JP2017173263A - Insulation resistance measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow for measuring insulation resistance while a DC circuit is in operation without changing connections of the DC circuit.SOLUTION: An insulation resistance measurement device comprises; a measurement unit configured to measure a positive pole/earth potential difference, or a potential difference between a positive pole and earth with a first resistor connected therebetween, and a negative pole/earth potential difference, or a potential difference between a negative pole and earth with a second resistor connected therebetween, of a DC circuit having a grounded neutral point between the positive pole and the negative pole; and an acquisition unit configured to acquire a value related to insulation resistance of the DC circuit based on a result of the measurement made by the measurement unit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an insulation resistance measuring apparatus.

  Conventionally, a technique for measuring the insulation resistance of a DC circuit in a state where the DC circuit is operating is known.

Japanese Patent Laid-Open No. 7-63801

However, in the conventional technique, in order to measure the insulation resistance of the DC circuit, an ammeter may be connected in series between the positive electrode and the ground or between the negative electrode and the ground. For this reason, in the prior art, in order to measure the insulation resistance of the DC circuit, it may be necessary to change the connection of the DC circuit during operation. Here, when the configuration of the circuit in operation is changed, the circuit may be damaged due to an error in the change work or the like.
The present invention has been made in view of the above points, and provides an insulation resistance measuring device that measures insulation resistance without changing the connection of a DC circuit when the DC circuit is in an operating state. Objective.

  One aspect of the present invention relates to a DC circuit in which a neutral point of a positive electrode and a negative electrode is grounded to the ground, and the positive electrode and the ground in a state where a first resistor is connected between the positive electrode and the ground. A measurement unit that measures a positive electrode-to-ground potential difference that is a potential difference, and a negative electrode-to-ground potential difference that is a potential difference between the negative electrode and the ground in a state where a second resistor is connected between the negative electrode and the ground; An acquisition unit that acquires a value related to an insulation resistance of the DC circuit based on a measurement result measured by the measurement unit.

  In the insulation resistance measuring apparatus according to one aspect of the present invention, whether or not a convergence condition is satisfied for at least one of the positive electrode-to-ground potential difference and the negative electrode-to-ground potential difference, which are measurement results measured by the measurement unit. A convergence determination unit that determines whether or not the measurement result is determined by the convergence determination unit to satisfy a convergence condition, and acquires a value related to an insulation resistance of the DC circuit.

  ADVANTAGE OF THE INVENTION According to this invention, when a DC circuit is an operation state, the insulation resistance measuring apparatus which measures insulation resistance can be provided, without changing the connection of a DC circuit.

It is a figure which shows an example of a structure of the DC circuit of 1st Embodiment. It is a figure which shows an example of the connection of the DC circuit of 1st Embodiment, and an insulation resistance measuring apparatus. It is a figure which shows an example of a structure of the insulation resistance measuring apparatus of 1st Embodiment. It is the 1st figure showing the outline of the direct-current circuit of a 1st embodiment. It is a 2nd figure which shows the outline | summary of the DC circuit of 1st Embodiment. It is a 3rd figure which shows the outline | summary of the DC circuit of 1st Embodiment. It is a flowchart which shows an example of operation | movement of the insulation resistance measuring apparatus of 1st Embodiment. It is a figure which shows an example of a structure of the insulation resistance measuring apparatus of 2nd Embodiment. It is a graph which shows an example of time transition of the positive electrode resistance potential difference of a 2nd embodiment. It is a figure which shows an example of a structure of the insulation resistance measuring apparatus of 3rd Embodiment. It is a figure which shows an example of a structure of the insulation resistance measuring apparatus of the modification 1. It is a figure which shows the table | surface showing an example of the acquisition information of the modification 1. It is a figure which shows an example of a structure of the insulation resistance measuring apparatus of the modification 2.

[First Embodiment: Description of Configuration of DC Circuit]
Hereinafter, the configuration of a DC circuit to be measured by which the insulation resistance measuring apparatus 1 of the present embodiment measures the insulation resistance will be described with reference to the drawings.
FIG. 1 is a diagram illustrating an example of the configuration of the DC circuit DCC according to the first embodiment.
The DC circuit DCC of the present embodiment is a circuit that operates with a DC voltage supplied from the AC / DC converter BC. The AC / DC converter BC is a device that converts AC power supplied to the AC / DC converter BC into DC power.
Specifically, as shown in FIG. 1, the positive electrode terminal of the AC / DC converter BC and the positive electrode BSP of the bus BS are connected. Further, the negative electrode terminal of the AC / DC converter BC and the negative electrode BSN of the bus BS are connected.
In the following description, the positive electrode of the DC circuit DCC is also referred to as a positive electrode BSP. The negative electrode of the DC circuit DCC is also referred to as the negative electrode BSN.

  A storage battery BTT is connected to the bus BS. In the normal state where the AC / DC converter BC supplies power via the bus BS, the storage battery BTT stores the power supplied from the AC / DC converter BC. Further, when the supply of power from the AC / DC converter BC is cut off due to a disaster or the like, the storage battery BTT supplies a DC voltage to the bus BS by discharging the power stored in the storage battery BTT.

A plurality of circuits are connected to the bus BS. A DC voltage is supplied to the plurality of circuits from the AC / DC converter BC or the storage battery BTT via the bus BS.
Specifically, as shown in FIG. 1, a circuit C1, a circuit C2,..., A circuit Cn are connected to the bus BS. n is an integer of 2 or more. In the following description, when the circuit C1, the circuit C2,..., The circuit Cn are not distinguished, they are collectively referred to as a circuit C. The circuit C1, the circuit C2, the circuit Cn, and the bus BS are connected via the switch JB. The switch JB is a breaker that cuts off an overcurrent flowing into the circuit C from the AC / DC converter BC or the storage battery BTT via the bus BS, for example.

Specifically, the positive terminal of the circuit C1 and the positive terminal BSP of the bus BS are connected via a switch JBC1P. Further, the negative terminal of the circuit C1 and the negative electrode BSN of the bus BS are connected via a switch JBC1N. Further, the positive terminal of the circuit C2 and the positive electrode BSP of the bus BS are connected via a switch JBC2P. The negative terminal of the circuit C2 and the negative terminal BSN of the bus BS are connected via a switch JBC2N. In addition, the positive terminal of the circuit Cn and the positive electrode BSP of the bus BS are connected via a switch JBCnP. Further, the negative terminal of the circuit Cn and the negative terminal BSN of the bus BS are connected via a switch JBCnN. In the following description, the switch JBC1P, the switch JBC1N, the switch JBC2P, the switch JBC2N, the switch JBCnP, and the switch JBCnN are collectively referred to as the switch JB.
Thereby, a DC voltage is supplied to the circuit C from the AC / DC converter BC or the storage battery BTT via the bus BS. The circuit C operates with a DC voltage supplied from the AC / DC converter BC or the storage battery BTT via the bus BS.

  Although the case where the circuit C connected to the bus BS is a plurality of circuits C has been described above, the present invention is not limited to this. There may be one or more circuits C connected to the bus BS.

  In the following description, the potential difference between the positive electrode and the negative electrode of the DC voltage supplied by the AC / DC converter BC or the storage battery BTT is referred to as a positive electrode-negative electrode potential difference VPN. That is, the potential difference between the positive electrode BSP and the negative electrode BSN of the bus BS is the positive electrode-negative electrode potential difference VPN. Here, the positive electrode-negative electrode potential difference VPN is, for example, 110V.

[Configuration of DC ground fault relay]
A DC ground fault relay 64D is connected to the positive electrode BSP and the negative electrode BSN of the bus BS. The DC ground fault relay 64D is a device that issues an alarm when the insulation resistance of the DC circuit DCC drops to a predetermined value.
The DC ground fault relay 64D includes a voltage dividing resistor Rd1, a voltage dividing resistor Rd2, and a grounding resistor Re.

  The voltage dividing resistor Rd1 and the voltage dividing resistor Rd2 are connected in series between the positive electrode BSP and the negative electrode BSN of the bus BS. The positive / negative potential difference VPN, which is the potential difference between the positive electrode BSP and the negative electrode BSN of the bus BS, is divided by the voltage dividing resistor Rd1 and the voltage dividing resistor Rd2. The voltage value at the connection point of the voltage dividing resistor Rd1 and the voltage dividing resistor Rd2 is determined by the ratio of the resistance values of the voltage dividing resistor Rd1 and the voltage dividing resistor Rd2. In the following description, a connection point between the voltage dividing resistor Rd1 and the voltage dividing resistor Rd2 is referred to as a neutral point CP.

  The voltage dividing resistor Rd1 and the voltage dividing resistor Rd2 have the same resistance value. For example, the voltage dividing resistor Rd1 and the voltage dividing resistor Rd2 are both 2 kΩ. As a result, the positive / negative potential difference VPN is divided into 1: 1 by the voltage dividing resistor Rd1 and the voltage dividing resistor Rd2. The potential difference between the positive electrode BSP and the neutral point CP and the potential difference between the negative electrode BSN and the neutral point CP are the same potential difference. That is, the positive / negative electrode potential difference VPN is divided by half from the neutral point CP to the positive electrode BSP side and from the neutral point CP to the negative electrode BSN side.

Further, the neutral point CP is grounded via the ground resistance Re and the test terminal TT. The grounding resistor Re is, for example, a 10 kΩ resistor. The test terminal TT is a terminal for connecting and disconnecting the neutral point CP and the ground G in order to perform test measurement of the control device and electric circuit of the DC circuit DCC. Specifically, the test terminal TT can cut the neutral point CP and the ground G by inserting the test plug TPG into the test terminal TT.
The neutral point CP is grounded with high resistance to the ground G through a grounding resistor Re. That is, the DC circuit DCC is a non-grounded circuit that does not ground the AC / DC converter BC and the negative terminals of the storage battery BTT.

  As described above, the positive / negative potential difference VPN is 110V. The AC / DC converter BC and the storage battery BTT supply a DC voltage having a positive / negative potential difference VPN of 110 V to the circuit C via the bus BS. Further, the voltage value of the positive electrode BSP when the neutral point CP is used as a reference is + 55V. The voltage value of the negative electrode BSN when the neutral point CP is used as a reference is -55V.

[Insulation resistance of DC circuit]
When the DC circuit DCC has the above-described configuration, the insulation resistance of the DC circuit DCC is a combined resistance of a resistance between the circuit C and the ground G and a resistance between the bus BS circuit and the ground G. is there.

The insulation resistance of the circuit C is a resistance between the electric circuit of the circuit C and the ground G. Specifically, the resistance between the electric circuit of the circuit C1 and the ground G is between the circuit positive insulation resistance RPC1 between the positive terminal of the circuit C1 and the ground G, and between the negative terminal of the circuit C1 and the ground G. It is a circuit negative electrode insulation resistance RNC1. The resistance between the circuit C2 circuit and the ground G is such that the circuit positive insulation resistance RPC2 between the positive terminal of the circuit C2 and the ground G, and the circuit negative insulation between the negative terminal of the circuit C2 and the ground G. Resistor RNC2. In addition, the resistance between the circuit Cn circuit and the ground G includes circuit positive insulation resistance RPCn between the positive terminal of the circuit Cn and the ground G, and circuit negative insulation between the negative terminal of the circuit Cn and the ground G. Resistor RNCn.
In the following description, when the circuit positive insulation resistance RPC1, the circuit positive insulation resistance RPC2 and the circuit positive insulation resistance RPCn are not distinguished, they are described as circuit positive insulation resistance RPC. In the following description, when the circuit negative electrode insulation resistance RNC1, the circuit negative electrode insulation resistance RNC2, and the circuit negative electrode insulation resistance RNCn are not distinguished, they are described as the circuit negative electrode insulation resistance RNC.

The insulation resistance of the bus BS is a resistance between the electric circuit of the bus BS and the ground G.
Specifically, the resistance between the electric circuit of the bus BS and the ground G is between the bus positive insulation resistance RPBS between the positive electrode BSP of the bus BS and the ground G, and between the negative electrode BSN of the bus BS and the ground G. It is a bus negative electrode insulation resistance RNBS.

Therefore, the insulation resistance between the positive terminal of the DC circuit DCC and the ground G is a positive insulation resistance RP that is a combined resistance of the circuit positive insulation resistance RPC and the bus positive insulation resistance RPBS. Further, the insulation resistance between the negative terminal of the DC circuit DCC and the ground G is a negative insulation resistance RN that is a combined resistance of the circuit negative insulation resistance RNC and the bus negative insulation resistance RNBS.
In the following description, when the positive electrode insulation resistance RP of the DC circuit DCC and the negative electrode insulation resistance RN are not distinguished, they are described as the insulation resistance R of the DC circuit DCC. That is, the insulation resistance R of the DC circuit DCC is the positive insulation resistance RP and the negative insulation resistance RN.
When the DC circuit DCC is in a normal state in which no deterioration or the like occurs in the DC circuit DCC, the insulation resistance R has a resistance value of about several MΩ to several hundred MΩ. Therefore, when the DC circuit DCC is in a normal state in which no deterioration occurs, the voltage dividing resistor Rd1, the voltage dividing resistor Rd2, and the insulation resistance R have a sufficiently larger resistance value. In addition, the ground resistance Re and the insulation resistance R have a sufficiently large resistance value.

[Reduction of insulation resistance of DC circuit]
Here, the insulation resistance R may decrease due to some problem such as deterioration of the DC circuit DCC. When the resistance value of the insulation resistance R decreases, the balance of 1: 1 changes between the potential difference between the positive electrode BSP and the neutral point CP and the potential difference between the negative electrode BSN and the neutral point CP. In the case of this example, in the DC circuit DCC, 55V which is the voltage value of the positive electrode BSP when the neutral point CP is the reference, and -55V which is the voltage value of the negative electrode BSN when the neutral point CP is the reference. The balance changes. Specifically, when the positive electrode insulation resistance RP is deteriorated, the voltage value of the positive electrode BSP when the neutral point CP is used as a reference decreases, and the voltage value of the negative electrode BSN when the neutral point CP is used as a reference Rises. Similarly, when the negative electrode insulation resistance RN is deteriorated, the voltage value of the positive electrode BSP increases when the neutral point CP is used as a reference, and the voltage value of the negative electrode BSN decreases when the neutral point CP is used as a reference. To do.
If the state in which the insulation resistance R of the DC circuit DCC is lowered is left unattended, the DC circuit DCC may cause breakdown or burnout due to dielectric breakdown.
Therefore, in order to prevent dielectric breakdown of the DC circuit DCC, it is effective to quantitatively measure and manage the insulation resistance R of the DC circuit DCC.
Hereinafter, a configuration in which the insulation resistance measuring apparatus 1 of the present embodiment measures the insulation resistance R of the DC circuit DCC will be described.

[Connection between DC circuit and insulation resistance measuring device]
Hereinafter, the connection between the DC circuit DCC and the insulation resistance measuring apparatus 1 will be described with reference to the drawings.
FIG. 2 is a diagram illustrating an example of the connection between the DC circuit DCC and the insulation resistance measuring apparatus 1 according to the first embodiment.
As shown in FIG. 2, the insulation resistance measuring apparatus 1 is connected to a terminal block TB included in the DC circuit DCC. The terminal block TB includes a positive terminal TP, a negative terminal TN, and a ground terminal TE. A positive electrode BSP is connected to the positive electrode terminal TP. Further, the negative electrode BSN is connected to the negative electrode terminal TN. The ground terminal TE is grounded to the ground G. Therefore, the positive electrode BSP, the negative electrode BSN, and the ground G are connected to the insulation resistance measuring apparatus 1 via the terminal block TB.
The insulation resistance measuring device 1 is a portable device. The insulation resistance measuring apparatus 1 is used by a measurer of the insulation resistance R that circulates in an equipment room or the like where the DC circuit DCC is installed. The insulation resistance measuring apparatus 1 is connected to the DC circuit DCC by a measurer via a terminal block TB provided in the DC circuit DCC.
When the insulation resistance measuring apparatus 1 measures the insulation resistance R of the DC circuit DCC, the connection of the test terminal TT is changed. Specifically, when the insulation resistance measuring apparatus 1 measures the insulation resistance R of the DC circuit DCC, the neutral point CP and the ground G are disconnected by inserting the test plug TPG into the test terminal TT. .

  In the above description, the insulation resistance measuring device 1 is a portable device, and a case where a measurer who measures the insulation resistance R of the DC circuit DCC is a device connected to the DC circuit DCC at the time of measurement will be described. However, it is not limited to this. The insulation resistance measuring apparatus 1 may be permanently installed in an equipment room or the like where the DC circuit DCC is installed. In this case, the insulation resistance measuring apparatus 1 may measure the insulation resistance R related to the insulation resistance R of the DC circuit DCC constantly or periodically.

[Configuration of insulation resistance measuring device]
Hereinafter, the configuration of the insulation resistance measuring apparatus 1 will be described with reference to FIG.
FIG. 3 is a diagram illustrating an example of the configuration of the insulation resistance measuring apparatus 1 according to the first embodiment.
As shown in FIG. 3, the insulation resistance measuring apparatus 1 includes a control unit 100, a measurement unit 150, a first positive electrode side switch SP1, a first negative electrode side switch SN1, an insertion positive electrode resistor RIP, and an insertion negative electrode resistance. RIN and a start information input unit 160 are provided.

  The start information input unit 160 is connected to the control unit 100. The start information input unit 160 outputs start information SI indicating the start of measurement of the insulation resistance R to the control unit 100. The start information input unit 160 is, for example, a switch. Specifically, when start information input unit 160 is pressed by a measurer of insulation resistance R of DC circuit DCC, start information input unit 160 outputs start information SI to control unit 100.

  The positive terminal TP is connected to the measuring unit 150 via the first positive switch SP1. Moreover, the negative electrode terminal TN is connected to the measurement unit 150 via the first negative electrode side switch SN1. The first positive electrode side switch SP1 and the first negative electrode side switch SN1 are, for example, relays. The ground terminal TE is connected to the measurement unit 150. Opening and closing of the first positive electrode side switch SP1 and the first negative electrode side switch SN1 is controlled by the control unit 100.

The inserted positive electrode resistor RIP and the inserted negative electrode resistor RIN are resistors whose resistance values are known. Further, the inserted positive electrode resistor RIP and the inserted negative electrode resistor RIN are resistors used for measuring voltage. The inserted positive electrode resistance RIP and the inserted negative electrode resistance RIN are used to measure the voltage at a location where the voltage is required to be measured when the insulation resistance measuring apparatus 1 acquires the value of the insulation resistance R of the DC circuit DCC. .
In the following description, the potential difference between the potential of the positive electrode BSP and the potential of the ground G is referred to as a positive electrode-ground potential difference VP. The potential difference between the potential of the negative electrode BSN and the potential of the ground G is referred to as a negative electrode-to-ground potential difference VN.
The inserted positive electrode resistance RIP is used when measuring the positive electrode vs. ground potential difference VP. The inserted negative electrode resistance RIN is used when measuring the negative electrode-to-ground potential difference VN.
In the following description, the inserted positive electrode resistance RIP is also referred to as a first resistance. Further, the inserted negative electrode resistance RIN is also referred to as a second resistance.
Further, in the following description, when the inserted positive electrode resistance RIP and the inserted negative electrode resistance RIN are not distinguished, they are described as the insertion resistance RI.

The inserted positive electrode resistor RIP is connected to the ground G. Further, the insertion positive electrode resistor RIP is connected to the positive electrode BSP via the first positive electrode side switch SP1.
Specifically, the inserted positive electrode resistor RIP includes two terminals, a terminal tIP1 and a terminal tIP2. The terminal tIP1 of the insertion positive electrode resistance RIP, the first positive electrode side switch SP1, and the measurement unit 150 are connected. Further, the terminal tIP2 of the inserted positive electrode resistor RIP and the ground terminal TE are connected.
Further, the insertion negative resistance RIN is connected to the ground G. Further, the insertion positive electrode resistor RIP is connected to the negative electrode BSN via the first negative electrode side switch SN1.
Specifically, the insertion negative resistance RIN includes two terminals, a terminal tIN1 and a terminal tIN2. The terminal tIN1 of the insertion negative resistance RIN, the first negative switch SN1, and the measurement unit 150 are connected. The terminal tIN2 of the insertion negative resistance RIN and the ground terminal TE are connected.

The inserted positive electrode resistance RIP and the inserted negative electrode resistance RIN have the same resistance value. The insertion positive electrode resistance RIP and the insertion negative electrode resistance RIN are, for example, 2 MΩ.
The inserted positive electrode resistor RIP and the inserted negative electrode resistor RIN may have a resistance value other than 2 MΩ. Specifically, the inserted positive electrode resistance RIP and the inserted negative electrode resistance RIN may be resistance values that are threshold values for determining the quality of the insulation resistance R of the DC circuit DCC.

The measurement unit 150 measures the positive electrode ground potential difference VP as the positive electrode resistance potential difference RVP when the inserted positive electrode resistor RIP is connected between the positive electrode terminal TP and the ground terminal TE. Further, the measuring unit 150 measures the negative electrode-to-ground potential difference VN as the negative electrode resistance potential difference RVN when the inserted negative electrode resistor RIN is connected between the negative electrode terminal TN and the ground terminal TE.
The measurement unit 150 outputs the measured positive electrode resistance potential difference RVP and negative electrode resistance potential difference RVN to the acquisition unit 110.

  The measurement unit 150 is, for example, an analog / digital conversion circuit. The measuring unit 150 measures the potential difference between the positive terminal TP and the negative terminal TN and the ground terminal TE, converts the potential difference into a digital signal indicating the measured result, and outputs the digital signal to the control unit 100.

The control unit 100 includes a CPU (Central Processing Unit), and includes an acquisition unit 110 as its functional unit.
The acquisition unit 110 starts processing in response to the start information SI being input from the start information input unit 160. Specifically, the acquisition unit 110 controls the opening and closing of the first positive electrode side switch SP1 and the first negative electrode side switch SN1 in response to the start information SI being input.
The acquisition unit 110 outputs a positive electrode side opening / closing control signal SPS for controlling the opening / closing of the first positive electrode side switch SP1 to the first positive electrode side switch SP1. The opening and closing of the first positive electrode side switch SP1 is controlled based on the positive electrode side opening / closing control signal SPS input from the acquisition unit 110.
Moreover, the acquisition part 110 outputs the negative electrode side opening / closing control signal SNS which controls opening / closing of 1st negative electrode side switch SN1 to 1st negative electrode side switch SN1. The opening and closing of the first negative electrode side switch SN1 is controlled based on the negative electrode side opening / closing control signal SNS input from the acquisition unit 110.

The acquisition unit 110 receives the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN from the measurement unit 150 in accordance with the opening / closing of the first positive electrode side switch SP1 and the first negative electrode side switch SN1. The acquisition unit 110 acquires a value related to the insulation resistance R of the DC circuit DCC based on the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN. The values relating to the insulation resistance R are the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN input from the measurement unit 150, the value calculated by the acquisition unit 110 and acquired, and the value of the positive electrode-to-negative electrode potential difference VPN and the positive electrode insulation resistance RP The value of the resistor RN.
Hereinafter, details of the positive electrode resistance potential difference RVP, the negative electrode resistance potential difference RVN, and the positive electrode-negative electrode potential difference VPN input from the measurement unit 150 to the acquisition unit 110 will be described.

[Input of positive resistance potential difference]
Hereinafter, a case where the positive electrode resistance potential difference RVP is input from the measurement unit 150 to the acquisition unit 110 will be described.

The acquisition unit 110 controls the first positive electrode side switch SP1 to a closed state, and controls the first negative electrode side switch SN1 to an open state. Specifically, the acquisition unit 110 outputs a positive electrode side opening / closing control signal SPS for controlling the first positive electrode side switch SP1 to a closed state. Moreover, the acquisition part 110 outputs the negative electrode side opening / closing control signal SNS which controls 1st negative electrode side switch SN1 to an open state.
1st positive electrode side switch SP1 is controlled by a closed state, and 1st negative electrode side switch SN1 is controlled by an open state. In this case, an insertion positive resistance RIP is connected between the positive terminal TP and the ground terminal TE.

In the following description, a state in which the first positive electrode side switch SP1 is controlled to be closed and the first negative electrode side switch SN1 is controlled to be in an open state is referred to as a first state. When the first positive electrode side switch SP1 and the first negative electrode side switch SN1 are controlled to the first state, the inserted positive electrode resistance RIP is connected in parallel with the positive electrode insulation resistance RP between the positive electrode terminal TP and the ground terminal TE. The
The measuring unit 150 is applied to the inserted positive electrode resistor RIP connected in parallel with the positive electrode insulation resistance RP in response to the first positive electrode side switch SP1 and the first negative electrode side switch SN1 being controlled to the first state. The positive electrode resistance potential difference RVP is measured. The measurement unit 150 outputs the measured positive electrode resistance potential difference RVP to the acquisition unit 110.

Hereinafter, an outline of the positive electrode resistance potential difference RVP will be described with reference to FIG.
FIG. 4 is a first diagram illustrating an outline of the DC circuit DCC of the first embodiment. Specifically, FIG. 4 is a diagram illustrating the DC circuit DCC when the first positive electrode side switch SP1 and the first negative electrode side switch SN1 are controlled to the first state.
As described above, when the first positive electrode side switch SP1 and the first negative electrode side switch SN1 are controlled to the first state, the inserted positive electrode resistor RIP is connected between the positive electrode terminal TP and the ground terminal TE. Is done.
The measurement unit 150 outputs the positive electrode resistance potential difference RVP to the acquisition unit 110 in response to the first positive electrode side switch SP1 and the first negative electrode side switch SN1 being controlled to the first state. The acquisition unit 110 receives the positive electrode resistance potential difference RVP from the measurement unit 150.

[Input of negative resistance potential difference]
Hereinafter, a case where the negative electrode resistance potential difference RVN is input from the measurement unit 150 to the acquisition unit 110 will be described.
Returning to FIG. 3, the acquisition unit 110 controls the first negative electrode side switch SN <b> 1 to a closed state and controls the first positive electrode side switch SP <b> 1 to an open state. Specifically, the acquisition unit 110 outputs a negative electrode side opening / closing control signal SNS that controls the first negative electrode side switch SN1 to be in a closed state. Further, the acquisition unit 110 outputs a positive electrode side opening / closing control signal SPS that controls the first positive electrode side switch SP1 to be in an open state.
The first positive electrode side switch SP1 is controlled to be in an open state, and the first negative electrode side switch SN1 is controlled to be in a closed state. In this case, the insertion negative resistance RIN is connected between the negative terminal TN and the ground terminal TE.

In the following description, a state in which the first positive electrode side switch SP1 is controlled to be in an open state and the first negative electrode side switch SN1 is controlled in a closed state is referred to as a second state. When the first positive electrode side switch SP1 and the first negative electrode side switch SN1 are controlled to the second state, the inserted negative electrode resistance RIN is connected in parallel with the negative electrode insulation resistance RN between the negative electrode terminal TN and the ground terminal TE. The
The measuring unit 150 is applied to the inserted negative electrode resistor RIN connected in parallel with the negative electrode insulation resistance RN in response to the first positive electrode side switch SP1 and the first negative electrode side switch SN1 being controlled to the second state. The negative electrode resistance potential difference RVN is measured. The measurement unit 150 outputs the measured negative electrode resistance potential difference RVN to the acquisition unit 110.

The outline of the negative electrode resistance potential difference RVN will be described below with reference to FIG.
FIG. 5 is a second diagram illustrating an outline of the DC circuit DCC of the first embodiment. Specifically, FIG. 5 is a diagram illustrating the DC circuit DCC when the first positive electrode side switch SP1 and the first negative electrode side switch SN1 are controlled to the second state.
As described above, when the first positive electrode side switch SP1 and the first negative electrode side switch SN1 are controlled to the second state, the insertion negative electrode resistor RIN is connected between the negative electrode terminal TN and the ground terminal TE. Is done.
The measurement unit 150 outputs the negative electrode resistance potential difference RVN to the acquisition unit 110 in response to the first positive electrode side switch SP1 and the first negative electrode side switch SN1 being controlled to the second state. A negative resistance potential difference RVN is input from the measurement unit 150 to the acquisition unit 110.

[Acquisition of potential difference between positive electrode and negative electrode]
Hereinafter, a case where the acquisition unit 110 calculates and acquires the positive / negative electrode potential difference VPN based on the input from the measurement unit 150 will be described.
Returning to FIG. 3, the acquisition unit 110 controls the first positive electrode side switch SP <b> 1 to a closed state and controls the first negative electrode side switch SN <b> 1 to a closed state. Specifically, the acquisition unit 110 outputs a positive electrode side opening / closing control signal SPS for controlling the first positive electrode side switch SP1 to a closed state. Moreover, the acquisition part 110 outputs the negative electrode side opening / closing control signal SNS which controls 1st negative electrode side switch SN1 to a closed state.
Thereby, 1st positive electrode side switch SP1 is controlled by a closed state, and 1st negative electrode side switch SN1 is controlled by a closed state. In this case, an insertion positive resistance RIP is connected between the positive terminal TP and the ground terminal TE. In this case, the insertion negative resistance RIN is connected between the negative terminal TN and the ground terminal TE.

  In the following description, the state in which the first positive electrode side switch SP1 is controlled to be closed and the first negative electrode side switch SN1 is controlled to be in the closed state is referred to as a third state. That is, when the first positive electrode side switch SP1 and the first negative electrode side switch SN1 are controlled to the third state, the inserted positive electrode resistor RIP is connected between the positive electrode terminal TP and the ground terminal TE, and the negative electrode terminal TN An insertion negative resistance RIN is connected between the ground terminal TE.

Hereinafter, an outline of the positive / negative potential difference VPN will be described with reference to FIG.
FIG. 6 is a third diagram illustrating an outline of the DC circuit DCC of the first embodiment. Specifically, FIG. 3 is a diagram illustrating the DC circuit DCC when the first positive electrode side switch SP1 and the first negative electrode side switch SN1 are controlled to the third state.
As described above, when the first positive electrode side switch SP1 and the first negative electrode side switch SN1 are controlled to the third state, the insertion positive electrode resistor RIP is connected between the positive electrode terminal TP and the ground terminal TE. Is done. Further, the first negative electrode side switch SP1 and the first negative electrode side switch SN1 are controlled to be in the third state, whereby the insertion negative electrode resistor RIN is connected between the negative electrode terminal TN and the ground terminal TE.
The measurement unit 150 outputs the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN to the acquisition unit 110 in response to the first positive electrode side switch SP1 and the first negative electrode side switch SN1 being controlled to the third state. . The acquisition unit 110 receives the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN from the measurement unit 150. The acquisition unit 110 calculates the sum of the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN based on the input positive electrode resistance potential difference RVP and negative electrode resistance potential difference RVN. The acquisition unit 110 acquires the sum of the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN as a value indicating the positive electrode-negative electrode potential difference VPN.

The acquisition unit 110 acquires the insulation resistance R based on the acquired positive electrode resistance potential difference RVP in the first state, negative electrode resistance potential difference RVN in the second state, and positive electrode-negative electrode potential difference VPN in the third state.
Hereinafter, a configuration in which the acquisition unit 110 acquires the value of the insulation resistance R will be described.

[Acquisition of insulation resistance]
As described above, the acquisition unit 110 is based on the positive electrode resistance potential difference RVP in the first state, the negative electrode resistance potential difference RVN in the second state, and the positive electrode-negative electrode potential difference VPN in the third state input from the measurement unit 150. The insulation resistance R of the DC circuit DCC is acquired. Specifically, the acquisition unit 110 performs insulation on the positive electrode BSP side of the DC circuit DCC based on the positive electrode resistance potential difference RVP in the first state, the negative electrode resistance potential difference RVN in the second state, and the positive electrode-negative electrode potential difference VPN in the third state. The value of the positive electrode insulation resistance RP that is the resistance R is acquired. In addition, the acquisition unit 110 calculates the insulation resistance R on the negative electrode BSN side of the DC circuit DCC based on the positive electrode resistance potential difference RVP in the first state, the negative electrode resistance potential difference RVN in the second state, and the positive electrode-negative electrode potential difference VPN in the third state. The value of a certain negative electrode insulation resistance RN is acquired.

In the following description, the voltage value of the positive electrode-negative electrode potential difference VPN in the third state is described as Vpn. The voltage value of the positive electrode resistance potential difference RVP in the first state is described as Vp. Further, the voltage value of the negative electrode resistance potential difference RVN in the second state is described as Vn. The value of the positive electrode insulation resistance RP is described as Rp. Moreover, the value of the negative electrode insulation resistance RN is described as Rn.
Further, as described above, the inserted positive electrode resistor RIP and the inserted negative electrode resistor RIN have the same resistance value. In the following description, the resistance value of the inserted positive electrode resistor RIP and the inserted negative electrode resistor RIN is denoted as R.

  A relational expression among Rp, Vp, Vn, and Vpn is expressed by Expression (1).

  The relational expression among Rn, Vp, Vn, and Vpn is expressed by Expression (2).

As described above, the acquisition unit 110 acquires Vp and Vn. Further, the acquisition unit 110 calculates Vpn based on the acquired Vp and Vn. Also, the insertion positive resistance RIP and the insertion negative resistance RIN, which are the insertion resistance RI, are both 2 MΩ. Therefore, Vp, Vn, Vpn, and R are known values in the expressions (1) and (2).
The acquisition unit 110 calculates Rp, which is the resistance value of the positive electrode insulation resistance RP of the DC circuit DCC. In addition, the acquisition unit 110 calculates Rn that is a resistance value of the negative electrode insulation resistance RN of the DC circuit DCC. Thereby, the acquisition unit 110 acquires a value related to the insulation resistance R.

[Operation of insulation resistance measuring device]
Hereinafter, the operation of the insulation resistance measuring apparatus 1 will be described with reference to FIG.
FIG. 7 is a flowchart showing an example of the operation of the insulation resistance measuring apparatus 1 of the first embodiment.
As illustrated in FIG. 7, the start information input unit 160 outputs the start information SI to the acquisition unit 110 (step S100). The acquisition unit 110 determines whether or not the start information SI is input from the start information input unit 160 (step S110). The acquisition unit 110 holds the current state until the start information SI is input from the start information input unit 160 (step S110; NO). If the acquisition unit 110 acquires the start information SI from the start information input unit 160 (step S110; YES), the acquisition unit 110 advances the process to step S120. The acquisition unit 110 outputs a positive-side switching control signal SPS and a negative-side switching control signal SNS that control the first positive-side switch SP1 and the first negative-side switch SN1 to the first state (step S120). The measurement unit 150 measures the positive electrode resistance potential difference RVP in response to the first positive electrode side switch SP1 and the first negative electrode side switch SN1 being controlled to the first state, and outputs it to the acquisition unit 110 (step S130). ). The acquisition unit 110 receives the positive electrode resistance potential difference RVP from the measurement unit 150 (step S140).

  The acquisition unit 110 outputs a positive-side switching control signal SPS and a negative-side switching control signal SNS that control the first positive-side switch SP1 and the first negative-side switch SN1 to the second state (step S150). The measurement unit 150 measures the negative electrode resistance potential RVN in response to the first positive electrode side switch SP1 and the first negative electrode side switch SN1 being controlled to the second state and outputs the negative resistance potential difference RVN to the acquisition unit 110 (step S160). ). The acquisition unit 110 receives the negative resistance potential difference RVN from the measurement unit 150 (step S170).

  The acquisition unit 110 outputs a positive-side switching control signal SPS and a negative-side switching control signal SNS that control the first positive-side switch SP1 and the first negative-side switch SN1 to the third state (step S180). The measurement unit 150 measures the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN in response to the first positive electrode side switch SP1 and the first negative electrode side switch SN1 being controlled to the third state, and acquires the acquisition unit 110. (Step S190). The acquisition unit 110 receives the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN from the measurement unit 150 (step S195).

  The acquisition unit 110 calculates the sum of the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN based on the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN input in the third state (step S200). The acquisition unit 110 acquires the calculated sum of the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN as a value indicating the positive electrode-negative electrode potential difference VPN. The acquisition unit 110 calculates the value of the positive electrode insulation resistance RP based on the acquired positive electrode resistance potential difference RVP in the first state, negative electrode resistance potential difference RVN in the second state, and positive electrode-negative electrode potential difference VPN in the third state (step S210). ). Further, the acquisition unit 110 calculates the value of the negative electrode insulation resistance RN based on the acquired positive electrode resistance potential difference RVP in the first state, negative electrode resistance potential difference RVN in the second state, and positive electrode-negative electrode potential difference VPN in the third state ( Step S220).

[Summary of First Embodiment]
As described above, the insulation resistance measuring apparatus 1 of the present embodiment includes the first positive electrode side switch SP1, the first negative electrode side switch SN1, the measurement unit 150, the control unit 100, and the insertion resistance RI. Prepare.
The insulation resistance measuring apparatus 1 is an apparatus that measures the insulation resistance R of a DC circuit DCC having a configuration in which a neutral point CP between the positive electrode BSP and the negative electrode BSN is grounded to the ground G.
The control unit 100 includes a CPU, and includes an acquisition unit 110 as its functional unit. The acquisition unit 110 controls opening and closing of the first positive electrode side switch SP1 and the first negative electrode side switch SN1.

The measurement unit 150 measures a positive electrode resistance potential difference RVP that is a potential difference between the positive electrode BSP and the ground G in a state where the inserted positive electrode resistance RIP is connected between the positive electrode BSP and the ground G.
In addition, the measurement unit 150 measures a negative electrode resistance potential difference RVN that is a potential difference between the negative electrode BSN and the ground G in a state where the insertion negative resistance RIN is connected between the negative electrode BSN and the ground G.
The acquisition unit 110 receives the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN measured by the measurement unit 150 in the first state, the second state, and the third state.

The acquisition unit 110 acquires a value related to the insulation resistance R of the DC circuit DCC based on the measurement result measured by the measurement unit 150.
Specifically, the acquisition unit 110 acquires the positive electrode resistance potential difference RVP in the first state and the negative electrode resistance potential difference RVN in the second state, which are values related to the insulation resistance R, from the measurement unit 150. In addition, the acquisition unit 110 acquires the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN in the third state, and calculates the sum of the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN. The acquisition unit 110 acquires the sum of the calculated positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN as a positive electrode-negative electrode potential difference VPN that is a value related to the insulation resistance R. The acquisition unit 110 is a value related to the insulation resistance R based on the acquired positive electrode resistance potential difference RVP in the first state, negative electrode resistance potential difference RVN in the second state, and positive electrode-negative electrode potential difference VPN in the third state. The values of the positive electrode insulation resistance RP and the negative electrode insulation resistance RN are calculated. Thereby, the acquisition unit 110 acquires a value related to the insulation resistance R.

Here, in the conventional technique, when the measurer measures the insulation resistance of the DC circuit, the measurer may be required to manually connect and disconnect the insertion resistor to the DC circuit.
Therefore, in the conventional technique, it may be difficult for a measurer who measures the insulation resistance of a DC circuit to reduce the trouble of manually changing the connection of the DC circuit.

According to the insulation resistance measuring apparatus 1 of the present embodiment, the connection of the insertion resistor RI to the DC circuit DCC can be automatically switched. Specifically, the connection of the first positive electrode side switch SP1 and the first negative electrode side switch SN1 can be switched by the control of the acquisition unit 110. Thereby, the acquisition unit 110 can automatically acquire the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN.
According to the insulation resistance measuring apparatus 1 of the present embodiment, the insulation resistance R of the DC circuit DCC can be automatically acquired. That is, according to the insulation resistance measuring apparatus 1 of the present embodiment, it is possible to reduce the trouble of manually changing the connection of the insulation resistance R of the DC circuit DCC.

In the conventional technique, the inserted positive electrode resistor and the inserted negative electrode resistor may be configured by one resistor. Specifically, in the conventional technique, there is a case where the connection of a certain insertion resistor is appropriately changed and the positive electrode-to-ground potential difference and the negative electrode-to-ground potential difference are measured. In this case, there is a case where the positive and negative electrodes of the DC circuit are short-circuited by mistakenly connecting the insertion resistor.
Therefore, in the conventional technique, it is difficult to prevent the DC circuit from being damaged due to an operation error of an operator who connects the insertion resistor to the DC circuit.

The insulation resistance measuring apparatus 1 of this embodiment includes two insertion resistors RI. Specifically, the insulation resistance measuring apparatus 1 includes an inserted positive electrode resistance RIP and an inserted negative electrode resistance RIN. Further, the connection between the inserted positive electrode resistor RIP and the inserted negative electrode resistor RIN is controlled by the first positive electrode side switch SP1 and the first negative electrode side switch SN1. The insulation resistance measuring device 1 of the present embodiment has a configuration in which the positive electrode BSP and the negative electrode BSN are not short-circuited regardless of whether the first positive electrode side switch SP1 and the first negative electrode side switch SN1 are in the open / closed state. .
According to the insulation resistance measuring apparatus 1 of this embodiment, it is possible to prevent the DC circuit DCC from being damaged due to an operation error when the insertion resistor RI is connected to the DC circuit DCC.

[Second Embodiment: Convergence Determination]
As described above, the DC circuit DCC is connected to various facilities including the circuit C and the DC ground fault fault relay 64D. The various facilities are, for example, filters for removing noise such as external noise and rectifier ripple. Various facilities have a capacitance according to their characteristics. Therefore, the DC circuit DCC has a capacitance according to the characteristics of various facilities connected to the DC circuit DCC.
Further, as described in the first embodiment, the insulation resistance measuring apparatus 1 measures the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN using the inserted positive electrode resistance RIP and the inserted negative electrode resistance RIN, and the positive electrode-negative electrode potential difference VPN. Is calculated. Further, the insulation resistance measuring apparatus 1 acquires a value related to the insulation resistance R based on the measured positive electrode resistance potential difference RVP, negative electrode resistance potential difference RVN, and calculated positive electrode-negative electrode potential difference VPN.

Here, depending on the resistance value of the insertion resistor RI, a transient phenomenon due to the capacitance of the DC circuit DCC may affect fluctuations in the values of the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN. Specifically, a transient phenomenon may affect and it may take time until the values of the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN converge to a constant value after the insertion resistor RI is connected to the DC circuit DCC. More specifically, as the resistance values of the inserted positive electrode resistance RIP and the inserted negative electrode resistance RIN are larger, it may take time until the values of the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN converge.
In this case, depending on the timing at which the measurement unit 150 outputs the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN to the acquisition unit 110, the value related to the insulation resistance R acquired by the insulation resistance measurement device 1 may change.
Hereinafter, a configuration will be described in which the insulation resistance measuring apparatus 2 of the second embodiment accurately measures a value related to the insulation resistance R even when a transient phenomenon occurs in the DC circuit DCC.

[Configuration of insulation resistance measuring device]
The second embodiment of the present invention will be described below with reference to the drawings.
FIG. 8 is a diagram illustrating an example of the configuration of the insulation resistance measuring apparatus 2 according to the second embodiment.
In the first embodiment, the case where the acquisition unit 110 acquires a value related to the insulation resistance R based on the positive electrode resistance potential difference RVP, the negative electrode resistance potential difference RVN, and the calculated positive electrode-negative electrode potential difference VPN input from the measurement unit 150 has been described. .
The insulation resistance measuring apparatus 2 according to the second embodiment is the first in that the measurement unit 150 measures the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN after determining the convergence of the transient phenomenon due to the capacitance of the DC circuit DCC. Different from the embodiment.
Also in the insulation resistance measuring apparatus 1 of the first embodiment, it is possible to obtain a value related to the insulation resistance R. When a transient phenomenon occurs in the DC circuit DCC, the insulation resistance measurement device 1 of the first embodiment and the insulation resistance measurement device 2 of the second embodiment are more accurate with respect to the insulation resistance R. The value can be obtained.
In addition, about the structure similar to 1st Embodiment mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 8, the insulation resistance measuring apparatus 2 includes a control unit 200, a measurement unit 150, a first positive electrode side switch SP1, a first negative electrode side switch SN1, an insertion positive electrode resistor RIP, and an insertion negative electrode resistance. RIN and a start information input unit 160 are provided.
The start information input unit 160 is connected to the control unit 200.
The control unit 200 includes a CPU, and includes an acquisition unit 110 and a convergence determination unit 210 as functional units.
The start information input unit 160 outputs start information SI indicating the start of measurement of the insulation resistance R to the acquisition unit 110 provided in the control unit 200.

The acquisition unit 110 starts processing in response to the start information SI being input from the start information input unit 160. Specifically, the acquisition unit 110 changes the first positive electrode side switch SP1 and the first negative electrode side switch SN1 to the first state, the second state, and the third state in response to the start information SI being input. Control.
In response to the first positive electrode side switch SP1 and the first negative electrode side switch SN1 being controlled to the first state, the acquisition unit 110 supplies the positive electrode resistance potential difference RVP input from the measurement unit 150 to the convergence determination unit 210. Output. Further, the acquisition unit 110 determines the negative resistance potential difference RVN input from the measurement unit 150 in response to the first positive electrode side switch SP1 and the first negative electrode side switch SN1 being controlled to the second state. Output to 210.

[Details of convergence judgment unit]
The convergence determination unit 210 receives the positive resistance potential difference RVP in the first state and the negative resistance potential difference RVN in the second state from the acquisition unit 110. The convergence determination unit 210 converges when the change in the value due to the transient phenomenon of the input positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN converges, and when the change beyond a predetermined value is not observed, the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference. It is determined that RVN has converged.

Hereinafter, with reference to FIG. 9, details of the determination by which the convergence determination unit 210 determines the convergence of the positive electrode resistance potential difference RVP in the first state will be described.
FIG. 9 is a graph illustrating an example of a time transition of the positive electrode resistance potential difference RVP of the second embodiment.
A waveform WRVP represents a time transition of the value of the positive electrode resistance potential difference RVP in the first state with respect to the ground G.
Hereinafter, a case where the convergence determination unit 210 determines the convergence of the positive electrode resistance potential difference RVP in the first state input from the acquisition unit 110 will be described as an example. The convergence determination unit 210 performs the same determination for the determination of the convergence of the negative electrode resistance potential difference RVN in the second state input from the acquisition unit 110. Further, regarding the positive electrode-negative electrode potential difference VPN and the positive electrode-negative electrode potential difference VPN in the third state, the acquisition unit 110 does not output the convergence determination unit 210, and the convergence determination unit 210 does not determine convergence.

As described above, the measurement unit 150 measures the positive electrode resistance potential difference RVP in the first state.
Further, as described above, it may take time until the values of the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN converge to a constant value after the insertion resistor RI is connected to the DC circuit DCC. Specifically, as shown in FIG. 9, the value of the waveform WRVP indicating the time transition of the positive electrode resistance potential difference RVP converges as time elapses. More specifically, the waveform WRVP converges to a potential difference convergence value RVPC that is a value obtained by converging the positive electrode resistance potential difference RVP after a predetermined time has elapsed. The predetermined time is, for example, from when the inserted positive electrode resistance RIP is connected between the positive electrode BSP and the ground G or between the negative electrode BSN and the ground G until the electric charge is charged in the capacitance of the DC circuit DCC. It's time. The potential difference convergence value RVPC is a value of the positive electrode resistance potential difference RVP when electric charge is charged in the capacitance of the DC circuit DCC.

In the convergence determination unit 210, the positive resistance potential difference RVP output from the measurement unit 150 in response to the first positive electrode side switch SP1 and the first negative electrode side switch SN1 being controlled to the first state is obtained via the acquisition unit 110. Is input. Here, the time when the positive electrode resistance potential difference RVP is input from the acquisition unit 110 to the convergence determination unit 210 is time t0.
The convergence determination unit 210 acquires a voltage value VV1 that is the voltage value VV at time t0. The voltage value VV is a value of the positive electrode resistance potential difference RVP with respect to the ground G.
In addition, the convergence determination unit 210 acquires a voltage value VV2 that is a voltage value VV at time t1 after a preset time Δt that is a preset time from time t0 has elapsed.
Here, the set time Δt is the time required for the amount of charge charged in the capacitance of the DC circuit DCC to change. Specifically, the set time Δt is about several seconds.

  The convergence determination unit 210 compares the voltage value VV before the set time Δt elapses with the voltage value VV after the set time Δt elapses. In the following description, the absolute value of the difference between the voltage value VV before the set time Δt elapses and the voltage value VV after the set time Δt elapses is referred to as a voltage change value ΔV.

The convergence determination unit 210 determines that the positive electrode resistance potential difference RVP has not converged when the value of the voltage change value ΔV generated when the set time Δt elapses is greater than the threshold value TH.
The threshold value TH is, for example, the minimum value of the voltage change value ΔV when the positive electrode resistance potential difference RVP changes due to a transient phenomenon during the time indicated by the set time Δt.
Convergence determining unit 210 determines that positive electrode resistance potential difference RVP has converged when voltage change value ΔV generated by the elapse of set time Δt is smaller than threshold value TH.

Specifically, as shown in FIG. 9, convergence determination section 210 is based on voltage value VV1 at time t0 and voltage value VV2 that is voltage value VV at time t1 after elapse of set time Δt from time t0. Thus, the voltage change value ΔV1 is calculated. The voltage change value ΔV1 is a voltage change value ΔV between the voltage value VV1 at time t0 and the voltage value VV2 at time t1.
The convergence determination unit 210 determines that the positive electrode resistance potential difference RVP has not converged when the calculated voltage change value ΔV1 is greater than the threshold value TH. Further, when the voltage change value ΔV1 is smaller than the threshold value TH, it is determined that the positive electrode resistance potential difference RVP has converged.
The convergence determination unit 210 calculates the voltage change value ΔV until it is determined that the positive electrode resistance potential difference RVP has converged.

  In the above description, the convergence determination unit 210 has been described as determining that the positive electrode resistance potential difference RVP has converged when the voltage change value ΔV is smaller than the threshold value TH, but is not limited thereto. When the positive electrode resistance potential difference RVP converges with amplitude, the convergence determination unit 210 may determine that the positive electrode resistance potential difference RVP has converged when it is determined a plurality of times that the voltage change value ΔV is smaller than the threshold value TH. For example, the convergence determination unit 210 may determine that the positive electrode resistance potential difference RVP has converged when it is determined about 30 times when the voltage change value ΔV is smaller than the threshold value TH.

When the convergence determination unit 210 determines that the convergence has occurred, the convergence determination unit 210 outputs the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN to the acquisition unit 110.
The acquisition unit 110 generates a DC circuit based on the positive / negative potential difference VPN calculated in the third state, the positive resistance potential difference RVP in the first state and the negative resistance potential difference RVN in the second state input from the convergence determination unit 210. A positive electrode insulation resistance RP and a negative electrode insulation resistance RN, which are the insulation resistance R of the DCC, are acquired.
The method by which the acquisition unit 110 acquires the value related to the insulation resistance R is the same as that in the first embodiment, and thus description thereof is omitted.

[Summary of Second Embodiment]
As described above, the insulation resistance measuring apparatus 2 of the present embodiment includes the first positive electrode side switch SP1, the first negative electrode side switch SN1, the measurement unit 150, the start information input unit 160, and the control unit 200. And an insertion resistor RI.
The control unit 200 includes a CPU, and includes an acquisition unit 110 and a convergence determination unit 210 as functional units.

The measuring unit 150 measures a positive electrode resistance potential difference RVP that is a potential difference between the positive electrode BSP and the ground G in a state where the inserted positive electrode resistance RIP is connected between the positive electrode BSP and the ground G.
In addition, the measurement unit 150 measures a negative electrode resistance potential difference RVN that is a potential difference between the negative electrode BSN and the ground G in a state where the insertion negative resistance RIN is connected between the negative electrode BSN and the ground G.
The measurement unit 150 outputs the measured positive electrode resistance potential difference RVP and negative electrode resistance potential difference RVN to the acquisition unit 110.

The convergence determination unit 210 receives the positive electrode resistance potential difference RVP in the first state and the negative electrode resistance potential difference RVN in the second state measured by the measurement unit 150 via the acquisition unit 110. The convergence determination unit 210 determines whether or not a convergence condition is satisfied for the input values of the positive electrode resistance potential difference RVP in the first state and the negative electrode resistance potential difference RVN in the second state. The convergence determination unit 210 outputs the positive electrode resistance potential difference RVP in the first state determined to have converged and the negative electrode resistance potential difference RVN in the second state to the acquisition unit 110.
The convergence determination unit 210 inputs the positive resistance potential difference RVP in the first state and the negative resistance potential difference RVN in the second state determined to have converged by the convergence determination unit 210 to the acquisition unit 110.

The acquisition unit 110 acquires a value related to the insulation resistance R of the DC circuit DCC using the value determined by the convergence determination unit 210 when the measurement result of the measurement unit 150 satisfies the convergence condition.
Specifically, the acquisition unit 110 determines that the convergence determination unit 210 satisfies the convergence condition, the positive electrode resistance potential difference RVP in the first state and the negative electrode resistance potential difference RVN in the second state, and the positive electrode-negative electrode potential difference VPN in the third state. Based on the above, the values of the positive electrode insulation resistance RP and the negative electrode insulation resistance RN, which are the insulation resistance R of the DC circuit DCC, are obtained.

The insulation resistance measuring apparatus 2 according to the present embodiment determines whether or not the change in the value due to the transient phenomenon of the DC circuit DCC has converged for the positive electrode resistance potential difference RVP in the first state and the negative electrode resistance potential difference RVN in the second state. . In addition, the insulation resistance measuring apparatus 2 determines that the positive electrode resistance potential difference RVP in the first state and the second state are determined when it is determined that the positive electrode resistance potential difference RVP in the first state and the negative electrode resistance potential difference RVN in the second state have converged. Is used to calculate the value of the insulation resistance R.
Therefore, according to the insulation resistance measuring apparatus 2 of the present embodiment, a value related to the insulation resistance R of the DC circuit DCC can be obtained with higher accuracy.

  In the above description, the convergence determination unit 210 determines the convergence of the positive electrode resistance potential difference RVP in the first state and the negative electrode resistance potential difference RVN in the second state. However, the present invention is not limited to this. The convergence determination unit 210 may determine convergence of at least one value of the positive electrode resistance potential difference RVP in the first state and the negative electrode resistance potential difference RVN in the second state.

[Prior art: Insulation resistance accuracy according to insertion resistance value]
In the above description, the case where the insertion resistance RI of 2 MΩ is used when measuring the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN has been described.
Here, when the resistance value of the insertion resistor RI and the resistance value of the insulation resistance R of the DC circuit DCC are different from each other, an error may occur in the value of the insulation resistance R acquired by the insulation resistance measurement device 2.
Hereinafter, the case where the insulation resistance measuring apparatus 2 acquires the positive electrode insulation resistance RP will be described as an example.
As described above, the positive electrode insulation resistance RP is represented by Expression (1).

  Here, R (Vpn / Vn), which is the first term of the formula (1), is composed of R and Vpn which are constants and Vn which is a variable. In the case of the first term, the smaller the resistance value of the insertion resistor RI indicated by R, the smaller the value of the negative electrode resistance potential difference RVN, which is Vn, and an error is likely to occur in the measurement of the negative electrode resistance potential difference RVN. Similarly, for the negative electrode insulation resistance RN, the smaller the resistance value of the insertion resistance RI indicated by R, the smaller the value of the positive electrode resistance potential difference RVP, which is Vp, and an error is likely to occur in the measurement of the positive electrode resistance potential difference RVP.

In addition, R (Vp / Vn), which is the second term of the formula (1), is composed of R which is a constant and Vp and Vn which are variables. In the case of the second term, the closer the resistance value of the insertion resistor RI indicated by R and the resistance value of the insulation resistance R are, the less likely an error will occur in measurement. However, if the insulation resistance R changes due to deterioration or the like and a difference occurs between the resistance value of the insertion resistance RI and the resistance value of the insulation resistance R, an error is likely to occur in measurement.
The third term of the formula (1) is constituted by R which is a constant. Therefore, the third term does not affect the measurement error.

Hereinafter, an error of the insulation resistance R acquired by the insulation resistance measurement device 2 when the resistance value of the insulation resistance R of the DC circuit DCC and the resistance value of the insertion resistance RI are different will be described.
Specifically, an error of the insulation resistance R acquired by the insulation resistance measurement device 2 when the insulation resistance R of the DC circuit DCC is 100 MΩ and the insertion resistance RI is 100 kΩ will be described. In this case, Vp and Vn are both 0.11 V from the formula (1).

Here, when an error of +0.1 V occurs in Vn due to a measurement error of the measurement unit 150 included in the insulation resistance measurement device 2, the value of the positive electrode insulation resistance RP calculated from the equation (1) is 52.3 MΩ. . This indicates that the positive electrode insulation resistance RP acquired by the insulation resistance measuring device 2 is 52.3 MΩ with respect to the DC circuit DCC where the positive electrode insulation resistance RP is 100 MΩ.
When the resistance value of the insulation resistance R of the DC circuit DCC and the resistance value of the insertion resistance RI are different, the resistance value of the insulation resistance R acquired by the insulation resistance measuring device 2 is the resistance value of the insulation resistance R of the DC circuit DCC. It is very different from the resistance value.
That is, by selecting a value close to the resistance value of the insulation resistance R of the DC circuit DCC as the resistance value of the insertion resistance RI, the value of the insulation resistance R can be obtained with higher accuracy.

[Third Embodiment: Selection of Insertion Resistance]
The third embodiment of the present invention will be described below with reference to the drawings.
FIG. 10 is a diagram illustrating an example of the configuration of the insulation resistance measuring apparatus 3 according to the third embodiment.
The insulation resistance measuring device 3 according to the third embodiment obtains the insulation resistance R by using the insertion resistance RI which is a resistance value close to the value of the insulation resistance R of the DC circuit DCC. Different from the embodiment.
In addition, about the structure similar to 1st Embodiment and 2nd Embodiment mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 10, the insulation resistance measuring apparatus 3 includes a control unit 300, a measurement unit 150, a start information input unit 160, a first positive electrode side switch SP1, a second positive electrode side switch SP2, and a first negative electrode side switch SN1. And a second negative electrode side switch SN2, an insertion resistor RI, an insertion positive electrode low resistance LRIP, and an insertion negative electrode low resistance LRIN.

The inserted positive electrode low resistance LRIP is connected to the ground G. The inserted positive electrode low resistance LRIP is connected to the positive electrode BSP via the second positive electrode side switch SP2.
Specifically, the inserted positive electrode low resistance LRIP includes a terminal tIP3 and a terminal tIP4. The terminal tIP3 of the inserted positive electrode low resistance LRIP and the second positive electrode side switch SP2 are connected. Further, the inserted positive electrode low resistance LRIP terminal tIP4 and the ground terminal TE are connected. Moreover, 2nd positive electrode side switch SP2 and positive electrode terminal TP are connected.
The inserted negative electrode low resistance LRIN is connected to the ground G. Further, the insertion negative electrode low resistance LRIN is connected to the negative electrode BSN via the second negative electrode side switch SN2.
Specifically, the inserted negative electrode low resistance LRIN includes a terminal tIN3 and a terminal tIN4. The terminal tIN3 of the insertion negative electrode low resistance LRIN and the second negative electrode side switch SN2 are connected. The terminal tIN4 of the insertion negative electrode low resistance LRIN and the ground terminal TE are connected. The second negative electrode side switch SN2 and the negative electrode terminal TN are connected.
In the following description, when the inserted positive electrode low resistance LRIP and the inserted negative electrode low resistance LRIN are not distinguished, they are described as the inserted low resistance LRI.
The inserted positive electrode low resistance LRIP and the inserted negative electrode low resistance LRIN have the same resistance value. The insertion positive electrode low resistance LRIP and the insertion negative electrode low resistance LRIN are, for example, 100 kΩ.

The insertion low resistance LRI may be a resistance having a resistance value of 100 kΩ or a resistance other than 100 kΩ. For example, the insertion low resistance LRI is any resistance as long as the insertion low resistance LRI is not destroyed by the current flowing into the insertion low resistance LRI when the insulation resistance R of the DC circuit DCC causes dielectric breakdown. It may be a value.
Further, when the insulation resistance R causes dielectric breakdown, an accident current flows in the insertion low resistance LRI as a voltage indicated by the positive-negative potential difference VPN is applied to the insertion low resistance LRI. In this case, depending on the current value of the fault current flowing through the insertion low resistance LRI, the fault current may flow into other equipment connected to the DC circuit DCC, causing other equipment to malfunction. The insertion low resistance LRI is set to a resistance value at which an accident current flowing through the insertion low resistance LRI flows to another device connected to the DC circuit DCC, so that the other device does not malfunction. Specifically, the insertion low resistance LRI may have any resistance value as long as the resistance value is set so that the current flowing through the insertion low resistance LRI does not exceed several mA.

The control unit 300 includes a CPU, and includes an acquisition unit 310 as its functional unit.
The acquisition unit 310 controls the opening and closing of the first positive electrode side switch SP1, the second positive electrode side switch SP2, the first negative electrode side switch SN1, and the second negative electrode side switch SN2.
Specifically, the acquisition unit 310 transmits the positive-side switch control signal SPS for controlling the first positive-side switch SP1 and the second positive-side switch SP2 to the first positive-side switch SP1 and the second positive-side switch SP2. Output to. The opening and closing of the first positive electrode side switch SP1 and the second positive electrode side switch SP2 is controlled based on the positive electrode side opening / closing control signal SPS input from the acquisition unit 310.
In addition, the acquisition unit 310 outputs a negative electrode side open / close control signal SNS for controlling the first negative electrode side switch SN1 and the second negative electrode side switch SN2 to the first negative electrode side switch SN1 and the second negative electrode side switch SN2. . The first negative electrode side switch SN1 and the second negative electrode side switch SN2 are controlled to open and close based on a negative electrode side open / close control signal SNS input from the acquisition unit 310.

As described above, the acquisition unit 310 acquires the positive electrode resistance potential difference RVP in the first state and the negative electrode resistance potential difference RVN in the second state from the measurement unit 150. In addition, the acquisition unit 310 calculates the sum of the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN based on the positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN input in the third state. The acquisition unit 310 acquires the sum of the calculated positive electrode resistance potential difference RVP and the negative electrode resistance potential difference RVN as a value indicating the positive electrode-negative electrode potential difference VPN. Further, the acquisition unit 310 calculates the value of the insulation resistance R of the DC circuit DCC based on the acquired positive electrode resistance potential difference RVP in the first state, negative electrode resistance potential difference RVN in the second state, and positive electrode-negative electrode potential difference VPN in the third state. calculate.
Further, the acquisition unit 310 calculates based on the positive electrode resistance potential difference RVP in the first state, the negative electrode resistance potential difference RVN in the second state, and the positive electrode-negative electrode potential difference VPN in the third state, and acquires the insulation resistance R of the acquired DC circuit DCC. Determine the value. When determining that the value of the insulation resistance R is smaller than 10 MΩ, the acquisition unit 310 measures the positive low resistance potential difference LRVP and the negative low resistance potential difference LRVN. The acquisition unit 310 acquires the insulation resistance R based on the acquired positive electrode low resistance potential difference LRVP and negative electrode low resistance potential difference LRVN and the calculated positive electrode-negative electrode potential difference VPN.
The positive electrode low resistance potential difference LRVP is a positive electrode vs. ground potential difference VP when the inserted positive electrode resistor RIP and the inserted positive electrode low resistor LRIP are connected in parallel between the positive electrode terminal TP and the ground terminal TE. The negative electrode low resistance potential difference LRVN is the negative electrode-to-ground potential difference VN when the inserted negative electrode resistor RIN and the inserted negative electrode low resistance LRIN are connected in parallel between the negative electrode terminal TN and the ground terminal TE.

  In the above description, the acquisition unit 310 calculates the value of the insulation resistance R based on the positive electrode resistance potential difference RVP, the negative electrode resistance potential difference RVN, and the positive electrode-negative electrode potential difference VPN, and determines the acquired value. Although the case where the extremely low resistance potential difference LRVP, the negative electrode low resistance potential difference LRVN, and the positive electrode-negative electrode potential difference VPN are acquired and the insulation resistance R is calculated has been described, the invention is not limited thereto. The acquisition unit 310 includes an insulation resistance R based on the positive electrode resistance potential difference RVP, the negative electrode resistance potential difference RVN, and the positive electrode-negative electrode potential difference VPN, and an insulation resistance R based on the positive electrode low resistance potential difference LRVP, the negative electrode low resistance potential difference LRVN, and the positive electrode-negative electrode potential difference VPN. You may acquire two. The acquisition unit 310 may acquire only the insulation resistance R based on the positive electrode low resistance potential difference LRVP, the negative electrode low resistance potential difference LRVN, and the positive electrode-negative electrode potential difference VPN.

[Input of positive electrode low resistance potential difference]
Hereinafter, a case where the acquisition unit 310 receives the positive low resistance potential difference LRVP from the measurement unit 150 will be described.
The acquisition unit 310 controls the first positive electrode side switch SP1 and the second positive electrode side switch SP2 to the closed state, and controls the first negative electrode side switch SN1 and the second negative electrode side switch SN2 to the open state. Specifically, the acquisition unit 310 outputs a positive-side switching control signal SPS that controls the first positive-side switch SP1 and the second positive-side switch SP2 to be closed. Further, the acquisition unit 310 outputs a negative electrode side opening / closing control signal SNS that controls the first negative electrode side switch SN1 and the second negative electrode side switch SN2 to be in an open state.
The first positive electrode side switch SP1 and the second positive electrode side switch SP2 are controlled in a closed state, and the first negative electrode side switch SN1 and the second negative electrode side switch SN2 are controlled in an open state. In this case, the inserted positive resistance RIP and the inserted positive low resistance LRIP are connected in parallel with the positive insulation resistance RP between the positive terminal TP and the ground terminal TE.

  In the following description, the first positive electrode side switch SP1 and the second positive electrode side switch SP2 are controlled to be in a closed state, and the first negative electrode side switch SN1 and the second negative electrode side switch SN2 are controlled to be in an open state. Is described as a fourth state. That is, when the first positive-side switch SP1, the second positive-side switch SP2, the first negative-side switch SN1, and the second negative-side switch SN2 are controlled to the fourth state, the positive terminal TP and the ground terminal TE The inserted positive electrode resistance RIP, the inserted positive electrode low resistance LRIP, and the positive electrode insulation resistance RP are connected in parallel.

  The measuring unit 150 detects whether the first positive electrode side switch SP1, the second positive electrode side switch SP2, the first negative electrode side switch SN1, and the second negative electrode side switch SN2 are controlled to the fourth state. The extremely low resistance potential difference LRVP is output to the acquisition unit 310. The acquisition unit 310 receives the positive low resistance potential difference LRVP in the fourth state from the measurement unit 150.

[Input of negative electrode low resistance potential difference]
Hereinafter, a case where the negative electrode low resistance potential difference LRVN is input from the measurement unit 150 to the acquisition unit 310 will be described.
The acquisition unit 310 controls the first negative electrode side switch SN1 and the second negative electrode side switch SN2 to be in a closed state, and controls the first positive electrode side switch SP1 and the second positive electrode side switch SP2 to be in an open state. Specifically, the acquisition unit 310 outputs a negative electrode side opening / closing control signal SNS that controls the first negative electrode side switch SN1 and the second negative electrode side switch SN2 to be closed. In addition, the acquisition unit 310 outputs a positive-side switching control signal SPS that controls the first positive-side switch SP1 and the second positive-side switch SP2 to be in an open state.
The first positive electrode side switch SP1 and the second positive electrode side switch SP2 are controlled to be in an open state, and the first negative electrode side switch SN1 and the second negative electrode side switch SN2 are controlled to be in a closed state. In this case, the inserted negative electrode resistance RIN and the inserted negative electrode low resistance LRIN are connected in parallel with the negative electrode insulation resistance RN between the negative electrode terminal TN and the ground terminal TE.

  In the following description, the first positive electrode side switch SP1 and the second positive electrode side switch SP2 are controlled to be in the open state, and the first negative electrode side switch SN1 and the second negative electrode side switch SN2 are controlled to be in the closed state. Is described as a fifth state. That is, when the first positive-side switch SP1, the second positive-side switch SP2, the first negative-side switch SN1, and the second negative-side switch SN2 are controlled to the fifth state, the negative terminal TN and the ground terminal TE The inserted negative electrode resistance RIN, the inserted negative electrode low resistance LRIN, and the negative electrode insulation resistance RN are connected in parallel.

  The measuring unit 150 has a negative electrode according to the first positive electrode side switch SP1, the second positive electrode side switch SP2, the first negative electrode side switch SN1, and the second negative electrode side switch SN2 being controlled to the fifth state. The low resistance potential difference LRVN is output to the acquisition unit 310. The acquisition unit 310 receives the negative low resistance potential difference LRVN in the fifth state from the measurement unit 150.

[Acquisition of potential difference between positive electrode and negative electrode]
Hereinafter, a case where the acquisition unit 310 calculates and acquires the positive / negative electrode potential difference VPN based on the input from the measurement unit 150 will be described.
The acquisition unit 310 controls the first positive electrode side switch SP1, the second positive electrode side switch SP2, the first negative electrode side switch SN1, and the second negative electrode side switch SN2 to be closed. Specifically, the acquisition unit 310 outputs a positive-side switching control signal SPS that controls the first positive-side switch SP1 and the second positive-side switch SP2 to be closed. In addition, the acquisition unit 310 outputs a negative electrode side opening / closing control signal SNS that controls the first negative electrode side switch SN1 and the second negative electrode side switch SN2 to be closed.
Thereby, 1st positive electrode side switch SP1, 2nd positive electrode side switch SP2, 1st negative electrode side switch SN1, and 2nd negative electrode side switch SN2 are controlled to a closed state. In this case, the inserted positive electrode resistance RIP and the inserted positive electrode low resistance LRIP are connected in parallel between the positive electrode terminal TP and the ground terminal TE, and the inserted negative electrode resistance RIN and the inserted negative electrode low are connected between the negative electrode terminal TN and the ground terminal TE. Resistor LRIN is connected in parallel.
In the following description, the state in which the first positive electrode side switch SP1, the second positive electrode side switch SP2, the first negative electrode side switch SN1, and the second negative electrode side switch SN2 are controlled to be in a closed state is referred to as a sixth state. To do. That is, when the first positive-side switch SP1, the second positive-side switch SP2, the first negative-side switch SN1, and the second negative-side switch SN2 are controlled to the sixth state, the positive terminal TP and the ground terminal TE The inserted positive electrode resistor RIP and the inserted negative electrode low resistance LRIP are connected in parallel to each other, and the inserted negative electrode resistor RIN and the inserted negative electrode low resistance LRIN are connected in parallel between the negative electrode terminal TN and the ground terminal TE.
The measuring unit 150 acquires the first positive electrode side switch SP1, the second positive electrode side switch SP2, the first negative electrode side switch SN1, and the second negative electrode side switch SN2 in response to being controlled to the sixth state. The positive electrode low resistance potential difference LRVP and the negative electrode low resistance potential difference LRVN are output to the unit 310. The acquisition unit 310 receives the positive low resistance potential difference LRVP and the negative low resistance potential difference LRVN from the measurement unit 150. The acquisition unit 110 calculates the sum of the positive low resistance potential difference LRVP and the negative low resistance potential difference LRVN based on the input positive low resistance potential difference LRVP and negative negative resistance resistance difference LRVN. The acquisition unit 310 acquires the sum of the calculated positive electrode low resistance potential difference LRVP and the negative electrode low resistance potential difference LRVN as a value indicating the positive electrode-negative electrode potential difference VPN.

The acquisition unit 310 acquires the insulation resistance R based on the positive low resistance potential difference LRVP in the fourth state, the negative low resistance potential difference LRVN in the fifth state, and the positive-negative potential difference VPN in the sixth state.
Hereinafter, details of acquisition of the insulation resistance R of the acquisition unit 310 will be described.

[Acquisition of insulation resistance]
As described above, the acquisition unit 310 receives the positive low resistance potential difference LRVP in the fourth state, the negative low resistance potential difference LRVN in the fifth state, and the positive-negative potential difference VPN in the sixth state, which are input from the measurement unit 150. Based on the above, the insulation resistance R of the DC circuit DCC is acquired.
Specifically, the acquisition unit 310 determines the positive BSP of the DC circuit DCC based on the positive low resistance potential difference LRVP in the fourth state, the negative low resistance potential difference LRVN in the fifth state, and the positive-negative potential difference VPN in the sixth state. The value of the positive electrode insulation resistance RP that is the side insulation resistance R is acquired. Further, the acquisition unit 310 performs insulation on the negative electrode BSN side of the DC circuit DCC based on the positive low resistance potential difference LRVP in the fourth state, the negative low resistance potential difference LRVN in the fifth state, and the positive-negative potential difference VPN in the sixth state. The value of the negative electrode insulation resistance RN that is the resistance R is acquired.

In the following description, the voltage value of the positive electrode-negative electrode potential difference VPN is described as Vpn. Moreover, the voltage value of positive electrode low resistance potential difference LRVP is described as Vp. The voltage value of the negative electrode low resistance potential difference LRVN is described as Vn. The value of the positive electrode insulation resistance RP is described as Rp. Moreover, the value of the negative electrode insulation resistance RN is described as Rn.
Further, as described above, the inserted positive electrode resistor RIP and the inserted negative electrode resistor RIN have the same resistance value. Further, as described above, the inserted positive electrode low resistance LRIP and the inserted negative electrode low resistance LRIN have the same resistance value. That is, the resistance value of the combined resistance when the inserted positive electrode resistance RIP and the inserted positive electrode low resistance LRIP are connected in parallel, and the combined resistance value of the combined negative electrode resistance RIN and the inserted negative electrode low resistance LRIN when connected in parallel Are the same resistance values.
In the following description, the resistance value of the combined resistance when the inserted positive electrode resistance RIP and the inserted positive electrode low resistance LRIP are connected in parallel, and the combined resistance value when the inserted negative electrode resistance RIN and the inserted negative electrode low resistance LRIN are connected in parallel. The resistance value is written as R.
As described above, the relational expression among Rp, Vp, Vn, and Vpn is expressed by Expression (1). Further, as described above, the relational expression among Rp, Vp, Vn, and Vpn is expressed by Expression (2).

The acquisition unit 310 acquires Vp and Vn. Further, the acquisition unit 110 calculates Vpn based on the acquired Vp and Vn. Therefore, Vp, Vn, Vpn, and R are known values in the expressions (1) and (2).
The acquisition unit 310 acquires Rp, which is the resistance value of the positive electrode insulation resistance RP of the DC circuit DCC. In addition, the acquisition unit 310 acquires Rn that is the resistance value of the negative electrode insulation resistance RN of the DC circuit DCC.

  In addition, although the case where the control unit 300 includes only the acquisition unit 310 has been described above, the present invention is not limited to this. The control unit 300 may include a convergence determination unit 210. In this case, the convergence determination unit 210 determines the convergence of the positive low resistance potential difference LRVP in the fourth state and the negative low resistance potential difference LRVN in the fifth state input from the acquisition unit 310, and acquires the determined values. You may output to 310. Further, the acquisition unit 310 includes the acquired positive-negative potential difference VPN in the sixth state, the positive low-resistance potential difference LRVP in the fourth state determined by the convergence determination unit 210 and the negative low-resistance potential difference LRVN in the fifth state. Based on the above, the insulation resistance R may be calculated.

[Summary of Third Embodiment]
As described above, the insulation resistance measuring apparatus 3 according to this embodiment includes the control unit 300, the measurement unit 150, the start information input unit 160, the first positive electrode side switch SP1, the second positive electrode side switch SP2, and the first negative electrode. A side switch SN1, a second negative side switch SN2, an insertion resistor RI, and an insertion low resistance LRI are provided.
The control unit 300 includes a CPU, and includes an acquisition unit 310 as its functional unit.
The acquisition unit 310 controls the opening and closing of the first positive electrode side switch SP1, the second positive electrode side switch SP2, the first negative electrode side switch SN1, and the second negative electrode side switch SN2.

The measurement unit 150 includes a positive electrode low resistance potential difference LRVP which is a potential difference between the positive electrode BSP and the ground G in a state where the inserted positive electrode resistance RIP and the inserted positive electrode low resistance LRIP are connected in parallel between the positive electrode BSP and the ground G. Measure.
Further, the measurement unit 150 includes a negative electrode low resistance potential difference LRVN that is a potential difference between the negative electrode BSN and the ground G in a state where the inserted positive electrode resistance RIP and the inserted negative electrode low resistance LRIN are connected in parallel between the negative electrode BSN and the ground G. Measure.
The acquisition unit 310 receives the positive low resistance potential difference LRVP and the negative low resistance potential difference LRVN measured by the measurement unit 150 in the fourth state, the fifth state, and the sixth state.

The acquisition unit 310 acquires the value of the insulation resistance R of the DC circuit DCC based on the measurement result measured by the measurement unit 150.
Specifically, the acquisition unit 310 acquires the positive low resistance potential difference LRVP in the fourth state and the negative low resistance potential difference LRVN in the fifth state, which are values related to the insulation resistance R, from the measurement unit 150. The acquisition unit 310 acquires the positive low resistance potential difference LRVP and the negative low resistance potential difference LRVN in the sixth state, and calculates the sum of the positive low resistance potential difference LRVP and the negative low resistance potential difference LRVN. The acquisition unit 310 acquires the sum of the positive electrode low resistance potential difference LRVP and the negative electrode low resistance potential difference LRVN as a positive electrode-negative electrode potential difference VPN that is a value related to the insulation resistance R. In addition, the acquisition unit 310 determines the DC circuit DCC based on the acquired positive low resistance potential difference LRVP in the fourth state, negative low resistance potential difference LRVN in the fifth state, and positive-negative potential difference VPN in the sixth state. The values of the positive electrode insulation resistance RP and the negative electrode insulation resistance RN, which are the insulation resistance R, are acquired.

  Here, in the conventional technique, the resistance value of the insertion resistor used when measuring the insulation resistance of the DC circuit may be set uniquely. When the value of the insulation resistance of the DC circuit is different from the resistance value of the insertion resistor, it may be difficult to obtain the value of the insulation resistance of the DC circuit with higher accuracy.

The insulation resistance measuring device 3 of this embodiment acquires the insulation resistance R based on the positive electrode resistance potential difference RVP, the negative electrode resistance potential difference RVN, and the positive electrode-negative electrode potential difference VPN. Further, the insulation resistance measuring device 3 is positive when the acquired value of the insulation resistance R is close to the resistance value of the insertion low resistance LRI among the resistance value of the insertion resistance RI and the resistance value of the insertion low resistance LRI. The value of the insulation resistance R is acquired based on the low resistance potential difference LRVP, the negative electrode low resistance potential difference LRVN, and the positive electrode-negative electrode potential difference VPN.
According to the insulation resistance measuring apparatus 3 of the present embodiment, by using a resistance having a resistance value close to the value of the insulation resistance R of the DC circuit DCC among the insertion resistance RI or the insertion low resistance LRI, the insulation of the DC circuit DCC is used. The value of the resistance R can be acquired with higher accuracy.

[Variation 1: Storage of values related to insulation resistance]
Hereinafter, Modification 1 according to the third embodiment of the present invention will be described with reference to the drawings.
FIG. 11 is a diagram illustrating an example of the configuration of the insulation resistance measuring device 4 according to the first modification.
In the first embodiment, the second embodiment, and the third embodiment, the configuration in which the insulation resistance measuring device 1 acquires the insulation resistance R has been described.
In the first modification, the first embodiment, the second embodiment, and the third embodiment are provided in that the value related to the insulation resistance R acquired by the insulation resistance measurement device 4 and the date D when the insulation resistance R is acquired are stored in association with each other. Different from form.
In addition, about the structure and operation | movement similar to 1st Embodiment, 2nd Embodiment, and 3rd Embodiment mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 11, the insulation resistance measuring device 4 includes a control unit 300, a measurement unit 150, a start information input unit 160, a first positive electrode side switch SP1, a second positive electrode side switch SP2, and a first negative electrode side switch SN1. , A second negative electrode side switch SN2, an insertion resistor RI, an insertion low resistance LRI, and a storage unit 410.
The storage unit 410 stores acquisition information TI acquired by the acquisition unit 310 included in the control unit 300. The acquisition information TI is information in which the value related to the insulation resistance R of the DC circuit DCC acquired by the acquisition unit 310 is associated with the date D when the acquisition unit 310 acquires the value related to the insulation resistance R of the DC circuit DCC.

The values related to the insulation resistance R of the DC circuit DCC are the voltage value of the positive electrode resistance potential difference RVP in the first state acquired by the acquisition unit 310, the voltage value of the negative electrode resistance potential difference RVN in the second state, and the positive electrode vs. negative electrode potential difference VPN in the third state. Including the voltage value. Further, the value related to the insulation resistance R of the DC circuit DCC was calculated by the acquisition unit 310 based on the positive electrode resistance potential difference RVP in the first state, the negative electrode resistance potential difference RVN in the second state, and the positive electrode-negative electrode potential difference VPN in the third state. The resistance value of the insulation resistance R is included.
The value related to the insulation resistance R of the DC circuit DCC includes the voltage value of the positive low resistance potential difference LRVP in the fourth state acquired by the acquisition unit 310 and the voltage value of the negative low resistance potential difference LRVN in the fifth state.

Hereinafter, the details of the acquired information TI will be described with reference to FIG.
FIG. 12 is a table illustrating an example of the acquisition information TI according to the first modification.
As illustrated in FIG. 12, the acquisition information TI is information in which the value related to the insulation resistance R acquired by the acquisition unit 310 is associated with the date D when the value related to the insulation resistance R is acquired.
In this example, the acquisition part 310 acquires the value regarding the insulation resistance R of DC circuit DCC every day. Therefore, the acquired information TI includes a value related to the insulation resistance R of the DC circuit DCC every day.

As described above, the insulation resistance measuring device 4 of the first modification includes the control unit 300, the measurement unit 150, the start information input unit 160, the storage unit 410, the first positive electrode side switch SP1, and the second positive electrode side switch SP2. The first negative electrode side switch SN1, the second negative electrode side switch SN2, the insertion positive electrode resistance RIP, the insertion negative electrode resistance RIN, and the insertion low resistance LRI.
The storage unit 410 stores acquisition information TI acquired by the acquisition unit 310 included in the control unit 100. The acquisition information TI is information in which the value related to the insulation resistance R of the DC circuit DCC acquired by the acquisition unit 310 is associated with the date D when the acquisition unit 310 acquires the value related to the insulation resistance R of the DC circuit DCC. The storage unit 410 stores a value indicating the positive electrode resistance potential difference RVP in the first state acquired by the acquisition unit 310, a value indicating the negative electrode resistance potential difference RVN in the second state, and a value indicating the positive electrode-negative electrode potential difference VPN in the third state. And a value indicating the positive electrode low resistance potential difference LRVP in the fourth state, a value indicating the negative electrode low resistance potential difference LRVN in the fifth state, and the acquisition unit 310 having the positive electrode resistance potential difference RVP in the first state and the negative electrode resistance in the second state. The acquisition information TI that is calculated based on the potential difference RVN and the positive / negative potential difference VPN in the third state and includes the acquired resistance value of the insulation resistance R of the DC circuit DCC and the date / time D is stored.

According to the insulation resistance measuring device 4 of the present embodiment, the acquisition information TI in which the value related to the insulation resistance R of the DC circuit DCC and the date D when the value related to the insulation resistance R of the DC circuit DCC is acquired is stored. be able to. That is, according to the insulation resistance measuring apparatus 4 of the present embodiment, the degree of deterioration of the insulation resistance R of the DC circuit DCC can be observed quantitatively and with time.
By using the insulation resistance measuring device 4, the acquired information TI stored in the storage unit 410 can be processed by a PC (Personal Computer) or the like.
By using the insulation resistance measuring device 4, a maintenance manager who maintains and manages the DC circuit DCC refers to the acquisition information TI stored in the storage unit 410 and once determines the insulation resistance R of the DC circuit DCC for a plurality of days. Can be confirmed.
Further, by using the insulation resistance measuring device 4, the maintenance manager of the DC circuit DCC refers to the acquisition information TI stored in the storage unit 410 and refers to the date and time D when the insulation resistance R has changed. Can do.

  Further, the insulation resistance measuring device 4 may be connected to a network, and the maintenance manager of the DC circuit DCC may check the acquired information TI stored in the storage unit 410 via the network. In this case, according to the insulation resistance measuring device 4 of the present embodiment, it can be confirmed via the network that the insulation resistance R of the DC circuit DCC has changed. Further, in this case, according to the insulation resistance measuring device 4, it is possible to reduce the trouble for the maintenance manager to visit the equipment room or the like where the DC circuit DCC is installed.

In the above description, the acquisition information TI includes the positive electrode resistance potential difference RVP, the negative electrode resistance potential difference RVN, the positive electrode-negative electrode potential difference VPN, the positive electrode low resistance potential difference LRVP, the negative electrode low resistance potential difference LRVN, and the insulation resistance R. Although the case where it is the information matched with D was demonstrated, it is not restricted to this.
The acquired information TI includes at least one of a positive electrode resistance potential difference RVP, a negative electrode resistance potential difference RVN, a positive electrode-negative electrode potential difference VPN, a positive electrode low resistance potential difference LRVP, a negative electrode low resistance potential difference LRVN, and an insulation resistance R. It may be information associated with the date and time D.

In the above description, the acquisition information TI is associated with the value related to the insulation resistance R of the DC circuit DCC acquired by the acquisition unit 310 and the date D when the acquisition unit 310 acquires the value related to the insulation resistance R of the DC circuit DCC. However, the present invention is not limited to this.
The acquisition information TI may be information in which the value related to the insulation resistance R of the DC circuit DCC acquired by the acquisition unit 310 is associated with the time when the acquisition unit 310 acquires the value related to the insulation resistance R of the DC circuit DCC. Good.

In the above description, the date and time D included in the acquisition information TI has been described as being the date and time D when the acquisition unit 310 acquires a value related to the insulation resistance R of the DC circuit DCC.
The date and time D is the date and time when the measurement unit 150 measured any one of the positive electrode resistance potential difference RVP, the negative electrode resistance potential difference RVN, the positive electrode-negative electrode potential difference VPN, the positive electrode low resistance potential difference LRVP, and the negative electrode low resistance potential difference LRVN. It may be.

  Further, in the above description, the values of the insulation resistance R of the DC circuit DCC included in the acquired information TI are the positive resistance potential difference RVP in the first state, the negative resistance potential difference RVN in the second state, and the positive / negative potential difference VPN in the third state. Although the case where it is the value which the acquisition part 310 calculated based on was demonstrated, it is not restricted to this. The value of the insulation resistance R of the DC circuit DCC included in the acquired information TI includes a value indicating the positive low resistance potential difference LRVP in the fourth state, a value indicating the negative low resistance potential difference LRVN in the fifth state, and a value in the sixth state. The value of the insulation resistance R calculated by the acquisition unit 310 based on the value indicating the positive electrode-negative electrode potential difference VPN may be used.

[Modification 2: Display of values related to insulation resistance]
Hereinafter, with reference to FIG. 13, Modification 2 according to the third embodiment and Modification 1 will be described.
FIG. 13 is a diagram illustrating an example of the configuration of the insulation resistance measuring apparatus 5 according to the second modification.
The modification 2 is different from the third embodiment in that the insulation resistance measuring device 5 includes the display unit DP, acquires information about the insulation resistance R, and displays the information on the display unit DP.
In addition, about the structure and operation | movement similar to 1st Embodiment, 2nd Embodiment, 3rd Embodiment type | system | group, and the modification 1 mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 13, the insulation resistance measuring apparatus 5 includes a control unit 500, a measurement unit 150, a start information input unit 160, a first positive electrode side switch SP1, a second positive electrode side switch SP2, and a first negative electrode side switch SN1. , A second negative-side switch SN2, an insertion resistor RI, and an insertion low resistance LRI.
Further, as shown in FIG. 13, the display unit DP is connected to the insulation resistance measuring device 5.
The control unit 500 includes a CPU, and includes an acquisition unit 310 and a display control unit 510 as functional units. The acquisition unit 310 acquires the voltage value of the positive electrode resistance potential difference RVP in the first state, the voltage value of the negative electrode resistance potential difference RVN in the second state, the voltage value of the positive electrode-negative electrode potential difference VPN in the third state, and the fourth state. The display controller 510 is supplied with the voltage value of the positive low resistance potential difference LRVP and the negative polarity low resistance potential difference LRVN in the fifth state.
In addition, the acquisition unit 310 calculates and acquires the acquired insulation resistance R based on the positive electrode resistance potential difference RVP in the first state, the negative electrode resistance potential difference RVN in the second state, and the positive electrode-negative electrode potential difference VPN in the third state. Is supplied to the display control unit 510.

The display control unit 510 includes a value indicating the positive electrode resistance potential difference RVP in the first state, a value indicating the negative electrode resistance potential difference RVN in the second state, a value indicating the positive electrode-negative electrode potential difference VPN in the third state, and a fourth state. A value indicating the positive electrode low resistance potential difference LRVP, a value indicating the negative electrode low resistance potential difference LRVN in the fifth state, and a value regarding the insulation resistance R of the DC circuit DCC are input from the acquisition unit 310.
The display control unit 510 includes, on the display unit DP connected to the insulation resistance measuring device 5, a value indicating the positive electrode resistance potential difference RVP in the first state, a value indicating the negative electrode resistance potential difference RVN in the second state, and a positive electrode in the third state. A value indicating the negative electrode potential difference VPN, a value indicating the positive low resistance potential difference LRVP in the fourth state, a value indicating the negative low resistance potential difference LRVN in the fifth state, and a value relating to the insulation resistance R of the DC circuit DCC are displayed. Take control. The display unit DP is, for example, a liquid crystal display (Liquid Crystal Display). The display control unit 510 sequentially displays values related to the insulation resistance R of the DC circuit DCC on the display unit DP.
With the above-described configuration, according to the insulation resistance measuring device 5 of the modification, the value related to the insulation resistance R can be displayed on the display unit DP.

Moreover, in the insulation resistance measuring apparatus 5 of a modification, the value regarding the insulation resistance R is displayed sequentially. Thereby, the insulation resistance measuring apparatus 5 of a modification can display the value regarding the insulation resistance R on the display part DP in real time.
Here, “sequential display” means, for example, that the display is updated every short time with respect to the time required for the change of the insulation resistance R of the DC circuit DCC. Any spacing may be used.

  In the above description, the values of the insulation resistance R of the DC circuit DCC displayed on the display unit DP are the positive resistance potential difference RVP in the first state, the negative resistance potential difference RVN in the second state, and the positive / negative potential difference VPN in the third state. However, the present invention is not limited to this. The value of the insulation resistance R of the DC circuit DCC displayed on the display unit DP includes a value indicating the positive low resistance potential difference LRVP in the fourth state, a value indicating the negative low resistance potential difference LRVN in the fifth state, and a sixth state The value of the insulation resistance R calculated by the acquisition unit 310 based on the value indicating the positive / negative potential difference VPN in FIG.

  In addition, although the case where the insulation resistance measuring apparatus 5 includes the display unit DP has been described above, the present invention is not limited to this. The insulation resistance measuring device 5 may include a storage unit 410 and may store the acquisition information TI acquired by the acquisition unit 310 in the storage unit 410.

  In the above description, the case where the insulation resistance measurement device 1, the insulation resistance measurement device 2, the insulation resistance measurement device 3, the insulation resistance measurement device 4, and the insulation resistance measurement device 5 include the start information input unit 160 has been described. Not limited. The insulation resistance measurement device 1, the insulation resistance measurement device 2, the insulation resistance measurement device 3, the insulation resistance measurement device 4, and the insulation resistance measurement device 5 may not include the start information input unit 160. In this case, the acquisition unit 110 and the acquisition unit 310 may automatically start processing.

  In addition, each part with which the insulation resistance measuring device 1, the insulation resistance measuring device 2, the insulation resistance measuring device 3, the insulation resistance measuring device 4, and the insulation resistance measuring device 5 in each of the above embodiments is provided is realized by dedicated hardware. Or may be realized by a memory and a microprocessor.

  In addition, each part with which the insulation resistance measurement apparatus 1, the insulation resistance measurement apparatus 2, the insulation resistance measurement apparatus 3, the insulation resistance measurement apparatus 4, and the insulation resistance measurement apparatus 5 are comprised is comprised by memory and CPU (central processing unit), and insulation resistance The function of the measurement device 1, the insulation resistance measurement device 2, the insulation resistance measurement device 3, the insulation resistance measurement device 4 and the insulation resistance measurement device 5 is implemented by loading a program for realizing the functions of each unit and executing it. May be realized.

  In addition, a program for realizing the functions of the respective units included in the insulation resistance measurement device 1, the insulation resistance measurement device 2, the insulation resistance measurement device 3, the insulation resistance measurement device 4, and the insulation resistance measurement device 5 on a computer-readable recording medium Processing may be performed by recording, reading the program recorded on the recording medium into a computer system, and executing the program. Here, the “computer system” includes an OS and hardware such as peripheral devices.

Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, and a CD-ROM, and a storage device such as a hard disk built in the computer system. Furthermore, “computer-readable recording medium” is a program that dynamically holds a program for a short time, such as a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in this case includes a program that holds a program for a certain period of time. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and appropriate modifications may be made without departing from the spirit of the present invention. it can. You may combine the structure as described in each embodiment mentioned above.

1, 2, 3, 4, 5 ... insulation resistance measuring device, 100, 200, 300, 500 ... control unit, 110, 310 ... acquisition unit, 150 ... measurement unit, 160 ... start information input unit, 210 ... convergence determination unit , 410 ... storage unit, 510 ... display control unit, DCC ... DC circuit, R ... insulation resistance, RP ... positive electrode insulation resistance, RN ... negative electrode insulation resistance, RVN ... negative electrode resistance potential difference, RVP ... positive electrode resistance potential difference, LRVN ... negative electrode low Resistance potential difference, LRVP ... positive electrode low resistance potential difference, VPN ... positive electrode vs. negative electrode potential difference, VN ... negative electrode vs. earth potential difference, VP ... positive electrode vs. earth potential difference, BC ... AC / DC converter, BS ... bus, BSN ... negative electrode, BSP ... positive electrode, 64D: DC ground fault relay, Rd1, Rd2: Voltage dividing resistor, Re: Ground resistance, CP: Neutral point, BTT: Storage battery, RI: Insertion resistance, RIN: Insertion negative resistance, RIP: Insertion positive resistance, RI ... insertion low resistance, LRIN ... insertion negative electrode low resistance, LRIP ... insertion positive electrode low resistance, C, C1, C2, Cn ... circuit, JB, JBC1N, JBC1P, JBC2N, JBCnP, JBCnN, JBCnP ... switch, RPBS ... Bus positive insulation resistance, RNBS ... Bus negative insulation resistance, RPC, RPC1, RPC2, RPCn ... Circuit positive insulation resistance, RNC, RNC1, RNC2, RNCn ... Circuit negative insulation resistance, SP1 ... First positive switch, SP2 ... First 2 positive side switch, SN1 ... first negative side switch, SN2 ... second negative side switch, TB ... terminal block, TP ... positive terminal, TE ... earth terminal, TN ... negative terminal, TT ... test terminal, TPG ... Test plug, TI ... Acquired information, DP ... Display part

Claims (2)

For a DC circuit in which a neutral point between the positive electrode and the negative electrode is grounded to the ground, a positive electrode-ground potential difference that is a potential difference between the positive electrode and the ground in a state where a first resistor is connected between the positive electrode and the ground. And a measuring unit for measuring a negative electrode-to-ground potential difference that is a potential difference between the negative electrode and the ground in a state where a second resistor is connected between the negative electrode and the ground;
Based on the measurement result measured by the measurement unit, an acquisition unit for acquiring a value related to the insulation resistance of the DC circuit;
An insulation resistance measuring device comprising: A convergence determination unit that determines whether or not a convergence condition is satisfied for at least one of the positive electrode-to-ground potential difference and the negative-electrode-to-ground potential difference, which are measurement results measured by the measurement unit,
The insulation resistance measuring apparatus according to claim 1, wherein the acquisition unit acquires a value related to an insulation resistance of the DC circuit using the value determined by the convergence determination unit that the measurement result satisfies a convergence condition.

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