JP2017173176A - Insulation resistance monitoring device, and monitoring method of the same, as well as electrically-driven control instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to easily conduct measurements with the same measurement accuracy as an insulation resistance meter's.SOLUTION: An insulation resistance monitoring device 10 comprises: a voltage generation circuit 54 that is connected to a ground line 34 of a motor M; a synthesis circuit 52 that converts a voltage via a power source line 32 of the motor to insulation resistance; and reference resistance 58 that is arranged between the synthesis circuit 52 and a step-down circuit 56. After a voltage generating by the voltage generation circuit 54 is applied to the ground line 34 to be divided, the voltage is stepped down by the step-down circuit 56, and the stepped-down voltage is input into a control unit 42. That is, a linear insulation resistance value corresponding to the input voltage is computed by a computation unit 44, and thus, the insulation resistance value to be computed becomes a value to be corrected so as to fall within a range approximate to a so-called actual measurement value (a synonym of [an allowable range]). Accordingly, the insulation resistance value of the motor corresponding to the input voltage to the control unit is the linear insulation resistance value to be corrected to the allowable range of the actual measurement value, and therefore, measurements are easily achieved with the almost same measurement accuracy as an insulation resistance meter's.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an insulation resistance monitoring device that monitors the insulation resistance of an object to be measured such as a heater or a motor, a monitoring control method thereof, and an electric control device.

  Patent Document 1 discloses an apparatus that can significantly reduce inspection man-hours by automatically monitoring insulation deterioration of a three-phase induction motor in a machine tool or the like and displaying an inspection result to the outside (summary). (See “Assignments”). That is, Patent Document 1 detects ON / OFF of whether or not electric power is supplied to a motor by a detection unit, and automatically measures an insulation resistance based on an OFF output from the detection unit. At this time, the degree of insulation deterioration of the motor is determined by comparing the measured insulation resistance value with a preset threshold value (see paragraph “0010”).

  Further, in Patent Document 1, if the measurement control unit performs control such that the measurement is performed a plurality of times while the motor is stopped and the measurement results are stored in the storage unit in time series, the operator can perform a plurality of measurement results. Information useful for motor management such as motor deterioration characteristics and progress patterns is obtained by referring to the history consisting of (see paragraph “0011”). Furthermore, since Patent Document 1 determines deterioration based on a plurality of measurement results, determination accuracy and reliability are improved compared to a case where determination is performed based on a single measurement result (paragraph number “0012”). reference).

  On the other hand, as a measuring instrument for measuring an insulation resistance value of a motor or the like, a mega tester (synonymous with “insulation resistance meter”) that performs measurement manually is used. Since the mega tester performs measurement by applying a high voltage measurement voltage to the motor, the measurement accuracy is good by approximating so-called actual measurement values.

JP 2004-251689 A

  By the way, in Patent Document 1, “It is preferable that the power supply for inspection is a direct current or alternating current with a small electromotive force of about several volts or a pulse power supply from the viewpoint of malfunction or measurement accuracy” (paragraph number “ 0023 "). That is, since the “inspection power supply is a small electromotive force of about several volts”, a weak current flows through the power line and the like, and it is considered that the measurement accuracy is lowered with such a weak current. .

  On the other hand, in the mega tester, measurement is performed by applying a high-voltage measurement voltage to the motor. If the motor power line is connected to an inverter or servo amplifier device, these control devices may be damaged during measurement. There is. That is, when a contact-type mega tester is used, since the motor power line described above is removed from the control device and measured, it takes a lot of time and labor depending on the equipment. For this reason, a technique as disclosed in Patent Document 1 has been disclosed, but its measurement accuracy is low.

  Accordingly, an object of the present invention is to provide an insulation resistance monitoring device, a monitoring control method thereof, and an electric control device that can be easily measured with substantially the same measurement accuracy as an insulation resistance meter.

  The insulation resistance monitoring device of the present invention is an insulation resistance monitoring device that monitors the insulation resistance of the object to be measured, and is connected to the power line of the object to be measured, and the voltage passing through the power line is Conversion means for converting to insulation resistance, voltage generation means connected to the ground wire of the object to be measured, step-down means for reducing the voltage applied to the exchange means connected to the conversion means, and the conversion means And a reference resistance arranged between the step-down means and a voltage obtained by dividing by the insulation resistance of the means to be measured and the reference resistance obtained by applying the voltage generated by the voltage generation means to the ground wire Is input via the step-down means, and a storage means that is stored in advance as a linear insulation resistance value in a linear algorithm in which the insulation resistance value based on the voltage is corrected to be within the allowable range of the actual measurement value; ,Up Based on the voltage input to the control unit comprises a calculating means for calculating a linear insulation resistance value of the storage means corresponding to the input voltage.

  According to the present invention, in the above-described insulation resistance monitoring apparatus, the safety means for keeping the voltage generating means off while the object to be measured is driven is configured such that the relay linked to the operation stop of the object to be measured is off. A first safety means for detecting whether or not, and an off signal from the first safety means and a second safety means for switching a control signal from the control means based on the off signal. Anyway. Furthermore, the present invention provides the above-described insulation resistance monitoring device, further comprising a timer for confirming the operation stop of the insulation resistance monitoring device, and the control means turns off the insulation resistance monitoring device based on the confirmation signal of the timer. May be.

  Further, according to the present invention, in each of the above-described insulation resistance monitoring devices, the conversion unit synthesizes each voltage passing through the plurality of power supply lines of the device under test into an overall insulation resistance of the device under test. It may be a combining means. Furthermore, the electric control device of the present invention may be an external control device in a built-in mode in which each of the above-described insulation resistance monitoring devices is integrated.

  The insulation resistance monitoring and control method of the present invention includes a voltage generating means connected to the ground wire of the device under test, a conversion means for converting a voltage passing through the power line of the device under test into an insulation resistance, In an insulation resistance monitoring device comprising a conversion means and a reference resistance arranged between a voltage reduction means for stepping down a voltage applied to the conversion means, an insulation resistance value based on the voltage is within a range that approximates an actual measurement value. Insulation resistance and reference resistance of the measured device obtained by applying the voltage generated by the voltage generating means to the ground wire, which is stored in advance as a linear insulation resistance value in a linear algorithm corrected so as to be The voltage obtained by voltage division is input to the control means via the step-down means, and based on the voltage input to the control means, the linear insulation resistance value of the storage means corresponding to the input voltage is obtained. Calculation means for calculating.

  In the present invention, a voltage obtained by dividing by the insulation resistance and the reference resistance of the device to be measured is input to the control device, and the calculation device calculates the linear insulation resistance value corresponding to this input voltage. The resistance value is a value that is corrected so as to be within a range approximate to a so-called actually measured value (synonymous with “allowable range”). That is, according to the present invention, since the insulation resistance value of the object to be measured corresponding to the input voltage of the control means is a linear insulation resistance value that is corrected to the allowable range of the actual measurement value, the measurement is substantially the same as the insulation resistance meter. It can be easily measured with accuracy.

It is a top view of the insulation resistance monitoring apparatus in a present Example. It is a circuit diagram regarding the insulation resistance monitoring apparatus shown in FIG. FIG. 3 is a timing chart of the circuit shown in FIG. 2. It is a flowchart figure regarding the monitoring mode of the insulation resistance monitoring apparatus shown in FIG. It is a subroutine figure regarding the measurement discrimination mode in the monitoring mode in FIG. It is a conceptual curve figure of the secular fall in the insulation resistance value of a motor as shown in FIG. FIG. 3 is a conceptual graph of voltage and insulation resistance divided before a step-down circuit as shown in FIG. 2. It is a measurement graph figure in insulation resistance value 0.1-10Mohm. It is a measurement graph figure in insulation resistance value 10-100Mohm. It is a measurement graph figure of the insulation resistance which connected Drawing 8 and Drawing 9. It is a measurement graph figure of the insulation resistance which correct | amended the connection vicinity of the curves in FIG. FIG. 3 is a graph of a linear voltage resistance conversion algorithm stored in the memory shown in FIG. 2. It is a calculation conceptual diagram of the linear insulation resistance value based on the linear algorithm shown in FIG.

  Hereinafter, a specific embodiment of a mode for carrying out the present invention will be described.

Hereinafter, based on FIG.1 and FIG.2, the insulation resistance monitoring apparatus 10 which is one Embodiment of this invention is demonstrated. The insulation resistance monitoring device 10 is a device that monitors the insulation resistance of an object to be measured. The object to be measured here is a single phase or a plurality of phases such as a three-phase motor M and a heater. In other words, the insulation resistance monitoring device 10 is a so-called mega tester measurement type monitoring device, and is connected to the external control device S shown in FIG.
(Schematic configuration of insulation resistance monitoring device)

As shown in FIG. 1, the insulation resistance monitoring device 10 is detachably connected to the monitoring device main body 12 with an electric wire 20 (see FIG. 2) such as a monitoring wire. The monitoring device main body 12 is provided with a display 14 and a plurality of lighting devices 16 on its display surface 12A, and signal lines (not shown) are connected to both ends (upper and lower sides in FIG. 1) of the display surface 12A. A plurality of terminals 18 are arranged. In addition, the monitoring apparatus main body 12 has a box shape of a substantially one hand size.
(Configuration of control system of insulation resistance monitoring device)

  As shown in FIG. 2, the insulation resistance monitoring device 10 includes a CPU (central processing unit) 40 that is a control unit and a calculation unit, a synthesis circuit 52 that is a synthesis unit (also means “conversion unit”), a voltage A voltage generation circuit 54 serving as a generation unit, a step-down circuit 56 serving as a step-down unit, a reference resistor 58, and a power supply circuit 38 are provided. Here, the power supply circuit 38 in the insulation resistance monitoring apparatus 10 that supplies power for starting up the CPU 40 and the like is a so-called insulation type, and is separated from the voltage generation circuit 54 by the ground. The wiring of the power supply circuit 38 is not shown except for the portion connected to the CPU 40. This is to prevent complication when connecting a plurality of wires to each electronic component other than the CPU 40.

The insulation resistance monitoring apparatus 10 includes a display circuit 64 for displaying numerical values and the above-described indicator 14, a lighting circuit 66 for lighting each color, and the above-described lighting device 16. Based on the CPU 40, the lighting device 16 or the display device 14 is turned on or displayed, or turned off or not displayed.
(Configuration related to conversion means or composition means)

  As shown in FIG. 2, the external control device S is configured to be mounted and controlled with, for example, a three-phase induction motor (hereinafter also simply referred to as “motor”) M, and therefore, a motor driver for the motor M. 30 is connected. Three power lines 32 are connected between the motor driver 30 and the motor M, respectively, and the motor M and the motor driver 30 are grounded by ground wires 34 and 36, respectively. That is, the ground wire 36 of the motor driver 30 is connected to the ground wire 34 of the motor M.

  On the other hand, the electric wire 20 is connected to the ground wire 36 and the voltage generation circuit 54 that generates, for example, DC (direct current) 500V or 250V, and the electric power generated by the voltage generation circuit 54 is transmitted to the motor driver 30 via the ground wire 36. Supplied to. In general, the motor driver 30 frequency-converts power from a three-phase AC power source (not shown) of the external control device S and supplies the driving power to the motor M to drive-control the motor M.

  The synthesizing circuit 52 and the three power supply lines 32 which are conversion means or synthesizing means are connected to each other via three monitoring lines (synonymous with “electric wires”) 20, and the synthesizing circuit 52 has three windings. Combining each leakage current generated in the line. That is, the voltage passing through the three power supply lines 32 in the motor M to be measured is combined and converted (synonymous with “transformation”) by combining the respective leakage currents via the combining circuit 52 having a resistor (not shown). )

The combined leakage current flows to the ground through a resistor (not shown) in the combining circuit 52, and the voltage applied to the resistor (not shown) at that time is divided by the reference resistor 58 shown in FIG. The voltage applied to the step-down circuit 56 is stepped down to 1/100, for example, 5 to 0V. In the case of a single-phase motor or heater, for example, there is no need to synthesize leakage current because there is only one power line 32. In other words, the synthesis circuit 52 in this case can be said to be a conversion means, that is, a conversion circuit. In this embodiment, the measurable range may be changed by changing the reference resistance 58.
(Configuration related to safety measures)

  As shown in FIG. 2, the insulation resistance monitoring apparatus 10 includes a safety circuit 60 that is a first safety means and an AND circuit 62 that is a second safety means. First, the safety circuit 60 that keeps the voltage generation circuit 54 off during the operation of the external control device S (that is, driving of the motor M) is based on the off check (Off Chck) signal from the external control device S. The auxiliary contact configuration is linked to the stoppage of S.

  That is, in the safety circuit 60, when the variable (magnet) relay, which is an auxiliary contact that is off during the operation of the external control device S, is stopped (ie, the signal output from the external control device S). It is set to be off. And CPU40 detects that the external control apparatus S (namely, motor M) is a stop mode by the OFF signal of the safety circuit 60 being input.

Next, the AND circuit 62 is provided as a switching circuit as a hardware safety measure (synonymous with “correspondence”) other than simple signal communication of the CPU 40. That is, the monitoring device 10 is set so that both the off signal of the safety circuit 60 and the confirmation signal from the CPU 40 based on the off signal of the safety circuit 60 are switched to turn on the voltage generation circuit 54. .
(Configuration related to CPU 40)

  The CPU 40 shown in FIG. 2 includes a control unit 42 that constitutes a part of the control means, a computation part 44 that constitutes a part of the computation means, a memory 46 that is a storage means, and A that converts analog to digital. / D48 and timer 50 are incorporated. The CPU 40 is set to generate a confirmation signal based on the count value of the timer 50 after detecting the off signal (that is, the motor stop signal) from the safety circuit 60.

  Based on this confirmation signal, the control unit 42 of the CPU 40 outputs an AND signal to the AND circuit 62. The timer 50 of the CPU 40 is also used as an interlock (meaning “start-up guarantee” of the insulation resistance monitoring apparatus 10 itself so as not to accept an operation preparation signal from the external control device S during measurement), and the CPU 40 is an AND circuit. An AND-off signal for turning off 62 is output, and the timer 50 is turned on / off to turn off the interlock. That is, according to the present embodiment, it is possible to prevent any unforeseen situation (synonymous with “malfunction”) during communication of various signals, so that erroneous measurement can be avoided and the external control device S and insulation resistance can be monitored. Failure of the device 10 is prevented.

  The step-down circuit 56 has a voltage Vo obtained by dividing the voltage Vin generated by the voltage generation circuit 54 by the insulation resistance value Rm of the motor M obtained by applying the voltage Vin to the ground wire 34 and the reference resistance value Rref of the reference resistance 58. Entered. As an expression, Vo = Vin × (Rref / (Rm / Rref)). This voltage Vo is stepped down by the step-down circuit 56 and input to the control unit 42 of the CPU 40. And this control part 42 calculates the linear insulation resistance (refer FIG. 13) value corresponding to the input voltage Vo based on the input voltage Vo.

In the memory 46, for example, an insulation resistance value Rm of the motor M based on the input voltage Vo corresponds to a linear insulation resistance value corresponding to a linear voltage resistance conversion algorithm (hereinafter also simply referred to as “linear algorithm”) as shown in FIG. Are stored in advance. Further, the memory 46 stores a program for controlling various processes such as the monitoring process in the insulation resistance monitoring apparatus 10. The CPU 40 governs the overall operation of the insulation resistance monitoring device 10. For example, when an operation preparation signal is input to the CPU 40, the CPU 40 performs monitoring processing based on the operation preparation signal.
(Configuration related to the interface)

  As shown in FIG. 2, the insulation resistance monitoring apparatus 10 includes an operation preparation signal (indicated as “S” of the signal in FIG. 3) input unit 70 as an interface I / F, a measurement signal output unit 72, A device abnormality signal output unit 74 and a resistance lowering signal output unit 76 are provided. And these input part 70, output part 72, etc. are each connected to the terminal which is not illustrated of external control equipment S which is electric control equipment, such as FA equipment, for example. The external control device S can be integrated with the insulation resistance monitoring device 10 or the like (hereinafter also referred to as “embedding mode”) and can be adapted to various devices.

The external control device S includes various switches (not shown), a display device such as a lamp, and an alarm device such as a buzzer. When the external control device S is operated, for example, by pressing an operation switch (not shown) of the insulation resistance monitoring device 10, an operation switch signal (synonymous with “operation preparation signal”) is output to the insulation resistance monitoring device 10 shown in FIG. 2. It is configured to be. Therefore, this operation switch signal is input to the operation preparation signal input unit 70 of the insulation resistance monitoring device 10, and when the external control device S is stopped, the above-described operation stop signal of the external control device S is input to the safety circuit 60.
(Operation of this embodiment)

  The operation of the insulation resistance monitoring apparatus 10 and the monitoring process of the CPU 40 will be described mainly using the timing chart shown in FIG. 3 and the flowcharts shown in FIGS. 4 and 5. The monitoring process of the CPU 40 is executed by loading a program when an operation preparation signal is input. The processing routine to be executed is represented by the flowcharts of FIGS. 4 and 5, and these programs are stored in advance in the program area of the memory 46 (see FIG. 2).

  First, when a power switch (not shown) of the external control device S shown in FIG. 2 is turned on, as shown in FIG. 3, the power of the insulation resistance monitoring device 10 is input (rises) and the insulation resistance monitoring device 10 measures. A medium signal (S) is output (starts up) to the external control device S. After that, the operation resistance signal (S) from the external control device S is input (rises) to the insulation resistance monitoring device 10 and the off check signal (S) is also input (rises).

  That is, in step 100 shown in FIG. 4, it is determined whether or not an operation preparation signal is input. If step 100 is positive, that is, if an operation preparation signal is input, it is determined in step 101 whether the safety circuit 60 (see FIG. 2) has been turned off. Specifically, it is determined whether or not an off signal of the safety circuit 60 based on the off check signal from the external control device S is input to the CPU 40.

  When step 100 or step 101 is negative, it waits for the input of each signal, that is, an operation preparation signal or an off signal. Here, as shown in FIG. 3, the equipment of the external control device S is in operation until the operation preparation signal input falls (also “off check signal input” at the same time). Therefore, the insulation resistance monitoring apparatus 10 shown in FIG. 2 uses the timer 50 in order to ensure a sufficient time until the motor M stops rotating.

  That is, as shown in FIG. 3, the CPU 40 starts counting the timer 50 when the operation preparation signal and the off signal described above fall. Then, when a predetermined count value T1 (for example, a count value for 2 seconds) is reached, the CPU 40 causes the measuring signal to fall and starts counting by the timer 50 (see step 102).

  In step 104 shown in FIG. 4, the CPU 40 determines whether or not the timer 50 is a predetermined count value T2 (for example, a count value for 1.5 seconds). If step 104 is negative, it waits for a predetermined time (synonymous with “count value”) to elapse. On the other hand, if step 104 is positive, the CPU 40 outputs an AND signal (synonymous with “confirmation signal”) to the AND circuit 6 in step 106 and outputs an interlock signal to the external control device S or the like in step 108.

  Thereafter, in step 110, the CPU 40 determines whether or not the voltage generation circuit 54 is on. That is, when the AND signal and the OFF signal from the safety circuit 60 (see FIG. 2) are respectively input to the AND circuit 62, the voltage generation circuit 54 is turned ON and the DC 500V insulated in the insulation resistance monitoring device 10 is supplied. (Or DC 250V or the like) is generated (synonymous with “generation”) for a predetermined time (for example, 2 seconds).

  That is, when step 110 is affirmative, the CPU 40 causes the voltage generation circuit 54 to output a voltage (rise) when the timer 50 reaches the count value T2 as shown in FIG. In this case, the CPU 40 turns on the lighting device (location “measurement” shown in FIG. 1) 16 in step 112. Then, the CPU 40 causes the voltage generating circuit 54 to generate a voltage over the predetermined count value T3 (as described above, the count value for 2 seconds).

  Further, the CPU 40 blinks the display dots on the display 14 while counting the count value T3. On the other hand, the CPU 40 stops (falls) the voltage generation of the voltage generation circuit 54 and at the same time raises a signal or the like to display a measured value (step 135, etc.) as will be described later or output an insulation lowering signal. (Step 134).

  Further, as shown in FIG. 3, the measurement time TS is preset (synonymous with “program”) in the memory 46 so as to be a total value of the count values T2 to T4, for example, 5 seconds. Then, the CPU 40 stops outputting the in-measurement signal for the measurement time TS. If step 110 is negative, the process waits until the voltage generation circuit 54 is turned on. Further, as described above, the voltage generation circuit 54 stops generating (falls) after the count value T3 has elapsed.

  Next, in step 114, the CPU 40 determines whether or not it is a regular measurement (for example, voltage DC 500V). If step 114 is negative, an NG signal is output to the external control device S via the device abnormality signal output unit 74 shown in FIG. 2 in step 116, and the process proceeds to end processing described later. That is, if step 114 is negative, the measured voltage is not normal, and the CPU 40 shown in FIG. 2 displays this fact on the external control device S and ends.

  On the other hand, if step 114 is positive, the process proceeds to the measurement discrimination mode (see “subroutine” shown in FIG. 5) in step 118. Next, the migration process will be described. As shown in FIG. 5, the CPU 40 determines in step 130 whether or not the resistance value is 100 MΩ or more. If step 130 is positive, that is, if the resistance value is 100 MΩ or more, the CPU 40 displays, for example, Hi on the display 14 shown in FIG.

  If step 130 is negative, that is, if the resistance value is 100 MΩ or less, it is determined in step 132 whether the resistance value is in the range of 99 to 1 MΩ. When step 132 is affirmative, that is, within the range of 99 to 1 MΩ, the resistance value (MΩ) calculated by the calculation unit 44 of the CPU 40 is displayed on the display unit 14 at step 135.

  Here, calculation processing of the resistance value MΩ in the calculation unit 44 (a concept including “calculation data” and the like) will be described. First, as shown in FIG. 6, the motor insulation resistance is, for example, when the elapsed time of the motor (such as the time due to deterioration due to mist or the like entering the motor due to environmental changes or the like) has passed about one year. It suddenly drops. The vertical axis in FIG. 6 is the insulation resistance value (MΩ), and the horizontal axis is the elapsed time.

  Further, as shown in FIG. 7, the relationship between the voltage (Vo) and the insulation resistance (MΩ) is such that the output voltage Vo is low when the insulation resistance is high according to experimental data considering the characteristics of the circuit (see FIG. 2). On the other hand, when the insulation resistance is high, the output voltage Vo becomes a value close to the applied voltage of 500V. The basic algorithm is created by measuring a reference resistor that can be varied from 0.1 MΩ to 199.9 MΩ in a 0.1 MΩ step. In FIG. 7, the vertical axis represents the output voltage (Vo), and the horizontal axis represents the insulation resistance value (MΩ).

  That is, the insulation resistance measurement algorithm (graph) based on the experimental data as described above is created by dividing the above-described 0.1 MΩ to 99.9 MΩ into two parts, for example, as shown in FIGS. 8 and 9. Draw a curve. 8 and 9, the horizontal axis represents the input voltage (V) to the A / D, and the vertical axis represents the insulation resistance value (MΩ). When the two are connected and combined, the broadband insulation resistance measurement algorithm becomes a curve as shown in FIG.

  In this curve (basic) algorithm, the measurement accuracy should be taken into consideration in the vicinity of the junction of the curves in FIGS. 8 and 9 (around voltage 2.15 V) (see FIG. 10). Then, the linear algorithm as shown in FIG. 11 is within a range (synonymous with “allowable range”) that approximates the actual measurement value based on experimental data or the like in order to ensure the measurement accuracy of the above-described joining range. The following correction was made. In FIG. 11, the horizontal axis represents the input voltage V to A / D, and the vertical axis represents the insulation resistance value (Ω).

  Specifically, a linearity voltage resistance conversion algorithm as shown in FIG. 12 is stored in the memory 46 shown in FIG. 2, and the control unit 42 and the calculation unit 44 calculate the insulation resistance value based on this linear algorithm. . Therefore, in this embodiment, the CPU 40 calculates a linear insulation resistance (see FIG. 13) value corresponding to the input voltage Vo based on the input voltage Vo. For example, when 1.85 V (or 0, 47 V) is input as an input voltage to the A / D 48 shown in FIG. 7 (see FIG. 12), the linear voltage resistance conversion stored in the memory 46 by the calculation unit 44 is performed. The insulation resistance value of the motor M is corrected and converted to 40 MΩ (or 10 MΩ) based on an algorithm (a method different from the threshold value or the calculation formula).

  As shown in FIG. 13, when 1.88 V (or 0, 49 V) or the like is an input voltage, the insulation resistance value is corrected and converted to 40 MΩ (or 10 MΩ) or the like. Here, the CPU 40 has a capability of measuring a resistance value at a resolution of 0.1 MΩ in 10 bits (1024 gradations). This measurement range is 100 MΩ maximum to 0.1 MΩ minimum, and when 4.9 V (or 0,005 V) is the input voltage (see FIG. 13), the insulation resistance value is 100 MΩ or more (or 0. 1 MΩ).

  If the corrected insulation resistance value is calculated by the calculation unit 44 to be 100 MΩ or more, the CPU 40 displays Hi on the display unit 14, and if the insulation resistance value is calculated to be 0.1 MΩ, the CPU 40 displays Low on the display unit 14. Is displayed. Then, after the processing of step 131 and step 135 shown in FIG. 5 is completed, in step 136, the CPU 40 outputs a normal signal. That is, the lighting device 16 (a portion in the normal range) shown in FIG.

  If step 132 is negative, that is, outside the range of 99 to 1 MΩ, the CPU 40 displays low on the display unit 14 as described above, and at step 134 the insulation lowering signal is shown in FIG. The external control device S is output via the output unit 76 (see FIG. 3). That is, according to the present embodiment, the external control device S can automatically determine the quality of the motor M through communication with the insulation resistance monitoring device 10, and the external control device S can manage the monitoring history. In addition, when the process of step 136 and step 134 is complete | finished, the process of this subroutine is complete | finished.

  Returning to the flowchart shown in FIG. 4, after the processing of step 116 or step 118 is completed, an AND-off signal is output to the AND circuit 62 (see FIG. 2) in step 120, and a lock-off timer (shown in FIG. 2) is displayed in step 112. (Same as “Timer 50”). In step 124, the CPU 40 determines whether or not the lock-off timer is a count value.

  If step 124 is positive, a lock-off signal (synonymous with “confirmation signal”) is output to the external control device S or the like in step 126. And when the process of step 126 is complete | finished, the process of this flowchart is complete | finished. If step 124 is negative, the process waits for a predetermined time (synonymous with “count value”) to elapse. In addition, the measurement discrimination mode shown in FIG. 4 is repeated every predetermined time if, for example, the timer 50 (see FIG. 2) is set to be performed every predetermined time. That is, the above-described program processing flow (see FIGS. 4 and 5) is an example, and can be changed as appropriate without departing from the gist of the present invention.

  In the present embodiment, as described above, the voltage obtained by dividing by the insulation resistance of the motor M and the reference resistor 58 is input to the control unit 42, and the calculation unit 44 calculates the linear insulation resistance value corresponding to this input voltage. Therefore, the calculated insulation resistance value is a value that is corrected so as to be within a range approximate to the actually measured value (synonymous with “allowable range”). That is, according to the present embodiment, since the insulation resistance value of the motor M corresponding to the input voltage of the control unit 42 is a linear insulation resistance value corrected to an allowable range of the actual measurement value, it is substantially the same as the insulation resistance meter. It can be easily measured with measurement accuracy.

  DESCRIPTION OF SYMBOLS 10 ... Insulation resistance monitoring apparatus, 20 ... Monitoring line, 32 ... Power supply line, 34, 36 ... Ground wire, 40 ... CPU, 42 ... Control part (control means), 44 ... Calculation part (calculation means), 46 ... Memory ( Storage means), 50 ... timer, 52 ... compositing circuit (conversion means or combining means), 54 ... voltage generating circuit (voltage generating means), 56 ... voltage step-down circuit (voltage reducing means), 58 ... reference resistor, 60 ... safety circuit ( (First safety means), 62 ... AND circuit (second safety means), S ... external control device (electric control device), M ... motor (measurement object)

Claims (6)

An insulation resistance monitoring device for monitoring the insulation resistance of an object to be measured,
Conversion means for converting a voltage connected to the power line of the device under test and passing through the power line into an insulation resistance of the device under test;
Voltage generating means connected to the ground wire of the object to be measured;
A step-down means for stepping down a voltage applied to the exchange means connected to the conversion means;
A reference resistor disposed between the converting means and the step-down means;
Control means for inputting a voltage obtained by dividing the voltage generated by the voltage generating means to the ground wire by the insulation resistance of the means to be measured and the reference resistance, which is input via the step-down means;
Storage means pre-stored as a linear insulation resistance value in a linear algorithm corrected so that the insulation resistance value based on the voltage is within an allowable range of the actual measurement value;
An insulation resistance monitoring device, comprising: a computing means for computing a linear insulation resistance value of the storage means corresponding to the input voltage based on a voltage inputted to the control means. The insulation resistance monitoring device according to claim 1,
Safety means for keeping the voltage generating means off while the object to be measured is driven includes: first safety means for detecting whether a relay linked to the operation stop of the object to be measured is turned off; An insulation resistance monitoring device comprising: an off signal from a first safety means and a second safety means for switching a control signal from the control means based on the off signal.   3. The insulation resistance monitoring device according to claim 1 or 2, further comprising a timer for confirming operation stop of the insulation resistance monitoring device, wherein the control means turns off the insulation resistance monitoring device based on a confirmation signal of the timer. Insulation resistance monitoring device.   The insulation resistance monitoring apparatus according to any one of claims 1 to 3, wherein the conversion unit converts each voltage passing through a plurality of power lines of the device under test as a whole in the device under test. Insulation resistance monitoring device which is also a synthesis means for synthesizing into the insulation resistance of.   The electric control apparatus which is an external control apparatus of the assembly mode which integrates the insulation resistance monitoring apparatus of any one of Claim 1 thru | or 4 integrally. Voltage generating means connected to the earth wire of the device under test, conversion means for converting the voltage passing through the power line of the device under test into insulation resistance, the conversion means and the voltage applied to the conversion means In an insulation resistance monitoring device comprising a reference resistor arranged between step-down means for stepping down,
The insulation resistance value based on the voltage is stored in the storage means in advance as a linear insulation resistance value in a linear algorithm corrected so as to be within a range that approximates the actual measurement value,
A voltage obtained by dividing the voltage generated by the voltage generating means with the insulation resistance of the means to be measured and the reference resistance obtained by applying the voltage to the ground wire is input to the control means via the step-down means,
An insulation resistance monitoring and control method in which the computing means computes the linear insulation resistance value of the storage means corresponding to the input voltage based on the voltage inputted to the control means.

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