Estimation device, estimation method, and estimation program

Abstract

To provide an estimation device, an estimation method, and an estimation program with which it is possible to improve the accuracy of estimating the airflow of an air blower that cools a secondary battery.SOLUTION: An estimation device 10 for estimating the airflow of an air blower that cools a secondary battery includes: an acquisition unit 130 that acquires the revolution speed and torque of the rotary part of an air blower 2; an airflow index value calculation unit 131 that calculates an airflow index value corresponding to the acquired revolution speed and torque, on the basis of a known relationship between the revolution speed and torque of the air blower 2 and an airflow index value that indicates a decrease in the airflow of the air blower 2 due to the matter adhering to a filter 3 disposed to the air blower; a correction value calculation unit 132 that calculates a correction value for correcting the airflow index value, on the basis of battery state information indicating the state of the secondary battery correlated to the contraction of a cooling air passage attributable to the expansion of the second battery; and an airflow index value correction unit 133 that corrects the airflow index value using the correction value.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This disclosure relates to an estimation device, estimation method, and estimation program for estimating the airflow rate of a fan used to cool a secondary battery. [Background technology]

[0002] Currently, electric vehicles, hybrid vehicles, plug-in hybrid vehicles, and other vehicles that use electricity as a driving force utilize rechargeable batteries such as lithium-ion batteries and nickel-metal hydride batteries. Various technologies have been proposed to estimate the airflow rate of the fans used to cool these rechargeable batteries.

[0003] As an example of such technology, Patent Document 1 discloses a control device for a cooling system that determines the airflow performance of a cooling system by referring to airflow performance information that correlates the torque and actual rotational speed of the output shaft of the electric motor of a rotating machine with the airflow performance based on the ease of airflow through the filter, based on the torque and actual rotational speed of the electric motor of the rotating machine. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-148660 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the control device disclosed in Patent Document 1 does not take into account the reduction in the flow path of the cooling air caused by the expansion of the secondary battery, so there was room to improve the accuracy of estimating the airflow rate of the blower used to cool the secondary battery.

[0006] This disclosure aims to solve these problems by providing an estimation device, estimation method, and estimation program that can improve the accuracy of estimating the airflow rate of a fan used to cool a secondary battery. [Means for solving the problem]

[0007] An estimation device that estimates the air volume of a blower for cooling a secondary battery according to an embodiment, an acquisition unit that acquires the rotational speed and torque of the rotating part of the blower; an air volume index value calculation unit that calculates an air volume index value corresponding to the acquired rotational speed and torque based on a known correspondence relationship between the rotational speed and torque of the rotating part of the blower and an air volume index value that is an index value indicating a decrease in the air volume of the blower due to deposits on a filter provided in the blower; a correction value calculation unit that calculates a correction value for correcting the air volume index value based on battery state information indicating the state of the secondary battery that correlates with a reduction in the flow path of the cooling air caused by expansion of the secondary battery; and an air volume index value correction unit that corrects the calculated air volume index value using the correction value.

[0008] The correction value may be a ratio between a first air volume corresponding to the battery state information when the air volume index value is calculated and a second air volume in a predetermined reference state of the secondary battery.

[0009] The correction value calculation unit may calculate the first air volume and the second air volume based on a regression equation having, as an objective variable, an air volume calculated based on any one of the rotational speed, the current supplied to the blower, and the voltage supplied to the blower, and having, as an explanatory variable, battery state information indicating the state of the secondary battery when the air volume is calculated.

[0010] The correction value calculation unit may determine a correction value corresponding to the battery state information indicating the state of the secondary battery based on a known correspondence relationship between the battery state information and the correction value.

[0011] The battery state information may include the state of charge, salt concentration, and internal pressure of the secondary battery.

[0012] An estimation method for estimating the air volume of a blower for cooling a secondary battery according to an embodiment, wherein a computer acquires the rotational speed and torque of the rotating part of the blower, Based on the known correspondence between the rotational speed and torque of the rotating part of the blower and the air volume index value, which is an index value indicating the reduction in the air volume of the blower due to deposits on the filter provided in the blower, calculate the air volume index value corresponding to the obtained rotational speed and torque. Based on the battery state information indicating the state of the secondary battery, which correlates with the reduction in the flow path of the cooling air due to the expansion of the secondary battery, calculate a correction value for correcting the calculated air volume index value. Use the correction value to correct the calculated air volume index value.

[0013] An estimation program for estimating the air volume of a blower for cooling a secondary battery causes a computer to acquire the rotational speed and torque of the rotating part of the blower, Based on the known correspondence between the rotational speed and torque of the rotating part of the blower and the air volume index value, which is an index value indicating the reduction in the air volume of the blower due to deposits on the filter provided in the blower, calculate the air volume index value corresponding to the obtained rotational speed and torque. Based on the battery state information indicating the state of the secondary battery, which correlates with the reduction in the flow path of the cooling air due to the expansion of the secondary battery, calculate a correction value for correcting the calculated air volume index value. Use the correction value to correct the calculated air volume index value.

Effect of the Invention

[0014] According to the present disclosure, it is possible to provide an estimation device, an estimation method, and an estimation program that can improve the estimation accuracy of the air volume of a blower for cooling a secondary battery.

Brief Description of the Drawings

[0015] [Figure 1] It is a diagram showing an example of a secondary battery pack. [Figure 2] It is a block diagram showing an example of the configuration of the estimation device. [Figure 3] It is a diagram showing the known correspondence between the rotational speed and torque of the rotating part of the blower and the air volume retention rate Qretain. [Figure 4] It is a flowchart showing the process of calculating the correction value CorQ. [Figure 5] This figure shows an example of a regression line according to the first embodiment. [Figure 6] This flowchart shows an example of the processing performed by the estimation device according to the first embodiment. [Figure 7] This figure shows the known correspondence between battery state information and correction values ​​according to the second embodiment. [Modes for carrying out the invention]

[0016] <First Embodiment> Various embodiments will be described below with reference to the drawings. Figure 1 shows an example of a secondary battery pack 1. A blower 2 for cooling one or more secondary batteries housed within the secondary battery pack 1 is arranged adjacent to the secondary battery pack 1. A filter 3 is installed at the air intake of the blower 2. A flow path (not shown) for cooling the secondary batteries is formed inside the secondary battery pack 1. This flow path can be reduced by the expansion of the secondary batteries housed within the secondary battery pack 1.

[0017] Figure 2 is a block diagram showing the configuration of an estimation device 10 according to one embodiment. The estimation device 10 is a device for estimating the airflow rate of cooling air for a secondary battery. A specific example of the estimation device 10 is an ECU (Electronic Control Unit) installed in a vehicle.

[0018] The estimation device 10 comprises a communication interface (I / F) 11, a storage device 12, and an arithmetic unit 13. The communication I / F 11 is an interface for sending and receiving signals between the estimation device 10 and the secondary battery and other devices installed in the vehicle.

[0019] The memory device 12 is a memory device that stores the estimation program executed by the arithmetic unit 13 and various information processed by the arithmetic unit 13.

[0020] The arithmetic unit 13 is an arithmetic unit such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The arithmetic unit 13 executes an estimation method for estimating the airflow rate of the cooling air for the secondary battery by executing an estimation program stored in the memory device 12. The estimation program includes an acquisition unit 130, an airflow index value calculation unit 131, a correction value calculation unit 132, and an airflow index value correction unit 133. Alternatively, an integrated circuit such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit) may execute these programs.

[0021] The acquisition unit 130 is a program that acquires information about the blower 2 and information about the secondary battery. The information about the blower 2 includes the rotational speed of the rotating parts (e.g., blower or fan) of the blower 2 and the torque applied to the rotating parts. The information about the secondary battery includes the current value and voltage value supplied by the secondary battery to the blower 2. The acquisition unit 130 can acquire the rotational speed of the rotating parts of the blower 2 from a sensor that detects the rotational speed of the rotating parts of the blower 2 via the communication I / F 11. The acquisition unit 130 can also acquire the torque from a sensor that detects the torque of the rotating parts of the blower 2 via the communication I / F 11. Furthermore, the acquisition unit 130 can acquire the value of the current supplied to the blower 2 from a current sensor (not shown) that detects the current of the secondary battery. Furthermore, the acquisition unit 130 can acquire the value of the voltage supplied to the blower 2 from a voltage sensor (not shown) that detects the voltage of the secondary battery.

[0022] The airflow index calculation unit 131 is a program that calculates the airflow index value. The airflow index value is an index value that indicates the estimated airflow of the cooling air for the secondary battery. In this embodiment, the airflow maintenance rate Q is used as the airflow index value. retain The following will be adopted: Air volume maintenance rate Q retain This is the ratio (%) of the actual airflow of the blower 2 to the airflow of the blower 2 when no dust or other deposits are attached to the filter 3. Therefore, the airflow maintenance rate Q retainThis may indicate a decrease in the airflow rate of the blower 2 due to deposits on the filter 3. Specifically, the airflow index value calculation unit 131 calculates the rotational speed and torque of the rotating part of the blower 2 and the airflow maintenance rate Q, as shown in Figure 3. retain Based on the known correspondence, the airflow maintenance rate Q corresponding to the rotational speed and torque acquired by the acquisition unit 130 is determined by the acquisition unit 130. retain It is possible to calculate this.

[0023] The correction value calculation unit 132 calculates the airflow maintenance rate Q retain Correction value Cor Q This is a program that calculates the correction value Cor. Figure 4 shows the correction value Cor Q This flowchart shows the process for calculating the airflow rate. In step S1, the correction value calculation unit 132 calculates multiple airflow rates Q based on various rotational speeds of the rotating part of the blower 2.

[0024] More specifically, the correction value calculation unit 132 acquires the rotational speed of the rotating part of the blower 2. Then, based on the known correspondence between the rotational speed of the blower 2's rotating part and the airflow rate Q, the correction value calculation unit 132 calculates the airflow rate Q corresponding to the acquired rotational speed. The correspondence between rotational speed and airflow rate Q is obtained by measuring the airflow rate Q output by the blower 2 at various rotational speeds. Furthermore, the correspondence between rotational speed and airflow rate Q can be expressed by a mathematical formula or by a map such as a graph.

[0025] Furthermore, the correction value calculation unit 132 can also calculate the airflow rate Q based on the current or voltage supplied to the blower 2. Specifically, the correction value calculation unit 132 acquires the value of the current or voltage supplied to the blower 2. Then, based on the known correspondence between the value of the current or voltage supplied to the blower 2 and the airflow rate Q, the correction value calculation unit 132 calculates the airflow rate Q corresponding to the acquired current or voltage value. The correspondence between the current or voltage value and the airflow rate Q can be obtained by measuring the airflow rate Q of the blower 2 supplied with currents or voltages of various magnitudes.

[0026] In step S2, the correction value calculation unit 132 derives a regression equation with the plurality of air volumes Q calculated in step S1 as the target variable and the plurality of battery state information indicating the state of the secondary battery when the air volume Q is calculated as the explanatory variable. The battery state information is information indicating the state of the secondary battery correlated with the reduction of the flow path of the cooling air due to the expansion of the secondary battery. The battery state information includes the charging rate, salt concentration, and internal pressure of the secondary battery. FIG. 5 is a diagram showing an example of the regression line indicated by the above regression equation.

[0027] In step S3, the correction value calculation unit 132 calculates the air volume Q retain corresponding to the battery state information x means indicating the state of the secondary battery when the air volume maintenance rate Q means is calculated, based on the following formula 1. The air volume Q means corresponds to the first air volume.

Equation

[0028] In step S4, the correction value calculation unit 132 calculates the air volume Q ref in the reference state of the secondary battery, based on the following formula 2. The reference state is a state where the flow path of the cooling air in the secondary battery is not reduced. The air volume Q ref corresponds to the second air volume.

Equation

[0029] In step S5, the correction value calculation unit 132 calculates the correction value Cor means using the air volume Q ref and the air volume Q Q , based on the following formula 3. The correction value Cor Q is for the air volume Q means and the air volume Q refThis corresponds to the ratio of Q. Specifically, the correction value calculation unit 132 calculates the airflow Q. means Air volume Q ref By dividing by the correction value Cor Q It is possible to calculate this.

number

[0030] The airflow index value correction unit 133 is a program that corrects the airflow index value calculated by the airflow index value calculation unit 131. In this embodiment, the airflow index value correction unit 133 corrects the airflow index value Cor based on formula 4. Q Using the airflow maintenance rate Q retain This corrects the airflow index value correction unit 133, specifically the airflow maintenance rate Q. retain Correction value Cor Q By dividing by Q, the corrected airflow maintenance rate Q retain_filter The airflow maintenance rate Q can be calculated. retain_filter This represents the airflow maintenance rate, which reflects the effects of clogging of filter 3 and the reduction in the cooling airflow path.

number

[0031] Figure 6 is a flowchart showing an example of the process performed by the estimation device 10. In step S11, the acquisition unit 130 acquires the rotational speed and torque of the rotating part of the blower 2. In step S12, the airflow index value calculation unit 131 calculates the rotational speed and torque of the rotating part of the blower 2 and the airflow maintenance rate Q. retain Based on the known correspondence, the airflow maintenance rate Q corresponding to the rotational speed and torque acquired by the acquisition unit 130 is determined by the acquisition unit 130. retain The correction value calculation unit 132 calculates the correction value Cor according to the method described with reference to Figure 4. Q The airflow index value correction unit 133 calculates the correction value Cor Q Using the airflow index value Q retain Correct it.

[0032] In the embodiment described above, the airflow index value calculation unit 131 calculates an airflow index value corresponding to the acquired rotational speed and torque, based on a known correspondence between the rotational speed and torque of the rotating part of the blower 2 and the airflow index value indicating the decrease in airflow of the blower 2 due to deposits on the filter 3. Next, the correction value calculation unit 132 calculates a correction value to correct the airflow index value based on battery state information indicating the state of the secondary battery which correlates with the reduction in the flow path of the cooling air caused by the expansion of the secondary battery. Then, the airflow index value correction unit 133 corrects the airflow index value calculated by the airflow index value calculation unit 131 using the correction value calculated by the correction value calculation unit 132. As a result, the airflow index value based on the decrease in airflow of the blower 2 due to deposits on the filter 3 is corrected by the correction value based on battery state information which correlates with the reduction in the flow path of the cooling air in the secondary battery, so that an airflow index value that reflects the effects of deposits on the filter 3 and the effects of the reduction in the flow path of the cooling air is derived. As a result, the estimation accuracy of the airflow of the blower that cools the secondary battery can be improved.

[0033] <Second Embodiment> In the second embodiment, the correction value calculation unit 132 can calculate a correction value corresponding to the battery state information of a secondary battery based on a known correspondence between the battery state information of the secondary battery and the correction value. The battery state information includes the charge level, salt concentration, and internal pressure of the secondary battery. Figure 7 is a diagram showing the known correspondence between the battery state information and the correction value according to the second embodiment. Based on such a known correspondence, the correction value calculation unit 132 can determine a correction value corresponding to the battery state information of the secondary battery. The airflow index value correction unit 133 can correct the airflow index value calculated by the airflow index value calculation unit 131 using the correction value determined in this way.

[0034] In yet another embodiment, the airflow reduction rate may be used as the airflow index value. The airflow index value calculation unit 131 can calculate the airflow reduction rate based on the airflow maintenance rate. For example, if the airflow maintenance rate is 80%, the airflow reduction rate will be 20 (=100-80)%. The airflow index value correction unit 133 applies a correction value Cor to the airflow reduction rate calculated by the airflow index value calculation unit 131. QBy multiplying this by a predetermined correction coefficient, the airflow reduction rate can be corrected.

[0035] The estimated program described above, when loaded into a computer, includes a set of instructions (or software code) for causing the computer to perform one or more of the functions described in the embodiments. The program may be stored in a non-temporary computer-readable medium or a physical storage medium. Examples, but not limited to, include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technologies, CD-ROM, digital versatile disk (DVD), Blu-ray® disc or other optical disc storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices. The program may be transmitted over a temporary computer-readable medium or a communication medium. Examples, but not limited to, include temporary computer-readable medium or a communication medium that includes propagating signals of electrical, optical, acoustic or other forms. In addition to the ECU, a computer includes various devices such as a PC (Personal Computer), server, CPU, MPU, FPGA, ASIC, etc.

[0036] This disclosure is not limited to the embodiments described above, and may be modified as appropriate without departing from the spirit of this disclosure. [Explanation of Symbols]

[0037] 1. Rechargeable battery pack 2. Blower 3 filters 10 Estimation device 11 Communication Interface 12 Storage device 13 Arithmetic unit 130 Acquisition Department 131 Airflow Index Value Calculation Unit 132 Correction Value Calculation Unit 133 Airflow index value correction unit

Claims

1. An estimation device for estimating the airflow rate of a fan used to cool a secondary battery, An acquisition unit that acquires the rotational speed and torque of the rotating part of the blower, An airflow index calculation unit calculates an airflow index value corresponding to the acquired rotation speed and torque, based on a known correspondence between the rotation speed and torque of the rotating part of the blower and an airflow index value, which is an index value indicating the decrease in airflow of the blower due to deposits on the filter provided on the blower. A correction value calculation unit calculates a correction value to correct the calculated airflow index value based on battery state information indicating the state of the secondary battery which correlates with the reduction of the cooling airflow path due to the expansion of the secondary battery, An airflow index value correction unit corrects the calculated airflow index value using the correction value. including, Estimation device.

2. The estimation device according to claim 1, wherein the correction value is the ratio of a first airflow corresponding to battery state information indicating the state of the secondary battery when the airflow index value is calculated, and a second airflow in a predetermined reference state of the secondary battery.

3. The estimation device according to claim 2, wherein the correction value calculation unit calculates the first airflow and the second airflow based on a regression equation in which the airflow calculated based on any of the rotational speed, the current supplied to the blower, and the voltage supplied to the blower is the objective variable, and battery state information indicating the state of the secondary battery when the airflow is calculated is the explanatory variable.

4. The estimation device according to claim 1, wherein the correction value calculation unit determines a correction value corresponding to the battery state information indicating the state of the secondary battery based on a known correspondence between the battery state information and the correction value.

5. The estimation device according to any one of claims 1 to 4, wherein the battery state information includes the charge level, salt concentration, and internal pressure of the secondary battery.

6. An estimation method for estimating the airflow rate of a fan used to cool a secondary battery, wherein a computer... The rotational speed and torque of the rotating part of the blower are obtained, Based on the known correspondence between the rotational speed and torque of the rotating part of the blower and the airflow index value, which is an index value indicating the decrease in airflow of the blower due to deposits on the filter provided on the blower, the airflow index value corresponding to the acquired rotational speed and torque is calculated. Based on battery state information indicating the state of the secondary battery, which correlates with the reduction in the cooling airflow path due to the expansion of the secondary battery, a correction value is calculated to correct the calculated airflow index value. The calculated airflow index value is corrected using the correction value. Estimation method.

7. An estimation program for estimating the airflow rate of a fan used to cool a secondary battery, which provides a computer with the following information: The rotational speed and torque of the rotating part of the blower are acquired. Based on a known correspondence between the rotational speed and torque of the rotating part of the blower and the airflow index value, which is an index value indicating the decrease in airflow of the blower due to deposits on the filter provided on the blower, the airflow index value corresponding to the acquired rotational speed and torque is calculated. Based on battery state information indicating the state of the secondary battery, which correlates with the reduction in the cooling airflow path due to the expansion of the secondary battery, a correction value is calculated to correct the calculated airflow index value. The airflow index value is corrected using the correction value. Estimation program.

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