JP2022077370A - Insulation resistance monitoring device - Google Patents

Abstract

To monitor the state of an insulation resistance to facilitate forming a maintenance plan for an object to be measured compared to before.SOLUTION: An insulation resistance calculator 11 calculates an insulation resistance value of an object to be measured. The insulation resistance predictor 12 calculates an insulation resistance predicted value indicating a future insulation resistance value based on current and past insulation resistance values calculated by the insulation resistance calculator 11. An insulation life predictor 13 calculates an insulation life indicating a remaining period until the insulation resistance predicted value becomes equal to or less than a threshold based on the insulation resistance predicted value. A display 16 notifies a user of the insulation life.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an insulation resistance monitoring device.

The Electricity Business Act requires that high-voltage power receiving and transforming equipment and electrical equipment such as switchboards be inspected legally once a year. In addition, the business operator also conducts self-inspection of electrical equipment such as motors connected to the switchboard once a week to once a month according to its own management standards.

However, the objects to be inspected by self-inspection (measured objects) include a wide variety of electrical equipment and devices, and the actual number is too large to handle in reality. Therefore, an insulation resistance monitoring device for automating self-inspection has been developed.

Patent Document 1 discloses an insulation deterioration monitoring device capable of monitoring the progress of insulation deterioration even during operation. The apparatus of Patent Document 1 generates an alarm signal when the insulation resistance exceeds a set value or when the rate of change of the insulation resistance exceeds a specified value.

Japanese Unexamined Patent Publication No. 6-311791

It is necessary to inspect or repair the object to be measured before the insulation resistance of the object to be measured deteriorates. However, according to the apparatus of Patent Document 1, the insulation resistance of the object to be measured is decisively deteriorated (when the insulation resistance exceeds the set value) or immediately before (the rate of change of the insulation resistance is a specified value). The alarm signal is not generated until (when it exceeds), and it is difficult to secure sufficient time for inspection and repair. Therefore, it is required to monitor the state of insulation resistance so that it is easier to make a maintenance plan for the object to be measured than before.

An object of the present disclosure is to provide an insulation resistance monitoring device capable of monitoring the state of insulation resistance so that it is easier to make a maintenance plan for an object to be measured than before.

The insulation resistance monitoring device according to one aspect of the present invention is
An insulation resistance monitoring device that monitors the insulation resistance of the object to be measured.
An insulation resistance calculator that calculates the insulation resistance value of the object to be measured, and
An insulation resistance predictor that calculates an insulation resistance prediction value indicating a future insulation resistance value based on the current and past insulation resistance values calculated by the insulation resistance calculator.
An insulation life predictor that calculates the insulation life, which indicates the remaining period until the insulation resistance prediction value becomes equal to or less than the threshold value, based on the insulation resistance prediction value.
It is provided with an output device for notifying the insulation life.

This makes it possible to monitor the state of insulation resistance so that it is easier to make a maintenance plan for the object to be measured than in the past.

According to the insulation resistance monitoring device according to one aspect of the present invention.
The insulation resistance predictor calculates the speed and acceleration at which the insulation resistance value changes with time, and calculates the insulation resistance prediction value based on the insulation resistance value, the speed, and the acceleration.

As a result, the predicted insulation resistance value and the insulation life can be calculated with high accuracy in consideration of the speed and acceleration of the insulation resistance value.

According to the insulation resistance monitoring device according to one aspect of the present invention.
The insulation resistance predictor calculates the speed, acceleration, and jerk at which the insulation resistance value changes over time, and predicts the insulation resistance based on the insulation resistance value, the speed, the acceleration, and the jerk. Calculate the value.

As a result, the predicted insulation resistance value and the insulation life can be calculated with higher accuracy in consideration of the speed, acceleration, and jerk of the insulation resistance value.

According to the insulation resistance monitoring device according to one aspect of the present invention.
When the current insulation resistance value increases from the insulation resistance value calculated immediately before the current time, the insulation life predictor presents the insulation life calculated before the insulation resistance value increases. Set as insulation life.

This makes it possible to reduce the error caused by the temporary increase in the insulation resistance value.

According to the insulation resistance monitoring device according to one aspect of the present invention.
The insulation resistance calculator calculates the insulation resistance value of the object to be measured in response to a control signal from the outside of the insulation resistance monitoring device.

Thereby, for example, the insulation resistance value, the insulation resistance predicted value, and the insulation life can be calculated in a predetermined time cycle.

According to the insulation resistance monitoring device according to one aspect of the present invention.
The output device includes a display device, and the display device is
With the insulation life
The current insulation resistance value and
The time change of the insulation resistance predicted value from the present time to the time when the insulation resistance predicted value becomes equal to or less than the threshold value is displayed.

This makes it possible to recognize the tendency of deterioration of the insulation resistance.

The insulation resistance monitoring device according to one aspect of the present invention is
An alarm device for notifying that the current insulation resistance value is equal to or lower than the threshold value is further provided.

As a result, the object to be measured can be appropriately inspected or repaired.

According to the insulation resistance monitoring device according to one aspect of the present invention, it is possible to monitor the state of insulation resistance so that it is easier to make a maintenance plan for the object to be measured than before.

It is a block diagram which shows the structure of the motor system which includes the insulation resistance monitoring apparatus 8 which concerns on embodiment. It is a flowchart which shows the insulation resistance monitoring process which is executed by the processing apparatus 10 of FIG. It is a figure for demonstrating the calculation example of the insulation resistance predicted value and insulation life in steps S13 to S14 of FIG. It is a figure for demonstrating another calculation example of the insulation resistance predicted value and insulation life in steps S13 to S14 of FIG. It is a flowchart which shows the modification of the insulation resistance monitoring processing executed by the processing apparatus 10 of FIG.

Hereinafter, embodiments relating to one aspect of the present disclosure will be described with reference to the drawings. In each drawing, the same reference numerals indicate similar components.

[Embodiment]
Hereinafter, the insulation resistance monitoring device according to the embodiment will be described.

[Structure example of embodiment]
FIG. 1 is a block diagram showing a configuration of a motor system including an insulation resistance monitoring device 8 according to an embodiment. The motor system of FIG. 1 includes a three-phase AC power supply 1, a power line L, a circuit breaker 2, a three-phase motor 3, a zero-phase current transformer 4, a ground fault direction relay 5, an instrument transformer 6, and a ground fault overvoltage relay 7. , Insulation resistance monitoring device 8, and control device 9. In the example of FIG. 1, the case where the insulation resistance monitoring device 8 measures the insulation resistance of the three-phase motor 3 as the object to be measured is shown.

The three-phase AC power supply 1 is connected to the three-phase motor 3 via the power line L, and supplies the three-phase AC power to the three-phase motor 3. A circuit breaker 2 is inserted into the power line L.

The zero-phase current transformer 4 detects the zero-phase current flowing in the power line L when the insulation state of the three-phase motor 3 or the power line L is poor, and monitors the detected zero-phase current with the ground fault direction relay 5 and the insulation resistance. It is sent to the insulation resistance calculator 11 (described later) of the apparatus 8. The ground fault direction relay 5 generates an alarm when the zero-phase current exceeds a predetermined threshold value.

The instrument transformer 6 detects a zero-phase voltage generated in the power line L when the insulation state of the three-phase motor 3 or the power line L is poor, and uses the detected zero-phase voltage as the ground fault direction relay 5 and the ground fault overvoltage relay 7. , And to the insulation resistance calculator 11 (described later) of the insulation resistance monitoring device 8. The ground fault overvoltage relay 7 generates an alarm when the zero-phase voltage exceeds a predetermined threshold value.

The insulation resistance monitoring device 8 monitors the insulation resistance of the three-phase motor 3 or the power line L. The insulation resistance monitoring device 8 includes an insulation resistance calculator 11, an insulation resistance predictor 12, an insulation life predictor 13, a storage device 14, a comparator 15, a display device 16, an alarm device 17, and a communication device 18. The insulation resistance calculator 11, the insulation resistance predictor 12, the insulation life predictor 13, the storage device 14, and the comparator 15 are collectively referred to as a “processing device 10”.

The insulation resistance calculator 11 calculates the insulation resistance value of the three-phase motor 3 based on the zero-phase current and the zero-phase voltage using Ohm's law. The insulation resistance calculator 11 sends the calculated insulation resistance value to the insulation resistance predictor 12. The insulation resistance calculator 11 may further send the calculated insulation resistance value to at least one of the display device 16 and the communication device 18.

The insulation resistance predictor 12 calculates an insulation resistance prediction value indicating a future insulation resistance value based on the current and past insulation resistance values calculated by the insulation resistance calculator 11. The insulation resistance predictor 12 sends the calculated insulation resistance prediction value to the insulation life predictor 13. The insulation resistance predictor 12 may further send the calculated insulation resistance prediction value to at least one of the display device 16 and the communication device 18.

The insulation life predictor 13 calculates the insulation life indicating the remaining period until the insulation resistance predicted value becomes equal to or less than the threshold value based on the insulation resistance predicted value. The insulation life predictor 13 sends the calculated insulation life to the display device 16. The insulation life predictor 13 may further send the calculated insulation life to the communication device 18.

The storage device 14 stores a history of insulation resistance values and other variables used to calculate the insulation resistance prediction value and the insulation life. Further, the storage device 14 may store at least one of the calculated insulation resistance predicted value and the insulation life.

The comparator 15 determines whether or not the current insulation resistance value is equal to or less than a predetermined threshold value K, and sends the determination result to the alarm device 17. The threshold value K may be set to, for example, a value determined by law or the like, or may be set to a value obtained by adding a predetermined margin to a value determined by law or the like. For example, according to the ministry ordinance that establishes technical standards for electrical equipment, when the working voltage is 300V or less and the voltage to ground is 150V or less, the insulation resistance value is set to 0.1MΩ or more, and the working voltage is 300V. When the voltage is less than or equal to 150V and the voltage to ground is higher than 150V, the insulation resistance value is determined to be 0.2MΩ or more, and when the working voltage is higher than 300V, the insulation resistance value is determined to be 0.4M or more.

The display device 16 displays at least the calculated insulation life. The display device 16 is an example of an output device that notifies the user of the calculated insulation life. Further, the display device 16 may display the current insulation resistance value. Further, the temporal change of the insulation resistance predicted value from the present time to the time when the insulation resistance predicted value becomes equal to or less than the threshold value may be displayed.

The alarm device 17 generates a visual or auditory alarm signal in order to notify the user that the current insulation resistance value is equal to or lower than the threshold value based on the determination result of the comparator 15.

The communication device 18 is connected to an external control device 9. The processing device 10 may be activated in response to a control signal from the outside of the insulation resistance monitoring device 8, for example, in response to a trigger signal received from the control device 9 by the communication device 18. In this case, when the communication device 18 receives the trigger signal from the control device 9, the insulation resistance calculator 11 calculates the insulation resistance value of the three-phase motor 3, and the insulation resistance predictor 12 predicts the insulation resistance of the three-phase motor 3. The value is calculated, and the insulation life predictor 13 calculates the insulation life of the three-phase motor 3. The communication device 18 may transmit the calculated insulation resistance value, the predicted insulation resistance value, and the insulation life to the control device 9.

[Operation example of the embodiment]
FIG. 2 is a flowchart showing an insulation resistance monitoring process executed by the processing device 10 of FIG.

In step S11, the processing device 10 determines whether or not the communication device 18 has received the trigger signal from the control device 9. If YES, the process proceeds to step S12, and if NO, the process repeats step S11.

In step S12, the insulation resistance calculator 11 calculates the current insulation resistance value, and displays the calculated insulation resistance value on the display device 16.

In step S13, the insulation resistance predictor 12 calculates the insulation resistance prediction value, and displays the calculated insulation resistance prediction value on the display device 16.

In step S14, the insulation life predictor 13 calculates the insulation life prediction value, and displays the calculated insulation life prediction value on the display device 16.

According to the process of FIG. 2, by starting the operation in response to an external trigger signal, for example, the insulation resistance value, the insulation resistance predicted value, and the insulation life can be calculated in a predetermined time cycle. can.

FIG. 3 is a diagram for explaining a calculation example of the insulation resistance predicted value and the insulation life in steps S13 to S14 of FIG. In the example of FIG. 3, the insulation resistance predictor 12 calculates the speed and acceleration at which the insulation resistance value changes with time, and calculates the insulation resistance prediction value based on the insulation resistance value, speed, and acceleration.

The horizontal axis of FIG. 3 indicates the time t represented by the parameter n. t (n) indicates the present time, t (n-1), t (n-2), ... Indicates the past time point when the insulation resistance value was calculated, and t (n + 1), t (n + 2), ... Indicates insulation. Indicates a future point in time when the predicted resistance is calculated. The unit time Δt (n) for calculating the velocity and acceleration of the insulation resistance value is defined by the following equation.

Δt (n) = t (n) -t (n-1)

The unit time Δt (n) may be set to, for example, several days, several weeks, or several months. The time point at which the multiple of the unit time Δt (n) is added to the current time point t (n) is set as the future time point t (n + 1), t (n + 2), ...

The vertical axis of FIG. 3 shows the insulation resistance value and the insulation resistance predicted value. R (n) indicates the current insulation resistance value, R (n-1), R (n-2), ... Indicates the past insulation resistance value, and R (n + 1), R (n + 2), ... Is calculated. The future insulation resistance value to be calculated, that is, the predicted insulation resistance value is shown. K indicates a predetermined threshold value of insulation resistance. As described above, the threshold value K may be set to, for example, a value determined by laws and regulations, or may be set to a value obtained by adding a predetermined margin to the value determined by laws and regulations.

Based on the current and past insulation resistance values R (n), R (n-1), R (n-2), the speeds V (n-1) and V (n) of the insulation resistance values are calculated by the following equations. do.

V (n-1) = (R (n-2) -R (n-2)) / (t (n-1) -t (n-2))
V (n) = (R (n-1) -R (n)) / Δt (n)

Based on the speeds V (n-1) and V (n) of the insulation resistance value, the acceleration A (n) of the insulation resistance value is calculated by the following equation.

A (n) = V (n) -V (n-1)

Based on the velocity V (n) of the insulation resistance value and the acceleration A (n), the velocity prediction value V (n + 1) indicating the velocity of the insulation resistance value at the future time point t (n + 1) is calculated by the following equation.

V (n + 1) = V (n) + A (n)

Based on the velocity prediction value V (n + 1), the insulation resistance prediction value R (n + 1) at the future time point t (n + 1) is calculated by the following equation.

R (n + 1) = R (n)-(V (n + 1) × Δt (n))

Similarly, the speed prediction value V (n + 2) and the insulation resistance prediction value R (n + 2) at the future time point t (n + 2) are calculated by the following equations.

V (n + 2) = V (n + 1) + A (n)
R (n + 2) = R (n + 1)-(V (n + 2) × Δt (n))

Similarly, the calculation of the speed prediction value and the insulation resistance prediction value is repeated, and the speed prediction value V (n + i) and the insulation resistance prediction value R (n + i) at the future time point t (n + i) are calculated by the following equations.

V (n + i) = V (n + i-1) + A (n)
R (n + i) = R (n + i-1)-(V (n + i) × Δt (n))

The predicted insulation resistance value R (n + i-1) at the time point t (n + i-1) is larger than the threshold value K, and the predicted insulation resistance value R (n + i) at the time point t (n + i) is equal to or less than the threshold value K. Then, the insulation life D (n) at the present time t (n) is calculated by the following equation.

D (n) = (Δt (n) × (i-1)) + (R (n + i-1) -K) / V (n + i)

According to the example of FIG. 3, the insulation resistance predictor 12 has current and past insulation resistance values R (n), R (n-1), R (n-2), calculated by the insulation resistance calculator 11. Based on ..., the predicted insulation resistance values R (n + 1), R (n + 2), ..., Which indicate the future insulation resistance values, can be calculated. The insulation resistance predictor 12 calculates the speed and acceleration at which the insulation resistance value changes with time, and determines the insulation resistance prediction values R (n + 1), R (n + 2), ... Based on the insulation resistance value, speed, and acceleration. calculate. The insulation life predictor 13 has an insulation life D (n) indicating the remaining period until the insulation resistance predicted value becomes the threshold value K or less based on the insulation resistance predicted values R (n + 1), R (n + 2), ... Can be calculated.

FIG. 4 is a diagram for explaining other calculation examples of the insulation resistance predicted value and the insulation life in steps S13 to S14 of FIG. In the example of FIG. 4, the insulation resistance predictor 12 calculates the speed, acceleration, and jerk at which the insulation resistance value changes with time, and predicts the insulation resistance based on the insulation resistance value, speed, acceleration, and jerk. Calculate the value.

According to the example of FIG. 4, in addition to each parameter used in the example of FIG. 3, the time derivative of the velocity of the insulation resistance value, that is, the jerk J (n) is calculated by the following equation.

J (n) = A (n) -A (n-1)

Based on the velocity V (n), acceleration A (n), and jerk J (n) of the insulation resistance value, the velocity prediction value V (n + 1) indicating the velocity of the insulation resistance value at the future time point t (n + 1) is obtained. Calculate by the following formula.

V (n + 1) = V (n) + A (n) + J (n)

Based on the velocity prediction value V (n + 1) or jerk J (n), the acceleration A (n + 1) at the future time point t (n + 1) is calculated by the following equation.

A (n + 1) = V (n + 1) -V (n) = A (n) + J (n)

Similarly, the velocity prediction value V (n + 2) and the jerk at the future time point t (n + 2) are calculated by the following equations.

V (n + 2) = V (n + 1) + A (n + 1) + J (n)
A (n + 2) = V (n + 2) -V (n + 1) = A (n + 1) + J (n)

In the example of FIG. 4, the predicted insulation resistance values R (n + 1) and R (n + 2) are calculated in the same manner as in the case of FIG.

Similarly, the calculation of the speed prediction value and the insulation resistance prediction value is repeated, and the speed prediction value V (n + i) and the insulation resistance prediction value R (n + i) at the future time point t (n + i) are calculated by the following equations.

V (n + i) = V (n + i-1) + A (n + i-1) + J (n)
R (n + i) = R (n + i-1)-(V (n + i) × Δt (n))

In the example of FIG. 4, the insulation life D (n) at the present time t (n) is calculated by the following equation as in the case of FIG.

D (n) = (Δt (n) × (i-1)) + (R (n + i-1) -K) / V (n + i)

According to the example of FIG. 4, the insulation resistance predictor 12 has current and past insulation resistance values R (n), R (n-1), R (n-2), calculated by the insulation resistance calculator 11. Based on ..., the predicted insulation resistance values R (n + 1), R (n + 2), ..., Which indicate the future insulation resistance values, can be calculated. The insulation resistance predictor 12 calculates the speed, acceleration, and jerk at which the insulation resistance value changes with time, and the insulation resistance prediction value R (n + 1), based on the insulation resistance value, speed, acceleration, and jerk. R (n + 2), ... Can be calculated. The insulation life predictor 13 has an insulation life D (n) indicating the remaining period until the insulation resistance predicted value becomes the threshold value K or less based on the insulation resistance predicted values R (n + 1), R (n + 2), ... Can be calculated.

According to the example of FIG. 4, by calculating the jerk of the insulation resistance value, the insulation resistance predicted value and the insulation life can be calculated with higher accuracy than in the case of FIG.

As described above, the display device 16 may display the temporal change of the insulation resistance predicted value from the present time to the time when the insulation resistance predicted value becomes equal to or less than the threshold value. In this case, the display device 16 may display a graph showing the predicted insulation resistance value with respect to time. By displaying such a graph, the user can recognize the tendency of deterioration of the insulation resistance.

In general, the insulation resistance value of the object to be measured is considered to gradually decrease as time passes from the start of use. However, depending on the environment in which the object to be measured is used, the insulation resistance value may temporarily increase due to vibration or the like. If the insulation life is calculated based on such a temporarily increased insulation resistance value, the insulation life may be calculated longer than the actual value. Next, with reference to FIG. 5, a method for reducing an error caused by a temporary increase in the insulation resistance value will be described.

FIG. 5 is a flowchart showing a modified example of the insulation resistance monitoring process executed by the processing device 10 of FIG.

In step S11, the processing device 10 determines whether or not the communication device 18 has received the trigger signal from the control device 9. If YES, the process proceeds to step S12, and if NO, the process repeats step S11.

In step S12, the insulation resistance calculator 11 calculates the current insulation resistance value, and displays the calculated insulation resistance value on the display device 16.

In step S13, the insulation resistance predictor 12 increases the insulation resistance value R (n) at the current time t (n) from the insulation resistance value R (n-1) calculated at the immediately preceding time point t (n-1). It is determined whether or not the test has been performed, and if YES, the process proceeds to step S16, and if NO, the process proceeds to step S14.

In step S14, the insulation resistance predictor 12 calculates the insulation resistance prediction value, stores the calculated insulation resistance prediction value in the storage device 14, and displays the calculated insulation resistance prediction value on the display device 16. ..

In step S15, the insulation life predictor 13 calculates the insulation life prediction value, stores the calculated insulation life in the storage device 14, and displays the calculated insulation life prediction value on the display device 16.

In step S16, the insulation resistance predictor 12 reads the insulation resistance prediction value from the storage device 14 and displays it on the display device 16.

In step S17, the insulation life predictor 13 reads the insulation life from the storage device 14 and displays it on the display device 16.

The insulation resistance predictor 12 and the insulation life predictor 13 also execute steps S16 to S17 instead of steps S14 to S15 when the insulation resistance value R (n) is equal to the insulation resistance value R (n-1). You may. As a result, the amount of calculation of the insulation resistance predictor 12 and the insulation life predictor 13 can be reduced.

According to the process of FIG. 5, when the current insulation resistance value is higher than the insulation resistance value calculated at the time immediately preceding the current time, the insulation resistance predictor 12 is calculated before the insulation resistance value is increased. The predicted insulation resistance value is displayed on the display device 16, and the insulation life predictor 13 sets the insulation life calculated before the insulation resistance value increases as the current insulation life. As a result, it is possible to reduce errors in the predicted insulation resistance value and the insulation life due to the temporary increase in the insulation resistance value.

[Effect of embodiment]
The insulation resistance value deteriorates over time due to environmental factors (temperature, humidity, dust) or mechanical factors (vibration, impact). In the past, it was confirmed that the measured insulation resistance value did not fall below the standard value. Therefore, there is a problem that the deterioration tendency with respect to the measurement period cannot be grasped, and the remaining period until the insulation resistance value falls below the reference value cannot be grasped.

According to the insulation resistance monitoring device 8 according to the embodiment, the insulation resistance predicted value can be calculated based on the current and past insulation resistance values, and the insulation life can be calculated based on the insulation resistance predicted value. Therefore, the insulation resistance monitoring device 8 can monitor the state of the insulation resistance so that it is easier to make a maintenance plan for the object to be measured than before.

[Other variants]
Although the embodiments of the present disclosure have been described in detail above, the above description is merely an example of the present disclosure in all respects. Needless to say, various improvements and modifications can be made without departing from the scope of the present disclosure. For example, the following changes can be made. In the following, the same reference numerals will be used for the same components as those in the above embodiment, and the same points as in the above embodiment will be omitted as appropriate. The following modifications can be combined as appropriate.

The output device that outputs the calculated insulation life is not limited to the display device 16, and may include a device that outputs aurally such as a speaker, or may include a remote device connected via a communication line.

The insulation resistance monitoring device 8 may be connected to any other object to be measured instead of the three-phase motor 3. The object to be measured includes, for example, a power supply device, a timer, a relay, a shared socket, a DIN rail, a waterproof cover, a temperature controller, a switch, and the like.

The insulation resistance monitoring device may be configured to generate an alarm signal when the rate at which the insulation resistance value changes with time exceeds a predetermined threshold value.

The insulation resistance monitoring device sets the insulation resistance value specified by law as the lower limit, sets the insulation resistance value first measured after starting the insulation resistance monitoring process as the upper limit, and sets the upper limit and lower limit. A value that divides the interval between the values at a predetermined ratio may be set as the threshold value of the insulation resistance value. As a result, it is possible to automatically set a threshold value in which a predetermined margin is added to the insulation resistance value determined by laws and regulations.

[summary]
The insulation resistance monitoring device according to each aspect of the present disclosure may be expressed as follows.

The insulation resistance monitoring device according to one aspect of the present disclosure monitors the insulation resistance of the object to be measured. In the insulation resistance monitoring device 8, the insulation resistance calculator 11 calculates the insulation resistance value of the object to be measured. The insulation resistance predictor 12 calculates an insulation resistance prediction value indicating a future insulation resistance value based on the current and past insulation resistance values calculated by the insulation resistance calculator 11. The insulation life predictor 13 calculates the insulation life indicating the remaining period until the insulation resistance predicted value becomes equal to or less than the threshold value based on the insulation resistance predicted value. The output device notifies the insulation life.

According to the insulation resistance monitoring device according to one aspect of the present disclosure, the insulation resistance predictor 12 calculates the speed and acceleration at which the insulation resistance value changes with time, and insulates based on the insulation resistance value, speed, and acceleration. Predicted resistance may be calculated.

According to the insulation resistance monitoring device according to one aspect of the present disclosure, the insulation resistance predictor 12 calculates the speed, acceleration, and jerk at which the insulation resistance value changes with time, and the insulation resistance value, speed, acceleration, and so on. And the predicted value of insulation resistance may be calculated based on the jerk.

According to the insulation resistance monitoring device according to one aspect of the present disclosure, when the current insulation resistance value increases from the insulation resistance value calculated at the time immediately preceding the current time, the insulation life predictor 13 has an insulation resistance value. The insulation life calculated before the increase may be set as the current insulation life.

According to the insulation resistance monitoring device according to one aspect of the present disclosure, the insulation resistance calculator 11 may calculate the insulation resistance value of the object to be measured in response to a control signal from the outside of the insulation resistance monitoring device 8. ..

According to the insulation resistance monitoring device according to one aspect of the present disclosure, the output device may include a display device 16. The display device 16 may display the insulation life, the current insulation resistance value, and the temporal change of the insulation resistance predicted value from the present time to the time when the insulation resistance predicted value becomes equal to or less than the threshold value.

The insulation resistance monitoring device according to one aspect of the present disclosure may further include an alarm 17 for notifying that the current insulation resistance value is equal to or less than the threshold value.

According to the insulation resistance monitoring device according to one aspect of the present invention, it is possible to monitor the state of insulation resistance so that it is easier to make a maintenance plan for the object to be measured than before.

1 Three-phase AC power supply 2 Circuit breaker 3 Three-phase motor 4 Zero-phase current transformer 5 Ground fault direction relay 6 Instrument transformer 7 Ground fault overvoltage relay 8 Insulation resistance monitoring device 9 Control device 10 Processing device 11 Insulation resistance calculator 12 Insulation resistance predictor 13 Insulation life predictor 14 Storage device 15 Comparer 16 Display device 17 Alarm device 18 Communication device L Power line

Claims (7)

An insulation resistance monitoring device that monitors the insulation resistance of the object to be measured.
An insulation resistance calculator that calculates the insulation resistance value of the object to be measured, and
An insulation resistance predictor that calculates an insulation resistance prediction value indicating a future insulation resistance value based on the current and past insulation resistance values calculated by the insulation resistance calculator.
An insulation life predictor that calculates the insulation life, which indicates the remaining period until the insulation resistance prediction value becomes equal to or less than the threshold value, based on the insulation resistance prediction value.
The output device for notifying the insulation life is provided.
Insulation resistance monitoring device. The insulation resistance predictor calculates the speed and acceleration at which the insulation resistance value changes with time, and calculates the insulation resistance prediction value based on the insulation resistance value, the speed, and the acceleration.
The insulation resistance monitoring device according to claim 1. The insulation resistance predictor calculates the speed, acceleration, and jerk at which the insulation resistance value changes over time, and predicts the insulation resistance based on the insulation resistance value, the speed, the acceleration, and the jerk. Calculate the value,
The insulation resistance monitoring device according to claim 1. When the current insulation resistance value increases from the insulation resistance value calculated immediately before the current time, the insulation life predictor presents the insulation life calculated before the insulation resistance value increases. Set as insulation life,
The insulation resistance monitoring device according to any one of claims 1 to 3. The insulation resistance calculator calculates the insulation resistance value of the object to be measured in response to a control signal from the outside of the insulation resistance monitoring device.
The insulation resistance monitoring device according to any one of claims 1 to 4. The output device includes a display device, and the display device is
With the insulation life
The current insulation resistance value and
The time change of the insulation resistance predicted value from the present time to the time when the insulation resistance predicted value becomes equal to or less than the threshold value is displayed.
The insulation resistance monitoring device according to any one of claims 1 to 5. Further equipped with an alarm for notifying that the current insulation resistance value is below the threshold value.
The insulation resistance monitoring device according to any one of claims 1 to 6.

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