JP2022185444A - Contact life diagnosis method of electrical equipment and device - Google Patents

Abstract

To achieve a higher accuracy of a life diagnosis of a contact in electrical equipment.SOLUTION: Each of closing and opening of a contact 11 of an electromagnetic contactor 1 is set to one operation, and an arc energy Warc of an arc discharge is calculated by one operation (a step S113). Also, in accordance with the arc energy Warc, a consumption amount Mloss of the contact 11, which was consumed by the one operation is calculated (a step S114), and an accumulation consumption amount RMloss is calculated by accumulating the consumption amount Mloss (a step S115). Then, diagnosis of a life of the contact 11 is made in accordance with the accumulation consumption amount RMloss (steps S116 to S119).SELECTED DRAWING: Figure 5

Description

TECHNICAL FIELD The present invention relates to a contact life diagnosis method and apparatus for diagnosing the life of a contact in an electrical device.

Short-term arc discharge occurs in the contact points of electrical equipment when they are opened and closed, which causes deterioration of the surrounding insulation, as well as wear and transfer due to melting and evaporation of the contact points. and operating characteristics deteriorate. In order to take measures such as replacement or suspension of use before the life of the reed contact reaches the end of its life, for example, in Cited Document 1, the cumulative value of the arc energy is obtained each time the switching operation is performed, and the effective value is directly calculated from the cumulative value of the arc energy. The cumulative wear amount of contacts is obtained. Then, the service life of the contact is diagnosed according to the accumulated wear amount.

JP 2020-091945 A

When the contacts are opened or closed, the relationship between arc energy per time and contact consumption per time is not linear. Therefore, if the cumulative wear amount of the contact is obtained directly from the cumulative value of the arc energy, an error may occur, which affects the accuracy of life diagnosis.
SUMMARY OF THE INVENTION An object of the present invention is to diagnose the lifespan of contacts in electrical equipment with higher accuracy.

A method for diagnosing the contact life of an electrical device according to one aspect of the present invention includes closing and opening the contact of the electrical device as one operation, and calculating the arc energy of the arc discharge for each operation. a step of calculating the consumption amount of the contact that has been consumed in one operation according to the arc energy; a step of calculating the accumulated consumption amount by accumulating the consumption amount; and diagnosing the life of the contacts.

A reed contact life diagnosis device for an electrical device according to another aspect of the present invention includes closing and opening the reed contacts of the electrical device as one operation, and measuring the arc energy of the arc discharge for each operation. Arc energy calculation unit that calculates, a consumption amount calculation unit that calculates the consumption amount of the contact that has been consumed in one operation according to the arc energy, and a cumulative consumption amount that calculates the cumulative consumption amount by accumulating the consumption amount A calculation unit and a life diagnosis unit for diagnosing the life of the contact according to the accumulated wear amount are provided.

According to the present invention, the wear amount of the contact is calculated from the arc energy for each operation, and the cumulative wear amount is calculated by accumulating the calculated amounts, so errors can be suppressed. Therefore, it is possible to more accurately diagnose the life span of the contacts in the electrical equipment.

It is a figure which shows the reed contact life diagnostic apparatus of an electrical equipment. It is a block diagram of a control part. It is a figure which shows the characteristic data. 7 is a flow chart showing diagnostic model setting processing. 4 is a flowchart showing lifespan diagnosis processing; It is a figure explaining arc discharge.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. Note that each drawing is schematic and may differ from the actual one. Moreover, the following embodiments are intended to exemplify devices and methods for embodying the technical idea of the present invention, and are not intended to limit the configurations to those described below. That is, the technical idea of the present invention can be modified in various ways within the technical scope described in the claims.

<<First embodiment>>
"Constitution"
FIG. 1 is a diagram showing a reed contact life diagnosis device for electrical equipment.
Here, the contact life diagnosis device 3 includes an electromagnetic contactor 1 (electrical equipment) and an electronic thermal relay 2 . The electromagnetic contactor 1 and the electronic thermal relay 2 constitute an electromagnetic switch, and are connected between the power source 4 and the electric motor 5 in, for example, a three-phase AC electric circuit. Electronic thermal relay 2 is an overload relay.

Inside the case of the electromagnetic contactor 1, a fixed iron core, a movable iron core arranged opposite to the fixed iron core, and an exciting coil 6 arranged on the outer periphery of the main leg of the fixed iron core are accommodated. The electromagnetic contactor 1 is provided with primary side terminal portions 7a to 7c connected to the electric circuit on the power supply 4 side and secondary side terminal portions 8a to 8c connected to the electric circuit on the electronic thermal relay 2 side. . A fixed contact 9 having a fixed contact 9a and a movable contact 10 having a movable contact 10a are provided between the primary side terminal portion 7a and the secondary side terminal portion 8a. The fixed contact 9 a and the movable contact 10 a are contacts 11 of the electromagnetic contactor 1 . Further, the contact points 11 having the configuration described above are also provided between the other primary side terminal portion 7b and the secondary side terminal portion 8b and between the primary side terminal portion 7c and the secondary side terminal portion 8c.

In the closing operation of the electromagnetic contactor 1, when the excitation coil 6 is excited, the movable core is attracted to the fixed core against the return spring. When the movable contact 10a comes into contact with the fixed contact 9a, the closed contact 11 is brought into a closing state. On the other hand, in the opening operation of the magnetic contactor 1, when the excitation coil 6 is de-energized, the movable core is stopped to be attracted, so that the movable core is pushed back by the return spring. When the movable contact 10a is separated from the fixed contact 9a, the reed contact 11 is opened to provide a cut-off state. In this manner, the contact 11 is opened and closed by the movable contact 10a coming into contact with and separating from the fixed contact 9a.
A push button switch 12 is a switch for starting the electric motor 5 , and a push button switch 13 is a switch for stopping the electric motor 5 .

The electronic thermal relay 2 includes a current sensor 15 , a voltage sensor 16 and a control section 17 .
The current sensor 15 is provided between the secondary side terminal portions 8a to 8c of the electromagnetic contactor 1 and the electric motor 5, and measures a current value I flowing through the electric paths 18a to 18c.
The voltage sensor 16 detects the voltage Vin between the power source 4 and the primary side terminals 7a to 7c of the electromagnetic contactor 1, and the voltage between the secondary side terminals 8a to 8c of the electromagnetic contactor 1 and the electronic thermal relay 2. The inter-electrode voltage V of the magnetic contactor 1 is measured by inputting the inter-electrode voltage value Vout.

FIG. 2 is a block diagram of the controller.
The control unit 17 includes a processing calculation unit 18 , a cutoff output unit 19 , a storage unit 20 , an input unit 21 and a display unit 22 . The processing calculation unit 18 includes a cutoff unit 23 , a diagnosis model setting unit 24 and a life diagnosis unit 25 .
Constituent devices of these control units 17 are specifically realized by general-purpose information processing devices such as personal computers and workstations, and include, for example, a CPU, a ROM, a RAM, and the like as main components. Also, the control unit 17 is connected to a network and configured to be able to exchange data.

The breaking output unit 19 stops supplying the exciting current to the exciting coil 6 of the magnetic contactor 1 when a command to open the magnetic contactor 1 is output from the breaking unit 23 of the processing calculation unit 18 . do.
The input unit 21 is an input unit, such as a setting dial and push buttons, which is operated by the user for setting.
The display unit 22 is display means such as a display and a lamp.
The breaking unit 23 receives the current value I from the current sensor 15, and outputs a command to open the magnetic contactor 1 to the breaking output unit 19 when an overload current _IMAX flows through the electric circuits 18a to 18c. do.

Based on the model information of the electromagnetic contactor 1 input from the input unit 21, the diagnostic model setting unit 24 selects the model of the electromagnetic contactor 1 to be diagnosed from among a plurality of pieces of information stored in advance in the storage unit 20. selects and stores various information corresponding to Specifically, it stores characteristic data DT _CT indicating the relationship between the arc energy _Warc and the amount of wear M _loss , and threshold values M1 and M2 for the cumulative amount of wear RM _loss .
The life diagnosis unit 25 considers each of closing and opening the contact 11 of the electromagnetic contactor 1 to be one operation, and calculates the consumption amount of the contact 11 due to arc discharge for each operation, Diagnose the life of the contact 11.

During the opening and closing operation of the contact 11 of the electromagnetic contactor 1, arc discharge occurs between the fixed contact 9a and the movable contact 10a. When the magnetic contactor 1 is used for a long time, the fixed contact 9a and the movable contact 10a melt and evaporate due to the _arc energy Warc generated during arc discharge, and the consumption M _loss increases. Through experiments in which the magnetic contactor 1 is repeatedly opened and closed in advance, characteristic data DT _CT indicating the relationship between the _arc energy Warc generated in one operation and the consumption amount M _loss consumed in one operation is obtained. There are a plurality of characteristic data DT _CT and thresholds M1 and M2 for each model CT of the electromagnetic contactor 1 .

FIG. 3 is a diagram showing characteristic data.
(a) in the figure is one characteristic data DT _CT stored in the storage unit 20 . The horizontal axis is the arc energy _Warc of the arc discharge generated in one operation, and the vertical axis is the consumption M amount M _loss of the contact 11 consumed in one operation, and the larger the _arc energy Warc , the consumption amount M _loss increases. The relationship between the _arc energy _Warc and the amount of consumption M _loss is not linear (proportional relationship) but nonlinear like an exponential _{function .} becomes larger.
(b) in the drawing is a plurality of characteristic data DT _CTn stored in the storage unit 20 . n is a natural number not including 0 (positive integer). There are a plurality of characteristic data DT _CT for each model CT of the electromagnetic contactor 1 . That is, the relationship between the arc energy _Warc and the amount of consumption M _loss varies depending on the model CT of the magnetic contactor 1, from small to large.

Next, diagnostic model setting processing executed by the diagnostic model setting unit 24 will be described.
FIG. 4 is a flowchart showing diagnostic model setting processing.
The diagnostic model setting process is executed as an initial setting when the electromagnetic contactor 1 is installed.
First, in step S101, the model CT of the electromagnetic contactor 1 input via the input unit 21 is read and stored.
In the subsequent step S102, among the data stored in the storage unit 20, the characteristic data DT _CT corresponding to the model CT to be diagnosed is read and stored.
In the subsequent step S103, among the data stored in the storage unit 20, the thresholds M1 and M2 for the cumulative wear amount RM _loss in the model CT to be diagnosed are read and stored, and then the process ends. The threshold value M1 corresponds to the wear amount M _loss at which the contact 11 needs to be replaced quickly. The threshold value M2 is a value smaller than the threshold value M1, and is a value that indicates that the contact 11 should be replaced soon.

Next, life diagnosis processing executed by the life diagnosis section 25 will be described.
FIG. 5 is a flowchart showing lifespan diagnosis processing.
The lifespan diagnosis process is executed for each operation, each of closing and opening the contact 11 of the electromagnetic contactor 1 being one operation.
First, in step S111, the arc current I _arc detected by the current sensor 15 when the contact 11 is opened and closed is read.
In the subsequent step S112, the inter-electrode voltage detected by the voltage sensor 16 when the contact 11 is opened and closed is read as the arc voltage V _arc .

In the subsequent step S113, the arc energy _Warc generated in one operation is calculated according to the _arc current _Iarc and the arc voltage Varc, as shown in the following equation (1). That is, it is calculated by integrating the product of the arc current I _arc and the arc voltage V _arc over the discharge time t. The discharge time t is an operating time for contacting the contact 11 or an operating time for separating the contact 11 .
W _arc =∫(I _arc ×V _arc )dt (1)
In the subsequent step S114, the characteristic data _{DT_CT} is referred to, and the wear amount _{M_loss} of the contact 11 is calculated according to the _arc energy Warc.

In the subsequent step S115, the cumulative wear amount RM _loss is calculated by accumulating the wear amount M _loss . That is, a new cumulative wear amount RM _loss is calculated by adding the wear amount M _loss calculated this time to the currently stored cumulative wear amount RM _loss . Immediately after replacing the newly installed magnetic contactor 1 or the contact 11, the accumulated wear amount RM _loss is reset to the initial value of zero.
In the subsequent step S116, it is determined whether or not the accumulated wear amount RM _loss is smaller than the threshold value M1. Here, when the cumulative wear amount RM _loss is smaller than the threshold value M1 (determination in S116 is "Yes"), it is determined that prompt replacement of the contact 11 is not necessary, and the process proceeds to step S117. On the other hand, when the cumulative wear amount RM _loss is equal to or greater than the threshold value M1 (determination in S116 is "No"), it is determined that the contact 11 needs to be replaced quickly, and the process proceeds to step S119.

In step S117, it is determined whether or not the accumulated wear amount RM _loss is smaller than the threshold value M2. Here, when the cumulative wear amount RM _loss is smaller than the threshold value M2 (determination in S117 is "Yes"), it is determined that the time to replace the contact 11 is not near, and the process ends. On the other hand, when the cumulative wear amount RM _loss is equal to or greater than the threshold value M2 (determination in S117 is "No"), it is determined that the contact 11 should be replaced soon, and the process proceeds to step S118.
In step S118, warning information indicating that the time to replace the contact 11 is near is displayed on the display unit 22, and then the process ends.
In step S119, replacement information indicating that prompt replacement of the contact 11 is required is displayed on the display unit 22, and the process ends.

From the above, the process of step S113 corresponds to the "step of calculating the arc energy" and the "arc energy calculation unit", and the process of step S114 corresponds to the "step of calculating the consumption amount" and the "consumption amount calculation unit". ing. Further, the process of step S115 corresponds to the "process of calculating the accumulated consumption amount" and the "accumulated consumption amount calculation unit", and the processes of steps S116 and S117 correspond to the "process of diagnosing the life span" and the "life diagnosis unit". is doing. Further, the processing of steps S118 and S119 corresponds to "the step of displaying the diagnosis result", and the display unit 22 corresponds to the "display unit".

《Action》
Next, main effects of the embodiment will be described.
FIG. 6 is a diagram explaining arc discharge.
A large arc discharge occurs in the opening operation of separating the contacts 11 of the magnetic contactor 1, but arc discharge also occurs in the closing operation of bringing the contacts 11 of the magnetic contactor 1 into contact. Therefore, closing and opening the contacts 11 of the electromagnetic contactor 1 must be regarded as one operation, and it is necessary to diagnose the consumption state of the contacts 11 for each operation.

When the contact 11 is opened or closed, the relationship between the arc energy _Warc per time and the consumption M _loss per time is not linear, but nonlinear like an exponential function as shown in FIG. Become.
Therefore, in the method and apparatus for diagnosing the contact life of electric equipment in the embodiment, closing and opening the contact 11 of the electromagnetic contactor 1 are each performed as one operation, and arc discharge arc is performed for each operation. Energy _Warc is calculated (step S113). Further, the wear amount M _loss of the contact 11 worn in one operation is calculated according to the _arc energy Warc (step S114), and the cumulative wear amount RM _loss is calculated by accumulating the wear amount M _loss ( step S115). Then, the service life of the contact 11 is diagnosed according to the cumulative wear amount RM _loss (steps S116 to S119).

Specifically, the cumulative wear amount RM _loss is compared with the threshold value M1, and when the cumulative wear amount RM _loss is equal to or greater than the threshold value M1 (determination at S116 is "No"), prompt replacement of the contact 11 is required. judge there is. On the other hand, when the cumulative wear amount RM _loss is smaller than the threshold value M1 (determination in S116 is "Yes"), the cumulative wear amount RM _loss is compared with the threshold value M2. When the cumulative wear amount RM _loss is equal to or greater than the threshold value M2 (determination in S117 is "No"), it is determined that the contact 11 should be replaced soon. On the other hand, when the cumulative wear amount RM _loss is smaller than the threshold value M2 (determination in S117 is "Yes"), it is determined that the time to replace the contact 11 is not near.
In this way, the amount of wear M _loss of the contact 11 is calculated from the _arc energy Warc for each operation, and the accumulated amount of wear RM _loss is calculated by accumulating them, so errors can be suppressed. . Therefore, life diagnosis of the contact 11 in the electromagnetic contactor 1 can be performed with higher accuracy.

Further, when _calculating the consumption amount M _loss , as shown in _FIG . With reference to _CT , the consumption amount M _loss is calculated according to the _arc energy Warc. This makes it possible to easily calculate the consumption amount M _loss of the contact 11 that is consumed in one operation.
Moreover, there are a plurality of characteristic data DT _CT for each model CT of the electromagnetic contactor 1 . Then, when calculating the consumption amount M _loss , the characteristic data DT _CT corresponding to the model CT of the electromagnetic contactor 1 to be diagnosed among the plurality of characteristic data DT _CTn is referred to. Thereby, it is possible to refer to the optimum characteristic data DT _CT suitable for the model CT of the magnetic contactor 1, and it is possible to further improve the calculation accuracy of the wear amount M _loss .

When calculating the _arc energy Warc, the product of the arc voltage _Varc and the arc current _Iarc in the arc discharge is integrated over the discharge time t according to the formula (1) described above. This makes it possible to easily and accurately calculate the _arc energy Warc. Moreover, since the voltage sensor 16 for detecting the arc voltage V _arc is simply added to the configuration of the general electronic thermal relay 2, an increase in cost can be suppressed. There is also a method of measuring the temperature of the contact 11 and estimating the arc energy.
Also, the diagnostic result of the life of the contact 11 is displayed. Thereby, the user can accurately grasp the consumption state of the contact 11 .

Specifically, when the cumulative wear amount RM _loss is smaller than the threshold value M2 (determination in S117 is "Yes"), the contact 11 is in good condition, and the notification to the user is omitted (not displayed). As a result, it is possible to minimize the information to be notified to the user and reduce the annoyance. On the other hand, when the cumulative wear amount RM _loss is smaller than the threshold value M1 (determination at S116 is "Yes") and the cumulative wear amount RM _loss is equal to or greater than the threshold value M2 (determination at S117 is "No"), the contact 11 is replaced. Warning information indicating that the time to do so is near is displayed (S118). Accordingly, it is possible to call attention to the user before prompt replacement of the contact 11 is required. Further, when the cumulative wear amount RM _loss is equal to or greater than the threshold value M1 (determination in S116 is "No"), replacement information indicating that prompt replacement of the contact 11 is required is displayed (S119). As a result, the user can be urged to quickly replace the contact 11 .

Next, a comparative example will be described.
Conventionally, it has been considered to first obtain the cumulative value RW _arc of the arc energy _Warc , and then directly obtain the cumulative wear amount RM _loss from the cumulative value RW _arc . However, as described above, when the contact 11 is opened or closed, the relationship between the arc energy _Warc per time and the consumption M _loss per time is not linear. Therefore, if the cumulative wear RM _loss is directly obtained from the cumulative value RW _arc of the _arc energy Warc, an error may occur in the cumulative wear RM _loss , which may affect the accuracy of life diagnosis.

<<Modification>>
In the embodiment, the display unit 22 is hidden when the cumulative wear amount RM _loss is smaller than the threshold value M2, and information is displayed on the display unit 22 only when the cumulative wear amount RM _loss is equal to or greater than the threshold value M2. , but not limited to. That is, the display unit 22 may always display the remaining amount of the contact 11 . In other words, the remaining amount of the contact 11 is displayed immediately after installation or replacement, and the remaining amount of the contact 11 gradually decreases as the cumulative wear amount RM _loss increases. may

Although the configuration for reading the characteristic data DT _CT from the storage unit 20 has been described in the embodiment, the configuration is not limited to this. That is, it may be obtained from the outside through network communication.
Although the configuration in which the user sets the input unit 21 and inputs the model information of the electromagnetic contactor 1 has been described in the embodiment, the configuration is not limited to this. For example, the model information of the electromagnetic contactor 1 may be estimated from the energizing current of the exciting coil 6, or may be input from the outside through network communication.
In the embodiment, the configuration for displaying the notification to the user on the display unit 22 has been described, but the configuration is not limited to this. That is, the notification may be made to the outside through network communication.

DESCRIPTION OF SYMBOLS 1... Electromagnetic contactor 2... Electronic thermal relay 3... Reed life diagnostic device 4... Power supply 5... Electric motor 6... Exciting coil 7a... Primary side terminal part 7b... Primary side terminal part 7c... Primary side terminal part 8a... Secondary side terminal part 8b... Secondary side terminal part 8c... Secondary side terminal part 9... Fixed contact 9a... Fixed contact 10... Movable contact 10a... Movable contact , 11... Electromagnetic contactor, 11... Contact, 12... Push button switch, 13... Push button switch, 15... Current sensor, 16... Voltage sensor, 17... Control unit, 18... Processing calculation unit, 19... Cutoff output unit , 20...storage unit, 21...input unit, 22...display unit, 23...blocking unit, 24...diagnostic model setting unit, 25...life diagnosis unit, CT...model, DT _CT ...characteristic data, I...current value, I _arc ... arc current, I _MAX ... overload current, M1 ... threshold value, M2 ... threshold value, M _loss ... consumption amount, RM _loss ... cumulative consumption amount, RW _arc ... cumulative value, t ... discharge time, V ... voltage between electrodes, V _arc ... arc voltage, Vin ... voltage value, Vout ... voltage value, _Warc ... arc energy

Claims (10)

A step of calculating the arc energy of the arc discharge for each operation, each of closing and opening the contacts of the electrical equipment as one operation;
a step of calculating a consumption amount of the contact that has been consumed in one operation according to the arc energy;
calculating an accumulated amount of consumption by accumulating the amount of consumption;
and a step of diagnosing the life of the contact in accordance with the cumulative wear amount. In the step of calculating the amount of consumption, characteristic data indicating the relationship between the arc energy generated in one operation and the amount of consumption consumed in one operation is referred to, and the amount of consumption is calculated according to the arc energy. 2. The method for diagnosing the contact life of electrical equipment according to claim 1, wherein the contact life is calculated. wherein the characteristic data are plural for each model of the electric device;
3. The electrical equipment according to claim 2, wherein in the step of calculating the consumption amount, the characteristic data corresponding to the model of the electrical equipment to be diagnosed is referred to among the plurality of characteristic data. Contact life diagnosis method. The electric device according to any one of claims 1 to 3, wherein in the step of calculating the arc energy, the product of the arc voltage and the arc current in the arc discharge is integrated over the discharge time. contact life diagnosis method. 5. The method for diagnosing the life of a contact of an electric device according to claim 1, further comprising a step of displaying a diagnostic result of the life of the contact. an arc energy calculation unit for calculating the arc energy of the arc discharge for each operation, each of closing and opening the contacts of the electric device being regarded as one operation;
A consumption amount calculation unit that calculates the consumption amount of the contact that has been consumed in one operation according to the arc energy;
a cumulative consumption amount calculation unit that calculates a cumulative consumption amount by accumulating the consumption amount;
and a life diagnosis unit for diagnosing the life of the contact according to the accumulated wear amount. The consumption amount calculation unit refers to characteristic data indicating the relationship between the arc energy generated in one operation and the consumption amount consumed in one operation, and calculates the consumption amount according to the arc energy. 7. The contact life diagnosis device for electric equipment according to claim 6, characterized in that: wherein the characteristic data are plural for each model of the electric device;
8. The contact life of the electric device according to claim 7, wherein the wear amount calculation unit refers to the characteristic data corresponding to the model of the electric device to be diagnosed among the plurality of characteristic data. diagnostic equipment. The electric appliance according to any one of claims 6 to 8, wherein the arc energy calculation unit calculates the product of the arc voltage and the arc current in the arc discharge by integrating with the discharge time. Contact life diagnosis device. 10. The contact life diagnosis device for electrical equipment according to claim 6, further comprising a display section for displaying a life diagnosis result of the contact.

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