Multi-path current measurement device

Abstract

In order to solve the problem of detection stability of conventional shunt resistor current detectors, the present invention ensures stability of current detection by branching the path from the shunt resistor to the current calculation processor into multiple branch paths, connecting the shunt resistor to each branch path using multiple branch contacts, and allowing the current flowing from the processor to the shunt resistor to be calculated multiple times.

Description

[Technical Field]

[0001] The present invention relates to a shunt-type current measuring device and a current measuring method for measuring a current using a shunt resistor. [Background technology]

[0002] Devices that use shunt resistors to measure the current flowing through them are well known. Conventional current measurement devices that use shunt resistors (shunt-type current measurement devices) measure the current flowing through the shunt resistor by measuring the shunt resistor voltage from the contacts at both ends of the shunt resistor Rs, as shown in Figure 1.

[0003] However, such conventional shunt resistance measuring devices / measuring circuits cause a problem in that they are unable to measure important currents in the battery management system (BMS) when a break in the wiring or damage to electronic components occurs due to an impact. Current measurement is extremely important for ensuring the safety of electric vehicles, particularly, and a lack of current measurement information can lead to serious issues affecting the safety of the driver, such as fire.

[0004] The prior art related to this issue is as follows: [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Republic of Korea Patent No. 10-199801 Summary of the Invention [Problem to be solved by the invention]

[0006] For this reason, the present invention aims to solve the above-mentioned problems and provide a current measuring device or current measuring circuit that can measure current through an extra measurement path even if part of the current measuring device is damaged, and that can not only ensure the reliability of current measurement but also detect the presence or absence of an overcurrent. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the present invention provides a current measuring device comprising a processor that receives the outputs of the first and second contacts at both ends of a shunt resistor and calculates the voltage across the shunt resistor, wherein the outputs of the first and second contacts are each branched into three or more branch paths, and the outputs of each branch are input to different input terminals of the processor.

[0008] At least one of the three or more branch paths is set as an input path for overcurrent protection, and at least two of the branch paths have the same path parameters and provide the same signal for calculating the current measurement value.

[0009] On the other hand, the processor of the current measuring device of the present invention comprises a current value calculation module that calculates three or more current values ​​from signals input from a plurality of input terminals, an overcurrent detection module that detects an overcurrent from at least one of the three or more current values, and a current value verification module that compares at least two or more of the remaining current values ​​among the three or more current values ​​excluding the current value input to the overcurrent detection module, and calculates one selected from the current values ​​input to the current value verification module as the measured current value.

[0010] The present invention also provides a current measurement method including a multiple voltage signal receiving step in which a processor receives voltage signals from two or more voltage signal paths branched from a single contact, a multiple shunt current value calculation step in which the processor calculates the current values ​​flowing to shunt resistors from the voltage signals received from the two or more voltage signal paths, a shunt current value comparison step in which the processor compares the calculated shunt current values ​​with a predetermined reference range, and a measured current value output step in which the shunt current value within the predetermined reference range is output as a final measured current value as a result of the comparison in the shunt current value comparison step, and the current measurement method further includes an overcurrent determination step in which any one of the current values ​​calculated in the multiple shunt current value calculation step is designated as an overcurrent determination current value, and if the overcurrent determination current value is equal to or greater than the predetermined reference value, it is determined that an overcurrent has occurred. [Effects of the Invention]

[0011] According to an embodiment of the present invention, even if part of the current measuring device is damaged, the current can be measured via an extra measurement path, ensuring the reliability of the current measurement and even making it possible to detect the presence or absence of an overcurrent.

[0012] The drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical concepts of the present invention as well as the content of the invention, and therefore the present invention should not be interpreted as being limited to only the matters depicted in the drawings. [Brief explanation of the drawings]

[0013] [Figure 1] 1 shows the main components of a current measurement device with a single measurement path; [Figure 2] 1 is a diagram showing the main components of a current measurement device having multiple measurement paths; DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention is based on a known current measurement device using a shunt resistor. Conventional current measurement devices form a voltage measurement path from first and second contacts on both ends of the shunt resistor, and calculate the value of the current flowing through the shunt resistor by measuring the voltage across the shunt resistor in a processor.

[0015] However, current measurement devices using such conventional technology have the problem that if an impact causes damage to the shunt resistor contacts or damage to the voltage measurement path, there will be gaps in the current measurement data.

[0016] In order to solve such problems, the present invention provides a current measuring device having the following configuration.

[0017] 1. Current measuring device according to the present invention

[0018] (1) Shunt resistor Rs

[0019] A resistor with a known resistance is provided to measure the voltage across it to measure the current flowing through the shunt resistor.

[0020] The shunt resistor has first and second contacts designated A and B in FIGS. 1 and 2, respectively.

[0021] (2) Voltage measurement paths 11 to 13, 11' to 13'

[0022] The current measurement path is a path that connects the first and second contacts at both ends of the shunt resistor Rs to the input terminal of the processor 200, and the processor 200 receives the voltage value across the shunt resistor from this path.

[0023] Fig. 1 shows a case where the voltage measurement path is formed as one pair, while Fig. 2 shows a case where the voltage measurement paths 11-13, 11'-13' are branched into three branch path pairs. In this case, the present invention has three pairs of branch contacts 10, 20, 30, 10', 20', 30' that are connected to the first and second contacts of the shunt resistor, respectively.

[0024] Although FIG. 2 shows each of the first and second contacts branching into three branch paths, the present invention may be configured to have more than three branch paths.

[0025] (3) Voltage sensing circuit 100

[0026] A voltage sensing circuit 100 may be connected to the voltage measurement path of the present invention. The voltage sensing circuit 100 is disposed between the branch contact and the input terminal of the processor, with an input terminal connected to the branch contact and an output terminal connected to the input terminal of the processor, senses the voltage across the shunt resistor and provides it to the input terminal of the processor, and configures path parameters by arranging a sensing resistor (not shown), a sensing capacitor (not shown), a signal amplifier, an analog-digital converter (ADC), etc. for each branch path to sense the voltage across the shunt resistor.

[0027] The path parameters include the sensing resistance and sensing capacitance of the path. At least two of the three or more branch paths of the present invention have the same path parameters (sensing resistance and sensing capacitance) and transmit signals to the processor so that the theoretically identical voltage values ​​are measured. The path parameters of at least one path are set so that the output value can be compared with a predetermined overcurrent reference current value to detect overcurrent. An ADC may be included at the final output terminal of each path of the voltage sensing circuit 100.

[0028] (4) Processor 200

[0029] The end point of the voltage measurement path of the present invention is configured with a processor having a number of input terminals that receive inputs from each branch path. After the input terminal, the processor may include an ADC circuit if not provided in the voltage sensing circuit.

[0030] The processor 200 may include a current calculation module (not shown), an overcurrent detection module (not shown), and a current value verification module (not shown). Each module described below is defined as a group of software algorithms installed in the processor, and calculates the output of each algorithm based on the signals received at each input terminal.

[0031] (i) Current Value Calculation Module 210

[0032] The current value calculation module calculates the voltage values ​​across the shunt resistor input from the multiple paths received by the input terminal, and calculates the current values ​​for each path flowing through the shunt resistor by combining the known shunt resistance value and the path parameter values ​​described above.

[0033] Although the voltage value may be calculated differently depending on the path parameter value for each branch path, at least two branch paths are set to have the same path parameter value so that the same current value is calculated in the absence of a fault. Therefore, at least two calculated current values ​​should theoretically have the same value.

[0034] On the other hand, at least one current calculation value is a current value for overcurrent detection calculated from a combination of a path parameter value and a shunt resistance value that are set so that the magnitude relationship with the predetermined overcurrent reference current value described above can be compared.

[0035] (ii) Current Value Verification Module 220

[0036] The current value verification module compares the at least two theoretically identically calculated current values, and if the difference between the two current values ​​is equal to or greater than a predetermined reference value, selects the correct current value and calculates it as the final current measurement value. For example, if one branch path is damaged and no current is detected, the current value calculated from the undamaged branch path can be calculated as the final current measurement value.

[0037] The current value verification module may further perform current value verification by having data of predetermined maximum and minimum current values ​​and comparing the data with the compared and selected current value in order to select an error-free current value. If the selected current value is greater than the predetermined maximum current value or less than the predetermined minimum current value, a correct current calculation cannot be performed, and a total error in the current detection device can be detected.

[0038] (iii) Overcurrent detection module 230

[0039] The overcurrent detection module detects whether the current flowing through the shunt resistor is an overcurrent by comparing the at least one current value for overcurrent detection with a predetermined overcurrent reference current value.

[0040] 2. Current measurement method according to the present invention

[0041] The procedure for measuring a current using the current measuring device of the present invention described above will now be described.

[0042] First, a multipath is formed, which is a voltage signal path that branches into two or more paths from the contact point of the shunt resistor on the current path to the current calculation processor.

[0043] Next, a processor receives multiple voltage signals from the two or more voltage signal paths, and then performs a multiple shunt current value calculation step of calculating current values ​​flowing through shunt resistors from the voltage signals received from the two or more voltage signal paths. At this time, the two or more voltage signal paths have their path parameters set to be identical so that they theoretically output identical voltage signals.

[0044] The processor performs a shunt current value comparison step in which each calculated shunt current value is compared with a predetermined reference range, and as a result of the comparison in the shunt current value comparison step, outputs a shunt current value within the predetermined reference range as the final measured current value.

[0045] Alternatively, the multiple paths may be composed of three or more multiple paths. In this case, an overcurrent determination step may be further performed in which any one of the current values ​​calculated in the multiple shunt current value calculation step is designated as an overcurrent determination current value, and if the overcurrent determination current value is equal to or greater than a predetermined reference value, it is determined that an overcurrent has occurred. [Explanation of symbols]

[0046] 100 Voltage Sensing Circuit 200 processors 10, 20, 30, 10', 20', 30' Branch contact 210 Current value calculation module 220 Current Value Verification Module 230 Overcurrent Detection Module

Claims

1. first and second contacts across the shunt resistor; a processor that receives the outputs of the first and second contacts and calculates a voltage across a shunt resistor; Equipped with The current measuring device wherein the outputs of the first and second contacts are each branched into three or more branch paths, and the outputs of each branch are input to different input terminals of the processor.

2. The current measuring device according to claim 1 , wherein at least one of the three or more branch paths is set as an input path for overcurrent protection.

3. at least two of the three or more branched pathways have identical pathway parameters; The processor:

3. The current measuring device according to claim 1, wherein the validity of the measurement value is verified by comparing the measurement values ​​via at least two branch paths having the same path parameters.

4. a shunt resistor disposed on the current path; first and second contacts across the shunt resistor; a pair of branch paths, each of which has one end connected to the first and second contacts and the other end branched into three or more paths; branch contacts to which the other branched ends of the pair of branch paths are respectively connected; a processor having a plurality of input terminals to which the outputs of the branch contacts are respectively input; A current measuring device comprising:

5. The processor: a current value calculation module that calculates three or more current values ​​from signals input from the plurality of input terminals; an overcurrent detection module that detects an overcurrent from at least one current value among the three or more current values; a current value verification module that compares at least two of the remaining current values, excluding the current value input to the overcurrent detection module, among the three or more current values; Equipped with The current measuring device according to claim 4 , wherein one selected from the current values ​​input to the current value verification module is calculated as the measured current value.

6. 6. The current measuring device according to claim 5, further comprising a voltage sensing circuit arranged between the branch contact and the input terminal of the processor, the voltage sensing circuit having an input end connected to the branch contact and an output end connected to the input terminal of the processor, the voltage sensing circuit sensing the voltage across the shunt resistor and providing the voltage to the input terminal of the processor.

7. Each path of the voltage sensing circuit is 7. The current measurement device of claim 6, comprising a sensing resistor and a sensing capacitor to determine the path parameters of each path.

8. 8. The current measuring device according to claim 7, wherein at least two of the paths are set to have the same path parameters.

9. A current measurement method for a current measurement device, comprising: a multiple voltage signal receiving step in which a processor receives voltage signals from two or more voltage signal paths branched from one contact; a multi-shunt current value calculation step in which the processor calculates a current value flowing to a shunt resistor from each of the voltage signals received from the two or more voltage signal paths; a shunt current value comparison step of comparing each of the calculated current values ​​with a predetermined reference range; a measured current value output step of outputting a shunt current value within a predetermined reference range as a final measured current value as a result of the comparison in the shunt current value comparison step; A current measurement method comprising:

10. 10. The current measurement method according to claim 9, further comprising an overcurrent determination step of designating any one of the current values ​​calculated in the multiple shunt current value calculation step as an overcurrent determination current value, and determining that an overcurrent exists if the overcurrent determination current value is equal to or greater than a predetermined reference value.

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