MEASURING SYSTEM

Abstract

A measuring system comprises a voltage converter circuit that converts and outputs a voltage between a first terminal and a second terminal, and a computing device that detects anomalies in the voltage converter circuit. The voltage converter circuit comprises: a first output circuit that outputs a first output voltage obtained by multiplying a potential of the first terminal with respect to a predetermined reference potential by a conversion gain; a second output circuit that outputs a second output voltage obtained by multiplying a potential of the second terminal with respect to the reference potential by a conversion gain; and a third output circuit that outputs a third output voltage obtained by multiplying a voltage between the first terminal and the second terminal by a conversion gain.The conversion gains of the first output circuit, the second output circuit, and the third output circuit can be set to values ​​of at least one first group and one second group, and the ratio between a first group conversion gain and a second group conversion gain set in the third output circuit differs from the ratio between a first group conversion gain and a second group conversion gain set in the first output circuit or the second output circuit.The computing device comprises the following: a voltmeter which measures the first output voltage, the second output voltage and the third output voltage, and a diagnostic unit which, using conversion gains of a selected group, which is one of the first group and the second group, calculates a first conversion value, a second conversion value and a third conversion value corresponding to input voltages of the first output circuit, the second output circuit and the third output circuit, based on the first output voltage, the second output voltage and the third output voltage, and determines that an anomaly exists if the sum of the first conversion value and the second conversion value deviates from the third conversion value by at least one predetermined value.

Description

Technical field

[0001] The present invention relates to a measuring system. State of the art

[0002] A configuration is known in which a high voltage is measured after a voltage has been reduced by a predetermined gain. In a case where there are multiple voltage ranges of measurement targets, a method for switching gains according to the measurement target is known.PTL 1 discloses a voltage sensing device comprising: a first resistor designed to divide a voltage of a sensing unit into a first divided voltage value, a second resistor designed to divide the first divided voltage into a second divided voltage value, and a test pattern insertion circuit unit comprising a switching element, wherein the test pattern insertion circuit unit is connected to a junction at the same potential as the first divided voltage value and, based on the second divided voltage value, determines a state of the first resistor when the switching element is non-conducting. Citation list of patent literature

[0003] PTL 1: JP 2020-112526 A Summary of the invention Technical problem

[0004] The technology described in PTL 1 presents the problem that there is still room for further improvement in reliability. Solution to the problem

[0005] A measuring system according to a first aspect of the present invention comprises a voltage converter circuit which converts and outputs a voltage between a first terminal and a second terminal, and a computing device which detects an anomaly of the voltage converter circuit, wherein the voltage converter circuit comprises: a first output circuit which outputs a first output voltage obtained by multiplying a potential of the first terminal with respect to a predetermined reference potential by a conversion gain, a second output circuit which outputs a second output voltage obtained by multiplying a potential of the second terminal with respect to the reference potential by a conversion gain, and a third output circuit which outputs a third output voltage.which is obtained by multiplying a voltage between the first terminal and the second terminal by a conversion gain, wherein the conversion gains of the first output circuit, the second output circuit, and the third output circuit can be set to values ​​of at least one first group and one second group, wherein the ratio between a first-group conversion gain and a second-group conversion gain set in the third output circuit differs from the ratio between a first-group conversion gain and a second-group conversion gain set in the first output circuit or the second output circuit, and wherein the computing device comprises: a voltmeter measuring the first output voltage, the second output voltage, and the third output voltage, and a diagnostic unit,which, using conversion gains of a selected group, one of the first and the second groups, calculates a first conversion value, a second conversion value, and a third conversion value corresponding to the input voltages of the first output circuit, the second output circuit, and the third output circuit, based on the first output voltage, the second output voltage, and the third output voltage, and determines that an anomaly exists if the sum of the first conversion value and the second conversion value differs from the third conversion value by at least a predetermined value. Advantageous effects of the invention

[0006] According to the present invention, it is possible to detect a gain switching failure without limiting a situation and to improve reliability. Brief description of the drawings

[0007] They show: Fig. 1 a configuration diagram of a measurement system, Fig. 2 a hardware configuration diagram of a computing device, Fig. 3. A flowchart showing the processing of a diagnostic unit. Fig. 4. A diagram to illustrate one output of each group in a specification example. Fig. 5 a diagram showing a connection of an output circuit according to a third modification, Fig. 6. A diagram showing an output for each group accordingly. Fig. 5 shows, and Fig. 7 a diagram to illustrate a calculation example according to a second embodiment. Description of embodiments - First embodiment -

[0008] Below, a first embodiment of a measuring system is described with reference to the Fig. 1 to 4 described. (Configuration)

[0009] Fig. Figure 1 is a configuration diagram of a measuring system 1. The measuring system 1 comprises a voltage converter circuit 100 and a computing device 200. A high-voltage (HV) voltage of 101 V is applied to the voltage converter circuit 100 from an HV power supply 101. The HV voltage of 101 V is a high voltage, such as 800 V, and direct measurement is difficult. Therefore, the voltage converter circuit 100 converts the HV voltage of 101 V into a low voltage, and a voltmeter integrated into the computing device 200 measures the low voltage. For the computing device 200 to measure the voltage with high accuracy, it is desirable that the voltage be of a large value while remaining within a measurable range.

[0010] Furthermore, the measurement target of the voltage converter circuit 100 and the computing device 200 is not always the same high-voltage power supply 101. Therefore, the voltage converter circuit 100 switches the gains described below according to the high-voltage power supply 101 being measured, so that the computing device 200 can measure the voltage with high accuracy. The computing device 200 can calculate the voltage of the high-voltage power supply 101 based on the measured voltage and the gain values ​​used for the measurement by the voltage converter circuit 100.

[0011] The voltage converter circuit 100 comprises a first output circuit 11, a second output circuit 12, a third output circuit 13, a gain-modifying unit 102, a standard instruction unit 110, a correction instruction unit 114, a differential compensation circuit 115, and first to fourth voltage divider resistors R1 to R4. The input voltage of the first output circuit 11 is designated as the first input voltage VI1, and the output voltage of the first output circuit 11 is designated as the first output voltage VO1. The input voltage of the second output circuit 12 is designated as the second input voltage VI2, and the output voltage of the second output circuit 12 is designated as the second output voltage VO2. The input voltage of the third output circuit 13 is designated as the third input voltage VI3, and the output voltage of the third output circuit 13 is designated as the third output voltage VO3.The third input voltage VI3 is equal to the sum of the first input voltage VI1 and the second input voltage VI2.

[0012] The first through fourth voltage divider resistors, R1 to R4, divide the 101V supply voltage. In this embodiment, for the sake of simplicity, the first through fourth voltage divider resistors, R1 to R4, have the same value. However, the first through fourth voltage divider resistors, R1 to R4, can have different values. A section between the second voltage divider resistor, R2, and the third voltage divider resistor, R3, is connected to ground. If the 101V supply voltage is 1000V, the first input voltage, VI1, is +250V, the second input voltage, VI2, is -250V, and the third input voltage, VI3, is +500V.

[0013] The positive side of the fourth voltage divider resistor R4 is referred to as the first potential point P1, the section between the fourth voltage divider resistor R4 and the third voltage divider resistor R3 is referred to as the second potential point P2, the section between the third voltage divider resistor R3 and the second voltage divider resistor R2 is referred to as the third potential point P3, the section between the second voltage divider resistor R2 and the first voltage divider resistor R1 is referred to as the fourth potential point P4, and the negative side of the first voltage divider resistor R1 is referred to as the fifth potential point P5. Hereinafter, the second potential point P2 will also be referred to as the "first terminal" and the fourth potential point P4 will also be referred to as the "second terminal".

[0014] For each of the first output circuit 11, the second output circuit 12, and the third output circuit 13, one of two gains is set by the gain-changing unit 102. The gains may differ from each other, but the gain switching is performed simultaneously. Hereinafter, the two set gains are referred to as "Group A" and "Group B." Furthermore, the group set in the voltage converter circuit 100 is referred to below as a "circuit utilization group," and the group recognized as being used by the computing device 200 is referred to as a "device recognition group." Although in Fig. 1 For the sake of clarity of the drawing, a detailed description is omitted; the first output circuit 11 and the second output circuit 12 are differential amplifier circuits.

[0015] In the first output circuit 11, the second output circuit 12, and the third output circuit 13, values ​​of group A gains or values ​​of group B gains are set simultaneously. For example, a situation is not provided in which a group A gain is set in the first output circuit 11 and group B gains are set in the second output circuit 12 and the third output circuit 13. The group A gains for the first output circuit 11, the second output circuit 12, and the third output circuit 13 could, for example, be "0.1, 0.1, 0.3", and the group B gains could, for example, be "0.02, 0.02, 0.4".In this case, the gain of the second output circuit 12 is set to “0.1” and the gain of the third output circuit 13 is set to “0.3”, because group A is used when the gain of the first output circuit 11 is set to “0.1”.

[0016] When it receives a change command from the standard instruction unit 110 or the correction instruction unit 114, the gain change unit 102 switches the gains of the first output circuit 11, the second output circuit 12, and the third output circuit 13. The standard instruction unit 110 is an instruction unit that is operated manually by an operator or by an adjustment device (not shown). The correction instruction unit 114 is an instruction unit that is operated by the computing device 200.

[0017] Although the standard instruction unit 110 and the correction instruction unit 114 are actuated by different units, the effect on the gain-change unit 102 is the same, regardless of which unit is actuated. The differential compensation circuit 115 is a circuit that compensates for the difference between the standard instruction unit 110 and the correction instruction unit 114. Fig. 1. Both the standard instruction unit 110 and the correction instruction unit 114 are connected to the differential compensation circuit 115 and via the differential compensation circuit 115 to the gain change unit 102, but it is also possible for only one of the standard instruction unit 110 and the correction instruction unit 114 to be connected to the differential compensation circuit 115.

[0018] The standard instruction unit 110 and the correction instruction unit 114 can have the same or different hardware configurations. For example, the standard instruction unit 110 can be a push-button switch, and when pressed, a predetermined voltage from a pre-provided voltage source can be applied to the gain-modifying unit 102. For example, the correction instruction unit 114 can be a contact to which an electrical signal from the computing device 200 is applied, and the computing device 200 can apply a predetermined voltage when it is determined that a correction of the gains is necessary. The differential compensation circuit 115 can be either an analog circuit, a digital circuit, or a combination thereof.Furthermore, if the outputs of the standard instruction unit 110 and the correction instruction unit 114 are equal, the voltage converter circuit 100 does not need to have the differential compensation circuit 115.

[0019] The computing device 200 comprises a voltage measuring unit 210 and a diagnostic unit 220. The voltage measuring unit 210 is a voltmeter with a fixed measuring range. It measures the first output voltage VO1, the second output voltage VO2, and the third output voltage VO3 and outputs a measurement result to the diagnostic unit 220. The reference for the voltage measurement by the voltage measuring unit 210 is ground potential. The voltage measuring unit 210 can contain three voltmeters or one voltmeter and one circuit. The voltage measuring unit 210 outputs a measured value unchanged to the diagnostic unit 220 and does not output a calculation result to the diagnostic unit 220 using any amplification. The voltage measuring unit 210 further calculates the HV voltage 101V using the amplifications of the device detection group and outputs the HV voltage from the computing device 200.

[0020] The diagnostic unit 220 calculates the first input voltage VI1, the second input voltage VI2, the third input voltage VI3, and the HV voltage 101V using the voltage values ​​measured by the voltage measurement unit 210. The diagnostic unit 220 also detects a mismatch between the device detection group and the circuit utilization group. If it detects an unintended gain circuit, the diagnostic unit 220 issues a gain circuit instruction to the correction instruction unit 114 of the voltage converter circuit 100.

[0021] The gain of each output circuit is modified by the gain modification unit 102 based on the input to the standard instruction unit 110 or the correction instruction unit 114, but is occasionally changed unintentionally due to a circuit failure or the like. The computing device 200 receives the values ​​of the gains of group A and group B in advance, as well as information about the circuit usage group. Since the computing device 200 does not receive the value of the HV voltage 101V in advance, an unintentional change in the gains cannot be detected from the measured value itself. In other words, the computing device 200 detects a change in the gains using the correlation between the measured values.

[0022] The diagnostic unit 220 of the computing device 200 calculates a deviation DF using the following expressions 1 to 4. G1 to G3 in expressions 1 to 3 are gains of the first output circuit 11, the second output circuit 12, and the third output circuit 13. In expressions 1 to 3, the computing device 200 specifies the gain value of the device detection group of group A and group B. It should be noted that VO1 and VO2 in the following expressions 1 and 2 are not the measured first output voltage VO1 and second output voltage VO2, but are values ​​obtained by excluding a bias value. HVP=VO1 / G1 HVN=−VO2 / G2 HVC=VO3 / G3 DF=HVP+HVN−HVC

[0023] The diagnostic unit 220 determines that it is normal if the deviation DF is less than a predetermined threshold, and determines that an anomaly exists if the deviation DF is greater than or equal to the predetermined threshold. If the voltage converter circuit 100 and the diagnostic unit 220 use the same gain values, the deviation DF is essentially zero. Furthermore, if the voltage converter circuit 100 and the computing device 200 use different gain values—in other words, if the gains of the group other than the device detection group are used in the voltage converter circuit 100—the deviation DF will be non-zero. If the deviation DF is greater than or equal to the predetermined threshold, the diagnostic unit 220 instructs the correction instruction unit 114 of the voltage converter circuit 100 to change the gains.

[0024] Fig. Figure 2 is a hardware configuration diagram of the computing device 200. The computing device 200 comprises a CPU 41, which is a central processing unit, a ROM 42, which is a read-only memory device, a RAM 43, which is a read / write memory device, a voltmeter 44, and a signal output unit 45. The computing device 200 is a microcomputer, a single-board computer, an electronic control device, or the like. The CPU 41 implements the diagnostic unit 220 by developing a program stored in the ROM 42 in the RAM 43 and executing the program. The voltmeter 44 can measure at least one range, for example, 0 to 5 V. The signal output unit 45 is hardware for issuing an operating instruction to the correction instruction unit 114.The signal output unit 45 only needs to be able to output a signal according to the hardware configuration of the correction instruction unit 114, and, for example, only needs to be able to output a predetermined voltage signal.

[0025] The computing device 200 can, instead of the combination of the CPU 41, the ROM 42, and the RAM 43, include a field-programmable gate array (FPGA), which is a rewritable logic circuit, or an application-specific integrated circuit (ASIC). Furthermore, instead of the combination of the CPU, ROM, and RAM, the computing device 200 can be implemented by a combination of different configurations, for example, a combination of a CPU, a ROM, a RAM, and an FPGA. (Operation of the diagnostic unit)

[0026] Fig. Figure 3 is a flowchart showing the processing of diagnostic unit 220. Diagnostic unit 220 performs the following steps: Fig. The processing shown in Figure 3 is carried out at each predetermined time, for example, every minute or every hour. The computing device 200 executes the processing of this flowchart using the enhancements of the device detection group.

[0027] First, in step S301, the diagnostic unit 220 calculates the deviation DF using the output of the voltage measurement unit 210. In the subsequent step S302, the diagnostic unit 220 uses the deviation DF calculated in step S301 to determine whether it is less than the threshold value. If so, the diagnostic unit 220 determines that no anomaly exists, meaning the circuit usage group and the device detection group are identical, and terminates the processing. If not, the diagnostic unit 220 determines that an anomaly exists and proceeds to step S303.

[0028] In step S303, the diagnostic unit 220 instructs the correction instruction unit 114 to change the gains. This instruction consists, for example, of applying a predetermined voltage to the correction instruction unit 114. In the subsequent step S304, the diagnostic unit 220 recalculates the deviation DF after step S303, using the output of the voltage measurement unit 210. The purpose of the recalculation is to confirm that the gains used by the voltage converter circuit 100 have been changed according to the correction instruction in step S303. Therefore, there may be a waiting period of several seconds after the execution of step S303.

[0029] In the subsequent step S305, the diagnostic unit 220 uses the deviation DF calculated in step S304 to determine whether it is smaller than the threshold value. If so, the diagnostic unit 220 determines that the correction instruction in step S303 is functioning correctly and the problem is resolved, and terminates the process. Fig. 2 processing shown. If this is not the case, the diagnostic unit 220 continues with step S306. Since the correction is not carried out in step S306, although a correction instruction was transmitted to the voltage converter circuit 100, the diagnostic unit 220 changes the device detection group to the other group as the next best action and terminates the processing shown in Fig. 2 shown processing methods. (Example of a determination)

[0030] The gain is generally determined by the ratio between the maximum value that can be measured by the voltmeter and the maximum voltage output by the measurement target. If the measurement target is assumed to be changed, it is common practice to change the maximum voltage output by the measurement target and determine a variety of gains, while keeping the maximum value measurable by the voltmeter at a fixed value. According to the present embodiment, the gain is determined by intentionally changing the maximum value measurable by the voltmeter. The purpose of this change is to determine the group of gains. In the determination example described below, the maximum voltage in the third output circuit 13 is changed for each group.

[0031] The following describes a detail of the gain setting and calculation in a case where the high-voltage (HV) voltage to be measured is 101 V, 800 V, and 1200 V. In this example, the gains corresponding to 800 V are set to group A, and the gains corresponding to 1200 V are set to group B. The maximum voltage of the third output voltage VO3 is 4.5 V in the case of 1200 V and 4.8 V in the case of 800 V. These values ​​are set to 4.8 V, for example, by providing a margin of 0.2 V to 5.0 V, which is the upper measuring limit of the voltmeter integrated into the voltage measuring unit 210, and to 4.5 V by reducing the value by 0.3 V for the purpose of distinguishing the groups described above.

[0032] The third input voltage VI3 is divided by the voltage divider resistor to 400 V when the HV voltage is 101 V or 800 V, and to 600 V when the HV voltage is 101 V or 1200 V. Therefore, the gain of the third output circuit is 4.5 V / 400 V = 0.01125 in group A and 4.8 V / 600 V = 0.008 in group B. The first input voltage VI1 and the second input voltage VI2 are differential amplifier circuits with a bias voltage of 2.5 V, and the measurement ranges are 200 V and 300 V, respectively, due to voltage division. This means that the gain in group A is 2.0 V / 200 V = 0.01, and the gain in group B is 2.0 V / 300 V = 0.0067.

[0033] Fig. Figure 4 is a diagram showing the output of each group in the setting example. In the diagram, the first output voltage VO1 is indicated by a solid line, the second output voltage VO2 by a dashed line, and the third output voltage VO3 by a dash-dotted line. In group A, the maximum HV voltage is 101 V (800 V). The first output voltage VO1 through the third output voltage VO3 are 4.8 V, 0.5 V, and 4.8 V, respectively, at this point. In group B, the maximum HV voltage is 101 V (1200 V). The first output voltage VO1 through the third output voltage VO3 are 4.5 V, 0.5 V, and 4.8 V, respectively, at this point. The lower part of each diagram in Fig. 4 is the maximum value of each input voltage, i.e., the value at the right end of the graph, given in parentheses.

[0034] The third circuit gain ratio GR3, which is the ratio between the gain of group A and the gain of group G as determined in the third output circuit 13, and the first circuit gain ratio GR1, which is the ratio between the gain of group A and the gain of group G as determined in the first output circuit 11, are as follows. The second circuit gain ratio GR2, which is the ratio between the gain of group A and the gain of group G as determined in the second output circuit 12, is equal to the first circuit gain ratio GR1. GR3=0.01125 / 0.008=1.406 GR1=0.01 / 0.0067=1.492

[0035] Since the ratio between the third circuit gain GR3 and the first circuit gain GR1 is approximately 0.942, the difference is about 5.8%. Assuming that the voltage measurement accuracy in the voltage measurement unit 210 is 2%, it is desirable for the difference to be 4.5%, which is achieved by doubling the measurement accuracy to 4% and further adding a margin of 0.5%. The ratio between the third circuit gain GR3 and the first circuit gain GR1 in this example satisfies the condition that it differs by at least 4.5%.

[0036] If the HV voltage in group A is 101V and 400V (half the maximum value in group A), then, due to the voltage divider resistors, the first input voltage VI1 and the second input voltage VI2 are both 100V, and the third input voltage VI3 is 200V, resulting in the following outputs: The first output voltage VO1 is 2.5V + 100V x 0.01V = 3.5V. The second output voltage VO2 is 2.5V - 100V x 0.01V = 1.5V. The third output voltage VO3 is 200V x 0.01125V = 2.25V. In this case, the computation device 200 calculates the deviation DF as follows when group A is detected.

[0037] HVP is calculated as 100 V by dividing 1 V by 0.01, excluding the bias of 2.5 V, where G1 is the result. Similarly, HVN is calculated as 100 V. HVC is calculated as 200 V by dividing 2.25 V by 0.01125, where G3 is the result. Therefore, the diagnostic unit 220 calculates the deviation DF as 100 + 100 - 200, which equals 0.

[0038] However, if the computing device 200 detects group B, the deviation DF is calculated as follows. HVP is calculated as 149.25 V by dividing 1 V by 0.0067, which is G1. Similarly, HVN is calculated as 149.25 V. HVC is calculated as 281.25 V by dividing 2.25 V by 0.008, which is G3. Therefore, the deviation DF is 149.25 + 149.25 - 281.25 = 17.25, that is, non-zero. Therefore, the diagnostic unit 220 can detect a gain switching failure, in other words, a mismatch between the circuit utilization group and the device detection group, using a suitable threshold such as "5" or "10".

[0039] According to the first embodiment described above, the following advantageous effects can be obtained. (1) The measuring system 1 comprises the voltage converter circuit 100, which converts and outputs a voltage between the first terminal and the second terminal, and the computing device 200, which detects an anomaly of the voltage converter circuit 100.The voltage converter circuit 100 has the first output circuit 11, which outputs a first output voltage VO1, obtained by multiplying a potential at the second potential point P2, which is the first terminal, with respect to a predetermined reference potential with a conversion gain; has the second output circuit 12, which outputs a second output voltage VO2, obtained by multiplying a potential at the fourth potential point P4, which is the second terminal, with respect to the reference potential with a conversion gain; and has the third output circuit 13, which outputs a third output voltage VO3, obtained by multiplying a voltage between the second potential point P2 and the fourth potential point P4 with a conversion gain.The conversion gains of the first output circuit 11, the second output circuit 12, and the third output circuit 13 can be set to values ​​of at least group A and group B. The third circuit gain ratio GR3, which is a ratio between the conversion gain of group A and the conversion gain of group B as defined in the third output circuit 13, differs from the first circuit gain ratio GR1, which is a ratio between the conversion gain of group A and the conversion gain of group B as defined in the first output circuit 11.The computing device 200 comprises the voltage measuring unit 210, which includes a voltmeter that measures the first output voltage VO1, the second output voltage VO2, and the third output voltage VO3, and the diagnostic unit 220, which calculates the first input voltage VI1, the second input voltage VI2, and the third input voltage VI3 based on the first output voltage VO1, the second output voltage VO2, and the third output voltage VO3 using the conversion gains of group A or group B, and detects that an anomaly exists if the sum of the first input voltage VI1 and the second input voltage VI2 differs from the third input voltage VI3 by a predetermined value or more. Therefore, gain switching failure can be detected without any restrictions on the situation, and reliability can be improved. (2) If the diagnostic unit 220 detects that an anomaly is present (NO in step S302 in Fig. 3) The computing device 200 transmits a correction instruction to the correction instruction unit 114 (step S303) to change the conversion gains of the first output circuit 11, the second output circuit 12, and the third output circuit 13 to the conversion gains of the other group. Therefore, the gains of the voltage converter circuit 100, which were changed due to a failure, can be modified. (3) If the diagnostic unit 220 detects that an anomaly exists after the computing device 200 has changed the conversion gains of the first output circuit 11, the second output circuit 12 and the third output circuit 13 to the conversion gains of the selected group (NO in S305 in Fig. 3) The computing device 200 calculates the first input voltage VI1, the second input voltage VI2, and the third input voltage VI3 using the conversion gains of the group that differs from the currently detected group (S306). Therefore, the computing device 200 can continuously measure the HV voltage 101V even if the gain settings in the voltage converter circuit 100 cannot be corrected by switching the gains used by the computing device 200. (4) A ratio is established which differs by at least 4.5% from the third circuit gain ratio GR3, which is the ratio between the gain of group A and the gain of group G established in the third output circuit 13, and from the first circuit gain ratio GR1, which is the ratio between the gain of group A and the gain of group G established in the first output circuit 11. Therefore, the computing device 200 can reliably detect a gain switching failure in the voltage converter circuit 100. (First modification)

[0040] According to the first embodiment described above, the voltage converter circuit 100 has four voltage divider resistors, namely the first voltage divider resistor R1 to the fourth voltage divider resistor R4. However, the voltage converter circuit 100 can have at least two voltage divider resistors. This means that the first voltage divider resistor R1 and the fourth voltage divider resistor R4 need not be provided, and only the second voltage divider resistor R2 and the third voltage divider resistor R3 may be provided. (Second modification)

[0041] According to the first embodiment described above, if an anomaly is detected, a correction instruction is first transmitted to the voltage converter circuit 100 (NO in S302, S303 in Fig. 3), and only in a case where the subsequently calculated deviation DF is greater than or equal to the threshold, its detection group is changed (S306). However, the diagnostic unit 220 can change its own detection group without transmitting a correction instruction. In this case, the process can proceed to step S306 if, in step S302 in Fig. 3 a negative finding is made.

[0042] According to the present modification, the following advantageous effects can be obtained. (5) If the diagnostic unit 220 detects that an anomaly is present, the computing device 200 calculates the first input voltage VI1, the second input voltage VI2, and the third input voltage VI3 using the conversion gains of one of group A and group B, which is not currently detected. (Third modification)

[0043] According to the first embodiment described above, a differential amplifier circuit is used as the first output circuit 11 and the second output circuit 12. However, the first output circuit 11 and the second output circuit 12 do not necessarily have to use a differential amplifier circuit. In this case, a technique similar to that described in the first embodiment above can also be used.

[0044] Fig. Figure 5 is a diagram illustrating the connection of output circuits according to the present modification, and Fig. Figure 6 is a diagram to explain the expenditures of each group accordingly. Fig. 5. However, this corresponds to Fig. 6, similar to in Fig. 4, group A in a case where the HV voltage is 101V 800V and group B in a case where the HV voltage is 101V 1200V. (Fourth modification)

[0045] According to the first embodiment described above, the output voltage ranges of the third output circuit 13 differ between group A and group B; however, the output voltage ranges of the first output circuit 11 and the second output circuit 12 can also differ. Furthermore, all output voltage ranges from the first output circuit 11 to the third output circuit 13 can differ. In any case, it is sufficient if the ratio between the third circuit gain GR3 and the first circuit gain GR1 has a difference of at least 4.5%. (Fifth modification)

[0046] According to the first embodiment described above, the voltage converter circuit 100 and the computing device 200 were described as separate configurations. However, the voltage converter circuit 100 and the computing device 200 can also be designed as a single unit. In this case, the voltage converter circuit 100 and the computing device 200 can be collectively referred to as a "voltage measuring device". - Second embodiment -

[0047] A second embodiment of a measuring system is described with reference to Fig. 7. In the following description, the same components as those of the first embodiment are designated with the same reference numerals, and the main differences are described. Points not explicitly described are similar to those in the first embodiment. The present embodiment differs from the first embodiment mainly in that the number of reinforcement groups is four.

[0048] The configuration and processing of the voltage converter circuit 100 according to the second embodiment are similar to those according to the first embodiment, except that the gain-changing unit 102 has four adjustable gain groups and that the first voltage divider resistor R1 and the fourth voltage divider resistor R4 are not provided. The configuration and processing of the computing device 200 are similar to those of the first embodiment. An example of gain setting is described below.

[0049] To handle many ranges of the HV voltage 101V, while enabling the computing device 200 to determine the difference between the circuit utilization group and the device detection group, the maximum output voltage of the third output circuit 13, for example, can be set in a variety of ways. If the voltage converter circuit 100 and the diagnostic unit 220 use the same gain, the calculated deviation DF is approximately 0 V. Furthermore, the deviation DF is not zero if the circuit utilization group and the device detection group are different, and the circuit utilization group can also be determined from the value of the deviation DF.

[0050] As an example, specifications are described here for a case where the maximum measuring range of the HV voltage 101 V comprises four types of 400 V, 600 V, 800 V, and 1200 V. According to the present embodiment, amplification groups are designated as Group A, Group B, Group C, and Group D, in the order of the maximum measuring ranges described above. The maximum voltages of the third output circuit 13 are set successively to 4.00 V, 4.19 V, 4.39 V, and 4.60 V. According to the present embodiment, the gains of the third output circuit 13 in series are 4.00 V / 400 V = 0.01, 4.19 V / 600 V = 0.006983, 4.39 V / 800 V = 0.005488 and 4.60 V / 1200 V = 0.003833, since the voltage converter circuit 100 does not have the first voltage divider resistor R1 and the fourth voltage divider resistor R4.

[0051] In the first output circuit 11 and the second output circuit 12, the amplitude of the output voltage is fixed at a maximum of 2.00 V with respect to the input voltages of 200 V, 300 V, 400 V, and 600 V. At this time, the gains of the PC voltages are 0.005, 0.003333, 0.0025, and 0.00166, respectively. Therefore, the gain ratios for the four gains are 0.01 / 0.005 = 2.000, 0.006983 / 0.003333 = 2.095, 0.005488 / 0.0025 = 2.195, and 0.003833 / 0.001667 = 2.300. These four gain ratios all differ from each other by at least 4.5%.

[0052] Fig. Figure 7 is a diagram illustrating a calculation example in the second embodiment. Fig.Figure 7 includes a voltage table 801, a gain ratio table 802, and a deviation table 803. Voltage table 801 describes the gains and the values ​​used to calculate the gains in each group described above. The gain of the second output circuit 12 is equal to the gain of the first output circuit 11. Gain ratio table 802 describes differences in the gain ratios of the respective groups. In particular, gain ratio table 802 describes the difference between the ratio in the upper group in the drawing and the gain ratio of the left group in the drawing. Gain ratio table 802 shows that each group has a difference of at least 0.045, that is, 4.5%.

[0053] Deviation Table 803 specifies deviations DF when 300 V is applied. Specifically, the circuit utilization group is shown on the left of the figure, and the device detection group is shown in the upper part of the figure. A diagonally placed zero indicates that the deviation DF is zero when the circuit utilization group and the device detection group are identical. As shown in Deviation Table 803, in a case where the circuit utilization group and the device detection group do not match, the deviation DF is a non-zero value, and it can be understood that a gain switching failure can be detected if the difference between the circuit utilization group and the device detection group can be identified by means of a suitable threshold such as "5".

[0054] In the embodiments and modifications described above, the functional block configuration serves only as an example. Some functional configurations shown as separate functional blocks may be designed as a single unit, or a configuration shown in a functional block diagram may be divided into two or more functions. Furthermore, some of the functions of each functional block may be contained within another functional block.

[0055] The embodiments and modifications described above can be combined. Although various embodiments and modifications have been described above, the present invention is not limited to these. Other aspects conceivable within the scope of the technical concept of the present invention are also included within the scope of protection of the present invention. Reference symbol list 1 measuring system 11 first output circuit 13 third output circuit 100 voltage converter circuit 101 HV power supply 102 Gain Change Unit 110 Standard Instruction Unit 114 Correction instruction unit 115 Differential compensation circuit 200 calculating device 210 Voltage measuring unit 220 diagnostic unit DF deviation GR1 first circuit gain ratio GR3 third circuit gain ratio P2 second potential point P4 fourth potential point VI1 first input voltage VI3 third input voltage VO1 first output voltage VO3 third output voltage QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2020-112526 A

[0003]

Claims

[1] Measuring system comprising a voltage converter circuit which converts and outputs a voltage between a first terminal and a second terminal, and a computing device which detects an anomaly of the voltage converter circuit, wherein The voltage converter circuit has the following features: a first output circuit which outputs a first output voltage obtained by multiplying a potential of the first terminal with respect to a predetermined reference potential by a conversion gain, a second output circuit which outputs a second output voltage obtained by multiplying a potential of the second terminal with respect to the reference potential by a conversion gain, and a third output circuit which outputs a third output voltage obtained by multiplying a voltage between the first terminal and the second terminal by a conversion gain, wherein the conversion gains of the first output circuit, the second output circuit and the third output circuit can be set to values ​​of at least one first group and one second group, and the ratio between a conversion gain of the first group and a conversion gain of the second group, which were set in the third output circuit, differs from the ratio between a conversion gain of the first group and a conversion gain of the second group, which were set in the first output circuit or the second output circuit, and the computing device has the following: a voltmeter that measures the first output voltage, the second output voltage, and the third output voltage, and A diagnostic unit which, using conversion gains of a selected group, which is one of the first group and the second group, calculates a first conversion value, a second conversion value and a third conversion value according to input voltages of the first output circuit, the second output circuit and the third output circuit based on the first output voltage, the second output voltage and the third output voltage, and determines that an anomaly exists if the sum of the first conversion value and the second conversion value deviates from the third conversion value by at least one predetermined value. [2] Measuring system according to claim 1, wherein the computing device calculates the first conversion value, the second conversion value and the third conversion value using conversion gains of a group which is not the selected group of the first group and the second group when the diagnostic unit detects that an anomaly is present. [3] Measuring system according to claim 1, wherein the computing device changes the conversion gains of the first output circuit, the second output circuit and the third output circuit to the conversion gains of the selected group when the diagnostic unit detects that an anomaly is present. [4] Measuring system according to claim 3, wherein the computing device calculates the first conversion value, the second conversion value and the third conversion value using conversion gains of a group which is not the selected group of the first group and the second group, when the diagnostic unit detects that an anomaly is present after the computing device has changed the conversion gains of the first output circuit, the second output circuit and the third output circuit to conversion gains of the selected group. [5] Measuring system according to claim 1, wherein the ratio between a conversion gain of the first group and a conversion gain of the second group, which were set in the third output circuit, is set to a ratio which differs by at least 4.5% from the ratio of a conversion gain of the first group and a conversion gain of the second group, which were set in the first output circuit or the second output circuit.

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