JP2006337130A - Flying capacitor type voltage measurement device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flying capacitor type voltage measurement device having voltage measurement function and insulating detection function of a voltage source. <P>SOLUTION: The flying capacitor type voltage measurement device comprises an operation mode selection circuit 4, connected to a flying capacitor 3 and selecting two operation modes of a voltage measurement mode for measuring individual voltages of each voltage source V1-V5 of a high-voltage power source V and an insulating detection mode for detecting an insulating state of the high-voltage power source; an interface circuit 6 connected between a sample switch 5 and a voltage measurement means 7 and that is supplied to the voltage measurement means 7, by converting voltage supplied to the sample switch 5 into voltage into ground potential; and a control means 7 for selecting the operating mode of the operating mode selection circuit 4 and controlling the opening and closing of switches S1-S6 of multiplexers 1 and 2 and a sample switch 4, in response to the operation mode selected. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flying capacitor type voltage measuring apparatus, and more particularly to a flying capacitor type voltage measuring apparatus having an insulation detection function.

  As a device for measuring the voltage of each individual battery (voltage source) constituting a high-voltage power source in a high-voltage power source configured by connecting a large number of batteries (voltage source) in series like a power source of an electric vehicle, There is a flying capacitor type voltage measuring device. Such an apparatus is disclosed in, for example, Japanese Patent Application Laid-Open No. 11-248755 (Patent Document 1).

In the flying capacitor type voltage measuring device disclosed in the above publication, the voltage of the voltage source is temporarily stored in the capacitor by a switch, and then the switch between the voltage source and the capacitor is disconnected, and the signal processing side and the capacitor are connected, The voltage of each voltage source is multiplexed and captured while maintaining insulation.
Japanese Patent Laid-Open No. 11-248755

  However, the above-described conventional apparatus has a problem that it is necessary to provide a separate ground fault sensor in order to detect the insulation state of the voltage source only by the voltage measurement function of the voltage source, and the efficiency of the system is poor.

  In view of the above-described problems, an object of the present invention is to provide a flying capacitor type voltage measuring apparatus having a voltage measuring function and an insulation detecting function of a voltage source.

  A flying capacitor type voltage measuring device according to claim 1 includes N voltage sources connected in series, and is connected to a high voltage power source insulated from a ground potential, a flying capacitor, and the N voltage sources. A multiplexer including (N + 1) switches for selectively connecting the (N + 1) voltage detection terminals to the flying capacitor, voltage measuring means, and a voltage across the flying capacitor are supplied to the voltage measuring means. A flying capacitor type voltage measuring apparatus having a sample switch, wherein the voltage measuring mode is connected to the flying capacitor and measures an individual voltage of each voltage source of the high-voltage power source and an insulation detection for detecting an insulation state of the high-voltage power source An operation mode selection circuit for selecting two operation modes, the sample switch and the previous mode An interface circuit connected between the voltage measuring means and converting the voltage supplied via the sample switch to a voltage with respect to the ground potential and supplying the voltage measuring means, and an operation mode of the operation mode selection circuit is selected. And a control means for controlling opening and closing of the switch of the multiplexer and the sample switch in accordance with the selected operation mode.

  According to a second aspect of the present invention, in the flying capacitor type voltage measuring device according to the first aspect, the multiplexer is one of (N + 1) voltage detection terminals connected to the N voltage sources connected in series. A first multiplexer that selectively connects the odd-numbered voltage detection terminal to one terminal side of the flying capacitor, and the even-numbered voltage detection terminal of the (N + 1) voltage detection terminals as the flying capacitor. And a second multiplexer selectively connected to the other terminal side.

  According to a third aspect of the present invention, in the flying capacitor type voltage measuring device according to the first aspect, the multiplexer is one of (N + 1) voltage detection terminals connected to the N voltage sources connected in series. A plurality of switches that selectively connect each of the first to Nth voltage detection terminals to one terminal side of the flying capacitor, and a second to (N + 1) th voltage among the (N + 1) voltage detection terminals. And a plurality of switches for selectively connecting the detection terminals to the other terminal side of the flying capacitor.

  According to a fourth aspect of the present invention, in the flying capacitor type voltage measuring device according to the first aspect, the multiplexer includes the (N + 1) voltage detection terminals connected to the N voltage sources connected in series. The (N + 1) switches selectively connected to the flying capacitor, the first to Nth switches among the (N + 1) voltage sample switches, and one terminal of the flying capacitor, respectively, N diodes connected in polarity conducting from a switch to the flying capacitor, and between the second to (N + 1) th switch of the (N + 1) switches and the other terminal of the flying capacitor, Each of the N diodes connected in polarity conducting from the flying capacitor to the switch. Characterized in that it further comprises a de.

  According to a fifth aspect of the present invention, in the flying capacitor type voltage measuring device according to any one of the first to fourth aspects, the operation mode selection circuit is configured to charge the flying capacitor according to the selection of the operation mode. It is characterized by switching.

  According to a sixth aspect of the present invention, in the flying capacitor type voltage measuring device according to any one of the first to fourth aspects, the operation mode selection circuit charges the flying capacitor in accordance with the selection of the operation mode. In addition to switching the resistance, the flying capacitor is connected in the voltage measurement mode, and a capacitor having a larger capacity than the flying capacitor is connected in place of the flying capacitor in the insulation detection mode.

  According to a seventh aspect of the present invention, in the flying capacitor type voltage measuring device according to the fifth or sixth aspect, the interface circuit includes a voltage dividing circuit including a resistor that functions as a voltage dividing resistor together with a charging resistor of the operation mode selection circuit. It is characterized by being.

  According to the flying capacitor type voltage measuring apparatus of the first to fourth aspects, the function of the ground fault sensor for detecting the insulation state of the high voltage power source can be built in, and the cost and space for the ground fault sensor hardware can be reduced.

  According to the flying capacitor type voltage measuring device of the fifth and sixth aspects, the detection accuracy of the insulation detection mode can be improved without degrading the performance of the voltage measurement mode.

  According to the flying capacitor type voltage measuring apparatus of the seventh aspect, since the charging resistor is also used as the voltage dividing resistor, the component cost is reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  (First Embodiment) FIG. 1 is a circuit diagram showing the configuration of a flying capacitor type voltage measuring apparatus according to a first embodiment of the present invention.

  The flying capacitor type voltage measuring device includes first and second multiplexers 1 and 2 connected to voltage detection terminals T1 to T6 of a high-voltage power supply V, bipolar flying capacitors 3, an operation mode selection circuit 4, a sample switch 5, An I / F (interface) circuit 6 and a microcomputer (hereinafter referred to as a microcomputer) 7 are included.

  High-voltage power supply V includes N (in this embodiment, for example, N = 5) voltage sources (for example, single cells) V1 to V5 connected in series, and is insulated from the ground potential. Each of the voltage sources V1 to V5 is connected to (N + 1) (for example, six in this embodiment) voltage detection terminals T1 to T6. The voltage detection terminals T1 and T6 are a positive terminal and a negative terminal of the high-voltage power supply V, respectively.

  The multiplexer 1 includes switches S1, S3, S5 having one terminal connected to each voltage detection terminal T1, T3, T5. The multiplexer 2 includes switches S2, S4, and S6 having one terminal connected to each of the voltage detection terminals T2, T4, and T6.

  The other terminals of the switches S1, S3, and S5 are each connected to the operation mode selection circuit 4, and the other terminals of the switches S2, S4, and S6 are each connected to one terminal of the flying capacitor 3.

  The operation mode selection circuit 4 includes a parallel connection circuit of a switch S7 and a resistor R1, and one terminal of the parallel connection circuit is connected to the other terminals of the switches S1, S3, and S5, and the other terminal is the flying capacitor 3. Is connected to the other terminal.

  Sample switch 5 includes switches S8 and S10 connected to one terminal of operation mode selection circuit 4, and switches S9 and S11 connected to one terminal of flying capacitor 3. The other terminals of the switches S8 to S11 are connected to the I / F circuit 6.

  The I / F circuit 6 is for converting a voltage supplied to the input port A / D of the microcomputer 7 through the sample switch 5 into a voltage with respect to the ground potential, and is configured by a resistor R3 and a resistor R4. As will be described later, the resistors R3 and R4 together with the resistor R1 of the operation mode selection circuit 4 constitute a voltage dividing circuit that divides the voltage across the flying capacitor 3 as a voltage dividing resistor. One terminal of the resistor R3 is connected to the other terminal of the switches S9 and S10 of the sample switch 5, and the other terminal is grounded. One terminal of the resistor R4 is connected to the other terminals of the switches S8 and S11 of the sample switch 4 and the input port A / D of the microcomputer 7, and the other terminal is grounded.

  The microcomputer 7 is supplied with a drive voltage from the power supply + Vcc to its power supply port Vcc, and is supplied with a voltage from its I / F circuit 6 to its input port A / D. Each of the switches S1 to S6, the switch S7 of the operation mode selection circuit 4, and the switches S8 to S11 of the sample switch 5 function as control means for switching control according to an operation mode to be described later.

  With the above-described configuration, the flying capacitor type voltage measuring apparatus detects a voltage measurement mode for measuring individual voltages of the voltage sources V1 to V5 of the high-voltage power supply V and insulation detection for detecting an insulation state (ground fault state) of the high-voltage power supply V. The operation mode can be selected and operated. Hereinafter, each operation mode will be described.

  In the voltage measurement mode, first, when the switch S7 of the operation mode selection circuit 4 is closed and the switch S1 of the first multiplexer 1 and the switch S2 of the second multiplexer 2 are closed from the initial state where all the switches are open. The voltage source V1, the voltage detection terminal T1, the switch S1, the switch S7, the flying capacitor 3, the switch S2, and the voltage detection terminal T2 form a closed circuit. Thereby, the voltage of the voltage source V1 is charged in the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity.

  Next, the switches S1, S2 and S7 are opened, the switches S8 and S9 of the sample switch 5 are closed for a predetermined period, and the voltage across the flying capacitor 3, that is, the voltage of the voltage source V1 is set to the resistor R1, the sample switch 5 and the I / F. This is supplied to the input port A / D of the microcomputer 7 via the circuit 6. At this time, the voltage across the flying capacitor 3, that is, the voltage of the voltage source V1, is divided by the voltage dividing ratio determined by the resistors R1, R3, and R4 and supplied to the input port A / D of the microcomputer 7. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as the voltage of the voltage source V1.

  Next, after the voltage charged in the flying capacitor 3 is sufficiently discharged by a reset switch (not shown), the switches S8 and S9 are opened, and then the switches S2, S3 and S7 are closed. A closed circuit is formed by the terminal T2, the switch S2, the flying capacitor 3, the switch S7, the switch S3, and the voltage detection terminal T3. Thereby, the voltage of the voltage source V2 is charged to the flying capacitor 3 so that the polarity is opposite to that at the time of measurement of the voltage source V1, that is, the terminal side of the flying capacitor 3 connected to the switch S2 has a positive polarity. The

  Next, the switches S2, S3 and S7 are opened, the switches S11 and S10 of the sample switch 5 are closed for a predetermined period, and the voltage across the flying capacitor 3, that is, the voltage of the voltage source V2 is set to the resistor R1, the sample switch 5 and the I / F. This is supplied to the input port A / D of the microcomputer 7 via the circuit 6. At this time, the voltage at both ends of the flying capacitor 3, that is, the voltage of the voltage source V2, is inverted by the switches S11 and S10 to have the same polarity as when the voltage source V1 is measured, and is determined by the resistors R1, R3, and R4. The voltage is divided at a voltage dividing ratio and supplied to the input port A / D of the microcomputer 7. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as the voltage of the voltage source V2.

  Similarly, values indicating the voltages of the voltage sources V3, V4, and V5 are read by the microcomputer 7 by combinations of the switches S3 and S4, S4 and S5, S5 and S6, respectively. Further, the total voltage of all the voltage sources V1 to V5, that is, the high voltage of the high voltage power source V can be read by the microcomputer 7 by the combination of the switches S1 and S6. Note that the switches S8 and S9 of the sample switch 5 are closed when measuring the voltages of the odd-numbered voltage sources V1, V3 and V5, but the switches 11 and 11 of the sample switch 5 are measured when measuring the voltages of the even-numbered voltage sources V2 and V4. Since 10 is closed and the polarity is inverted, a voltage of the same polarity is always supplied to the input port A / D of the microcomputer 7.

  Next, in the insulation detection mode, first, when the switch S1 of the first multiplexer 1 and the switch S6 of the second multiplexer 2 are closed from the initial state where all the switches are open, the voltage sources V1 to V5 and the voltage detection are detected. A closed circuit is formed by the terminal T1, the switch S1, the resistor R1, the flying capacitor 3, the switch S6, and the voltage detection terminal T6. Thereby, the high voltage of the high voltage power supply V is charged in the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity.

  Next, the switches S1 and S6 are opened, the switches S8 and S9 of the sample switch 5 are closed for a predetermined period, and the voltage across the flying capacitor 3, that is, the high voltage of the high voltage power source V is applied to the resistor R1, the sample switch 5 and the I / F circuit. 6 is supplied to the input port A / D of the microcomputer 7. At this time, the voltage across the flying capacitor 3, that is, the high voltage of the high voltage power supply V is divided by the voltage dividing ratio determined by the resistors R 1, R 3 and R 4 and supplied to the input port A / D of the microcomputer 7. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as the high voltage of the high voltage power source V.

  Next, after the voltage charged in the flying capacitor 3 is sufficiently discharged by a reset switch or the like (not shown), the switch S9 is closed and the switch S1 is closed, so that the voltage sources V1 to V5, the voltage detection terminal T1, the switch A closed circuit is formed by S1, resistor R1, flying capacitor 3, switch S9, resistor R3, ground potential, ground fault resistor Rn on the negative terminal side of high-voltage power supply V, and voltage detection terminal T6. Thereby, the voltage according to the value of the ground fault resistance Rn is charged in the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity.

  Next, the switch S1 is opened, then the switch S8 is closed for a predetermined period, and the voltage across the flying capacitor 3 is supplied to the input port A / D of the microcomputer 7 via the resistor R1, the sample switch 5 and the I / F circuit 6. To do. At this time, the voltage across the flying capacitor 3, that is, the voltage corresponding to the value of the ground fault resistance Rn is divided by the voltage division ratio determined by the resistors R1, R3, and R4, and is applied to the input port A / D of the microcomputer 7. Supplied. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as a voltage corresponding to the value of the ground fault resistance Rn.

  The microcomputer 7 calculates the value of the ground fault resistance Rn on the negative terminal side of the high voltage power supply V based on the voltage corresponding to the value of the ground fault resistance Rn read this time and the high voltage of the high voltage power supply V read last time. . (Note that the ground fault resistance calculation method is the same as the method disclosed in Japanese Patent Application Laid-Open No. 2004-170103, Japanese Patent Application Laid-Open No. 2004-245632, etc. previously proposed by the applicant. Will not be described in detail.

  Next, after the voltage charged in the flying capacitor 3 is sufficiently discharged by a reset switch or the like (not shown), when the switch S6 is closed while the switch S8 is closed, the voltage sources V1 to V5, the voltage detection terminal T1, the high voltage A closed circuit is formed by the ground fault resistance Rp, the ground potential, the resistance R4, the resistance R2, the switch S8, the resistance R1, the flying capacitor 3, the switch S6, and the voltage detection terminal T6 on the positive terminal side of the power supply V. Thereby, the voltage according to the value of the ground fault resistance Rp is charged in the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity.

  Next, the switch S6 is opened, then the switch S9 is closed for a predetermined period, and the voltage across the flying capacitor 3 is supplied to the input port A / D of the microcomputer 7 via the resistor R1, the sample switch 5 and the I / F circuit 6. To do. At this time, the voltage across the flying capacitor 3, that is, the voltage corresponding to the value of the ground fault resistance Rp is divided by the voltage division ratio determined by the resistors R 1, R 3 and R 4, and is applied to the input port A / D of the microcomputer 7. Supplied. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as a voltage corresponding to the value of the ground fault resistance Rp.

  The microcomputer 7 calculates the value of the ground fault resistance Rp on the positive terminal side of the high voltage power supply V based on the voltage corresponding to the value of the ground fault resistance Rp read this time and the high voltage of the high voltage power supply V read last time. .

  Finally, the microcomputer 7 determines the insulation state of the high-voltage power supply V from the calculated values of the negative terminal side ground fault resistance Rn and the positive terminal side ground fault resistance Rp. For example, the ground fault resistance Rp on the positive terminal side of the high-voltage power supply V is compared with a predetermined reference resistance value. If the value of the ground fault resistance Rp is equal to or lower than the reference resistance value, an insulation failure occurs. It is determined that

  Thus, according to the flying capacitor type voltage measuring apparatus of the first embodiment, in the voltage measurement mode, the voltage sources V1 to V5 of the high-voltage power supply V can be measured, and in the insulation detection mode, It is possible to detect the insulation or ground fault state of the high-voltage power supply V.

  In the voltage measurement mode and the insulation detection mode, the opening / closing of each of the flying capacitor 3, the first multiplexer 1, the second multiplexer 2, the operation mode selection circuit 4, and the sample switch 5 is sequence-controlled as described above. The voltage measurement operation and the insulation detection operation of the voltage source can be made possible only with this. Such sequence control can be executed by a software program of the microcomputer 7.

  (Second Embodiment) FIG. 2 is a circuit diagram showing the configuration of a flying capacitor type voltage measuring apparatus according to a second embodiment of the present invention.

  The flying capacitor type voltage measuring device includes short-circuit protection current limiting resistors R11 to R16 connected to voltage detection terminals T1 to T6 of the high voltage power supply V, a multiplexer 12, a unipolar flying capacitor 3, an operation mode selection circuit 4, and a sample. It includes a switch 5, an I / F (interface) circuit 6, and a microcomputer 7 as voltage measuring means.

  High-voltage power supply V includes N voltage sources (for example, single cells) V1-V5 connected in series (in this embodiment, for example, N = 5). Each of the voltage sources V1 to V5 is connected to (N + 1) (for example, six in this embodiment) voltage detection terminals T1 to T6.

  Multiplexer 12 includes switches S12-S16 having one terminal connected to current limiting resistors R11-R15, respectively, and switches S17-S21 having one terminal connected to current limiting resistors R12-R16, respectively.

  The other terminals of the switches S12 to S16 are each connected to the operation mode selection circuit 4, and the other terminals of the switches S17 to S21 are respectively connected to one terminal of the flying capacitor 3.

  The operation mode selection circuit 4 includes a parallel connection circuit of a switch S7 and a resistor R1. One terminal of the parallel connection circuit is connected to the other terminal of the switches S12 to S16, and the other terminal is the other terminal of the flying capacitor 3. Connected to the terminal.

  The sample switch 5 includes a switch S8 connected to one terminal of the operation mode selection circuit 4 and a switch S9 connected to one terminal of the flying capacitor 3. The other terminals of the switches S8 and S9 are connected to the I / F circuit 6.

  The I / F circuit 6 is for converting a voltage supplied to the input port A / D of the microcomputer 7 through the sample switch 5 into a voltage with respect to the ground potential, and is configured by a resistor R3 and a resistor R4. As will be described later, the resistors R3 and R4 together with the resistor R1 of the operation mode selection circuit 4 constitute a voltage dividing circuit that divides the voltage across the flying capacitor 3 as a voltage dividing resistor. One terminal of the resistor R3 is connected to the other terminal of the switches S9 and S10 of the sample switch 5, and the other terminal is grounded. One terminal of the resistor R4 is connected to the other terminals of the switches S8 and S11 of the sample switch 4 and the input port A / D of the microcomputer 7, and the other terminal is grounded.

  The microcomputer 7 is supplied with a drive voltage from the power supply + Vcc to its power supply port Vcc, and is supplied with a voltage from its I / F circuit 6 to its input port A / D. Each of the switches S1 to S6, the switch S7 of the operation mode selection circuit 4, and the switches S8 to S11 of the sample switch 5 function as control means for switching control according to an operation mode to be described later.

  With the above-described configuration, the flying capacitor type voltage measuring apparatus according to the second embodiment can be operated by selecting two operation modes of a voltage measurement mode and an insulation detection mode. Hereinafter, each operation mode will be described.

  In the voltage measurement mode, first, when the switch S7 of the operation mode selection circuit 4 is closed and the switches S12 and S17 of the multiplexer 12 are closed from the initial state where all the switches are open, the voltage source V1, the voltage detection terminal T1, A closed circuit is formed by the current limiting resistor R11, the switch S12, the switch S7, the flying capacitor 3, the switch S17, the current limiting resistor R12, and the voltage detection terminal T2. Thereby, the voltage of the voltage source V1 is charged in the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity.

  Next, the switches S12, S17, S7 are opened, the switches S8, S9 of the sample switch 5 are closed for a predetermined period, and the voltage across the flying capacitor 3, that is, the voltage of the voltage source V1, is set to the resistor R1, the sample switch 5, and the I / F. This is supplied to the input port A / D of the microcomputer 7 via the circuit 6. At this time, the voltage across the flying capacitor 3, that is, the voltage of the voltage source V1, is divided by the voltage dividing ratio determined by the resistors R1, R3, and R4 and supplied to the input port A / D of the microcomputer 7. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as the voltage of the voltage source V1.

  Next, after the voltage charged in the flying capacitor 3 is sufficiently discharged by a reset switch (not shown), the switches S8 and S9 are opened, and then the switches S13, S18 and S7 are closed. A closed circuit is formed by the terminal T2, the current limiting resistor R12, the switch S13, the switch S7, the flying capacitor 3, the switch S18, the current limiting resistor R13, and the voltage detection terminal T3. Thereby, the voltage of the voltage source V2 is charged to the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity, as in the measurement of the voltage source V1.

  Next, the switches S13, S18 and S7 are opened, the switches S8 and S9 of the sample switch 4 are closed for a predetermined period, and the voltage across the flying capacitor 3, that is, the voltage of the voltage source V2 is set to the resistor R1, the sample switch 5 and the I / F. This is supplied to the input port A / D of the microcomputer 7 via the circuit 6. At this time, the voltage across the flying capacitor 3, that is, the voltage of the voltage source V2, is divided by the voltage dividing ratio determined by the resistors R1, R3, and R4 and supplied to the input port A / D of the microcomputer 7. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as the voltage of the voltage source V2.

  Similarly, values indicating the voltages of the voltage sources V3, V4, and V5 are read by the microcomputer 7 by combinations of the switches S14 and S19, S15 and S20, S16 and S21, respectively. Further, the combination of the switches S12 and S21 allows the microcomputer 7 to read the total voltage of all the voltage sources V1 to V5, that is, the high voltage of the high voltage power supply V. In the second embodiment, since the flying capacitor 3 is charged in the same direction when measuring the voltages of all the voltage sources V1 to V5, the input port A / D of the microcomputer 7 always has a voltage of the same polarity. Is supplied.

  Next, in the insulation detection mode, first, when the switches S12 and S21 of the multiplexer 12 are closed from the initial state where all the switches are open, the voltage sources V1 to V5, the voltage detection terminal T1, the current limiting resistor R11, the switch A closed circuit is formed by S12, the resistor R1, the flying capacitor 3, the switch S21, the current limiting resistor R16, and the voltage detection terminal T6. Thereby, the high voltage of the high voltage power supply V is charged in the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity.

  Next, the switches S12 and S21 are opened, the switches S8 and S9 of the sample switch 5 are closed for a predetermined period, and the voltage across the flying capacitor 3, that is, the high voltage of the high voltage power source V is applied to the resistor R1, the sample switch 5 and the I / F circuit. 6 is supplied to the input port A / D of the microcomputer 7. At this time, the voltage across the flying capacitor 3, that is, the high voltage of the high voltage power supply V is divided by the voltage dividing ratio determined by the resistors R 1, R 3 and R 4 and supplied to the input port A / D of the microcomputer 7. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as the high voltage of the high voltage power source V.

  Next, after the voltage charged in the flying capacitor 3 is sufficiently discharged by a reset switch or the like (not shown), when the switch S12 is closed while the switch S9 is closed, the voltage detection terminal T1, the current limiting resistor R11, the switch A closed circuit is formed by S12, the resistor R1, the flying capacitor 3, the switch S9, the resistor R3, the ground potential, the ground fault resistor Rn on the negative terminal side of the high-voltage power supply V, and the voltage detection terminal T6. Thereby, the voltage according to the value of the ground fault resistance Rn is charged in the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity.

  Next, the switch S12 is opened, then the switch S8 is closed for a predetermined period, and the voltage across the flying capacitor 3 is supplied to the input port A / D of the microcomputer 7 via the resistor R1, the sample switch 5 and the I / F circuit 6. To do. At this time, the voltage across the flying capacitor 3, that is, the voltage corresponding to the value of the ground fault resistance Rn is divided by the voltage division ratio determined by the resistors R1, R3, and R4, and is applied to the input port A / D of the microcomputer 7. Supplied. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as a voltage corresponding to the value of the ground fault resistance Rn.

  The microcomputer 7 calculates the value of the ground fault resistance Rn on the negative terminal side of the high voltage power supply V based on the voltage corresponding to the value of the ground fault resistance Rn read this time and the high voltage of the high voltage power supply V read last time. .

  Next, when the voltage charged in the flying capacitor 3 is sufficiently discharged by a reset switch or the like (not shown), the switch S21 is closed and the switch S21 is closed, so that the voltage detection terminal T1 and the positive terminal side of the high-voltage power supply V are closed. A grounding resistance Rp, ground potential, resistance R4, resistance R2, switch S8, resistance R1, flying capacitor 3, switch S21 and voltage detection terminal T6 form a closed circuit. Thereby, the voltage according to the value of the ground fault resistance Rp is charged in the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity.

  Next, the switch S21 is opened, then the switch S9 is closed for a predetermined period, and the voltage across the flying capacitor 3 is supplied to the input port A / D of the microcomputer 7 via the resistor R1, the sample switch 5 and the I / F circuit 6. To do. At this time, the voltage across the flying capacitor 3, that is, the voltage corresponding to the value of the ground fault resistance Rp is divided by the voltage division ratio determined by the resistors R 1, R 3 and R 4, and is applied to the input port A / D of the microcomputer 7. Supplied. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as a voltage corresponding to the value of the ground fault resistance Rp.

  The microcomputer 7 calculates the value of the ground fault resistance Rp on the positive terminal side of the high voltage power supply V based on the voltage corresponding to the value of the ground fault resistance Rp read this time and the high voltage of the high voltage power supply V read last time. .

  Finally, the microcomputer 7 determines the insulation state of the high-voltage power supply V from the calculated values of the negative terminal side ground fault resistance Rn and the positive terminal side ground fault resistance Rp. For example, the ground fault resistance Rp on the positive terminal side of the high-voltage power supply V is compared with a predetermined reference resistance value. If the value of the ground fault resistance Rp is equal to or lower than the reference resistance value, an insulation failure occurs. It is determined that

  Thus, according to the flying capacitor type voltage measuring device of the second embodiment, in the voltage measurement mode, the voltage sources V1 to V5 of the high-voltage power supply V can be measured, and in the insulation detection mode, It is possible to detect the insulation or ground fault state of the high-voltage power supply V.

  In addition, the voltage measurement mode and the insulation detection mode can be isolated from the voltage measurement operation of the voltage source only by sequentially controlling the flying capacitor 3, the multiplexer 12, the operation mode selection circuit 4, and the sample switch 5 as described above. The detection operation can be made possible. Such sequence control can be executed by a software program of the microcomputer 7.

  (Third Embodiment) FIG. 3 is a circuit diagram showing the configuration of a flying capacitor type voltage measuring apparatus according to a third embodiment of the present invention.

  The flying capacitor type voltage measuring device includes a multiplexer 12, a flying capacitor 3, a sample switch 5, an I / F circuit 6, a microcomputer 7 as voltage measuring means, and diodes 17a to 17e, 18b connected to a voltage detection terminal of a high voltage power source V. To 18f and correction circuits 19-1 to 19-5 as correction means.

  High-voltage power supply V includes N voltage sources (for example, single cells) V1-V5 connected in series (in this embodiment, for example, N = 5). Each of the voltage sources V1 to V5 is connected to (N + 1) (for example, six in this embodiment) voltage detection terminals T1 to T6.

  The multiplexer 12 includes (N + 1) (for example, 6 in this embodiment) switches S22 to S27 connected to the voltage detection terminals T1 to T6, respectively. The first to fifth switches S22 to S26 are connected to one terminal of the operation mode selection circuit 4 through five diodes 17a to 17e, respectively. Each of the diodes 17a to 17e has a polarity that conducts from the sample switches S22 to S26 to one terminal of the operation mode selection circuit 4, that is, its anode is on the side of each switch S22 to S26 and its cathode is the operation mode selection circuit 4 It is connected so that it may become one terminal side.

  The second to sixth switches S23 to S27 are connected to one terminal (for example, the-terminal) of the flying capacitor 3 via the five diodes 18b to 18f, respectively. Each of the diodes 18b to 18f is connected in such a manner that the polarity is conducted from the flying capacitor 3 to the switches S23 to S27, that is, the anode is on the flying capacitor 3 side and the cathode is on the switches S23 to S27 side. .

  The operation mode selection circuit 4 includes a parallel connection circuit of a switch S7 and a resistor R1. One terminal of the parallel connection circuit is connected to the cathodes of the diodes 17a to 17e, and the other terminal is the other terminal of the flying capacitor 3. It is connected to the.

  The sample switch 5 includes a switch S8 connected to one terminal of the operation mode selection circuit 4 and a switch S9 connected to one terminal of the flying capacitor 3. The other terminals of the switches S8 and S9 are connected to the I / F circuit 6.

  The I / F circuit 6 is for converting a voltage supplied to the input port A / D of the microcomputer 7 through the sample switch 5 into a voltage with respect to the ground potential, and is configured by a resistor R3 and a resistor R4. As will be described later, the resistors R3 and R4 together with the resistor R1 of the operation mode selection circuit 4 constitute a voltage dividing circuit that divides the voltage across the flying capacitor 3 as a voltage dividing resistor. One terminal of the resistor R3 is connected to the other terminal of the switches S9 and S10 of the sample switch 5, and the other terminal is grounded. One terminal of the resistor R4 is connected to the other terminals of the switches S8 and S11 of the sample switch 4 and the input port A / D1 of the microcomputer 7, and the other terminal is grounded.

  The microcomputer 7 is supplied with a drive voltage from the power supply + Vcc to its power supply port Vcc, and is supplied with a voltage from its I / F circuit 6 to its input port A / D. Each of the switches S1 to S6, the switch S7 of the operation mode selection circuit 4, and the switches S8 to S11 of the sample switch 5 function as control means for switching control according to an operation mode to be described later.

  Further, correction circuits 19-1 to 19-5 are connected to the input ports A / D2 to A / D6 of the microcomputer 7, respectively. The correction circuit 19-1 includes a resistor 19a-1 and diodes 19b-1 and 19c-1 connected in series to the + Vcc power source, and the connection point between the resistor 19a-1 and the diode 19b-1 is the input port A of the microcomputer 7. / D2 is connected. Similarly, the correction circuit 19-5 includes a resistor 19a-5 and diodes 19b-5 and 19c-5 connected in series to the + Vcc power source, and the connection point between the resistor 19a-5 and the diode 19b-5 is the microcomputer 7's. It is connected to the input port A / D6. (The correction circuits 19-2 to 19-4 having the same configuration are also connected to the input ports A / D3 to A / D5, respectively, but are not shown here.)

  The diode is a 4-element package containing two elements, one for the voltage measurement line and the other for the correction circuit. For example, a combination of the diode 17a and the diode 19b-1, a combination of the diode 18b and the diode 19c-1, a combination of the diode 17e and the diode 19b-5, and a combination of the diode 18f and the diode 19c-5 are each in the same package product. (The diodes in the correction circuits 19-2 to 19-4 (not shown) are also in the same package product by the same combination as described above.)

  With the above-described configuration, the flying capacitor type voltage measuring apparatus according to the third embodiment can be operated by selecting two operation modes of a voltage measurement mode and an insulation detection mode. Hereinafter, each operation mode will be described.

  In the voltage measurement mode, first, when the switch S7 of the operation mode selection circuit 4 is closed and the switches S22 and S23 of the multiplexer 12 are closed from the initial state where all the switches are open, the voltage source V1, the voltage detection terminal T1, The switch S22, the diode 17a, the switch S7, the flying capacitor 3, the diode 18b, the switch S23, and the voltage detection terminal T2 form a closed circuit. Thereby, the voltage of the voltage source V1 is charged in the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity.

  Next, the switches S22, S23 and S7 are opened, the switches S8 and S9 of the sample switch 5 are closed for a predetermined period, and the voltage across the flying capacitor 3, that is, the voltage of the voltage source V1 is set to the resistor R1, the sample switch 5 and the I / F. This is supplied to the input port A / D of the microcomputer 7 via the circuit 6. At this time, the voltage across the flying capacitor 3, that is, the voltage of the voltage source V1, is divided by the voltage dividing ratio determined by the resistors R1, R3, and R4 and supplied to the input port A / D of the microcomputer 7. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as the voltage of the voltage source V1.

  Next, after the voltage charged in the flying capacitor 3 is sufficiently discharged by a reset switch (not shown), the switches S8 and S9 are opened, and then the switches S23, S24 and S7 are closed. A closed circuit is formed by the terminal T2, the switch S23, the diode 17b, the switch S7, the flying capacitor 3, the diode 18c, the switch S24, and the voltage detection terminal T3. Thereby, the voltage of the voltage source V2 is charged to the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity, as in the measurement of the voltage source V1.

  Next, the switches S23, S24 and S7 are opened, the switches S8 and S9 of the sample switch 5 are closed for a predetermined period, and the voltage across the flying capacitor 3, that is, the voltage of the voltage source V2 is set to the resistor R1, the sample switch 5 and the I / F. This is supplied to the input port A / D of the microcomputer 7 via the circuit 6. At this time, the voltage across the flying capacitor 3, that is, the voltage of the voltage source V2, is divided by the voltage dividing ratio determined by the resistors R1, R3, and R4 and supplied to the input port A / D of the microcomputer 7. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as the voltage of the voltage source V2.

  Similarly, values indicating the voltages of the voltage sources V3, V4 and V5 are read by the microcomputer 7 by the combination of the switches S24 and S25, S25 and S26, S26 and S27, respectively. Further, the combination of the switches S22 and S27 enables the microcomputer 7 to read the total voltage of all the voltage sources V1 to V5, that is, the high voltage of the high voltage power source V. In the third embodiment, since the flying capacitor 3 is charged in the same direction when measuring the voltages of all the voltage sources V1 to V5, the input port A / D of the microcomputer 7 always has a voltage of the same polarity. Is supplied.

  Next, in the insulation detection mode, first, when the switches S22 and S27 of the multiplexer 12 are closed from the initial state where all the switches are open, the voltage sources V1 to V5, the voltage detection terminal T1, the switch S22, the diode 17a, the resistance A closed circuit is formed by R1, the flying capacitor 3, the diode 18f, the switch S27, and the voltage detection terminal T6. Thereby, the high voltage of the high voltage power supply V is charged in the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity.

  Next, the switches S22 and S27 are opened, the switches S8 and S9 of the sample switch 5 are closed for a predetermined period, and the voltage across the flying capacitor 3, that is, the high voltage of the high voltage power source V is applied to the resistor R1, the sample switch 5 and the I / F circuit. 6 is supplied to the input port A / D of the microcomputer 7. At this time, the voltage across the flying capacitor 3, that is, the high voltage of the high voltage power supply V is divided by the voltage dividing ratio determined by the resistors R 1, R 3 and R 4 and supplied to the input port A / D of the microcomputer 7. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as the high voltage of the high voltage power source V.

  Next, after the voltage charged in the flying capacitor 3 is sufficiently discharged by a reset switch or the like (not shown), when the switch S22 is closed while the switch S9 is closed, the voltage detection terminal T1, the switch S22, the diode 17a, the resistance A closed circuit is formed by R1, the flying capacitor 3, the switch S9, the resistor R3, the ground potential, the ground fault resistor Rn on the negative terminal side of the high-voltage power supply V, and the voltage detection terminal T6. Thereby, the voltage according to the value of the ground fault resistance Rn is charged in the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity.

  Next, the switch S22 is opened, then the switch S8 is closed for a predetermined period, and the voltage across the flying capacitor 3 is supplied to the input port A / D of the microcomputer 7 via the resistor R1, the sample switch 5 and the I / F circuit 6. To do. At this time, the voltage across the flying capacitor 3, that is, the voltage corresponding to the value of the ground fault resistance Rn is divided by the voltage division ratio determined by the resistors R1, R3, and R4, and is applied to the input port A / D of the microcomputer 7. Supplied. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as a voltage corresponding to the value of the ground fault resistance Rn.

  The microcomputer 7 calculates the value of the ground fault resistance Rn on the negative terminal side of the high voltage power source V based on the voltage corresponding to the value of the ground fault resistance Rn read this time and the high voltage of the high voltage power source V read last time. .

  Next, when the voltage charged in the flying capacitor 3 is sufficiently discharged by a reset switch or the like (not shown) and then the switch S27 is closed while the switch S8 is closed, the voltage detection terminal T1 and the positive terminal side of the high-voltage power supply V are closed. The ground fault resistance Rp, ground potential, resistance R4, resistance R2, switch S8, resistance R1, flying capacitor 3, switch S27 and voltage detection terminal T6 form a closed circuit. Thereby, the voltage according to the value of the ground fault resistance Rp is charged in the flying capacitor 3 so that the terminal side of the flying capacitor 3 connected to the switch S7 has a positive polarity.

  Next, the switch S27 is opened, then the switch S9 is closed for a predetermined period, and the voltage across the flying capacitor 3 is supplied to the input port A / D of the microcomputer 7 via the resistor R1, the sample switch 5 and the I / F circuit 6. To do. At this time, the voltage across the flying capacitor 3, that is, the voltage corresponding to the value of the ground fault resistance Rp is divided by the voltage division ratio determined by the resistors R 1, R 3 and R 4, and is applied to the input port A / D of the microcomputer 7. Supplied. Thereby, the supplied divided voltage is converted into a digital value by A / D (analog / digital) conversion, and the value is read by the microcomputer 7 as a voltage corresponding to the value of the ground fault resistance Rp.

  The microcomputer 7 calculates the value of the ground fault resistance Rp on the positive terminal side of the high voltage power supply V based on the voltage corresponding to the value of the ground fault resistance Rp read this time and the high voltage of the high voltage power supply V read last time. .

  Finally, the microcomputer 7 determines the insulation state of the high-voltage power supply V from the calculated values of the negative terminal side ground fault resistance Rn and the positive terminal side ground fault resistance Rp. For example, the ground fault resistance Rp on the positive terminal side of the high-voltage power supply V is compared with a predetermined reference resistance value. If the value of the ground fault resistance Rp is equal to or lower than the reference resistance value, an insulation failure occurs. It is determined that

  As described above, according to the flying capacitor type voltage measuring apparatus of the third embodiment, in the voltage measurement mode, the voltage sources V1 to V5 of the high-voltage power supply V can be measured, and in the insulation detection mode, It is possible to detect the insulation or ground fault state of the high-voltage power supply V.

  In addition, the voltage measurement mode and the insulation detection mode can be isolated from the voltage measurement operation of the voltage source only by sequentially controlling the flying capacitor 3, the multiplexer 12, the operation mode selection circuit 4, and the sample switch 5 as described above. The detection operation can be made possible. Such sequence control can be executed by a software program of the microcomputer 7.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various deformation | transformation and application are possible.

  For example, in each of the above-described embodiments, the resistor R2 of the I / F circuit 6 may be deleted, and the voltage dividing circuit may be configured by the resistors R3 and R4 and the resistor R1 of the operation mode selection circuit 4. .

  In the above-described embodiments, in the insulation detection mode, the high voltage of the high voltage power supply V is first measured. However, this measurement is omitted, and the high voltage of the high voltage power supply V measured in the voltage measurement mode is measured. The value may be used. In this case, the measurement time in the insulation detection mode can be shortened and the accuracy can be improved.

  In the third embodiment, the correction circuit 19 is connected to the input port A / A when high detection accuracy is required such that the voltage loss due to the forward voltage drop of the two diodes affects the measurement result. Although the correction is made by connecting to D2, as another embodiment, when the voltage value supplied to the input port A / D1 is calculated by the microcomputer 7 without connecting the correction circuit 19, the above-mentioned loss amount is preliminarily calculated. You may make it anticipate.

  The configuration of the operation mode selection circuit 4 can be modified. In each of the above-described embodiments, the voltage measurement mode is for the purpose of measuring the voltage of the multi-channel voltage source at high speed and with high accuracy. Therefore, the flying capacitor 3 is desirably used in a fully charged state. The capacity and charging resistance do not want to be set too large. On the other hand, since the insulation detection mode is affected by the Y-con capacitance connected to the voltage source, in order to accurately detect insulation over a wide range, it is desirable to use a flying capacitor 3 having a somewhat large value. . For this reason, when it is desired to improve the detection accuracy of the ground fault resistance without degrading the performance of the voltage measurement mode, the charging resistance to the flying capacitor 3 is switched or the capacitance of the capacitor is switched as in the following modification. It can be realized by doing.

  Hereinafter, modifications of the operation mode selection circuit 4 will be described.

  FIG. 4 shows a first modification of the operation mode selection circuit 4. In FIG. 4, the operation mode selection circuit 4 includes a parallel connection circuit of a switch S7, a series connection body of a diode D1 and a resistor R1, and a series connection body of a diode D2 and a resistance R5. In the voltage measurement mode, the switch S7 is sequence-controlled so that it is closed when charging the flying capacitor 3 from the voltage source, is opened when supplied to the microcomputer 7, and is always opened in the insulation detection mode.

  FIG. 5 shows a second modification of the operation mode selection circuit 4. In FIG. 5, the operation mode selection circuit 4 includes a switch S7, a series connection body of a switch S28 and a resistor R1, and a parallel connection circuit of a resistor R5. In the voltage measurement mode, the switch S7 is closed when charging the flying capacitor 3 from the voltage source, is opened when supplied to the microcomputer 7, the switch S28 is always opened, and in the insulation detection mode, the switch S28 is It is closed when charging the flying capacitor 3 from the voltage source, opened when supplying to the microcomputer 7, and the sequence control is performed so that the switch S 7 is always opened.

  Both the first and second modified examples of the operation mode selection circuit 4 shown in FIGS. 4 and 5 are suitable for the respective charging resistances as in the first to third embodiments shown in FIGS. It is configured to switch to the one with the correct value.

  FIG. 6 shows a third modification of the operation mode selection circuit 4. In FIG. 6, the operation mode selection circuit 4 includes a switch S7 connected in series to the flying capacitor 3, and a switch S28, a resistor R5 and a capacitor 3A connected in series to a series connection body of the flying capacitor 3 and the switch S7. And a parallel connection body of the switch S29 and the resistor R1 between the cathodes of the diodes 17a to 17e and one terminal of the switch S8 of the sample switch 5. The capacity of the capacitor 3 </ b> A is set larger than the capacity of the flying capacitor 3. In the voltage measurement mode, the switch S7 is always closed, the switch S28 is always opened, and the switch S29 is closed when charging the flying capacitor 3, and is opened when supplied to the microcomputer 7, and in the insulation detection mode. The switch S28 is always closed, the switch S7 is always opened, and the switch S29 is closed when charging the flying capacitor 3 and is opened when supplied to the microcomputer 7.

  FIG. 7 shows a fourth modification of the operation mode selection circuit 4. In FIG. 7, the operation mode selection circuit 4 includes a switch S7 connected in series to the flying capacitor 3, a series connection of a resistor R6 and a diode D3 connected in parallel to the switch S7, and a series connection of the flying capacitor 3 and the switch S7. A series connection of a switch S28, a diode D1, a resistor R1 and a capacitor 3A connected in parallel to the body, and a series connection of a resistor R5 and a diode D2 connected in parallel to a series connection of a diode D1 and a resistor R1. Become. The capacity of the capacitor 3 </ b> A is set larger than the capacity of the flying capacitor 3. In the voltage measurement mode, the switch S7 is closed when charging the flying capacitor 3 from the voltage source, opened when supplying to the microcomputer 7, the switch S28 is always open, and in the insulation detection mode, the switch S28 is always open. It is closed and the switch S7 is sequenced so that it is always open.

  The third and fourth modifications of the operation mode selection circuit 4 shown in FIGS. 6 and 7 are each configured to switch both the charging resistor and the capacitor to values appropriate for the respective modes. .

It is a circuit diagram which shows the structure of the flying capacitor system voltage measuring apparatus which concerns on the 1st Embodiment of this invention. (First embodiment) It is a circuit diagram which shows the structure of the flying capacitor system voltage measuring apparatus which concerns on the 2nd Embodiment of this invention. (Second Embodiment) It is a circuit diagram which shows the structure of the flying capacitor system voltage measuring apparatus which concerns on the 3rd Embodiment of this invention. (Third embodiment) It is a circuit diagram which shows the 1st modification of the operation mode selection circuit in the flying capacitor system voltage measuring apparatus of this invention. It is a circuit diagram which shows the 2nd modification of an operation mode selection circuit. FIG. 10 is a circuit diagram showing a third modification of the operation mode selection circuit. It is a circuit diagram which shows the 4th modification of an operation mode selection circuit.

Explanation of symbols

V high voltage power supply V1 to V5 voltage source S1 to S6, S12 to S27 switch 1, 2, 12 multiplexer 3 flying capacitor 3A capacitor 4 operation mode selection circuit 5 sample switch 6 I / F (interface) circuit 7 microcomputer (voltage measuring means, Control means)
17a-17e, 18b-18f Diode

Claims (7)

A high voltage power source including N voltage sources connected in series and insulated from a ground potential, a flying capacitor, and (N + 1) voltage detection terminals connected to the N voltage sources are connected to the flying capacitor. A flying capacitor type voltage measuring device having a multiplexer including (N + 1) switches to be selectively connected, a voltage measuring unit, and a sample switch for supplying a voltage across the flying capacitor to the voltage measuring unit,
An operation mode selection circuit that is connected to the flying capacitor and selects two operation modes: a voltage measurement mode for measuring individual voltages of each voltage source of the high-voltage power supply; and an insulation detection mode for detecting an insulation state of the high-voltage power supply; ,
An interface circuit connected between the sample switch and the voltage measurement means, and converts the voltage supplied via the sample switch into a voltage with respect to a ground potential and supplies the voltage to the voltage measurement means;
A flying capacitor type voltage comprising: an operation mode of the operation mode selection circuit; and control means for controlling opening and closing of the switch of the multiplexer and the sample switch according to the selected operation mode. measuring device. In the flying capacitor type voltage measuring device according to claim 1,
The multiplexer selectively connects an odd-numbered voltage detection terminal among (N + 1) voltage detection terminals connected to the N voltage sources connected in series to one terminal side of the flying capacitor. And a second multiplexer that selectively connects an even-numbered voltage detection terminal of the (N + 1) voltage detection terminals to the other terminal side of the flying capacitor. Flying capacitor type voltage measuring device. In the flying capacitor type voltage measuring device according to claim 1,
The multiplexer selects the first to Nth voltage detection terminals among the (N + 1) voltage detection terminals connected to the N voltage sources connected in series to one terminal side of the flying capacitor, respectively. And a plurality of switches for selectively connecting the 2nd to (N + 1) th voltage detection terminals of the (N + 1) voltage detection terminals to the other terminal side of the flying capacitor, respectively. A flying capacitor type voltage measuring device. In the flying capacitor type voltage measuring device according to claim 1,
The multiplexer includes (N + 1) switches that selectively connect the (N + 1) voltage detection terminals connected to the N voltage sources connected in series to the flying capacitor;
Of the (N + 1) voltage sample switches, N switches connected from the first to the Nth switch and one terminal of the flying capacitor with polarity conducting from the switch to the flying capacitor, respectively. A diode,
Among the (N + 1) switches, the N to N switches connected from the second to the (N + 1) th switch and the other terminal of the flying capacitor, respectively, are connected with a polarity conducting from the flying capacitor to the switch. A flying capacitor type voltage measuring apparatus, further comprising a diode. In the flying capacitor type voltage measuring device according to any one of claims 1 to 4,
The operating mode selection circuit switches the charging resistance of the flying capacitor according to the selection of the operation mode. In the flying capacitor type voltage measuring device according to any one of claims 1 to 4,
The operation mode selection circuit switches the charging resistance of the flying capacitor according to the selection of the operation mode, connects the flying capacitor in the voltage measurement mode, and replaces the flying capacitor in the insulation detection mode. A flying capacitor type voltage measuring apparatus, wherein a capacitor having a larger capacity than the flying capacitor is connected. In the flying capacitor type voltage measuring device according to claim 5 or 6,
The said interface circuit is comprised by the voltage dividing circuit containing the resistance which functions as a voltage dividing resistor with the charging resistance of the said operation mode selection circuit. The flying capacitor system voltage measuring apparatus characterized by the above-mentioned.

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