Charge-discharge test method

Abstract

To efficiently conduct the charge-discharge test of a battery while minimizing the energy needed for lowering the humidity in a test room.SOLUTION: A test room 18 is controlled to a prescribed temperature. Thereafter, when the temperature and humidity in the test room 18 are not within a prescribed range, determination is made as to the presence of frost formation. When it is determined that there is frost formation, defrosting, as well as dehumidification to lower the temperature in the test room 18 by a prescribed value, are carried out, and the inside of the test room 18 is controlled to a prescribed temperature thereafter. Thereafter, when the temperature and humidity in the test room 18 are within a prescribed range, a charge-discharge test of a battery 22 is carried out.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a method for charging and discharging a battery.

Background Art

[0002] Patent Document 1 describes an apparatus for performing a charge and discharge test of a battery under a plurality of test schedules. Specifically, during the execution of the first test schedule, when the state of the battery (for example, shape change, internal pressure, surface temperature) satisfies a predetermined change condition, the apparatus executes the second test schedule.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, in a charge and discharge test, the battery is charged and discharged under preset temperature conditions. However, when frosting occurs on the cooler in the charge and discharge test chamber (for example, a thermostatic and humidistatic chamber), the cooling efficiency decreases, and it becomes difficult to perform charging and discharging under the set temperature conditions. Therefore, retesting may be required. Also, to significantly reduce the humidity in a thermostatic and humidistatic chamber in a high-humidity environment, a large amount of energy is required.

[0005] An object of the present disclosure is to efficiently perform a charge and discharge test of a battery while minimizing the energy required to reduce the humidity in the test chamber.

Means for Solving the Problems

[0006] One aspect of the present disclosure is a charge and discharge test method for performing a charge and discharge test of a battery in a test chamber, including an environmental control step of controlling the temperature in the test chamber to a predetermined temperature, and after the environmental control step, when the temperature and humidity in the test chamber are not within a predetermined range, a frosting determination step of determining the presence or absence of frosting in the test chamber, and when it is determined that there is frosting in the frosting determination step, a humidity control step of performing defrosting and dehumidifying the humidity in the test chamber to be lowered by a predetermined value and then shifting to the environmental control step, and after shifting to the environmental control step, when the temperature and humidity in the test chamber are within a predetermined range, a charge and discharge step of performing a charge and discharge test of the battery. The charge and discharge test method is characterized by including the above steps.

Effects of the Invention

[0007] According to the present disclosure, it is possible to efficiently perform a charge and discharge test of a battery while minimizing the energy required to reduce the humidity in the test chamber.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0009] FIG. 1 shows the configuration of a charge and discharge test system 10 according to an embodiment. The charge and discharge test system 10 is a system for performing a charge and discharge test of a battery, and includes a thermostatic and humidistatic chamber 12, a charge and discharge device 14, and a control device 16.

[0010] The constant temperature and humidity chamber 12 includes a test chamber 18 and an air conditioning chamber 20. The battery 22 to be tested is disposed within the test chamber 18. The air conditioning chamber 20 includes a temperature sensor 24, a humidity sensor 26, and a heat exchanger 28, and conditions the interior of the test chamber 18. The temperature sensor 24 measures the temperature within the test chamber 18, and the humidity sensor 26 measures the humidity within the test chamber 18. These measured values (temperature, humidity) are output to the control device 16. Commands for temperature and humidity are output from the control device 16 to the constant temperature and humidity chamber 12, and the heat exchanger 28 conditions the interior of the test chamber 18 according to the commands.

[0011] The charge and discharge device 14 charges and discharges the battery 22. A command indicating a charge and discharge pattern (for example, a current command) is output from the control device 16 to the charge and discharge device 14, and the charge and discharge device 14 charges and discharges the battery 22 according to the command indicating the charge and discharge pattern. Also, measured values (voltage, current) are output from the charge and discharge device 14 to the control device 16.

[0012] The control device 16 includes a storage unit 30 and a processing unit 32. The storage unit 30 stores various information. The processing unit 32 controls the constant temperature and humidity chamber 12 and the charge and discharge device 14. For example, the control device 16 may be a device (for example, a personal computer or a server) including a processor such as a CPU (Central Processing Unit) and a storage device such as a memory or a hard disk drive. In this case, the functions of the control device 16 are realized by the processor. As another example, the control device 16 may be configured by an electronic circuit.

[0013] Next, an outline of the operation of the charge and discharge test system 10 (that is, the charge and discharge test method) will be described. The control device 16 controls the temperature and humidity of the constant temperature and humidity chamber 12 according to a temperature map having a preset test pattern. An example of the temperature map is shown in FIG. 2. n is the order of the charge and discharge test, Tc(n) is the target temperature within the test chamber 18, and Nc is the maximum number of test conditions (map columns). The temperature map is stored in advance in the storage unit 30.

[0014] When the test conditions for temperature are satisfied, the control device 16 conducts a charge-discharge test by controlling the charge-discharge device 14. When the charge-discharge test is completed, the control device 16 controls the thermo-hygrostat chamber 12 to conduct a charge-discharge test under the next temperature condition.

[0015] When frosting occurs in the thermo-hygrostat chamber 12, the control device 16 causes the storage unit 30 to store information indicating the test conditions at the time when the frosting occurred. When the defrosting is completed, the control device 16 resumes the charge-discharge test from the test conditions stored in the storage unit 30. By doing so, even if the charge-discharge test is interrupted halfway, the automatic recovery operation (defrosting, re-setting of temperature) is performed, so that the charge-discharge test can be efficiently conducted. However, there is a possibility that frosting may occur again under the same environmental conditions. To prevent this, the control device 16 reduces the humidity in the test chamber 18 by a predetermined value and performs feedback of the test conditions so as not to cause frosting. When reducing the humidity by the thermo-hygrostat chamber 12 in an environment with high humidity, the required energy increases, but in this embodiment, the required energy can be minimized.

[0016] Hereinafter, with reference to FIG. 3, the charge-discharge test method will be described in detail. FIG. 3 shows a flowchart indicating the flow of the charge-discharge test method.

[0017] First, n is set to 1, and the control device 16 performs an environmental control step of controlling the inside of the test chamber 18 to a predetermined temperature (S01). The temperature command output from the control device 16 to the thermo-hygrostat chamber 12 is Tc(n), and the humidity command is Sc. Sc is the target humidity inside the test chamber 18. Tc(n) is determined by the temperature map shown in FIG. 2. The heat exchanger 28 adjusts the temperature and humidity inside the test chamber 18 according to the temperature command and the humidity command.

[0018] After the environmental control step, if the temperature and humidity in the laboratory 18 are not within the predetermined range, the control device 16 performs a defrosting determination step of determining the presence or absence of frosting in the thermostatic and humidistatic chamber 12. Specifically, when "Tc(n) - Δt < Tm < Tc(n) + Δt and Sc - Δs < Sm < Sc + Δs" is not satisfied (S02, N), the control device 16 performs the defrosting determination step (S03). Here, Tm is the temperature in the laboratory 18, Sm is the humidity in the laboratory 18, Δt is the temperature error range, and Δs is the humidity error range.

[0019] If it is determined that there is frosting in the defrosting determination step (S03, Y), the heat exchanger 28 performs defrosting under the control of the control device 16 (S04). Defrosting is performed until the defrosting is completed (S05, N, S04). When the defrosting is completed (S05, Y), the control device 16 sets the humidity command Sc to the command value (Sc - Δsc) (S06). The process proceeds to step S01. By doing so, dehumidification is performed so that the humidity in the laboratory 18 decreases by a predetermined value (= Δsc).

[0020] Thereafter, when the temperature and humidity in the laboratory 18 are within the predetermined range, the control device 16 performs a charge and discharge step of performing a charge and discharge test on the battery 22. Specifically, when "Tc(n) - Δt < Tm < Tc(n) + Δt and Sc - Δs < Sm < Sc + Δs" is satisfied (S02, Y), the control device 16 performs the charge and discharge step (S07). The charge and discharge device 14 charges and discharges the battery 22 under the control of the control device 16. The test is performed until the charge and discharge test is completed (S08, N, S07).

[0021] When the charge and discharge test is completed (S08, Y), the control device 16 sets the number n to the number (n + 1) (S09). If the number n is not greater than the maximum number of test conditions (Nc) (S10, N), the process proceeds to step S01. Each process after step S02 is executed according to the test conditions corresponding to the number n.

[0022] If the number n is greater than the maximum number of test conditions (Nc) (S10, Y), the process ends. Thereby, the charge and discharge test ends.

[0023] According to the present embodiment, it is possible to efficiently perform the charge and discharge test while minimizing the energy required to reduce the humidity in the laboratory 18.

[0024] When the temperature in the thermo-hygrostat chamber 12 drops, frosting occurs in the thermo-hygrostat chamber 12. Therefore, in the prior art, the temperature according to the predetermined temperature conditions cannot be reproduced by the thermo-hygrostat chamber 12, and it is necessary to perform the charge and discharge test again. In particular, it takes time to reproduce a low temperature, and it is troublesome to perform the charge and discharge test again each time. According to the present embodiment, when it is determined that there is frosting, after performing defrosting and dehumidifying so that the humidity in the laboratory 18 is lowered by a predetermined value, by performing the above-described environmental control step, it is possible to efficiently perform the charge and discharge test while minimizing the energy required to reduce the humidity in the laboratory 18.

Description of Reference Numerals

[0025] 10 Charge and discharge test system, 12 Thermo-hygrostat chamber, 14 Charge and discharge device, 16 Control device, 18 Laboratory, 20 Air-conditioned room, 22 Battery.

Claims

【Claim 1】 A charge and discharge test method for performing a charge and discharge test of a battery in a test chamber, comprising: an environment control step of controlling the temperature in the test chamber to a predetermined temperature; after the environment control step, if the temperature and humidity in the test chamber are not within a predetermined range, a frosting determination step of determining the presence or absence of frosting in the test chamber; if it is determined in the frosting determination step that there is frosting, a humidity control step of performing defrosting and dehumidifying so that the humidity in the test chamber is lowered by a predetermined value, and then shifting to the environment control step; after shifting to the environment control step, if the temperature and humidity in the test chamber are within a predetermined range, a charge and discharge step of performing a charge and discharge test of the battery; characterized by including: a charge and discharge test method.

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