JP5967327B1 - Insulation resistance measurement method for DC power supply circuit - Google Patents

Abstract

Insulation of a battery power source when an insulation resistance is lowered in a DC power supply circuit in which a large number of single cells are connected in series and parallel to supply power to a large number of loads from a non-grounded battery power source via a power feeding circuit. Provided is an insulation resistance measurement method capable of specifying a column battery and a single battery in which a failure has occurred, and a branch circuit and a load in which an insulation failure has occurred. When the insulation resistance of the power supply circuit and the battery power source are measured by the mode for measuring the insulation resistance of the power supply circuit and the mode of measuring the insulation resistance of the battery power supply, respectively, and when a decrease in the insulation resistance is detected, the power supply circuit By disconnecting the branch switch connected to the battery or the battery switch of the battery power supply one by one one after another, the insulation resistance of the power supply circuit and the battery power supply is recovered, so that the location of the insulation failure where the insulation resistance is reduced Identify. [Selection] Figure 6

Description

  The present invention provides a direct current that supplies power to a load from a battery power source configured by connecting one or a plurality of battery cells connected in series, such as a ship electric propulsion system or a photovoltaic power generation system. The present invention relates to an insulation resistance measurement method capable of measuring an insulation resistance in a power feeding circuit and identifying a location where insulation resistance is lowered and insulation failure occurs.

In particular, the electric propulsion system for ships, which is the object of the present invention, is in principle a non-grounded power supply circuit that does not ground the power supply circuit, and is defined in the relevant standards. Moreover, since the battery power source used for the electric propulsion system of a ship requires large capacity of high voltage and large current, a large number of unitized single cells are connected in series and parallel.
A large number of electric devices and devices are connected to the battery power source and a power supply path from the battery power source. Accordingly, when a large number of single cells constituting a battery power source, a power supply circuit from the battery power source, and a large number of electrical devices and devices connected thereto, a part of the electrical resistance and the device have a low insulation resistance and an insulation failure occurs, a ground fault occurs. There is a risk that it may develop into a short circuit accident, which is extremely dangerous.
However, in the conventional insulation resistance measuring apparatus known so far, for example, as shown in Patent Document 1, only the insulation resistance of a power supply circuit that is not grounded for supplying power from a battery power supply to a load is measured. It was.

The conventional insulation resistance measuring apparatus disclosed in Patent Document 1 is configured as shown in FIG.
In the conventional insulation resistance measuring apparatus shown in FIG. 8, detection resistors 101 to 105 constitute a T-type detection circuit, and signals 106 (voltage V 1), 108 (voltage V 2) and 107 are respectively output from resistors 102, 104 and 105. (Voltage V3) is obtained. These signals 106 to 108 are input to the primary sides of the isolation converters 109, 110, and 111, respectively, and are converted to secondary signals 112 to 114, respectively.

  Harmonic components are removed from the secondary signals 112 to 114 by the low-pass filters 115, 116, and 118 to become signals 119 to 121, of which the signals 119 and 120 are the positive divider 125, and the signals 120 and 121 are the negative electrodes. Input to the side divider 126 and division is performed. The polarity discriminator 122 discriminates the polarity of the signal 120. When the signal 120 has a positive (+) polarity, that is, when the voltage V3 has a (+) polarity, an output that turns on the signal 123 is generated and negative ( -) When polar, an output that turns on the signal 124 is generated.

When the polarity discriminator 122 (PC) outputs the signal 123 having the (+) polarity, the positive side calculators 125 and 131, the display device 135, and the alarm device 136 are operated to lock the negative side.
Similarly, when the polarity discriminator 122 outputs the (−) polarity signal 124, the negative side calculators 126 and 132, the display device 135, and the alarm device 136 are operated to lock the positive side.

  Hereinafter, a case where the polarity discriminator 122 (PC) outputs the (+) polarity signal 123 and measures the insulation resistance of the positive-side electric circuit will be described.

  The case of measuring the insulation resistance of the positive electrode side electric circuit will be described with reference to the measurement operation explanatory diagram of the insulation resistance of FIG.

  Here, the ratio of the resistance value R11 of the positive-side resistor 101 to the resistance value R12 of the resistor 102 or the resistance value R21 of the negative-side resistor 103 to the resistance value R22 of the resistor 104 is 1: 1/100, respectively. Although it is about ˜1: 1/25, an optimum value is selected depending on the voltage value of the circuit to be measured or the range of the insulation resistance value to be measured.

For example, when measuring the insulation resistance of a DC voltage 500V circuit, when the resistance values R11 and R21 of the detection resistors 101 and 103 are selected to be 1 MΩ, and the resistance values R12 and R22 of the detection resistors 102 and 104 are selected to be 10 KΩ, 9 is infinite (RPx = ∞), the current IPX flowing through the insulation resistance RPX shown in FIG. 9 is 0 and does not flow. As a result, both-end voltages V1 and V2 of the detection resistors 102 and 104 are V1 = V2, and the current IS flowing through the detection resistors 101, 102, 103, and 104 is V.
IS≈V / (R11 + R12 + R21 + R22)
Since the M potential is VP = VN = 250V and the resistance ratio of the resistors 101 and 102 is 1: 1/100, the resistors 102 and 104 have
V1 = V2 = 250V / 100 ≒ 2.5V
Will be generated.

Now, assuming that the resistance value RPx of the insulation resistance RPX of the positive circuit P of the power feeding circuit has decreased,
IPX = V ÷ (RPx + R3 + R21 + R22)
A ground current IPX flows, and both ends of the detection resistor 105 are V3 = IPX × R3
Is generated.
At this time, the voltage V1 across the detection resistor 102 is determined by the current IS, and the voltage V3 across the detection resistor 105 is determined by the current IPX. That is, when the resistance values of the resistor 101 and the insulation resistor RPX are sufficiently larger than the resistance values of the resistors 102 and 105, respectively, if R12 = R3, the ratio of the voltage values of V1 and V3 is the resistance value R11 of the detection resistor 101. Therefore, the voltage ratio n (= V1 / V3) between V1 and V3 is obtained, and the ratio n is multiplied by the resistance value R11 of the detection resistor 101, that is,
n × R11 = RPx
From this, the insulation resistance value RPx can be obtained.

  The above is performed as follows in the circuit of FIG.

  That is, the signal 106 indicating the voltage V1 across the detection resistor 102 becomes a signal 119 via the insulation converter 109 → the signal 112 → the low-pass filter 115 and is input to one of the dividers 125. Further, the signal 107 indicating the voltage V3 across the detection resistor 105 generated by the current IPX becomes the signal 120 via the insulation converter 110 → the signal 113 → the low-pass filter 116, and is input to the other of the divider 125, and the polarity Input to the discriminator 122.

  At this time, since the signal 120 has a positive (+) polarity, the polarity discriminator 122 discriminates the (+) polarity and outputs a signal 123 which is turned on, and the divider 125 and the multiplier 131 are put in the calculation state. The display device 135 and the alarm device 136 are switched to the positive electrode side. Further, the signal 124 that is turned off causes the divider 126 and the multiplier 132 to be in a non-computation state, and locks the operations of the display device 135 and the alarm device 136 on the negative electrode side.

  By the above switching, the divider 125 outputs a signal 127 indicating V1 / V3, which is the ratio n of the signal 119 and the signal 120, and inputs the signal 127 to one of the multipliers 131. The constant setter 129 outputs a signal 130 for setting the set value K to the same value as the detection resistors R11 and R21, and inputs the signal 130 to the other of the multiplier 131. Therefore, the multiplier 131 multiplies the output signal 127 from the divider 125 and the signal 130 indicating the constant K from the constant setter 129 and outputs a signal 133.

The signal 133 indicates an insulation resistance value RPx,
RPx = n × K = (V1 / V3) × R11 (1)
Is required.
In this equation (1), n is V1 / V3, and K is a constant having a value equal to the resistance value R11 of the resistor 101.

  The signal 133 indicating the insulation resistance value RPx is given to the display device 135 and displayed, while it is given to the alarm device 136, and an alarm is issued when it falls below the preset insulation resistance value. For safety management, an output signal 137 indicating an alarm from the alarm device 136 is recorded in an appropriate recording device together with a signal 133 indicating the insulation resistance value RPx in order to record a time-series change in the insulation resistance value. Process. If a measurement power source 138 and a power switch 139 are provided as shown in FIG. 8, the insulation resistance of the power supply circuit, device or apparatus in a non-energized state, that is, not in a live line state can be obtained by using these. Measurement is possible.

Next, a case where the insulation resistance of the negative electrode side electric circuit is measured will be described.
In this case, since the current INX flows through the insulation resistance RNX to be measured and the resistance 102 is replaced with the resistance 104, the insulation resistance value RNx to be obtained from the same relationship as described above is
RNx = n × K = (V2 / V3) × R21 (2)
Can be obtained as In this equation (2), n is V2 / V3, and K is a constant having a value equal to the resistance value R21 of the resistor 103.

  In the circuit of FIG. 8, the signals 106, 112, 119, 127, and 133 are converted to the signals 108, 114, 121, 128, and 134, the arithmetic circuits 125 and 131 are switched to the arithmetic circuits 126 and 132, the signal 123 is turned off, and the signal 124 is switched off. , And the resistance value RNx of the insulation resistance RNX of the negative-side electric circuit N can be measured in exactly the same manner as when measuring the resistance value RPx of the insulation resistance RPX of the positive-side electric circuit P.

  Assuming that the resistance value RPx of the insulation resistance is 1 MΩ, R11 = RPx = 1 MΩ, and R12 = R3 = 10 KΩ, from FIG. 9, V1 and V3 are equal to approximately 1.65 V, and the ratio n of both voltages is n = Since V1 / V3 = 1.65 / 1.65 = 1, 1 MΩ can be obtained from the equation (1) as the insulation resistance value RPx of the positive-side electric circuit.

Similarly, when the voltage ratio n = V1 / V3 = 10, the insulation resistance value RPx is obtained from the equation (1) as follows: RPx = (K = 1 MΩ) × (n = 10) = 10 MΩ
Is obtained.
Similarly, for a voltage ratio n = V1 / V3 = 100,
RPx = (K = 1 MΩ) × (n = 100) = 100 MΩ,
At a voltage ratio n = 0.1,
RPx = (K = 1 MΩ) × (n = 0.1) = 0.1 MΩ
Can be requested.

  When the voltage of the power supply 100 of the power feeding circuit varies, the currents IS, IPX and INX vary in proportion to this, and V1, V2 and V3 also vary, but the voltage ratios n = V1 / V3 and n = V2 / V3 does not change. Therefore, according to this conventional apparatus, even if the voltage of the power supply circuit to be measured fluctuates, the measurement value is not affected by this, and the advantage that the insulation resistance can be measured stably is obtained.

Japanese Patent No. 4525630

  However, in the conventional device described in Patent Document 1, the insulation resistance of the positive-side electric circuit and the negative-side electric circuit can be measured, but the insulation resistance of a battery power supply that is not grounded is measured, and a plurality of unit cells It is not possible to specify at which position of a series battery connected in series an insulation failure that reduces the insulation resistance, and to identify at which load the insulation failure that causes a reduction in insulation resistance occurs in the power supply circuit. I have not been told.

A large-capacity battery power supply is configured by connecting a large number of single cells in series and parallel, so that not only the occurrence of an insulation failure in which the insulation resistance decreases due to the measurement of insulation resistance, but also a plurality of series-connected batteries If it is possible to identify the position of a single cell in a row battery made up of single cells, the defective cell is replaced with a single cell having a normal insulation resistance. Insulation failure of the battery power supply can be repaired easily and quickly.
Similarly, in a power supply circuit to which a large number of various loads are connected, when the occurrence of an insulation failure that reduces the insulation resistance is detected, an insulation failure has occurred in any branch circuit or load in the power supply circuit. If it is possible to identify whether the insulation failure of the power supply circuit is easily or quickly, the insulation failure of the power feeding circuit can be repaired easily and by replacing the branch circuit or load having the insulation failure with a branch circuit or load having a normal insulation resistance. .

  For this reason, the present invention provides power supply from a battery power source to a load in a DC power supply circuit that feeds a large number of loads via a power supply circuit from an ungrounded battery power source configured by connecting a large number of single cells in series and parallel. The insulation resistance of the battery power supply itself can be measured as well as the insulation resistance of the power supply circuit. It is an object of the present invention to provide an insulation resistance measurement method capable of specifying a column battery in which an insulation failure has occurred and a single cell in the row battery, and a power supply circuit and a load in which the insulation failure has occurred. is there.

In order to solve such a problem, the invention of claim 1 is a battery in which a plurality of single cells are connected in series to form a column battery, and a plurality of the column batteries are connected in parallel via battery switches. In a DC power supply circuit comprising a power supply, connecting a power supply circuit to the battery power supply via a power supply switch, and supplying power to each device through a plurality of branch circuits connected to the power supply circuit via branch switches,
An insulation resistance measuring device configured to measure an insulation resistance by switching a measurement mode to a power supply circuit measurement mode for measuring an insulation resistance of a power supply circuit and a battery power supply measurement mode for measuring an insulation resistance of a battery power supply. The insulation resistance measuring device is fed in a state where the feeder switch is connected to a position closer to the battery power source than the feed switch of the feed feeder connected to the battery power source, and the devices are connected to the battery power source via a feeder feeder and a branch feeder. The insulation resistance measurement device measures and monitors the insulation resistance of the DC power feeding circuit with this insulation resistance measurement device in the electric circuit measurement mode, and the insulation resistance drop that the insulation resistance value of the measured insulation resistance falls below the reference insulation resistance value of the insulation resistance is detected. The battery switch, the power supply switch and the branch switch inserted in the battery power supply, the power supply circuit and the branch circuit are connected to the battery power supply. In this case, the measurement of the insulation resistance of the DC power supply circuit is repeated until the insulation resistance recovers to a value equal to or higher than the reference insulation resistance value while cutting one by one from the downstream switch. It is characterized in that a feeding electric circuit in which a decrease in insulation resistance occurs is specified.

  The invention of claim 2 switches the measurement mode of the edge resistance measurement device to the battery power supply measurement mode when the insulation resistance does not recover even if the branch switch and the power supply switch are all disconnected in the invention of claim 1 In addition, in the operation of measuring the insulation resistance while sequentially cutting the battery switches of each battery in the battery power source one by one, the measured insulation resistance is restored to a value equal to or higher than the reference insulation resistance value of the insulation resistance. It is characterized by identifying the column battery in which the insulation resistance drop in the battery power source has occurred by repeating the above.

  According to a third aspect of the invention, in the second aspect of the invention, the column battery in which the occurrence of a decrease in insulation resistance is specified is measured by the insulation resistance measuring device, and the column battery is measured based on the measured insulation resistance value. The single cell in which the insulation resistance lowering occurs is specified.

  The present invention includes a battery power source configured by connecting a plurality of single cells in series to form a column battery, and connecting a plurality of the column cells in parallel, and the battery power source is connected to a load via a power feeding circuit and a branch circuit. Insulation resistance measurement device is connected to the DC power supply circuit to measure and monitor the insulation resistance of the DC power supply circuit, and the insulation resistance value of the measured insulation resistance falls below the reference insulation resistance value of the insulation resistance. Is detected, and each switch of the DC power supply circuit is cut one by one in order from the downstream side when viewed from the battery power source, and the insulation resistance of the DC power supply circuit is measured. By repeatedly performing the process until it recovers to a value equal to or higher than the resistance value, the branch circuit or the like in which the insulation resistance is reduced is specified. Therefore, according to the present invention, not only can the insulation resistance of the DC power supply circuit be measured, but also the branch circuit in which the insulation resistance in the power supply circuit is reduced, or the column battery in which the insulation resistance in the battery power supply is reduced, and this column Since the single cell in the battery can be easily identified, it is possible to ensure the safety of the DC power supply circuit equipped with the battery power source and to easily and quickly perform the insulation resistance repair work.

The circuit block diagram which shows the Example of the insulation resistance measuring apparatus used for this invention. Explanatory drawing of the measurement operation | movement of the insulation resistance of the single row battery of the battery power supply in this invention. Explanatory drawing of the measurement operation | movement of the insulation resistance of the double row | line | column battery of the battery power supply in this invention. Explanatory drawing of the measurement operation | movement of the insulation resistance of the electric power feeding circuit by this invention. The figure which shows the measurement characteristic of the insulation resistance measuring apparatus used for this invention. The block diagram which shows the example of the DC electric power feeding circuit which measures and monitors insulation resistance by this invention. The flowchart which shows the Example of the process sequence of this invention. The circuit block diagram which shows the conventional insulation resistance measuring apparatus. Explanatory drawing of the measurement operation | movement of the conventional insulation resistance measuring apparatus.

Embodiments of the present invention will be described with reference to the embodiments shown in the drawings.
In principle, the power supply circuit in the DC power supply circuit of the ship's electric propulsion system targeted by the present invention is a non-grounded power supply circuit that is not grounded. In addition, since the battery power source used in the electric propulsion system for ships has a large capacity, it is possible to output a high voltage, large current DC power by connecting a large number of unit cells in series and parallel. Yes.
A large number of electric devices and devices are connected to a power supply circuit for supplying DC power from the battery power source.

FIG. 1 is a circuit configuration diagram showing an embodiment of an insulation resistance measuring apparatus used in the present invention which can be applied to a DC power feeding circuit of an electric propulsion system.
First, the configuration of this insulation resistance measuring apparatus and the basic measurement operation of insulation resistance will be described.

  In FIG. 1, B1 and B2 are series battery groups (in this case, column batteries) configured by connecting m (m is an integer of 2 or more) unit cells B11 to B1m and B21 to B2m connected in series. Called). A plurality of (in this case, two) battery cells B1 and B2 are connected in parallel to form a battery power source B. The positive (P) pole terminals of the column batteries B1 and B2 are respectively connected in parallel to the positive (P) pole output terminal P of the battery power supply B via the battery switches 1 and 2, and the negative (N) pole terminal is negative (N ) It is connected in parallel to the pole output terminal N. A positive (P) pole feeding circuit LP and a negative (N) pole feeding circuit LN are connected to the output terminals P and N of the battery power source B via the circuit switch 5 respectively. Between the power supply circuits LP and LN, a large number of electric devices and devices (not shown) are connected via branch circuits each having a branch switch, and the battery power supply B passes through the power supply circuits LP and LN. Then, DC power is supplied to the electrical equipment and devices that are the loads.

  The insulation resistance measuring unit IRM includes two sets of positive (P) pole side voltage detections configured by connecting first resistors R11 and R21 having high resistance values and second resistors R12 and R22 having low resistance values in series. A circuit 11 and a negative (N) pole side voltage detection circuit 12 are provided. The two sets of voltage detection circuits 11 and 12 are connected in series and connected between the positive and negative output terminals P and N of the battery power source B. Voltages depending on the reference current IS generated at both ends of the second resistors R12 and R22 of the voltage detection circuits 11 and 12 are taken out as reference voltages V1 and V2 via the insulation detectors 13 and 14, respectively.

The insulation resistance measuring unit IRM includes two sets of ground current detection circuits 15 and 16 for detecting a positive (P) polarity ground current IPX and a negative (N) polarity ground current INX flowing through the ground E. The ground current detection circuits 15 and 16 are configured by connecting a detection resistor R31, a diode DP, a switch Pa2, and a detection resistor R32, a diode DN, and a switch Na2, respectively.
The two sets of detection circuits 15 and 16 are connected in parallel with the opposite polarity of the diodes DP and DN, and are connected between the intermediate connection point M of the voltage detection circuits 11 and 12 and the ground point E. The The voltages V31 and V32 generated at both ends of the detection resistors R31 and R32 and depending on the ground currents IPX and INX are taken out via the insulation detectors 17 and 18.

  The division units 23, 24, 32, the calculation units 25, 26, the addition unit 31, the multiplication units 27, 28, 33, 38, and the constant setting units 34, 39 are voltages V 1, V 2, detected by the detection circuit, The insulation resistance value of the DC power supply circuit including the battery power supply B, the power supply circuits LP and LN, and the load is obtained by calculation from V31 and V32, and the part of the power supply circuit where the insulation resistance is reduced to cause the insulation failure, or the battery power supply column A measurement calculation unit that specifies a battery and a single cell by calculation is configured.

The measurement mode switch 35 is a switch that selectively switches the insulation resistance measurement mode to the battery power supply measurement mode for measuring the insulation resistance of the battery power supply B or the power supply circuit measurement mode for measuring the insulation resistance of the power supply circuits LP and LN. is there.
When the “battery power” position is selected with the measurement mode switch 35, the battery power measurement mode is entered. Measurement of the insulation resistance of the battery power source B configured by connecting the cells in series and parallel, and identifying the insulation failure point where the insulation resistance is reduced Measurement to be commanded.
Further, when the “feeding circuit” position is selected by the measurement mode switch 35, the feeding circuit measurement mode is set, and the positive (P) pole side feeding circuit LP of the feeding circuit fed from the battery power source B and the ground E and the negative (N) The measurement of the insulation resistance between the pole-side power supply circuit LN and the ground E is commanded. In this power supply circuit measurement mode, the insulation resistance of the entire DC power supply circuit including the battery power supply B, the power supply circuits LP and LN, the branch circuit, and the load is measured.

  The measurement polarity switching unit 36 is a switching unit that periodically and alternately switches the measurement on the P pole side and the measurement on the N pole side. When commanding the P pole side measurement, the “1” signal is used. Command signal PSS is output, and when the N pole side measurement is commanded, a command signal NSS of “1” signal is output.

  In addition, it is possible to switch and instruct whether to measure the insulation resistance of the battery power source B with one row battery (single row battery) or with a plurality of parallel row batteries (double row batteries). A double-row measurement switching unit 37 is provided. This single-row / double-row measurement switching unit 37 sets the output command signal SPS to “0” signal when commanding measurement of insulation resistance with a single-row battery, and commands measurement of insulation resistance of the double-row battery. Switches the command signal SPS to the “1” signal.

  Based on various command signals from the measurement mode switching unit 35, the measurement polarity switching unit 36, and the single row / double row measurement switching unit 37, the control unit 30 is provided with changeover switches Pa1, Pa2, It controls switching of Pa3, Na1, Na2, and Na3 and controls the calculation operation of the measurement calculation unit.

  Further, the monitoring / recording unit 40 records the measurement values obtained by the measurement calculation unit in time series, and constantly monitors the measurement values, and displays a display when it is detected that the measurement value is out of the normal range. It manages the safety of the DC power supply circuit equipped with a battery power source by displaying on the device 41 or giving an alarm via the alarm device 42.

The insulation resistance measuring device of the present invention configured as described above performs insulation resistance measurement in each mode of (1) a mode for measuring the insulation resistance of the power feeding circuit and (2) a mode for measuring the insulation resistance of the battery power source. To do.
The operation of the insulation resistance measuring device of the present invention in each measurement mode will be described below.

  The operation of the insulation resistance measurement unit IRM should be explained from the measurement mode of the insulation resistance of the power supply circuit. For convenience of explaining the internal operation of the insulation resistance measurement unit IRM, first, the measurement mode of the insulation resistance of the battery power supply The operation of will be described.

(1) Battery Power Insulation Resistance Measurement Mode In this measurement mode, the measurement mode switch 35 is switched to the “battery power” position to select a battery power insulation resistance measurement mode (sometimes referred to as a battery power measurement mode). At this time, the electric circuit switch 5 that connects the battery power source B and the electric power supply circuits LP and LN may be turned on or off.
When the measurement mode switch 35 is switched to the “battery power” position, the switching signal SS becomes a “1” signal, and the control unit 30 and the monitoring / recording unit 40 are instructed to measure the insulation resistance of the battery power source. In response to this switching signal SS, the control unit 30 switches the signals S1P and S1N to the division units 23 and 24 for calculating the insulation resistance on the power feeding circuit side from “1” to “0” signal and outputs them. As a result, the calculation operation of the division units 23 and 24 is locked (stopped), so that the operation of measuring the insulation resistance of the power feeding circuit is stopped.

  In addition, the control unit 30 outputs a signal S2 for instructing measurement of the insulation resistance on the battery power supply side as a “1” signal to the calculation unit 31 that performs calculations necessary for measurement of the insulation resistance on the battery power supply side. Thereby, the operation unit 31 is released from the operation lock state and enters the operation state.

  The measurement polarity switcher 36 alternately alternates a signal PSS for instructing measurement of the insulation resistance on the positive (P) pole side of the battery power supply B and a signal NSS for instructing measurement of the insulation resistance on the negative (N) pole side at appropriate cycles. A “1” signal is applied to the control unit 30.

  When receiving the P pole side measurement command signal PSS of the “1” signal, the control unit 30 outputs the P pole measurement selection signal PS and stops the N pole measurement selection signal NS. Thereby, in the P pole side measurement circuit, the selection switches Pa1, Pa2, and Pa3 are turned on. In the N pole side measurement circuit, the selection switches Na1, Na2, and Na3 are turned off. For this reason, the resistor R11 is short-circuited, the ground current detection circuit 15 on the P pole side is turned on, the ground current detection circuit 16 on the N pole side is turned off, and the measurement circuit is connected to the P pole side of the battery power source B. The insulation resistance is measured.

  Further, when the N pole measurement command NSS is received, the control unit 30 outputs the N pole measurement selection signal NS and stops the P pole measurement selection signal PS. Therefore, in the N pole measurement circuit, the selection switches Na1, Na2, Na3 is turned on, and in the P pole measurement circuit, the selection switches Pa1, Pa2, Pa3 are turned off, and the measurement circuit enters a state of measuring the insulation resistance on the N pole side.

(1-1) Insulation resistance measurement mode of single-column battery One column battery, for example, column battery B1, is selected from battery power sources B configured by connecting a plurality of column batteries in parallel, and the insulation resistance is measured. There are cases where the measurement is performed (here, this is referred to as single-row battery measurement), and cases where the insulation resistance of a plurality of column batteries B1, B2 connected in parallel is measured (here, this is referred to as double-row battery measurement). These are selected by the single row / double row measurement switching unit 37.

  In the case of selecting the double-row battery measurement, in the embodiment of FIG. 1, when the insulation resistance measurement, both the battery switches 1 and 2 are turned on, and when selecting the single-row battery measurement, the two battery switches 1 2, for example, only the battery switch 1 on the side of the column battery B 1 is turned on, and the other battery switch 2 is turned off. When the single-row battery measurement is selected by operating the battery switches 1 and 2, the single-row / double-row measurement switching unit 37 is set so that the single-row battery measurement is commanded. When single row battery measurement is commanded from the single row / double row measurement switching device 37, the command signal SPS output from the single row / double row measurement switching device 37 becomes a “0” signal, and the double row battery measurement is commanded. When this is done, the command signal SPS becomes a “1” signal.

  The command signal SPS output from the single row / double row measurement switching unit 37 is applied to the multiplier 38 as an operation command. When the command signal SPS is “1”, the multiplier 38 is set in the calculation operation state, and when it is “0”, the calculation operation is locked and the calculation operation is stopped.

  Here, since single-row battery measurement is selected, the command signal SPS of the “0” signal is output from the single-row / double-row measurement switching device 37 and is supplied to the multiplier 38. Then, the operation of multiplying the output of the arithmetic unit 31 by the constant 1/2 set in the constant setting unit 39 is stopped.

FIG. 2 shows an insulation resistance measurement state of the single row battery of the battery power source B, and the operation will be described using this state.
When the signal PSS commanding the P-pole side insulation resistance measurement is output from the measurement polarity switch 36, the control unit 30 sets the P-pole measurement selection signal PS to “1” and the N-pole measurement selection signal NS to “0”. " As a result, the switches Pa1, Pa2, and Pa3 are turned on, the switches Na1, Na2, and Na3 are turned off, and the P pole side insulation resistance measurement state is set.
In this state, when the switch Pa1 is turned on, the resistor R11 is short-circuited. Therefore, the reference current IS flows through the resistors R12, R21, and R22, and the reference voltage V1 is obtained from the resistor R12.

Here, when the resistance values of the resistors R11, R12, R21, and R22 are r11, r12, r21, and r22, respectively, and the voltage of the battery power source B is VB, the reference current IS is expressed by the following equation (3). It becomes. The resistance values r11 and r21 of the resistors R11 and R21 are selected to be equal high resistance values, and the resistance values r12 and r22 of the resistors R12 and R22 are selected to be equal low resistance values. The resistance values r31 and r32 of the detection resistors R31 and R32 of the ground current detection circuits 15 and 16 are selected to be equal to the resistance values r12 and r22 of the resistors R12 and R22.
Therefore, r11 = r21 >> r12 = r22 = r31 = r32.
IS = VB ÷ (r12 + r22 + r21) ≈VB ÷ r21 (3)
１２ r12 + r22 ≪ r21
Therefore, the reference voltage V1 generated across the resistor R12 is
V1 = r12 × IS (4)
It becomes.

  When the signal NSS commanding the N-pole side insulation resistance measurement is output from the measurement polarity switch 36, the control unit 30 sets the P-pole measurement selection signal PS to “0” and sets the N-pole measurement selection signal NS to “ 1 ”. As a result, the switches Na1, Na2, and Na3 are turned on, and the switches Pa1, Pa2, and Pa3 are turned off to enter the N-pole side insulation resistance measurement state.

In this state, when the switch Na1 is turned on, the resistor R21 is short-circuited. Therefore, the reference current IS shown in the equation (5) is passed through the resistors R11, R12, and R22, and from both ends of the resistor R22. A reference voltage V2 is obtained.
IS = VB ÷ (r11 + r12 + r22) ≈VB ÷ r11 (5)
１２ r12 + r22 ≪ r11
Therefore, the reference voltage V2 generated across the resistor R22 is
V2 = r22 × IS (6)
It becomes.
Here, since r11 = r21, the reference voltages V1 and V2 are equal even when the P pole side measurement and the N pole side measurement are switched.

At the time of measurement on the P pole side, as shown in FIG. 2, the insulation resistance is reduced by being grounded via the insulation resistance RX1 for some reason at the ground point S1 between the cells B11 and B12 of the column battery B1. When the insulation failure is lowered, the P pole of the battery cell B1 of the battery power source B → the switch Pa1 → the resistor R12 → the resistor R31 → the diode DP → the switch Pa2 → the ground E → the ground resistance RX1 → the connection point S1 of the battery cell B1. → The ground current IPX1 flows through the path of the N pole of the cell B11. The ground current IPX1 is expressed by the following equation (7).
IPX1 = VB1 (1-S1) ÷ (r11 + r31 + Rx1) (7)
Here, VB1 (1-S1) is the total voltage of the cells between the ground point S1 and the P pole of the column battery B1, r11 is the resistance value of the resistor R11, r31 is the resistance value of the resistor R31, and Rx1 is This is the insulation resistance value of the insulation resistance RX1.

The voltage V31 detected by the detection resistor R31 of the ground current detection circuit 15 is expressed by the following equation (8).
V31 = IPX1 × r31 (8)

In the next N pole side measurement, the switches Pa1 and Pa2 are turned off, and the switches Na1 and Na2 are turned on. Therefore, in this case, the ground current INX1 flows through the path of the N pole of the battery ground point S1, the insulation resistance RX1, the ground E, the switch Na2, the diode DN, the resistor R32, the resistor R22, the switch Na1, and the column battery B1. . The ground current INX1 is expressed by the following equation (9).
INX1 = VB1 (S1-m) ÷ (Rx1 + r32 + r22) (9)
Here, VB1 (S1-m) is the total voltage of the cells between the ground point S1 of the battery cell B1 and the battery power supply N pole, and r32 is the resistance value of the resistor R32.

A detection voltage V32 depending on the ground current INX1 is detected from both ends of the detection resistor R32 of the ground current detection circuit 16 as shown in the following equation (10).
V32 = INX1 × r32 (10)

  When an insulation failure such as grounding through the insulation resistance RX5 occurs at the grounding point S5 of the column battery B1, the single cell total voltage VB1 (1-S5) between the grounding point S5 and the P pole of the column battery B1 , And the P pole side ground current IPX5 and the N pole side ground current INX5 flowing by the unit cell total voltage VB1 (5-m) between the ground point S5 and the N pole of the column battery B1 are the P pole and the N pole ground, respectively. Detection voltages V31 and V32 are detected by detection resistors R31 and R32 of the current detection circuits 15 and 16, respectively.

  If a decrease in insulation resistance occurs at the grounding point S9 due to a grounding accident or the like, the total voltage VB1 (1-S9) of the cells between the grounding point S9 and the P pole of the column battery B1, and the grounding point S9 and the column battery The P pole side ground current IPX9 and the N pole side ground current INX9 based on the unit cell total voltage VB1 (S9-m) between the N poles of B1 are detected as detection voltages V31 and V32 by the detection resistors R31 and R32, respectively. .

  Here, since the resistance values r11, r21 and r12, r22 of each resistor are r11 = r21 >> r12 = r22, even if the P-pole side measurement and the N-pole side measurement are alternately switched as described above, the reference current If the IS and the reference voltages V1 and V2 do not change and the reference current IS is sufficiently large with respect to the ground currents IPX1, IPX5, IPX9, INX1, INX5, and INX9, the ground currents IPX and INX are the reference Even if superimposed with the current IS, the fluctuations of the reference voltages V1 and V2 can be made extremely small.

A calculation process for obtaining an insulation resistance value from the detection voltages V31 and V32 will be described with reference to FIG.
In the P pole side measurement, the switches Pa1, Pa2 and Pa3 are turned on by the P pole side selection signal PS from the control unit 30 and the switches Na1, Na2 and Na3 are turned off, so that the P pole side reference voltage V1 ( = R12 × IS) is given to the division unit 32 through the insulation detector 13 → the low pass filter 19 → the switch Pa3. The detection voltage V31 (= r31 × IPX1) is supplied to the division unit 23, the calculation unit 25, and the addition unit 31 through the insulation detector 17 → the low-pass filter 21.

  In the N pole side measurement, the switches Na1, Na2, and Na3 are turned on by the N pole side selection signal NS from the control unit 30, and the switches Pa1, Pa2, and Pa3 are turned off. (= R22 × IS) is given to the division unit 32 through the insulation detector 14 → the low-pass filter 20 → the switch Na3. The detection voltage V32 (= r32 × INX1) is given to the division unit 24, the calculation unit 26, and the addition unit 31 through the insulation detector 18 → the low-pass filter 22.

Since the measurement mode switch 35 is switched to the “battery power supply” position, the command signal S2 is given from the control unit 30 to the adding unit 31, and the adding unit 31 is in an addition operation state.
Further, the control unit 30 gives the addition unit 31 a read signal S3 that is synchronized with the switching command signals PSS and NSS from the measurement polarity switching unit 36. Thereby, the adding unit 31 reads and stores the P-pole side detection voltage V31 and the N-pole side detection voltage V32 in synchronization with the read signal S3, and adds the both detection voltages stored in each cycle. Then, the total voltage VE (= V31 + V32) is obtained and output to the division unit 32.

The division unit 32 executes the division of the total voltage VE (= V31 + V32) with the reference voltage V1 (V1 ÷ VE) and the division of the reference voltage V2 (V2 ÷ VE) to obtain the reference voltage and the total voltage. A voltage ratio VED with VE is obtained. This voltage ratio VED is applied to a multiplier 33, where it is multiplied by a constant K of a constant setter 34 which is set to a value equal to the resistance value r11 (r21) of the resistor R11 (R21). Rx can be determined.
That is, the insulation resistance value Rx of the insulation resistance RX can be obtained by the following (11).
Rx = V1 ÷ VE × r11 = V2 ÷ VE × r21 (11)

In FIG. 5, the vertical axis represents the voltage ratio VED (= V1 / VE, = V2 / VE) between the reference voltages V1 and V2 and the total detection voltage VE, and the horizontal axis represents the insulation resistance value Rx. It is a measurement characteristic line which shows a relationship.
From FIG. 5, if the voltage ratio VED between the reference voltages V1 and V2 and the total voltage VE of the detection voltage is 1, the insulation resistance value is 1 MΩ, and if the voltage ratio VED is 0.5, the voltage ratio is 0.5 MΩ. If VED is 2, the insulation resistance value Rx can be read from the value of the voltage ratio VED as 2 MΩ. Therefore, VED indicating the voltage ratio between the reference voltage and the detection voltage, which is the output of the division unit 32, indicates the insulation resistance value.

  The voltage ratio VED is given to the multiplier 33, and when the insulation resistance value needs to be corrected, the signal VEM corrected by the voltage ratio VED is output by multiplying the multiplier 33 by the constant K set in the constant setter 34. And recorded by the monitoring / recording unit 40.

Here, the reason why the total voltage VE is obtained by adding the P pole side detection voltage V31 and the N pole side detection voltage V32 in the adder 31 (VE = V31 + V32) will be described.
As described above, the P-pole side ground current IPX1 and the detection voltage V31 flowing from the P-pole side of the battery when the insulation resistance drop (insulation failure) occurs at the ground point S1 in FIG. The N pole side ground current INX1 and the detection voltage V32 flowing from the N pole side of the battery power supply are similarly expressed by the equations (9) and (10). IPX1 = VB1 (1-S1) ÷ (r11 + r31 + Rx1 (7)
V31 = IPX1 × r31 (8)
INX1 = VB1 (S1-m) ÷ (Rx1 + r32 + r22) (9)
V32 = INX1 × r32 (10)

  That is, the P pole side detection voltage V31 is the total voltage VB1 (1-S1) of the cell B11 of the column battery B1 between the ground point S1 and the P pole, and the N pole side detection voltage V32 is between the ground point S1 and the N pole. Since the total voltage VB1 (S1-m) of the cells B12 to B1m, the total voltage VE = V31 + V32 of the detection voltage is a voltage depending on the ground current obtained by dividing the total voltage VB of the column battery B1 by the insulation resistance value Rx. I can understand.

(1-2) Insulation Resistance Measurement of Double Row Battery In the above description, the insulation resistance measurement of one row (single row) of row batteries connected in series has been described. Next, a double row battery in which a plurality of row batteries are connected in parallel is described. The case of measuring the insulation resistance of the power supply will be described with reference to FIG.

The insulation resistance measurement of the battery power supply in a state where a plurality of column batteries are connected in parallel is performed with both the battery switches 1 and 2 turned on as shown in FIG. Here, naturally, the measurement mode switch 35 is switched to the “battery power” position.
When the insulation resistance RX1 decreases due to a grounding accident or the like at the grounding point S1 of the battery cell B1 in the first row, the P pole side measurement (switches Pa1, Pa2, Pa3 are on, switches Na1, Na2, Na3 are off) Sometimes, the ground current IPX1 expressed by the equation (7) flows from the first row battery B1.
IPX1 = VB1 (1-S1) / (r12 + r31 + Rx1) (7)
Further, the ground current IPX2 shown by the following (11) flows from the second row battery B2.
IPX2 = [(VB21 + VB22 + ... + VB2m)
− (VB12 +... + VB1m)] / (r12 + r31 + Rx1) (11)

Here, if the battery voltages of the column battery B1 and the column battery B2 are equal, the battery voltage of the numerator of the equation (11) becomes the voltage VB21 of the first-stage unit cell B21, so the ground current IPX2 is (12 (See FIG. 3 for the path through which the ground current flows).
IPX2 = VB21 ÷ (r12 + r31 + Rx1) (12)
That is, if the battery voltages of the single cells are equal, the detection resistor R31 flows from the first row of column batteries B1 to IPX1 and from the second row of cells B2 to IPX2. A current twice as much as that in the case of conducting will flow, resulting in a measurement error.

Similarly, in the N-pole side measurement, the detection resistor R32 includes a ground current INX1 from the first column battery B1 expressed by the equation (13) and a ground current from the second column battery B2l expressed by the equation (14). INX2 flows (see FIG. 3 for the path through which the ground current flows).
INX1 = (= VB12 +... + VB1m) /
(Rx1 + r32 + r22)
= VBA9 ÷ (Rx1 + r32 + r22) (13)
In this equation (13), VBA9 is (VB12 +... + VB1m).
INX2 = [(VB21 +... + VB2m) −VB11]
÷ (Rx1 + r32 + r22)
= VBB9 ÷ (Rx1 + r32 + r22) (14)
In this equation (14), VBB9 is [(VB21 +... + VB2m) −VB11].
Also in this case, if the battery voltages of the respective batteries are equal, the ground current INX1 flows from the first column battery B1 and the ground current INX2 flows from the second column battery B2 to the detection resistor R32. As a result, twice as much current flows as in the case of the measurement, and a measurement error occurs.

  In addition, even if there are two or more column batteries, if the battery voltages are equal, the total value of the ground currents flowing through the detection resistors R31 and R32 is only twice that of the single column battery.

  Therefore, in the case of the double-row battery measurement in which the insulation resistance RX of the battery power source in which a plurality of row batteries are connected in parallel is measured with the double-row connection, the single-row / double-row measurement switching device 37 shown in FIG. ”And a signal SPS for instructing a multiplication operation is supplied to the multiplication unit 38. Thereby, the multiplication unit 38 performs an operation of multiplying the detection voltage total value VE (= V31 + V32) by the constant “1/2” set in the constant setting unit 39, and obtains a signal VEh that is ½ of VE. . The output signal VEh is used instead of the total value signal VE, and the ratio of the reference voltages V1 and V2 is obtained by the division unit 32 in the same manner as in the case of the single-row battery measurement, whereby the insulation resistance of the battery power supply B is obtained. The value Rx can be measured.

  In the double-row battery measurement, when specifying a column battery having a reduced insulation resistance, when either the battery switch 1 or 2 provided in each column battery shown in FIG. If it is not detected and it is detected that the insulation resistance has been recovered, the column battery on which the battery switch is turned off can be identified as a column battery in which insulation failure has occurred and the insulation resistance has decreased.

(1-3) Measurement of location where battery power supply insulation failure occurs Next, measurement for specifying a location where an insulation failure (grounding) with reduced insulation resistance in the battery power supply is described will be described with reference to FIG.

In the measurement of the insulation resistance of a single-row battery, when specifying the position (location) where an insulation failure occurs, the position specification from the P pole side is performed by the calculation unit 25, and the position specification from the N pole side is performed by the calculation unit 26. It is executed by the operation.
The calculation unit 25 that identifies the position of the battery where the insulation failure with reduced insulation resistance has occurred from the P-pole side is the (m) th battery whose insulation failure position is from the P-pole by the calculation of equation (15). Ask for.
m (P) = (V31 ÷ VE) × M (15)
Here, V31 is a detection voltage of the P-pole side detection circuit 15, VE is a total voltage (VE = V31 + V32) obtained by adding the P-pole side detection voltage V31 and the N-pole side detection voltage V32, and M is a single cell series of column batteries. The number of connections. In the double-row battery measurement, the total voltage VE of the detection voltages needs to be VE = (V31 + V32) × 1/2 for the reason described above.

  The calculation value Vm of V31 / VE in the calculation unit 25 is the P pole side detection voltage V31 (equivalent to the voltage VB11 of the grounded battery B11) and the total voltage of the column battery. Therefore, by multiplying this by the number M of the battery cells connected in series in the column battery, it is confirmed that the number of cells with poor insulation in which the insulation resistance is reduced is the mth from the P pole. Can be calculated.

Similarly, the calculation unit 26 calculates the expression (16) based on the detection voltage V32 of the N pole side measurement and the total voltage VE (= V31 + V32) of the P and N bipolar detection voltages, thereby obtaining the insulation resistance. It can be determined that the unit cell with poor insulation in which the decrease has occurred is the mth cell from the N-pole side.
m (N) = (V32 ÷ VE) × M (16)

(2) Feeding Line Insulation Resistance Measurement Mode Next, the feeding mode insulation resistance measurement mode (also referred to as the feeding line measurement mode) in which the measurement mode switch 35 is switched to the “feeding line” position and the insulation resistance of the feeding line is measured. Exist).
In addition, the output signal shown in the parenthesis of each part in the insulation measuring apparatus of FIG. 1 is an output signal when this power feeding circuit insulation resistance measurement mode is selected.
When the measurement mode switch 35 is switched to the “feeding electric circuit” position, as shown in FIG. 4, the insulation resistance RXP between the P pole side feeding electric circuit LP fed from the battery power source B and the ground E, or the N pole side The resistance value RxP or RxN of the insulation resistance RXN between the electric circuit LN and the ground E can be measured. Since the battery power supply B and various devices that are not shown here are connected to the bipolar power supply circuits LP and LN, in this measurement mode, the insulation resistance of the entire DC power supply circuit including the battery power supply B and the various devices Will be measured.

  In this case, as shown in FIG. 4, the battery switches 1 and 2 and the electric circuit switch 5 are turned on, and the DC power is supplied from the battery power source B to a device (not shown) via the electric supply circuits LP and LN. To. When measuring the P pole side insulation resistance RXP, when the signal PSS of “1” signal is input from the measurement polarity switch 36, the control unit 30 determines the P pole side output in the battery power measurement mode described above. Instead of the signal PS to be selected, a signal NS for selecting the N pole side is output. When the measurement polarity switch 36 switches to the signal NSS for measuring the N-pole side insulation resistance RXN, the control unit 30 outputs a signal PS for selecting the P-pole side.

  For this reason, when the P-pole side insulation resistance RXP is measured, the switches Na1, Na2, and Na3 are turned on by the signal NS, and the switches Pa1, Pa2, and Pa3 are turned off. This is because the current polarity of the ground current IPX is opposite to that of the P-pole-side measured current (ground current) IPX1 in the insulation resistance measurement of the battery power source. This is because it is necessary to perform measurement by the N pole side measurement circuit 16.

At this time, since the switch Na1 is turned on, the resistor R21 is short-circuited. As a result, the ground current IPX flows through the path of the feed circuit LP → insulation resistance RX → ground E → switch Na2 → diode DN → detection resistor R32 → reference resistor R22 → battery power supply N pole, and the reference detected by the resistor R22 From the voltage V2 and the detection voltage V32 detected by the detection resistor R32, a process for obtaining the insulation resistance value RxP of the P-pole side insulation resistance RXP is performed.
This is because the divider 24 on the N pole side divides the reference voltage V2 by the detection voltage V32 to obtain the voltage ratio VEP, and the resistor 28 is set in the constant setting unit 34 by the multiplier 28. This is a process for obtaining an insulation resistance value RxP by multiplying a constant K having a value equal to the resistance value r21 of R21.
When measuring the insulation resistance of the power supply circuit, the detection resistor R3 detects the ground current IX due to the insulation resistance RX based on the total voltage VB of the battery power supply B, so that either of the detection circuits 15 and 16 is detected. The insulation resistance value can be obtained based on the detection voltage V3.

That is, the insulation resistance measurement of the P pole side feeding circuit LP is measured by using the N pole side detection circuit 16 of the battery power source, and the N pole side insulation resistance measurement of the feeding circuit is measured by the P pole side detection circuit of the battery power source. 15 is used.
Therefore, when the measurement mode switching device 35 is switched to the “feeding circuit” position, the switching operation of the P-pole side / N-pole side measurement switching device 36 is reversed to switch to the P-pole side. The switches Na1 and Na2 are turned on and the command signal S1N is turned on to operate the division unit 24 for calculating V2 ÷ V32 = VEN, and the output is supplied to the multiplication unit 28. The multiplier 28 multiplies the voltage ratio VEN by the constant K set to the resistance value (r21) set in the constant setter 34 and equal to the resistor R21 to obtain the insulation resistance value RxP of the insulation resistance. The pole-side insulation resistance value VEPX is output, recorded in the monitoring / recording unit 40, and displayed and alarmed.

  Also, when performing the N pole side measurement, the P pole side switches Pa1 and Pa2 are turned on, the command signal S1P is turned on, the division unit 23 for calculating V1 ÷ V31 = VEP is operated, and the output is multiplied by the multiplication unit 27. The multiplier 27 multiplies the voltage ratio VEP by a constant K set to a resistance value (r11) set in the constant setter 34 and equal to the resistor R11 to insulate the insulation resistance RXN of the N-pole power supply circuit LN. The resistance value RxN is obtained, output as the N pole side insulation resistance value VENX, recorded in the monitoring / recording unit 40, and displayed and alarmed.

  The monitoring / recording unit 40 can record and display each insulation resistance measurement data of the battery power supply or the power feeding circuit in time series by the switching signal SS from the insulation resistance measurement mode switch 35 so that the insulation resistance change can be monitored. In addition, when the measured insulation resistance value is lower than a preset reference insulation resistance value, an alarm indicating that an insulation failure has occurred is issued. Thereby, since the battery power supply in the electric propulsion system and the insulation resistance of the power feeding circuit can be constantly monitored, the safety of the DC power feeding circuit can be managed.

  As described above, the insulation resistance measuring apparatus used in the present invention switches between the battery power supply measurement mode for measuring the insulation resistance of the battery power supply and the power supply circuit measurement mode for measuring the insulation resistance of the power supply circuit. The insulation resistance of the DC power supply circuit is measured.

  Next, the insulation resistance of the DC power supply circuit is measured using such an insulation resistance measuring device, and when a decrease in the insulation resistance is detected, the location of the insulation failure in which the insulation resistance has been reduced by the present invention is specified. A method will be described.

FIG. 6 shows an example of a DC power supply circuit to be monitored for insulation resistance according to the present invention. The DC power supply circuit shown here is an example of a DC power supply circuit applied to an electric propulsion ship.
The battery power source B in this DC power supply circuit is configured by connecting a plurality of column batteries B1 to Bn, each of which is formed by connecting a plurality of single cells in series, in parallel via battery switches SB1 to SBn, respectively. The main power supply circuit LMF and the auxiliary machine power supply circuit LAF are connected in parallel to the output terminal O of the battery power source B via the main power supply switch SMF and the auxiliary machine power supply switch SAF.

Further, a branch electric circuit for supplying electric power to a driving device including electric motors M1 and M2 for driving a marine vessel propulsion device Pr is connected to the main electric supply electric circuit LMF via branch switches SM1 and SM2. The electric motors M1 and M2 include control inverters INV1 and INV2, respectively.
A branch electric circuit having a charging device CH composed of an AC generator G and a rectifier REC for charging a battery of the battery power source B is also connected to the main power supply electric circuit LMF via a branch switch SC.
Further, the auxiliary power supply circuit LAF is connected to branch circuits that supply power to the various auxiliary devices AL1 to ALn serving as loads via the branch switches SA1 to SAn, respectively.

  In this way, the DC power supply circuit is connected to the battery power source B via the main power supply switch SMF and the auxiliary power supply switch SAF, and to the main power supply circuit LMF and the auxiliary power supply circuit LAF. A branch electric circuit having propulsion motors M1 and M2, a charging device CH, and various auxiliary devices AL1 to ALn serving as loads is connected via SA1 to SAn.

  The insulation resistance measuring unit IRM is connected to a position upstream of the main power supply switch SMF and the auxiliary power supply switch SAF of the DC power supply circuit (position on the battery power supply side). The insulation resistance measuring unit IRM includes a measurement mode switching unit 35 for switching between a battery power supply measurement mode and a power feeding circuit measurement mode, and a monitoring / recording unit 40 for recording, displaying, and alarming measurement results in the measurement device IRM. When a decrease in insulation resistance due to insulation failure is detected, disconnection information for each switch such as the main power supply switch, auxiliary power supply switch, branch switch, battery switch, etc., when performing an operation to identify the location where the insulation failure has occurred. A switch state reading unit 50 for reading is provided.

FIG. 7 shows an example of a processing procedure executed in the control unit 30 of the insulation resistance measurement unit IRM in order to specify the location where the insulation failure (insulation resistance drop) occurs.
The measurement of the insulation resistance of the DC power supply circuit of FIG. 6 is performed by turning on the battery switches SB1 to SBn, the main power supply switch SMF, the auxiliary power supply switch SAF, and the branch switches SM1, SM2, SC, SA1 to SAn. A so-called live line in which power is supplied to the propulsion motors M1 and M2 and auxiliary devices AL1 to ALn serving as loads of the branch circuits through the power supply circuit LMF and the auxiliary power supply circuit LAF, or the battery of the battery power source B is charged by the charging device CH. Do in state.

In this state, when the insulation resistance measurement is started, in step S1, the measurement mode switch 35 is switched to the “power supply circuit” position or the “battery power supply” position to measure the insulation resistance of the power supply circuit. Or, a switching operation for selecting a battery power measurement mode for measuring the insulation resistance of the battery power is performed.
In step S2, the switching state of the measurement mode switching unit 35 is read, and it is determined whether or not the power feeding circuit measurement mode is set. When it is determined in step S2 that the electric circuit measurement mode is selected, the process proceeds from the YES branch to step S13, and the electric power supply circuit measurement mode is executed.
Here, when it is determined that the current measurement mode is not the battery circuit measurement mode, the battery power supply measurement mode is selected, so that the process proceeds from the NO branch to step S23 to execute the battery power supply measurement mode.

  If it is determined in step S2 that the electric circuit measurement mode is selected, the process proceeds from the YES branch of step S2 to step S13 of the power supply circuit measurement mode, and the insulation resistance measurement unit IRM performs the above-mentioned “(2) of the power supply circuit”. Measurement of the insulation resistance RXL of the power feeding circuit is performed by the method shown in the section “Insulation Resistance Measurement Mode”. The insulation resistance value RxL of the power feeding circuit measured in this way is recorded in the monitoring / recording unit 40. In step S14, the recorded insulation resistance value RxL is compared with a preset reference insulation resistance value RxS to determine whether the insulation resistance value RxL is lower than the reference edge resistance value RxS. Detects a decrease in insulation resistance.

  When the insulation of the feeder circuits LMF and LAF and the branch circuits connected to these feeder circuits and the various devices connected to the branch circuits are normally maintained, the measured insulation resistance value RxL is obtained from the reference resistance value RxS. It becomes larger and no decrease in insulation resistance is detected. Therefore, in this case, in step S14, it is determined that there is no decrease in insulation resistance, the process proceeds from the NO branch to step S23 in the battery power measurement mode, and the process proceeds to measurement of insulation resistance of the battery power.

  In step S23 in this battery power supply measurement mode, the battery power supply B is connected while the plurality of battery cells B1 to Bn are connected in parallel mainly by the method described in the section "(1-2) Measurement of insulation resistance of the double-row battery". The insulation resistance value RxB is measured.

The insulation resistance value RxB measured in step S23 is recorded in the monitoring / recording unit 40 each time as in the power feeding circuit measurement mode, and the recorded insulation resistance value RxB is recorded in step 24 as the reference insulation resistance value. It is determined whether or not it is lower than RxS, and occurrence of a decrease in insulation resistance is detected.
In step S24, the insulation resistance value Rxn recorded in the monitoring / recording unit 40 is compared with a preset reference insulation resistance value RxS, and whether or not the insulation resistance value Rxn is lower than the reference edge resistance value RxS is determined. Detects the occurrence of a decrease in insulation resistance.

  When the insulation of the row batteries B1 to Bn is normally maintained, the measured insulation resistance value RxB is larger than the reference resistance value RxS, and a decrease in insulation resistance is not detected. For this reason, in step S24, it is determined that there is no occurrence of a decrease in insulation resistance, and from the NO branch, the process returns to step S13, and shifts again to the power supply circuit measurement mode for measuring the measurement of the insulation resistance of the power supply circuit.

  In the measurement of the insulation resistance of the power supply circuit in steps S13 and S14 in the power supply circuit measurement mode and the measurement of the insulation resistance of the battery power supply in steps S23 and S24 in the battery power supply measurement mode, the insulation resistance due to an insulation failure is measured in either measurement. It is repeatedly executed until the occurrence of a drop is detected. Thereby, it is possible to monitor the insulation resistance between the power feeding circuit and the battery power source.

  In this way, when the insulation resistance between the power supply circuit and the battery power supply is monitored, if an insulation failure occurs in any of the power supply circuits LMF, LAF, and the branch circuit and various devices connected to these power supply circuits, The measured value RxL of the power feeding circuit insulation resistance RXL measured in step S13 in the measurement mode falls below the reference insulation resistance value RxS. Thereby, when the occurrence of a decrease in insulation resistance is detected in step S14 in the power feeding circuit measurement mode, the process proceeds from the YES branch of step S14 to the next step S15.

  Step S15 is a processing step for identifying a location where an insulation failure has occurred with reduced insulation resistance. Here, the branch switches SM1, SM2, SC connected to the main power supply circuit MFL and one of the branch switches SA1 to SAn connected to the auxiliary power supply circuit LAF from the branch switch at the downstream side when viewed from the battery power source B are provided. The insulation resistance RXL of the power feeding circuit is measured while disconnecting the branch circuits one by one from the power feeding circuit one by one.

The insulation resistance value RxL measured here is recorded in the monitoring / recording unit 40 as described above, and the insulation resistance value RxL is larger than the reference insulation resistance value RxS by comparing with the reference insulation resistance value RxS in step S16. Judgment processing of whether or not the insulation resistance value has been recovered is performed.
If the recovery of the insulation resistance is not detected by this, the branch circuit in which the insulation resistance is reduced due to the insulation failure is still connected to the feed lines LMF, LAF, and therefore, from the NO branch of step S16 to step S20. Proceed to

  In this step S20, the switch state reading unit 50 in FIG. 6 reads each time the switch for which the power feeding circuit has been disconnected in step 15, and determines from the history whether all the switches in the power feeding circuit have been disconnected. To do. If it is determined in step S20 that all the switches of the power feeding circuit have not been disconnected, the process returns to step S15 from the NO branch, and one disconnecting operation of the branch switch connected to the power feeding circuit is performed from the downstream side. Step by step, and repeat the process of measuring the insulation resistance of the feed circuit. It should be noted that the previously cut switch may be turned back on instead of being cut off during the subsequent processing.

If the recovery of insulation resistance is not detected even if all the switches from the branch switch to the circuit switch are disconnected and the branch circuit and the power supply circuit are disconnected from the battery power source B, an insulation failure has occurred in the power supply circuit. Therefore, it is foreseen that there may be an insulation failure in the battery power source B.
For this reason, when disconnection of all the switches of the power feeding circuit is detected in step S20, the process proceeds from the YES branch of step S20 to step S23 of the power supply side mode and shifts to the battery power supply measurement mode for measuring the insulation resistance of the battery power supply. Will do.

As described above, in the power feeding circuit measurement mode, the switches of the power feeding circuit are disconnected one by one from the downstream side, the insulation resistance is measured, and the processes of steps S15 and S16 for determining whether or not the insulation resistance has been restored are as follows. It is repeatedly executed until all the switches of the power feeding circuit are disconnected.
In this way, while repeating the insulation resistance measurement performed while disconnecting the power supply circuit switch one by one from the downstream side and the determination process of the insulation resistance recovery, when the insulation resistance recovery is detected, the YES branch of step S16 Then, the process proceeds to step S17.

If the recovery of the insulation resistance is detected in step S16, an insulation failure has occurred in the branch circuit to which the switch disconnected immediately before or the power feeding circuit belongs. For this reason, in step S17, the switch that has been disconnected immediately before it is detected that the insulation resistance has been recovered in step S16 is identified from the reading history of the disconnected switch, so that the branch circuit in which the insulation failure has occurred or the power feeding is performed. The electric circuit can be specified. The branch circuit or the power feeding circuit in which the occurrence of the insulation failure is identified in this way is recorded and displayed in the monitoring / recording unit 40 and is notified to the manager of the power feeding circuit.
In this way, by recording and displaying the location where the occurrence of the insulation failure is specified, the power feeding circuit measurement mode is completed, and the insulation recovery operation is performed on the branch circuit or the like where the insulation failure has occurred.

  The process proceeds from step S2, S14, S20, etc. in the power supply circuit measurement mode to the battery power supply measurement mode, and in step S23, the insulation resistance RX of the battery power supply B is measured while a plurality of column batteries are connected in parallel. The measured insulation resistance value Rx of the battery power source is recorded in the monitoring / recording unit 40 each time as described above. Then, in step 24, the recorded insulation resistance value Rx of the battery power source is compared with the reference insulation resistance value RxS to determine whether or not the insulation resistance has decreased.

  When the insulation of the row batteries B1 to Bn is normally maintained, the measured insulation resistance value Rx becomes larger than the reference insulation resistance value RxS, and a decrease in insulation resistance is not detected. For this reason, in step S24, since it is determined that the insulation resistance has not decreased, the process returns to step S13 in the electric circuit measurement mode from the NO branch, and the measurement and monitoring of the insulation resistance of the power supply circuit are performed again.

  However, if an insulation failure occurs somewhere in the battery power source B and an insulation resistance drop is detected at which the insulation resistance value Rx is equal to or less than the reference insulation resistance value RxS, the process proceeds from the YES branch of step S24 to step S25. A process for specifying the location where insulation failure occurs in the battery power source B is performed.

  In step 25, the insulation resistance RX of the battery power source B is measured while cutting the battery switches SB1 to SBn of the battery cells B1 to Bn of the battery power source B one by one in the same manner as in step 15 in the power feeding circuit measurement mode. And the process of recording the measured insulation resistance value Rx in the monitoring / recording unit 40 is performed.

Subsequently, in step S26, the recorded insulation resistance value Rx is compared with the reference insulation resistance value RxS to determine whether or not the insulation resistance has recovered to the reference insulation resistance value RxS or more.
As a result of this determination, if recovery of insulation resistance is not detected, the process proceeds from the NO branch of step S26 to step S30, and all battery switches (SB1 to SB1) of the battery power supply B are determined from the history of reading the disconnection state of each battery switch. A determination is made whether SBn) has been disconnected. If it is determined that all the battery switches (SB1 to SBn) are not disconnected, the process returns to step S25 to disconnect the next battery switch and measure the insulation resistance of the battery power supply B. The insulation resistance measurement process (insulation resistance recovery process) in step S25 is repeatedly executed until the measured insulation resistance value Rx recovers to a normal value equal to or higher than the reference insulation resistance value RxS.

  When the measured insulation resistance value Rxn of the battery power source B is restored to a normal value equal to or higher than the reference insulation resistance value RxS, the insulation resistance recovery is detected in step S26. From the YES branch of step S26, the process proceeds to the next step S27.

  In step 27, similarly to step S17 in the power feeding circuit measurement mode, the battery disconnected immediately before it was determined in step S26 that the insulation resistance was recovered from the reading history of the battery switches sequentially disconnected by the insulation resistance recovery process. A switch is specified, and processing for specifying a column battery in which insulation failure has occurred is performed from the specified battery switch. As a result, the column battery identified as having an insulation failure is recorded and displayed on the monitoring / recording unit 40 and is notified to the administrator of the power feeding circuit.

In step 27, when the identification of the column battery in which the insulation failure in which the insulation resistance decreases is completed, the process proceeds to step 28. In this step S28, with respect to the column battery specified as the column battery in which the insulation failure has occurred, the insulation resistance measuring device IRM uses the method described in the section “(1-3) Measurement of insulation failure position of battery power source”. , Measure the insulation resistance of the cell battery, and based on the measured value, execute a calculation to identify the unit cell in which insulation failure has occurred due to a decrease in insulation resistance, and identify the unit cell in which insulation failure has occurred Process.
When the unit cell in which the insulation failure has occurred is specified, this is recorded and displayed in the monitoring / recording unit 40 and is notified to the manager who manages this power feeding circuit.

  In this way, when an insulation failure in which the insulation resistance is reduced occurs in the battery power supply, the column battery in which the insulation failure has occurred and the single cell in which the insulation failure has occurred are identified, and this is recorded. The display ends the measurement and monitoring of the insulation resistance in the battery power supply measurement mode, and performs insulation recovery work such as replacement of the cell of the column battery in which insulation failure has occurred.

B: battery power sources B1 to Bn: battery cells B11 to B1m, B21 to B2m: single cell LP, LN: power supply line R11, R21: high resistance detection resistor R12, R22: low resistance detection resistor R31, R32: detection resistor DP, DN: diode IRM: insulation resistance measuring unit 1, 2: battery switch 5: power switch 11, 12: voltage detection circuits 13, 14, 17, 18: insulation voltage detectors 15, 16: ground Current detection circuits 19-22: Low-pass filters 23, 24, 32: Dividers 25, 26, 31: Calculators 27, 28, 33, 38: Multiplier 30: Control unit 34, 39: Constant setter 35: Measurement Mode switching unit 36: Measurement polarity switching unit 37: Single row / double row measurement switching unit 40: Monitoring / recording unit 41: Display unit 42: Alarm unit 50: Switch state reading unit

Claims (3)

A plurality of single cells are connected in series to form a column battery, and each column battery is provided with a battery power source configured by connecting a plurality of cells in parallel with each other through a battery switch. In a DC power feeding circuit that is connected and fed to each device through a plurality of branch circuits connected to the power supply circuit via branch switches, respectively.
An insulation resistance measuring device configured to measure an insulation resistance by switching a measurement mode to a power supply circuit measurement mode for measuring an insulation resistance of a power supply circuit and a battery power supply measurement mode for measuring an insulation resistance of a battery power supply. The insulation resistance measuring device is fed in a state where the feeder switch is connected to a position closer to the battery power source than the feed switch of the feed feeder connected to the battery power source, and the devices are connected to the battery power source via a feeder feeder and a branch feeder. The insulation resistance measurement device measures and monitors the insulation resistance of the DC power feeding circuit with this insulation resistance measurement device in the electric circuit measurement mode, and the insulation resistance drop that the insulation resistance value of the measured insulation resistance falls below the reference insulation resistance value of the insulation resistance is detected. The battery switch, the power supply switch and the branch switch inserted in the battery power supply, the power supply circuit and the branch circuit are connected to the battery power supply. In this case, the measurement of the insulation resistance of the DC power supply circuit is repeated until the insulation resistance recovers to a value equal to or higher than the reference insulation resistance value while cutting one by one from the downstream switch. A method for measuring an insulation resistance of a DC power supply circuit, wherein a power supply circuit in which a decrease in insulation resistance occurs is specified.   If the insulation resistance does not recover even if all of the branch switch and the power supply switch are disconnected, the measurement mode of the edge resistance measurement device is switched to the battery power supply measurement mode, and the battery switch of each column battery of the battery power supply is switched on. The operation of measuring the insulation resistance while cutting one by one in order is repeated until the measured insulation resistance is restored to a value equal to or higher than the reference insulation resistance value of the insulation resistance, thereby reducing the insulation resistance in the battery power source. The method of measuring an insulation resistance of a DC power feeding circuit according to claim 1, wherein the column battery in which the occurrence of the DC current occurs is specified.   An insulation resistance is measured by the insulation resistance measuring device for the column battery in which the occurrence of a decrease in insulation resistance is specified, and the unit cell in which the insulation resistance is reduced in the column battery is specified based on the measured insulation resistance value. Item 3. A method for measuring an insulation resistance of a DC power feeding circuit according to Item 2.