Multi-path current measuring device

Abstract

In order to solve the detection stability problem of a traditional shunt resistor current detector, a path formed by a shunt resistor and a path between the shunt resistor and a current calculation processor are divided into a plurality of branch paths, and the shunt resistor and the corresponding branch paths are connected through a plurality of branch contact points. Therefore, the processor can calculate the current flowing in the shunt resistor in various modes, so that the stability of current detection is ensured.

Description

Technical Field

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

[0002] Devices for measuring the current value flowing through a shunt resistor using a shunt resistor are well known. As Figure 1 shown, a conventional current measuring device (shunt current measuring device) using a shunt resistor measures the shunt resistor voltage at the contact points at both ends of the shunt resistor Rs to measure the current flowing through the shunt resistor.

[0003] However, when an electronic component is disconnected or damaged due to an impact, such a conventional shunt resistor measuring device / measuring circuit has a problem that an important current cannot be measured in a battery management system (BMS). Current measurement is crucial for ensuring driving safety, especially in the case of an electric vehicle, and omission of relevant current measurement information may cause serious problems directly related to driver safety issues, such as fire.

[0004] Related prior art includes the following.

[0005] Patent Document 1: Korean Registered Patent No.10-199801 Summary of the Invention

[0006] Technical Problem

[0007] Therefore, an object of the present invention is to solve the above problems and provide a current measuring device that can measure current through an additional measurement path even when some damage occurs to the current measuring device, further ensuring the reliability of current measurement, and also detecting whether there is an overcurrent.

[0008] Technical Solution

[0009] To solve the above problems, according to an aspect of the present invention, there is provided a current measuring device, the current measuring device including: a processor that receives outputs of a first contact point and a second contact point at both ends of a shunt resistor and calculates a voltage between both ends of the shunt resistor, wherein the outputs of the first contact point and the second contact point each branch into three or more branch paths such that the outputs of each branch are respectively input to different input terminals of the processor.

[0010] At least one of the three or more branch paths is set as an input path for overcurrent protection, and at least two branch paths have the same path parameters and provide signals for calculating the same current measurement value.

[0011] Meanwhile, the processor of the current measurement device of the present invention includes: a current value calculation module that calculates three or more current values based on signals received from the plurality of input terminals; an overcurrent detection module that detects overcurrent based on 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 three or more current values other than the current value input to the overcurrent detection module, and calculates one current value selected from the current values input to the current value verification module as the measured current value.

[0012] According to one aspect of the present invention, there is provided a current measurement method, the current measurement method including the following steps: a multi-voltage signal receiving step in which a processor receives voltage signals from two or more voltage signal paths respectively, the two or more voltage signal paths branching from one contact point; a multi-shunt current value calculation step in which the processor calculates the current values flowing through the shunt resistors respectively based on the voltage signals received from the two or more voltage signal paths; a shunt current value comparison step in which each calculated shunt current value is compared with a predetermined reference range; and a measured current value output step in which the shunt current value that is within the predetermined reference range as a comparison result in the shunt current value comparison step is output as the final measured current value, and the current measurement method further includes an overcurrent determination step in which any one of the current values calculated in the multi-shunt current value calculation step is designated as an overcurrent determination current value, and when the overcurrent determination current value is greater than or equal to a predetermined reference value, the overcurrent determination current value is determined as an overcurrent.

[0013] Advantageous Effects

[0014] According to the present invention, even if some damage occurs to the current measurement device, current measurement can be performed through an additional measurement path, thereby ensuring the reliability of current measurement and enabling overcurrent detection. Brief Description of the Drawings

[0015] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the above invention, are used to further understand the technical concept of the present invention. Therefore, the present invention should not be construed as being limited to the content described in these drawings.

[0016] Figure 1 is a diagram showing the main configuration of a current measurement device having a single measurement path.

[0017] Figure 2 is a diagram showing the main configuration of a current measurement device having multiple measurement paths. Detailed Description of the Embodiments

[0018] The present invention is based on a current measurement device using a known shunt resistor. Conventional current measurement devices form a voltage measurement path from a first contact point and a second contact point at both ends of the shunt resistor, and a processor measures the voltage between both ends of the shunt resistor to calculate the current value flowing through the shunt resistor.

[0019] However, in the current measurement device according to the prior art, when the shunt resistor contact point is damaged due to impact or the voltage measurement path is damaged, there will be a problem of missing current measurement data.

[0020] The present invention provides a current measurement device with the following configuration to solve this problem:

[0021] 1. The current measurement device according to the present invention

[0022] (1) Shunt resistor Rs

[0023] The shunt resistor is a resistor with a known resistance value, which is set to measure the current flowing through the shunt resistor by measuring the voltage between both ends of the shunt resistor.

[0024] The shunt resistor has a first contact point and a second contact point shown as A and B in Figure 1 and Figure 2 respectively.

[0025] (2) Voltage measurement paths 11 to 13 and 11' to 13'

[0026] The current measurement path is a path connecting the first contact point and the second contact point at both ends of the shunt resistor Rs to the input terminal of the processor 200, and the processor 200 receives the voltage value between both ends of the shunt resistor from this path.

[0027] Figure 1 shows the case where the voltage measurement path is formed as a pair, Figure 2 shows the case where the voltage measurement paths 11 to 13 and 11' to 13' are formed by branching into three pairs of branch paths. In this case, the present invention has three pairs of branch contact points 10, 20, 30, 10', 20', 30' respectively connected to the first contact point and the second contact point of the shunt resistor.

[0028] Figure 2 shows the case where each of the first contact point and the second contact point branches into three branch paths, but the present invention can be configured to have three or more branch paths.

[0029] (3) Voltage sensing circuit 100

[0030] The voltage sensing circuit 100 can be connected to the voltage measurement path of the present invention. The voltage sensing circuit 100 is disposed between the branch contact point and the input terminal of the processor. Its input stage is connected to the branch contact point, and its output stage is connected to the input terminal of the processor. The voltage sensing circuit 100 senses the voltage across the shunt resistor and provides this voltage to the input terminal of the processor. By including a sensing resistor (not shown), a sensing capacitor (not shown), a signal amplification element, and an ADC, path parameters are configured for each branch path, and the voltage across the shunt resistor is sensed.

[0031] The path parameters include the sensed resistance value and the sensed capacitance on the path. Among three or more branch paths of the present invention, at least two branch paths have the same path parameters (sensed resistance value and sensed capacitance), and theoretically transmit signals to the processor to measure the same voltage value. The path parameters of at least one path are set such that the output value can be compared in magnitude with a predetermined over-current reference current value, so as to apply it to over-current detection. For at least one path, the path parameters are set such that the magnitude relationship with the predetermined over-current reference current value can be compared, so as to apply its output value to over-current detection. The final output stage on each path of the voltage sensing circuit 100 may include an ADC.

[0032] (4) Processor 200

[0033] At the end of the voltage measurement path of the present invention, a processor is configured. The processor has a plurality of input terminals, and the plurality of input terminals receive inputs from each branch path. If an ADC circuit is not provided in the voltage sensing circuit, an ADC circuit may be included inside the processor and at the back end of the input stage.

[0034] The processor 200 may include a current calculation module (not shown), an over-current detection module (not shown), and a current value verification module (not shown). Each of the modules described below is defined as a set of software algorithms installed on the processor, and calculates the output of each algorithm based on the signals received at each input stage.

[0035] ① Current value calculation module 210

[0036] The current value calculation module calculates the voltage value across the shunt resistor of the multiple path inputs received through the input terminals, and combines the known shunt resistor value and the above path parameter values to calculate the current value of each path flowing through the shunt resistor.

[0037] The voltage value can be calculated in different ways according to the path parameter values of each branch path, but the path parameter values of at least two branch paths are set to be the same so that the same current value can be calculated in the absence of a fault. Therefore, theoretically, at least two current calculation values should have the same value.

[0038] Meanwhile, at least one current calculation value is the current value for overcurrent detection calculated according to the combination of the set path parameter value and the shunt resistor value, so that the magnitude relationship with the above-mentioned predetermined overcurrent reference current value can be compared.

[0039] ② Current value verification module 220

[0040] The current value verification module compares at least two current values that should theoretically be calculated to be the same, selects the current value without error in the case where the error is greater than the predetermined reference value, and calculates this current value as the final current measurement value. In this way, for example, if a 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.

[0041] The current value verification module can additionally perform current value verification by obtaining data of the predetermined maximum current value and minimum current value and further comparing them with the compared and selected current value in order to select the current value without error. If the selected current value is greater than the predetermined maximum current value or less than the predetermined minimum current value, an error that the correct current calculation is not performed in the entire current detection device can be detected.

[0042] ③ Overcurrent detection module 230

[0043] The overcurrent detection module compares at least one overcurrent detection current value with the predetermined overcurrent reference current value and detects whether the current flowing through the shunt resistor is an overcurrent.

[0044] 2. Current measurement method according to the present invention

[0045] The process of measuring current using the above-mentioned current measurement device of the present invention will be described.

[0046] First, configure a multi-path, which constitutes a voltage signal path that branches from the contact point of the shunt resistor on the current path into two or more paths to the current calculation processor.

[0047] Next, the processor receives a multi-voltage signal that receives voltage signals from each of two or more voltage signal paths. Thereafter, the processor performs a multi-shunt current value calculation step of calculating the current value flowing through the shunt resistor according to each voltage signal received from the two or more voltage signal paths. In this case, the path parameters of the two or more voltage signal paths are set to be the same so that the same voltage signal is theoretically output.

[0048] The processor performs a shunt current value comparison step that compares each calculated shunt current value with a predetermined reference range and outputs the shunt current value that is within the predetermined reference range as the comparison result in the shunt current value comparison step as the final measured current value.

[0049] Meanwhile, the multi-path can be composed of three or more multi-paths. In this case, an overcurrent determination step is performed, designating any one of the current values calculated in the multi-shunt current value calculation step as the overcurrent determination current value, and when the overcurrent determination current value is greater than or equal to a predetermined reference value, it is determined as an overcurrent.

[0050] The following are the symbols and names of the elements used in the drawings and the specification of the present invention.

[0051] 100 Voltage sensing circuit

[0052] 200 Processor

[0053] 10, 20, 30, 10', 20', 30' Branch contact points

[0054] 210 Current value calculation module

[0055] 220 Current value verification module

[0056] 230 Overcurrent detection module

Claims

1. A current measurement device, the current measurement device comprising: A first contact point and a second contact point located at both ends of a shunt resistor; And A processor, the processor receiving the outputs of the first contact point and the second contact point and calculating the voltage between both ends of the shunt resistor, wherein, The output of the first contact point and the output of the second contact point each branch into three or more branch paths, such that the outputs of each branch are respectively input to different input terminals of the processor.

2. The current measurement 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. The current measurement device according to claim 1, wherein, At least two of the three or more branch paths have the same path parameters, and The processor verifies the validity of the measured value by comparing the measured values passing through the at least two branch paths having the same path parameters.

4. A current measurement device, the current measurement device comprising: A shunt resistor, the shunt resistor being disposed on a current path; A first contact point and a second contact point, the first contact point and the second contact point being located at both ends of the shunt resistor; A pair of branch paths, one end of the pair of branch paths being connected to the first contact point and the second contact point, and the other end of the pair of branch paths respectively branching into three or more paths; Branch contact points, the branched other ends of the branch paths being respectively connected to the branch contact points; And A processor, the processor comprising a plurality of input terminals respectively receiving the outputs of the branch contact points.

5. The current measurement device according to claim 4, wherein, The processor comprises: A current value calculation module, the current value calculation module calculating three or more current values according to the signals received from the plurality of input terminals; An overcurrent detection module, the overcurrent detection module detecting overcurrent according to at least one of the three or more current values; and A current value verification module, the current value verification module comparing at least two or more of the three or more current values other than the current value input to the overcurrent detection module, and Calculating one current value selected from the current values input to the current value verification module as the measured current value.

6. The current measurement device according to claim 5, the current measurement device further comprising: A voltage sensing circuit, the voltage sensing circuit being disposed between the branch contact points and the input terminals of the processor, an input stage of the voltage sensing circuit being connected to the branch contact points, an output stage of the voltage sensing circuit being connected to the input terminals of the processor, and the voltage sensing circuit sensing the voltage between both ends of the shunt resistor and providing the voltage to the input terminals of the processor.

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

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

9. A current measuring method for a current measuring device, the current measuring method comprising the following steps: a multi-voltage signal receiving step, in which the processor receives voltage signals from two or more voltage signal paths respectively, and the two or more voltage signal paths branch from one contact point; a multi-shunt current value calculating step, in which the processor calculates the current values flowing through the shunt resistors respectively according to the voltage signals received from the two or more voltage signal paths respectively; a shunt current value comparing step, in which each calculated shunt current value is compared with a predetermined reference range; and a measured current value outputting step, in which the shunt current value within the predetermined reference range as a comparison result in the shunt current value comparing step is output as a final measured current value.

10. The current measuring method according to claim 9, the current measuring method further comprising the following steps: an overcurrent determining step, in which any one of the current values calculated in the multi-shunt current value calculating step is designated as an overcurrent determining current value, and when the overcurrent determining current value is greater than or equal to a predetermined reference value, the overcurrent determining current value is determined as an overcurrent.

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