiring the opening and closing points of the circuit breaker through a pressure sensor; the on-line automatic identification of the over travel state of the breaker contact is realized; s4: and according to the online automatic identification results of the over-travel state of the breaker contact in the steps S2 and S3, obtaining the final judgment result of the over-travel state of the breaker contact, and the invention finally aims to realize online monitoring of the mechanical characteristics of the breaker.)

1. The on-line monitoring method for the mechanical characteristics of the circuit breaker based on the multiple sensors is characterized by comprising the following steps:

s1: measuring the total stroke and the operation time of the circuit breaker by a displacement sensor;

s2: the method comprises the steps that an acceleration vibration sensor is used for collecting opening and closing acceleration vibration signals of a circuit breaker, the rigid opening and rigid closing points of the circuit breaker are obtained, the total stroke of the circuit breaker is combined to obtain the opening distance and the over travel of the circuit breaker, and therefore the on-line monitoring of the total stroke, the opening distance, the over travel, the average opening speed and the average closing speed of the circuit breaker is achieved; inputting an acceleration vibration signal into a trained contact over-travel state automatic identification mathematical model to realize the on-line automatic identification of the over-travel state of the circuit breaker contact;

s3: the on-line monitoring method comprises the following steps of obtaining the just opening and just closing points of the breaker through a pressure sensor, and obtaining the opening distance and the overtravel of the breaker by combining the total stroke of the breaker, so as to realize the on-line monitoring of the total stroke, the opening distance, the overtravel, the average opening speed and the average closing speed of the breaker; the on-line automatic identification of the over-travel state of the breaker contact is realized according to the over-travel of the breaker;

s4: and according to the online automatic identification result of the overtravel state of the breaker contact in the steps S2 and S3, obtaining the final judgment result of the overtravel state of the breaker contact.

2. The on-line monitoring method for mechanical characteristics of circuit breakers based on multiple sensors, as claimed in claim 1, wherein said training of the contact over-travel state automatic identification mathematical model comprises:

s21: determining the values of w and b which need to be initialized;

s22: randomly selecting feature points (x) from training samples _i,y _i) Then the predicted value is sign (w x) _i+ b), where w represents a proportional weight and b represents an offset value;

s23: in the prediction process, if sign (w x) is predicted _iIf + b) is less than or equal to 0, changing the values of w and b, and continuing prediction;

s24: the iteration steps S22 and S23 are repeated until the predicted value is less than the expected error.

3. The on-line monitoring method for mechanical characteristics of circuit breaker based on multiple sensors according to claim 2, characterized in that said modifying the values of w and b comprises:

calculate the total distance of all error points to the hyperplane:

4. The on-line monitoring method for mechanical characteristics of circuit breaker based on multiple sensors as claimed in claim 1, wherein said obtaining the final judgment result of the over-travel state of the circuit breaker contact according to the on-line automatic recognition result of the over-travel state of the circuit breaker contact in steps S2 and S3 comprises:

s41: if the online automatic identification results of the over travel states of the circuit breaker contacts in the steps S2 and S3 are completely the same, taking the online automatic identification result as a final judgment result;

s42: and if the online automatic identification results of the steps S2 and S3 on the over travel state of the breaker contact are not identical, the online automatic identification result is not taken as the final judgment result.

5. The on-line monitoring method for mechanical characteristics of circuit breakers based on multiple sensors, as claimed in claim 1, further comprising:

s5: the current of a coil of a driving motor of the circuit breaker operating mechanism is measured through a first current transformer, a current-time curve is drawn, and the similarity between the historical current-time curve and a standard current-time curve is compared through a current fingerprint identification technology, so that whether a fault exists in the driving structure is judged.

6. The on-line monitoring method for mechanical characteristics of circuit breakers based on multiple sensors, as claimed in claim 1, further comprising:

s6: and measuring the current of a coil of a driving motor of the circuit breaker operating mechanism through a second current transformer, drawing a current-time curve, and comparing the similarity of the historical current-time curve and a standard current-time curve through a current fingerprint identification technology so as to judge whether a driving structure has a fault.

7. Circuit breaker mechanical properties on-line monitoring device based on multisensor, its characterized in that includes:

the displacement sensor is used for measuring the total stroke and the running time of the circuit breaker;

the acceleration vibration sensor is arranged at the lower end of the pull rod of the circuit breaker and is used for acquiring opening and closing acceleration vibration signals of the circuit breaker;

the pressure sensor is arranged at the lower end of the vacuum bubble of the circuit breaker and is used for acquiring a pressure signal at the lower end of the vacuum bubble;

the on-line automatic identification module is used for inputting the acceleration vibration signal into the trained contact over-travel state automatic identification mathematical model to realize the on-line automatic identification of the over-travel state of the breaker contact;

the processing module is used for respectively obtaining the just opening and just closing points of the circuit breaker according to the pressure signal at the lower end of the vacuum bulb and the opening and closing acceleration vibration signal of the circuit breaker, and respectively obtaining the opening distance and the overtravel of the circuit breaker by combining the total stroke of the circuit breaker, so that the on-line monitoring of the total stroke, the opening distance, the overtravel, the average opening speed and the average closing speed of the circuit breaker is realized; the on-line automatic identification of the over-travel state of the breaker contact is realized according to the over-travel of the breaker;

and the judging module is used for obtaining a final judging result of the over-travel state of the contact of the circuit breaker according to the on-line automatic identification result of the over-travel state of the contact of the circuit breaker by the on-line automatic identification module and the processing module.

8. The on-line monitoring device for mechanical characteristics of circuit breaker based on multiple sensors according to claim 7, characterized in that the training of the contact over-travel state automatic recognition mathematical model comprises:

s21: determining the values of w and b which need to be initialized;

s22: randomly selecting feature points (x) from training samples _i,y _i) Then the predicted value is sign (w x) _i+ b), where w represents a proportional weight and b represents an offset value;

s23: in the prediction process, if sign (w x) is predicted _iIf + b) is less than or equal to 0, changing the values of w and b, and continuing prediction;

s24: the iteration steps S22 and S23 are repeated until the predicted value is less than the expected error.

9. The on-line monitoring device for mechanical characteristics of circuit breaker based on multiple sensors as claimed in claim 8, wherein said modifying the values of w and b comprises:

calculate the total distance of all error points to the hyperplane:

10. The on-line monitoring device for mechanical characteristics of circuit breaker based on multiple sensors as claimed in claim 7, wherein said obtaining the final judgment result of the over-travel state of the circuit breaker contact according to the on-line automatic recognition result of the over-travel state of the circuit breaker contact in steps S2 and S3 comprises:

s41: if the online automatic identification results of the over travel states of the circuit breaker contacts in the steps S2 and S3 are completely the same, taking the online automatic identification result as a final judgment result;

s42: and if the online automatic identification results of the steps S2 and S3 on the over travel state of the breaker contact are not identical, the online automatic identification result is not taken as the final judgment result.

Technical Field

The invention relates to the field of monitoring, in particular to a method and a device for monitoring mechanical characteristics of a circuit breaker on line based on multiple sensors.

Background

The circuit breaker plays an important role in a power system and has important significance for stable and safe operation of the power system. Among the mechanical parameters of the circuit breaker, the contact overtravel is an important performance parameter, the contact abrasion is serious due to the over-small overtravel, the contact of the circuit breaker is poor in contact, the contact generates heat seriously, and the mechanical structure of the contact is damaged due to the over-large overtravel.

The detection of the mechanical characteristics of the existing circuit breaker is basically limited to off-line detection due to the limitation of a judging technology of a just opening point and a just closing point, the off-line detection can realize the detection of parameters such as the total stroke, the opening distance, the over travel and the like of the circuit breaker by adding a small voltage signal into a circuit breaker loop at the moment of just opening and just closing and combining with a displacement sensor according to a current mutation point, but the running circuit breaker has high voltage access of thousands of volts to tens of thousands of volts in a main loop, and the problem of high voltage physical isolation cannot be solved at present by monitoring the current of the main loop, so that no better method can solve the problem of the on-line detection of the mechanical characteristics of the circuit breaker at present, the invention provides a method and a device for the on-line monitoring of the mechanical characteristics of the circuit breaker based on a plurality of sensors, and utilizes a pressure sensor, an, the problem of online monitoring of mechanical characteristics of the circuit breaker can be solved.

Disclosure of Invention

In order to solve the problems, the invention provides a method and a device for monitoring the mechanical characteristics of a circuit breaker on line based on multiple sensors.

The on-line monitoring method for the mechanical characteristics of the circuit breaker based on the multiple sensors comprises the following steps:

s1: measuring the total stroke and the operation time of the circuit breaker by a displacement sensor;

s2: the method comprises the steps that an acceleration vibration sensor is used for collecting opening and closing acceleration vibration signals of a circuit breaker, the rigid opening and rigid closing points of the circuit breaker are obtained, the total stroke of the circuit breaker is combined to obtain the opening distance and the over travel of the circuit breaker, and therefore the on-line monitoring of the total stroke, the opening distance, the over travel, the average opening speed and the average closing speed of the circuit breaker is achieved; inputting an acceleration vibration signal into a trained contact over-travel state automatic identification mathematical model to realize the on-line automatic identification of the over-travel state of the circuit breaker contact;

s3: the on-line monitoring method comprises the following steps of obtaining the just opening and just closing points of the breaker through a pressure sensor, and obtaining the opening distance and the overtravel of the breaker by combining the total stroke of the breaker, so as to realize the on-line monitoring of the total stroke, the opening distance, the overtravel, the average opening speed and the average closing speed of the breaker; the on-line automatic identification of the over-travel state of the breaker contact is realized according to the over-travel of the breaker;

s4: and according to the online automatic identification result of the overtravel state of the breaker contact in the steps S2 and S3, obtaining the final judgment result of the overtravel state of the breaker contact.

Preferably, the training of the contact over-travel state automatic identification mathematical model comprises:

s21: determining the values of w and b which need to be initialized;

s22: randomly selecting feature points (x) from training samples _i,y _i) Then the predicted value is sign (w x) _i+ b), where w represents a proportional weight and b represents an offset value;

s23: in the prediction process, if sign (w x) is predicted _iIf + b) is less than or equal to 0, changing the values of w and b, and continuing prediction;

s24: the iteration steps S22 and S23 are repeated until the predicted value is less than the expected error.

Preferably, the changing the values of w and b includes:

calculate the total distance of all error points to the hyperplane:

wherein M is the set of all error points; calculating w according to the minimum gradient descent method _i+1＝w _i+ηy _ix _i，b _i+1＝b _i+ηy _iWhere η represents the gradient values.

Preferably, the obtaining of the final judgment result of the over travel state of the breaker contact according to the online automatic identification result of the over travel state of the breaker contact in steps S2 and S3 includes:

s41: if the online automatic identification results of the over travel states of the circuit breaker contacts in the steps S2 and S3 are completely the same, taking the online automatic identification result as a final judgment result;

s42: and if the online automatic identification results of the steps S2 and S3 on the over travel state of the breaker contact are not identical, the online automatic identification result is not taken as the final judgment result.

Preferably, the method further comprises the following steps:

s5: the current of a coil of a driving motor of the circuit breaker operating mechanism is measured through a first current transformer, a current-time curve is drawn, and the similarity between the historical current-time curve and a standard current-time curve is compared through a current fingerprint identification technology, so that whether a fault exists in the driving structure is judged.

Preferably, the method further comprises the following steps:

s6: and measuring the current of a coil of a driving motor of the circuit breaker operating mechanism through a second current transformer, drawing a current-time curve, and comparing the similarity of the historical current-time curve and a standard current-time curve through a current fingerprint identification technology so as to judge whether a driving structure has a fault.

Circuit breaker mechanical properties on-line monitoring device based on multisensor includes:

the displacement sensor is used for measuring the total stroke and the running time of the circuit breaker;

the acceleration vibration sensor is arranged at the lower end of the pull rod of the circuit breaker and is used for acquiring opening and closing acceleration vibration signals of the circuit breaker;

the pressure sensor is arranged at the lower end of the vacuum bubble of the circuit breaker and is used for acquiring a pressure signal at the lower end of the vacuum bubble;

the on-line automatic identification module is used for inputting the acceleration vibration signal into the trained contact over-travel state automatic identification mathematical model to realize the on-line automatic identification of the over-travel state of the breaker contact;

the processing module is used for respectively obtaining the just opening and just closing points of the circuit breaker according to the pressure signal at the lower end of the vacuum bulb and the opening and closing acceleration vibration signal of the circuit breaker, and respectively obtaining the opening distance and the overtravel of the circuit breaker by combining the total stroke of the circuit breaker, so that the on-line monitoring of the total stroke, the opening distance, the overtravel, the average opening speed and the average closing speed of the circuit breaker is realized; the on-line automatic identification of the over-travel state of the breaker contact is realized according to the over-travel of the breaker;

and the judging module is used for obtaining a final judging result of the over-travel state of the contact of the circuit breaker according to the on-line automatic identification result of the over-travel state of the contact of the circuit breaker by the on-line automatic identification module and the processing module.

Preferably, the training of the contact over-travel state automatic identification mathematical model comprises:

s21: determining the values of w and b which need to be initialized;

s22: randomly selecting feature points (x) from training samples _i,y _i) Then the predicted value is sign (w x) _i+ b), where w represents a proportional weight and b represents an offset value;

s23: in the prediction process, if sign (w x) is predicted _iIf + b) is less than or equal to 0, changing the values of w and b, and continuing prediction;

s24: the iteration steps S22 and S23 are repeated until the predicted value is less than the expected error.

Preferably, the changing the values of w and b includes:

calculate the total distance of all error points to the hyperplane:

wherein M is the set of all error points; calculating w according to the minimum gradient descent method _i+1＝w _i+ηy _ix _i，b _i+1＝b _i+ηy _iWhere η represents the gradient values.

Preferably, the obtaining of the final judgment result of the over travel state of the breaker contact according to the online automatic identification result of the over travel state of the breaker contact in steps S2 and S3 includes:

s41: if the online automatic identification results of the over travel states of the circuit breaker contacts in the steps S2 and S3 are completely the same, taking the online automatic identification result as a final judgment result;

s42: and if the online automatic identification results of the steps S2 and S3 on the over travel state of the breaker contact are not identical, the online automatic identification result is not taken as the final judgment result.

The invention has the following beneficial effects:

the method comprises the steps that an acceleration vibration sensor is used for collecting opening and closing acceleration vibration signals of a breaker, the opening and closing points of the breaker are obtained, the total stroke of the breaker is combined to obtain the opening distance and the overtravel of the breaker, the total stroke, the opening distance, the overtravel, the average opening speed and the average closing speed of the breaker are monitored on line, the acceleration vibration signals are input into a trained contact overtravel state automatic identification mathematical model, and the on-line automatic identification of the contact overtravel state of the breaker is realized; the on-line monitoring method comprises the following steps of obtaining the just opening and just closing points of the breaker through a pressure sensor, and obtaining the opening distance and the overtravel of the breaker by combining the total stroke of the breaker, so as to realize the on-line monitoring of the total stroke, the opening distance, the overtravel, the average opening speed and the average closing speed of the breaker; the on-line automatic identification of the over-travel state of the breaker contact is realized according to the over-travel of the breaker; and obtaining a final judgment result of the over-travel state of the contact of the circuit breaker according to the online automatic identification result of the over-travel state of the contact of the circuit breaker, thereby finally realizing the monitoring of the mechanical characteristics of the circuit breaker.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a flow chart of a method for online monitoring of mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention;

fig. 2 is a flowchart of step S2 in a method for online monitoring mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention;

fig. 3 is a flowchart of step S4 in a method for online monitoring mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention;

fig. 4 is a flowchart of steps S5 and S6 in a method for online monitoring of mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention;

FIG. 5 is a graph of a standard current-time curve of a circuit breaker driving mechanism in a method for online monitoring of mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of an on-line monitoring device for mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a first current transformer and a second current transformer in an online monitoring device for mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of an opening command control unit, a closing state input unit, and an opening state input unit in the device for online monitoring of mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a power module in an online monitoring device for mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a communication module in an online monitoring device for mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a storage module in an online monitoring device for mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of a display module in an online monitoring device for mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention;

fig. 13 is a schematic structural diagram of an address selection module in an online monitoring device for mechanical characteristics of a circuit breaker based on multiple sensors according to an embodiment of the present invention.

Detailed Description

The technical solutions of the present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

The basic idea of the embodiment is to measure the total travel and the running time of the circuit breaker by a displacement sensor; the method comprises the steps that an acceleration vibration sensor is used for collecting opening and closing acceleration vibration signals of a breaker, the opening and closing points of the breaker are obtained, the total stroke of the breaker is combined to obtain the opening distance and the overtravel of the breaker, the total stroke, the opening distance, the overtravel, the average opening speed and the average closing speed of the breaker are monitored on line, the acceleration vibration signals are input into a trained contact overtravel state automatic identification mathematical model, and the on-line automatic identification of the contact overtravel state of the breaker is realized; the on-line monitoring method comprises the following steps of obtaining the just opening and just closing points of the breaker through a pressure sensor, and obtaining the opening distance and the overtravel of the breaker by combining the total stroke of the breaker, so as to realize the on-line monitoring of the total stroke, the opening distance, the overtravel, the average opening speed and the average closing speed of the breaker; the on-line automatic identification of the over-travel state of the breaker contact is realized according to the over-travel of the breaker; and obtaining a final judgment result of the over-travel state of the contact of the circuit breaker according to the online automatic identification result of the over-travel state of the contact of the circuit breaker, thereby finally realizing the monitoring of the mechanical characteristics of the circuit breaker.

Based on the above thought, an embodiment of the present invention provides an online monitoring method for mechanical characteristics of a circuit breaker based on multiple sensors, as shown in fig. 1, including:

s1: measuring the total stroke and the operation time of the circuit breaker by a displacement sensor;

s2: the method comprises the steps that an acceleration vibration sensor is used for collecting opening and closing acceleration vibration signals of a circuit breaker, the rigid opening and rigid closing points of the circuit breaker are obtained, the total stroke of the circuit breaker is combined to obtain the opening distance and the over travel of the circuit breaker, and therefore the on-line monitoring of the total stroke, the opening distance, the over travel, the average opening speed and the average closing speed of the circuit breaker is achieved; inputting an acceleration vibration signal into a trained contact over-travel state automatic identification mathematical model to realize the on-line automatic identification of the over-travel state of the circuit breaker contact;

s3: the on-line monitoring method comprises the following steps of obtaining the just opening and just closing points of the breaker through a pressure sensor, and obtaining the opening distance and the overtravel of the breaker by combining the total stroke of the breaker, so as to realize the on-line monitoring of the total stroke, the opening distance, the overtravel, the average opening speed and the average closing speed of the breaker; the on-line automatic identification of the over-travel state of the breaker contact is realized according to the over-travel of the breaker;

s4: and according to the online automatic identification result of the overtravel state of the breaker contact in the steps S2 and S3, obtaining the final judgment result of the overtravel state of the breaker contact.

In this embodiment, as shown in fig. 2, the training of the contact over-travel state automatic identification mathematical model includes:

s21: determining the values of w and b which need to be initialized;

s22: randomly selecting feature points (x) from training samples _i,y _i) Then the predicted value is sign (w x) _i+ b), where w represents a proportional weight and b represents an offset value;

s23: in the prediction process, if sign (w x) is predicted _iIf + b) is less than or equal to 0, changing the values of w and b, and continuing prediction;

s24: the iteration steps S22 and S23 are repeated until the predicted value is less than the expected error.

In this embodiment, altering the values of w and b includes:

calculate the total distance of all error points to the hyperplane:

wherein M is the set of all error points; calculating w according to the minimum gradient descent method _i+1＝w _i+ηy _ix _i，b _i+1＝b _i+ηy _iWhere η represents the gradient values.

The invention provides a novel method for identifying the over-travel state of a circuit breaker based on a multilayer perceptron.A plurality of groups of circuit breaker opening and closing acceleration vibration signals are collected by an acceleration vibration sensor, the vibration signal characteristics are extracted through the multilayer perceptron function, characteristic quantities are constructed, an automatic identification mathematical model of the over-travel state (larger, normal and smaller) of a contact is established, and after the circuit breaker is opened and closed, the collected circuit breaker action acceleration vibration signals are transmitted to the automatic identification mathematical model of the over-travel state of the contact, so that the automatic identification of the over-travel state of the contact of the circuit breaker can be realized.

For an input signal, if the input signal is

The input space is Y { +1, -1}, where X { X { (X) } ₁,……，X _n}，X _iIs a feature vector, and is a feature vector,

defining the spatial function from input to output as: where (x) sign (w.x + b) is the perceptron function, w is the example weight, b is the offset,

in this embodiment, as shown in fig. 3, the obtaining of the final judgment result of the over travel state of the breaker contact according to the online automatic identification result of the over travel state of the breaker contact in steps S2 and S3 includes:

s41: if the online automatic identification results of the over travel states of the circuit breaker contacts in the steps S2 and S3 are completely the same, taking the online automatic identification result as a final judgment result;

s42: and if the online automatic identification results of the steps S2 and S3 on the over travel state of the breaker contact are not identical, the online automatic identification result is not taken as the final judgment result.

The invention adopts the two judging methods of the over-travel state of the breaker contact, when the judging results of the two judging methods are consistent, the result is taken as the final judging result, if the judging results of the two judging methods are inconsistent, the result is not taken as the final judging result, thereby meeting the requirement that a power supply company needs double verification by adopting different methods for one event to prevent misjudgment and improving the reliability of judgment.

The method comprises the steps that an acceleration vibration sensor is used for collecting opening and closing acceleration vibration signals of a circuit breaker, the rigid opening and rigid closing points of the circuit breaker are obtained, the total stroke of the circuit breaker is combined to obtain the opening distance and the over travel of the circuit breaker, and therefore the on-line monitoring of the total stroke, the opening distance, the over travel, the average opening speed and the average closing speed of the circuit breaker is achieved; the on-line monitoring method comprises the following steps of obtaining the just opening and just closing points of the breaker through a pressure sensor, and obtaining the opening distance and the overtravel of the breaker by combining the total stroke of the breaker, so as to realize the on-line monitoring of the total stroke, the opening distance, the overtravel, the average opening speed and the average closing speed of the breaker; and realizing the on-line automatic identification of the over-travel state of the contact of the circuit breaker according to the over-travel of the circuit breaker.

In the process of closing and opening the circuit breaker, acceleration vibration signals acquired by the acceleration vibration sensor are different, and the acceleration vibration sensor is used for acquiring the mutation value of the acceleration vibration signal at the moment of contact or separation of the moving contact and the static contact when the circuit breaker is opened and closed, so that the rigid opening and rigid closing points of the circuit breaker are obtained. Similarly, in the process of switching on and switching off of the circuit breaker, pressure signals collected by the pressure sensor are different, and the sudden change value of the instantaneous pressure of contact or separation of the moving contact and the static contact when the circuit breaker is switched on and switched off is collected by the pressure sensor, so that the point where the circuit breaker is just switched on and off is obtained.

The displacement sensor can measure the total stroke amount of the vacuum bulb of the circuit breaker, namely the total stroke of the circuit breaker, and the opening distance and the overtravel of the circuit breaker can be obtained by combining the rigid opening and closing points of the circuit breaker. And the average opening speed and the average closing speed of the circuit breaker can be calculated by combining the closing time and the opening time of the circuit breaker.

And when the difference value between the parameter calculated according to the acceleration vibration signal and the parameter calculated according to the pressure signal is within a set range, calculating the average value of the parameter calculated according to the acceleration vibration signal and the pressure signal as a final parameter value, and if the difference value between the parameter calculated according to the acceleration vibration signal and the parameter calculated according to the pressure signal is larger than the set range, acquiring data again through the acceleration vibration sensor and the pressure sensor for calculation. The acceleration vibration sensor and the pressure sensor are used for respectively acquiring data, so that the requirement that power supply companies need double verification by adopting different methods for one event for preventing misjudgment is met, and the reliability of judgment is improved.

And comparing the overtravel of the breaker with the standard overtravel after acquiring the overtravel of the breaker, judging that the overtravel is larger when the overtravel is larger than the standard overtravel, and judging that the overtravel is smaller when the overtravel is smaller than the standard overtravel. The contact abrasion condition can be obtained according to the overtravel variable quantity, the abrasion is more serious when the overtravel is smaller, the contact resistance is larger, and the load capacity is reduced.

In this embodiment, in order to realize the monitoring of the energy storage driving mechanism of the circuit breaker, as shown in fig. 4, the method further includes:

s5: the current of a coil of a driving motor of the circuit breaker operating mechanism is measured through a first current transformer, a current-time curve is drawn, and the similarity between the historical current-time curve and a standard current-time curve is compared through a current fingerprint identification technology, so that whether a fault exists in the driving structure is judged.

In this embodiment, to implement monitoring of the circuit breaker operating mechanism, as shown in fig. 4, the method further includes:

s6: and measuring the current of a coil of a driving motor of the circuit breaker operating mechanism through a second current transformer, drawing a current-time curve, and comparing the similarity of the historical current-time curve and a standard current-time curve through a current fingerprint identification technology so as to judge whether a driving structure has a fault.

Fig. 5 is a standard graph of current-time of the circuit breaker driving mechanism, wherein point a shows that the electromagnetic driving mechanism link rod moves and the energy storage spring is deformed correspondingly; points C and D show that the electromagnetic driving mechanism connecting rod reaches the maximum displacement position; point E indicates the maximum displacement is reached; point F represents the start of the main control contact; point G indicates that the auxiliary contact also starts to operate; and point H represents the recovery of the electromagnetic connecting rod, and the energy storage spring has no deformation.

The relationship between the motor torque and the motor current is as follows:

wherein: t is motor torque; k _TIs a proportionality coefficient; phi is a _mIs an air gap flux; and I is the motor current. When the torque T of the motor is increased, the current I is increased according to a formula, so that the current of the motor is driven by the operating mechanism, and the stress condition of the connecting rod of the operating mechanism can be reflected indirectly.

The analogy is that human face characteristics need to be extracted in human face recognition, voice print recognition needs to be extracted in voice characteristics, and current fingerprint recognition is to be extracted in current characteristics. The method is characterized in that a plurality of characteristics such as current frequency spectrums and waveforms are collected and analyzed, and by combining current-time curves and current characteristic data of + 5% of envelope curves, the envelope curves of the current-time curves at the initial operation stage of the mechanical structure of the circuit breaker can be small, such as + 2-3%, and the envelope curves of the current-time curves at the later operation stage can be large, such as + 3-5%, so that whether the operating mechanism has the problems of coil breakage, mechanism jamming, insufficient driving force and the like can be judged. And meanwhile, the expected mechanical life of the circuit breaker is given according to the accumulated action times of the vacuum bubbles.

The invention respectively collects different data of the circuit breaker during online working through the displacement sensor, the acceleration vibration sensor, the pressure sensor, the first current transformer and the second current transformer, and realizes online monitoring of a plurality of parameters of the mechanical characteristics of the circuit breaker by combining the analysis of the data.

Based on the above method for online monitoring of mechanical characteristics of circuit breaker based on multiple sensors, in terms of corresponding hardware, the present embodiment further provides an online monitoring device for mechanical characteristics of circuit breaker based on multiple sensors, as shown in fig. 6, including: the displacement sensor is used for measuring the total stroke and the running time of the circuit breaker; the acceleration vibration sensor is arranged at the lower end of the pull rod of the circuit breaker and is used for acquiring opening and closing acceleration vibration signals of the circuit breaker; the pressure sensor is arranged at the lower end of the vacuum bubble of the circuit breaker and is used for acquiring a pressure signal at the lower end of the vacuum bubble; the on-line automatic identification module is used for inputting the acceleration vibration signal into the trained contact over-travel state automatic identification mathematical model to realize the on-line automatic identification of the over-travel state of the breaker contact; the processing module is used for respectively obtaining the just opening and just closing points of the circuit breaker according to the pressure signal at the lower end of the vacuum bulb and the opening and closing acceleration vibration signal of the circuit breaker, and respectively obtaining the opening distance and the overtravel of the circuit breaker by combining the total stroke of the circuit breaker, so that the on-line monitoring of the total stroke, the opening distance, the overtravel, the average opening speed and the average closing speed of the circuit breaker is realized; the on-line automatic identification of the over-travel state of the breaker contact is realized according to the over-travel of the breaker; and the judging module is used for obtaining a final judging result of the over-travel state of the contact of the circuit breaker according to the on-line automatic identification result of the over-travel state of the contact of the circuit breaker by the on-line automatic identification module and the processing module.

In this embodiment, the training of the contact over-travel state automatic identification mathematical model includes:

s21: determining the values of w and b which need to be initialized;

s22: randomly selecting feature points (x) from training samples _i,y _i) Then the predicted value is sign (w x) _i+ b), where w represents a proportional weight and b represents an offset value;

s23: in the prediction process, if sign (w x) is predicted _iIf + b) is less than or equal to 0, changing the values of w and b, and continuing prediction;

s24: the iteration steps S22 and S23 are repeated until the predicted value is less than the expected error.

In this embodiment, altering the values of w and b includes:

calculate the total distance of all error points to the hyperplane:

wherein M is the set of all error points; calculating w according to the minimum gradient descent method _i+1＝w _i+ηy _ix _i，b _i+1＝b _i+ηy _iWhere η represents the gradient values.

In this embodiment, obtaining the final determination result of the over travel state of the breaker contact according to the online automatic identification result of the over travel state of the breaker contact in steps S2 and S3 includes:

s41: if the online automatic identification results of the over travel states of the circuit breaker contacts in the steps S2 and S3 are completely the same, taking the online automatic identification result as a final judgment result;

s42: and if the online automatic identification results of the steps S2 and S3 on the over travel state of the breaker contact are not identical, the online automatic identification result is not taken as the final judgment result.

In order to realize the monitoring of the driving mechanism and the operating mechanism of the circuit breaker, as shown in fig. 7, the embodiment further includes: a first current transformer and a second current transformer. The current of an electromagnet coil of the energy storage driving mechanism of the circuit breaker is measured through a first current transformer, a current-time curve and an envelope line of current-time plus 5% are drawn, and whether a driving structure has a fault or not is judged according to a current fingerprint identification technology. And measuring the current of a coil of a driving motor of the circuit breaker operating mechanism through a second current transformer, drawing a current-time curve and an envelope curve of current-time plus 5%, and judging whether the operating mechanism has a fault according to a current fingerprint identification technology. And meanwhile, the expected mechanical life of the circuit breaker is given according to the accumulated action times of the vacuum bubbles.

In the present embodiment, the displacement sensor is a linear displacement sensor or an angular displacement sensor. For the air-insulated linear motion circuit breaker, a linear potentiometer type displacement sensor or a non-contact photoelectric displacement sensor or an electromagnetic linear displacement sensor is adopted for measuring the total stroke of the vacuum bubbles. The potentiometer-type displacement sensors or non-contact photoelectric displacement sensors or electromagnetic linear displacement sensors are three, are respectively arranged at the lower ends of the pull rods of the A phase, the B phase and the C phase of the circuit breaker, indirectly reflect the total stroke of each vacuum bubble of the circuit breaker through the variable quantity of the resistor, and further realize the online measurement of the total stroke and the running time of the circuit breaker.

For the gas-insulated circuit breaker, an angular displacement sensor is utilized, and the online measurement of the total stroke and the running time of the circuit breaker is realized by measuring the rotating angle of an operating structure of the circuit breaker; the installation of angle displacement sensor can with circuit breaker operation structure coaxial arrangement, make angle displacement sensor and circuit breaker operation structure pivot rotatory together, also can adopt friction pulley and circuit breaker operation structure pivot contact friction, the rotatory friction pulley that drives of circuit breaker operation structure pivot is rotatory, friction pulley and angle displacement sensor coaxial arrangement.

In this embodiment, the acceleration vibration sensor adopts a film acceleration vibration sensor, and there are three acceleration vibration sensors, which are respectively fixedly mounted at the lower end of each pull rod of the circuit breaker by screws and are used for collecting opening and closing acceleration vibration signals of the circuit breaker. The processing unit obtains the just opening and just closing points of the breaker according to the catastrophe points of the acceleration vibration signals when the breaker is opened and closed, and then obtains specific numerical values of opening distance and over travel by combining the displacement sensor, so that the on-line monitoring of the total stroke, the opening distance, the over travel, the average opening speed and the average closing speed of the breaker is realized.

In this embodiment, the pressure sensors are cake-shaped pressure sensors, and there are three pressure sensors, which are respectively installed at the lowest ends of the pressure springs at the lower ends of the vacuum bubbles of the circuit breakers. The processing unit obtains the just opening and just closing points of the circuit breaker according to the catastrophe points of the pressure signals when the circuit breaker is opened and closed, and then obtains specific numerical values of opening distance and over travel by combining with the displacement sensor, so that the on-line monitoring of the total stroke, the opening distance, the over travel, the average opening speed and the average closing speed of the circuit breaker is realized; the processing unit judges whether the breaker contact is abraded or not according to the over-travel variation of the breaker, so that the problem of online monitoring of the abrasion of the breaker contact is solved.

In this embodiment, the first current transformer and the second current transformer are all through hall current transformers and rated current 5ADC, the first current transformer measures the current of the electromagnet coil of the energy storage driving mechanism of the circuit breaker, and the processing unit compares the measured current with a standard current to judge whether the driving mechanism has the problems of coil breakage, mechanism jamming, insufficient driving force and the like; the second current transformer measures the current of a coil of a driving motor of the circuit breaker operating mechanism, and the processing unit judges whether the operating mechanism has the problems of coil breakage, mechanism jamming, insufficient driving force and the like by comparing the measured current with the standard current.

According to the invention, the acceleration vibration sensor and the pressure sensor are adopted, and the specific numerical values of the opening distance and the over travel are obtained by combining the displacement sensor, so that the on-line monitoring of the total travel, the opening distance, the over travel, the average switching-off speed and the average switching-on speed of the circuit breaker is respectively realized. According to the online automatic identification results of the over travel states of the breaker contacts of the online automatic identification module and the processing module, when the judgment results are consistent according to the collected data of the online automatic identification module and the processing module, the result is used as a final judgment result, and if the judgment results are inconsistent, the result is not used as the final judgment result. The requirement that the power supply company needs double verification by adopting different methods for one event to prevent misjudgment is met, and the reliability of judgment is improved.

As shown in fig. 8, as a preferred embodiment of the present invention, the apparatus further includes: the switching-off command control unit, the switching-on state input unit and the switching-off state input unit are connected with the processing unit. The switching-off command control unit is used for sending a switching-off command to the processing module, and the switching-on command unit is used for sending a switching-on command to the processing module, so that the switching-on and switching-off of the circuit breaker are controlled. The switching-on state input unit is used for inputting switching-on parameter values, and the switching-off state input unit is used for inputting switching-off parameter values.

As shown in fig. 9, as a preferred embodiment of the present invention, the apparatus further includes: and the power supply module is connected with the processing unit and used for supplying power to the processing unit.

As shown in fig. 10, as a preferred embodiment of the present invention, the apparatus further includes: and the communication module is connected with the processing unit and is used for transmitting the judgment result of the mechanical characteristic of the circuit breaker. The communication module adopts an RS485 module, transmits the judgment result of the mechanical characteristics of the circuit breaker and other acquired data to a server, an intelligent terminal and other devices, and is convenient for storing and analyzing the data.

As shown in fig. 11, as a preferred embodiment of the present invention, the apparatus further includes: and the memory module is connected with the processing unit and adopts an MB85RC04V memory to store data of the displacement sensor, the acceleration vibration sensor, the pressure sensor, the first current sensor and the second current sensor.

As shown in fig. 12, as a preferred embodiment of the present invention, the apparatus further includes: and the display module is connected with the processing unit and is used for displaying the judgment result of the mechanical characteristics of the circuit breaker. After the processing unit judges the mechanical characteristics of the circuit breaker, the judgment result is displayed on the display module, so that a user can conveniently obtain the judgment result.

As shown in fig. 13, as a preferred embodiment of the present invention, the apparatus further includes: and the address selection unit is connected with the processing unit and adopts a 10-bit dial switch. The address selection unit is used for carrying out different address settings on different circuit breakers so as to distinguish monitoring results of mechanical characteristics of different circuit breakers.

Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.