Charging and discharging test system, charging and discharging test method and program

Abstract

Provided are a charge-discharge test system, a charge-discharge test method, and a program that can increase the proportion of a test period during power sharing. A charge-discharge test system (10) includes a control device that controls a first bidirectional DC / DC converter (14) and a second bidirectional DC / DC converter (15) in a manner that performs power sharing between a test battery (11) and a non-test battery (12) during a charge-discharge test, and controls the operation of an AC / DC converter (13) according to power excess or power deficiency in a DC bus (16). The control device performs: a determination voltage acquisition process that acquires a determination voltage that is the voltage of the non-test battery (12); a voltage determination process that determines whether a forced condition set for the determination voltage is satisfied; and a forced process that, in the case where the forced condition is satisfied, controls the second bidirectional DC / DC converter (15) to perform forced discharge or forced charge of the non-test battery (12) in a manner that makes the forced condition not satisfied.

Description

Technical Field

[0001] This disclosure relates to a charge-discharge test system, charge-discharge test method, and procedure for conducting charge-discharge tests on secondary batteries. Background Technology

[0002] In recent years, hybrid vehicles, plug-in hybrid vehicles, and electric vehicles have become increasingly popular. These vehicles are equipped with rechargeable and discharging secondary batteries as driving batteries. As a technology related to such driving batteries, for example, Patent Document 1 discloses a charge-discharge testing system that connects the driving battery in parallel as a test battery for testing. This charge-discharge testing system tests the test battery while simultaneously sharing power (energy sharing) between the test battery and a non-test battery (a secondary battery that is not part of the test). Existing technical documents Patent documents

[0003] Patent Document 1: Japanese Patent Application Publication No. 2023-10581 Summary of the Invention The problem that the invention aims to solve

[0004] Specifically, for the aforementioned charge-discharge test system, the higher the proportion of the power sharing period during the test period, the greater the energy saving. Therefore, it is required that the charge-discharge test system increase the proportion of the power sharing period during the test period. Solution for solving the problem

[0005] A charge / discharge test system for solving the above-mentioned problems includes: a bidirectional AC / DC converter, one end of which is connected to an AC bus and the other end of which is connected to a DC bus; a first bidirectional DC / DC converter, one end of which is connected to the DC bus and the other end of which is connected to a test battery, which is a secondary battery and is the object of the charge / discharge test; a second bidirectional DC / DC converter, one end of which is connected to the DC bus and the other end of which is connected to a non-test battery, which is not the object of the charge / discharge test; and a control device that, during the charge / discharge test, controls the operation of the first bidirectional DC / DC converter and the second bidirectional DC / DC converter in such a way that power is shared between the test battery and the non-test battery through the DC bus, and controls the operation of the bidirectional AC / DC converter according to whether there is excess or insufficient power in the DC bus. The control device performs: a voltage acquisition process to acquire a determination voltage, which is the voltage of the non-test battery; a voltage determination process to determine whether a forced condition set for the determination voltage is met; and a forced process to control the operation of the second bidirectional DC / DC converter to perform forced discharge or forced charging of the non-test battery in a manner that prevents the forced condition from being met if the forced condition is met.

[0006] The charge / discharge testing method for solving the above-mentioned problem is a charge / discharge testing system comprising: a bidirectional AC / DC converter, one end connected to an AC bus and the other end connected to a DC bus; a first bidirectional DC / DC converter, one end connected to the DC bus and the other end connected to a test battery (a secondary battery) subject to charge / discharge testing; a second bidirectional DC / DC converter, one end connected to the DC bus and the other end connected to a non-test battery (a secondary battery not subject to charge / discharge testing); and a control device, which, during the charge / discharge test, controls the charge / discharge between the test battery and the non-test battery via the DC bus. The operation of the first bidirectional DC / DC converter and the second bidirectional DC / DC converter is controlled by sharing power between the batteries. Furthermore, the operation of the bidirectional AC / DC converter is controlled based on whether there is excess or insufficient power in the DC bus. The charge / discharge test method causes the control device to perform the following operations: acquire a determination voltage, which is the voltage of the non-test battery; determine whether a forced condition set for the determination voltage is met; and, if the forced condition is met, control the operation of the second bidirectional DC / DC converter to force discharge or force charge the non-test battery, so that the forced condition is not met.

[0007] The program for solving the above-mentioned problem is applicable to a charge-discharge test system, wherein the charge-discharge test system comprises: a bidirectional AC / DC converter, one end of which is connected to an AC bus and the other end of which is connected to a DC bus; a first bidirectional DC / DC converter, one end of which is connected to the DC bus and the other end of which is connected to a test battery, which is a secondary battery and is the object of the charge-discharge test; a second bidirectional DC / DC converter, one end of which is connected to the DC bus and the other end of which is connected to a non-test battery, which is not the object of the charge-discharge test; and a control device for sharing power between the test battery and the non-test battery via the DC bus during the charge-discharge test. The operation of the first bidirectional DC / DC converter and the second bidirectional DC / DC converter is controlled in a manner that allows the operation of the bidirectional AC / DC converter to be controlled based on whether there is excess or insufficient power in the DC bus. The program causes the control device to perform: a determination voltage acquisition process to acquire a determination voltage as the voltage of the non-test battery; a voltage determination process to determine whether a forced condition set for the determination voltage is met; and a forced processing process, whereby, if the forced condition is met, the operation of the second bidirectional DC / DC converter is controlled to perform forced discharge or forced charging of the non-test battery, so that the forced condition is not met. Invention Effects

[0008] According to this disclosure, it is possible to increase the proportion of power sharing during the testing period. Attached Figure Description

[0009] Figure 1 This is a diagram showing a simplified structure of the charge / discharge test system in the first embodiment. Figure 2 (a) is a diagram schematically illustrating an example of power sharing in the first embodiment. Figure 2 (b) is a diagram schematically illustrating another example of power sharing in the first embodiment. Figure 3 This is a flowchart illustrating an example of the forced boost process in the first embodiment. Figure 4 This is a flowchart illustrating an example of the forced charging process in the first embodiment. Figure 5 This is a flowchart illustrating an example of the forced discharge process in the first embodiment. Figure 6 This is a graph illustrating an example of the variation in the determination voltage, including forced charging, in the first embodiment. Figure 7 This is a graph illustrating an example of the variation in the determination voltage, including forced discharge, in the first embodiment. Figure 8 This is a flowchart illustrating an example of the forced boost process in the second embodiment. Figure 9 It is a graph used to illustrate the lower limit determination range and the upper limit determination range in the second embodiment. Figure 10 This is a graph used to illustrate the allowable descent amount in the second embodiment. Figure 11 This is a graph used to illustrate the allowable increase in the second embodiment. Figure 12 This is a graph illustrating an example of the variation in the determination voltage generated by the forced boost process in the second embodiment. Figure 13 This is a graph illustrating an example of the variation in the power supply to other devices in the third embodiment. Figure 14 This is a diagram showing a simplified structure of the charge / discharge test system in the third embodiment. Figure 15 This is a flowchart illustrating an example of the mandatory condition setting process in the third embodiment. Detailed Implementation

[0010] (First Implementation) Reference Figures 1 to 7 The first implementation method of the charge-discharge test system, charge-discharge test method and procedure is described.

[0011] like Figure 1 As shown, the charge / discharge test system 10 performs charge / discharge tests on the test batteries 11-1, 11-2, ..., 11-m (m is an integer of 3 or more) while sharing power (energy) with the non-test batteries 12-1, 12-2, ..., 12-n (n is an integer of 3 or more). The test batteries 11-1, 11-2, ..., 11-m and the non-test batteries 12-1, 12-2, ..., 12-n are, for example, various secondary batteries such as lithium-ion batteries, nickel-metal hydride batteries, and all-solid-state batteries (and also include energy-storing devices such as large-capacity capacitors like double-layer capacitors).

[0012] Furthermore, hereinafter, without distinguishing between test batteries 11-1, 11-2, ..., 11-m, they will be referred to as test battery 11, and without distinguishing between non-test batteries 12-1, 12-2, ..., 12-n, they will be referred to as non-test batteries 12. In this embodiment, the charge / discharge test system 10 includes three or more test batteries 11 and three or more non-test batteries 12. However, the charge / discharge test system 10 may also include fewer than three test batteries 11 and fewer than three non-test batteries 12.

[0013] The charge / discharge test system 10 is connected to the AC bus 3. In addition to being connected to the AC power source 4, the AC bus 3 is also connected to other equipment 5 located in facilities such as factories where the charge / discharge test system 10 is located. The AC bus 3 supplies AC power to the charge / discharge test system 10 and the other equipment 5.

[0014] The charge / discharge test system 10 includes a bidirectional AC / DC converter 13, a first bidirectional DC / DC converter 14-1, 14-2, ..., 14-m, a second bidirectional DC / DC converter 15-1, 15-2, ..., 15-n, and a control device 20.

[0015] Furthermore, the bidirectional AC / DC converter 13 will be simply referred to as AC / DC converter 13 below. Also, without distinguishing between the first bidirectional DC / DC converters 14-1, 14-2, ..., 14-m, they will be simply referred to as DC / DC converter 14. Without distinguishing between the second bidirectional DC / DC converters 15-1, 15-2, ..., 15-n, they will be simply referred to as DC / DC converter 15. Furthermore, in Figure 1 In this context, bidirectional AC / DC converters are simply labeled as AC / DC, and bidirectional DC / DC converters are simply labeled as DC / DC.

[0016] (Bidirectional AC / DC converter) One end of the AC / DC converter 13 is connected to the AC bus 3. The other end of the AC / DC converter 13 is connected to the DC bus 16. The AC / DC converter 13 converts the AC power in the AC bus 3 into DC power and supplies it to the DC bus 16. The AC / DC converter 13 converts the DC power in the DC bus 16 into AC power and supplies it to the AC bus 3. The operation of this AC / DC converter 13 is controlled by the control device 20.

[0017] (First bidirectional DC / DC converter) One end of the DC / DC converter 14 is connected to the AC / DC converter 13 via the DC bus 16. A test battery 11 is connected to the other end of the DC / DC converter 14. The DC / DC converter 14 charges and discharges the test battery 11. The DC / DC converter 14 discharges the test battery 11 by outputting the power stored in the test battery 11 to the DC bus 16. The DC / DC converter 14 charges the test battery 11 by supplying DC power from the DC bus 16 to the test battery 11. The operation of this DC / DC converter 14 is controlled by the control device 20. Furthermore, the DC / DC converter 14 detects various information related to the test battery 11, including its voltage, charging power during charging, and discharging power during discharging. The DC / DC converter 14 outputs the detected information about the test battery 11 to the control device 20.

[0018] (Second bidirectional DC / DC converter) One end of the DC / DC converter 15 is connected to the AC / DC converter 13 via the DC bus 16. A non-test battery 12 is connected to the other end of the DC / DC converter 15. The DC / DC converter 15 charges and discharges the non-test battery 12. The DC / DC converter 15 discharges the non-test battery 12 by outputting the power stored in it to the DC bus 16. The DC / DC converter 15 charges the non-test battery 12 by supplying DC power from the DC bus 16 to it. The operation of this DC / DC converter 15 is controlled by the control device 20. Furthermore, the DC / DC converter 15 detects various information related to the non-test battery 12, including its voltage, charging power during charging, and discharging power during discharging. The DC / DC converter 15 outputs the detected information about the non-test battery 12 to the control device 20.

[0019] (Control device) The control device 20 can be implemented, for example, by executing a program (software) using a hardware processor such as a CPU (Central Processing Unit). Furthermore, some or all of the components of the control device 20 can be implemented using hardware (including circuitry) such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), and GPU (Graphics Processing Unit), or through a combination of software and hardware. The program can be pre-stored in a storage device (not shown) equipped with a non-transitory storage medium such as an HDD (Hard Disk Drive) or flash memory, provided with the control device 20. The control device 20 can be implemented, for example, by including a Programmable Logic Controller (PLC).

[0020] The control device 20 performs a test process in which the operation of the DC / DC converter 14 is controlled by charging and discharging the test battery 11 according to a pre-set test mode. The control device 20 performs a power sharing process, in which the operation of the DC / DC converter 15 is controlled in such a way that power is shared between the test battery 11 and the non-test battery 12.

[0021] like Figure 2 As shown in (a), in the power sharing process, when the test battery 11 is controlled to be in a discharging state, the control device 20 controls the DC / DC converter 15 in such a way that the discharge power of the test battery 11 is supplied to the non-test battery 12 through the DC bus 16. Additionally, as... Figure 2 As shown in (b), when the test battery 11 is controlled to be in a charging state, the control device 20 controls the DC / DC converter 15 in such a way that the power stored in the non-test batteries 12 is supplied to the test battery 11 through the DC bus 16. The control device 20 controls the DC / DC converter 15 in such a way that the voltage of the non-test batteries 12 is made uniform based on the input voltage of each non-test battery 12.

[0022] The control device 20 performs a supply / feedback process to control the operation of the AC / DC converter 13 based on the excess or deficiency of power in the DC bus 16. In the supply / feedback process, when there is a power deficiency in the DC bus 16, the control device 20 controls the AC / DC converter 13 by supplying the DC bus 16 with an amount of power corresponding to the deficiency. When there is a surplus of power in the DC bus 16, the control device 20 controls the AC / DC converter 13 by feeding that surplus power back to the AC bus 3.

[0023] The control device 20 repeatedly performs forced boost processing in parallel with the power sharing processing. Forced boost processing refers to the process of forcibly charging and discharging the non-test battery 12 regardless of the charge / discharge state of the test battery 11. During forced boost processing, the control device 20 determines whether a forced condition for setting the voltage of the non-test battery 12 to the determination voltage Vj is met. When the forced condition is met, the control device 20 interrupts the power sharing processing to control the operation of the DC / DC converter 15 in a manner that makes the forced condition invalid.

[0024] (Forced boost process) Reference Figures 3-5 The forced voltage boost process will be explained. During the testing of the test battery 11, the control device 20 repeatedly executes the first forced voltage boost process as a forced voltage boost procedure. The first forced voltage boost process is a process that forces the non-test battery 12 to charge and discharge in order to maximize the utilization of the non-test battery 12's capacity.

[0025] like Figure 3 As shown, in the first forced voltage boost process, the control device 20 acquires the determination voltage Vj of the non-test battery 12 (determination voltage acquisition process: step S101). Next, the control device 20 compares the acquired determination voltage Vj with the forced charging voltage V1 and the forced discharging voltage V2 (voltage determination process: step S102). The forced charging voltage V1 is a value close to or equal to the lower limit voltage Vmin of the non-test battery 12. The forced discharging voltage V2 is a value close to or equal to the upper limit voltage Vmax of the non-test battery 12.

[0026] If the voltage Vj is determined to be above the forced charging voltage V1 and below the forced discharging voltage V2, the control device 20 temporarily terminates the first forced boost process (step S102: Yes).

[0027] If the voltage Vj is determined to be lower than the forced charging voltage V1 (step S102: Vj < V1), the control device 20 determines that the forced charging condition has been met, interrupts the power sharing process, and executes the forced charging process as one of the forced processes (step S103). The forced charging process is a process of forcibly charging the non-test battery 12, which has been fully discharged due to the power sharing process, and is a process that is independent of the charge and discharge state of the test battery 11. When the forced charging process ends, the control device 20 temporarily terminates the first forced voltage boost process.

[0028] On the other hand, if the voltage Vj is determined to be higher than the forced discharge voltage V2 (step S102: V2 < Vj), the control device 20 determines that the forced discharge condition has been met, interrupts the power sharing process, and executes the forced discharge process as one of the forced processes (step S104). The forced discharge process is a process of forcibly discharging the non-test battery 12, which has been fully charged due to the power sharing process, and is a process that is independent of the charge and discharge state of the test battery 11. When the forced discharge process ends, the control device 20 temporarily terminates the first forced boost process.

[0029] (Forced charging process) like Figure 4 As shown, in the forced charging process, the control device 20 controls the non-test battery 12 to a charging state by controlling the DC / DC converter 15 (step S201).

[0030] When the non-test battery 12 is controlled to be in a charging state, the control device 20 controls the AC / DC converter 13 to supply the combined power of the charging power of the test battery 11 and the charging power of the non-test battery 12 to the DC bus 16 when the test battery 11 is in a charging state.

[0031] Furthermore, when the test battery 11 is discharging, its discharge power is supplied to the non-test battery 12 through the DC bus 16. Also, if the discharge power of the test battery 11 is greater than the charging power of the non-test battery 12, the control device 20 controls the AC / DC converter 13 to feed the surplus power in the DC bus 16 back to the AC bus 3. Conversely, if the discharge power of the test battery 11 is less than the charging power of the non-test battery 12, the control device 20 controls the AC / DC converter 13 to supply the DC bus 16 with an amount of DC power corresponding to the shortfall.

[0032] Next, the control device 20 acquires the determination voltage Vj of the non-test battery 12 (step S202), and then determines whether the determination voltage Vj reaches the discharge start voltage V1d (step S203). The discharge start voltage V1d is a voltage lower than the forced discharge voltage V2.

[0033] If the voltage Vj is determined not to have reached the discharge start voltage V1d (step S203: No), the control device 20 repeatedly executes steps S202 and S203. On the other hand, if the voltage Vj is determined to have reached the discharge start voltage V1d (step S203: Yes), the control device 20 restarts the power sharing process (step S204) and ends the forced charging process.

[0034] (Forced discharge treatment) like Figure 5 As shown, in the forced discharge process, the control device 20 controls the non-test battery 12 to a discharge state by controlling the DC / DC converter 15 (step S301).

[0035] When the non-test battery 12 is controlled to be in a discharge state, the control device 20 controls the AC / DC converter 13 by feeding back the total discharge power of the test battery 11 and the discharge power of the non-test battery 12 to the AC bus 3 when the test battery 11 is in a discharge state.

[0036] Furthermore, when the test battery 11 is charging, the discharge power of the non-test battery 12 is supplied to the test battery 11 through the DC bus 16. Also, if the charging power of the test battery 11 is greater than the discharging power of the non-test battery 12, the control device 20 controls the AC / DC converter 13 to supply the DC bus 16 with an amount of DC power corresponding to the shortfall. On the other hand, if the discharging power of the non-test battery 12 is greater than the charging power of the test battery 11, the control device 20 controls the AC / DC converter 13 to feed the surplus power in the DC bus 16 back to the AC bus 3.

[0037] Next, the control device 20 acquires the determination voltage Vj of the non-test battery 12 (step S302), and then determines whether the determination voltage Vj reaches the charging start voltage V2c (step S303). The charging start voltage V2c is a voltage higher than the forced charging voltage V1.

[0038] If the voltage Vj is determined not to have reached the charging start voltage V2c (step S303: No), the control device 20 repeatedly executes steps S302 and S303. On the other hand, if the voltage Vj is determined to have reached the charging start voltage V2c (step S303: Yes), the control device 20 restarts the power sharing process (step S304) and ends the forced discharge process.

[0039] (The function of the first implementation method) like Figure 6As shown, when the forced charging condition (Vj < V1) is met during the execution of the power sharing process, the control device 20 interrupts the power sharing process and forces the non-test battery 12 to charge. Furthermore, the control device 20 restarts the power sharing process when it determines that the voltage Vj has reached the discharge start voltage V1d.

[0040] In addition, such as Figure 7 As shown, when the forced discharge condition (V2 < Vj) is met during the execution of the power sharing process, the control device 20 interrupts the power sharing process and forces the non-test battery 12 to discharge. Furthermore, the control device 20 restarts the power sharing process when it determines that the voltage Vj has reached the charging start voltage V2c.

[0041] The effects of the first embodiment will be explained. (1-1) According to the charge-discharge test system 10, it is possible to reduce the state in which the non-test battery 12 is kept at the upper limit voltage Vmax or the lower limit voltage Vmin. As a result, the capacity of the non-test battery 12 can be effectively utilized when power sharing occurs between the test battery 11 and the non-test battery 12. Consequently, the proportion of power sharing during the test period is increased, thereby enabling further energy saving of the charge-discharge test system.

[0042] (1-2) In addition, it can prevent the non-test battery 12 from becoming over-discharged or over-charged. As a result, the lifespan of the non-test battery 12 can be extended. (1-3) When the forced charging condition is met, the control device 20 maintains the non-test battery 12 in a charging state until the determination voltage Vj reaches the discharge start voltage V1d. Furthermore, since the discharge start voltage V1d is lower than the forced discharge voltage V2, even if the test battery 11 is in a discharging state when the power sharing process restarts, the non-test battery 12 can be charged using the test battery 11. As a result, the proportion of power sharing time can be further increased.

[0043] (1-4) When the forced discharge condition is met, the control device 20 maintains the non-test battery 12 in a discharged state until the determination voltage Vj reaches the charging start voltage V2c. Furthermore, since the charging start voltage V2c is higher than the forced charging voltage V1, even if the test battery 11 is in a charging state when the power sharing process restarts, the non-test battery 12 can be used to charge the test battery 11. As a result, the proportion of power sharing time can be further increased.

[0044] (Second Implementation) Reference Figures 8-12A second embodiment of the charge-discharge test system, method, and procedure will be described. Furthermore, the only difference between the charge-discharge test system, method, and procedure of the second embodiment and the first embodiment is the forced voltage boosting process. Therefore, in the second embodiment, the forced voltage boosting process will be described in detail, and the same reference numerals will be used for parts that are the same as in the first embodiment to omit their detailed description.

[0045] In the second embodiment, the control device 20 repeatedly performs a second forced boost process during the testing of the test battery 11 as a forced boost process. The second forced boost process is as follows: the non-test battery 12 is forcibly charged and discharged so that the determination voltage Vj varies in a balanced manner between the lower limit voltage Vmin and the upper limit voltage Vmax.

[0046] like Figure 8 As shown, in the second forced boost process, the control device 20 acquires the determination voltage Vj (determination voltage acquisition process: step S401). Next, the control device 20 compares the determined voltage Vj with the lower limit threshold voltage V3 and the upper limit threshold voltage V4 (step S402: first voltage determination process).

[0047] like Figure 9 As shown, the lower limit threshold voltage V3 is a value that is biased towards the lower limit voltage Vmin by the median value Vmid between the lower limit voltage Vmin and the upper limit voltage Vmax of the non-tested battery 12. Figure 9 In this context, the range of voltages lower than the lower limit threshold voltage V3, represented by a slant line with lower values ​​on the left and higher values ​​on the right, is called the lower limit judgment range. The upper limit threshold voltage V4 is a value that is closer to the upper limit voltage Vmax than the midpoint between the lower limit voltage Vmin and the upper limit voltage Vmax of the non-tested battery 12. Figure 9 In this process, the range of voltages higher than the upper limit threshold voltage V4, represented by a slash that is lower on the right and higher on the left, is called the upper limit determination range. Furthermore, the range that is above the lower limit threshold voltage V3 and below the upper limit threshold voltage V4 is called the no-boost range. That is, in step S402, the range in which the determination voltage Vj falls is determined.

[0048] When it is determined that the voltage Vj is within the range where boosting is not required (step S402: Yes), the control device 20 temporarily terminates the second forced boosting process. When the voltage Vj is determined to be within the lower limit range (step S402: Vj≤V3), the control device 20 calculates the voltage drop ΔVj(-) of the determined voltage Vj within the most recent unit time Δt. Furthermore, the control device 20 determines whether the calculated voltage drop ΔVj(-) is greater than the allowable drop ΔVp(-) (second voltage determination process: step S403). In other words, the control device 20 determines whether the determined voltage Vj drops by a amount greater than the allowable drop ΔVp(-).

[0049] like Figure 10 As shown, the allowable voltage drop ΔVp(-) refers to the amount of voltage drop that occurs when the judgment voltage Vj1 at time t1 reaches the lower limit voltage Vmin at time t2 after a predetermined time. The allowable voltage drop ΔVp(-) can be set separately for each judgment voltage Vj within the lower limit judgment range. In this case, the allowable voltage drop ΔVp(-) is preferably set to the following value: the closer the judgment voltage Vj is to the lower limit voltage Vmin, the smaller its allowable voltage drop ΔVp(-).

[0050] If the voltage drop ΔVj(-) is greater than the allowable drop ΔVp(-) (step S403: Yes), the control device 20 performs forced charging processing (step S404). On the other hand, if the voltage drop ΔVj(-) is less than or equal to the allowable drop ΔVp(-) (step S403: No), the control device 20 temporarily terminates the second forced boost processing.

[0051] That is, when the control device 20 determines that the voltage Vj is within the lower limit judgment range and the voltage drop ΔVj(-) is greater than the allowable drop ΔVp(-), it determines that the forced charging condition is met and performs forced charging processing. In other words, the control device 20 performs forced charging processing when it anticipates that the voltage of the non-test battery 12 will reach the lower limit voltage Vmin.

[0052] When the voltage Vj is within the upper limit of the determination range (step S402: V4≤Vj), the control device 20 calculates the voltage rise ΔVj(+) of the determined voltage Vj within the most recent unit time Δt. Furthermore, the control device 20 determines whether the calculated voltage rise ΔVj(+) is greater than the allowable rise ΔVp(+) (second voltage determination process: step S405). In other words, the control device 20 determines whether the determined voltage Vj rises by a rise greater than the allowable rise ΔVp(+).

[0053] like Figure 11As shown, the allowable rise amount ΔVp(+) is the voltage rise amount by which the judgment voltage Vj3 at time t3 reaches the upper limit voltage Vmax after a predetermined time t4. The allowable rise amount ΔVp(+) can be set separately for the judgment voltage Vj within the upper limit judgment range. In this case, the allowable rise amount ΔVp(+) is preferably set to the following value: the closer the judgment voltage Vj is to the upper limit voltage Vmax, the smaller its allowable rise amount ΔVp(+).

[0054] If the voltage rise ΔVj(+) is greater than the allowable rise ΔVp(+) (step S405: Yes), the control device 20 performs a forced discharge process (step S406). On the other hand, if the voltage rise ΔVj(+) is less than or equal to the allowable rise ΔVp(+) (step S405: No), the control device 20 temporarily terminates the second forced boost process.

[0055] That is, when the control device 20 determines that the forced discharge condition is met and performs forced discharge processing, the voltage Vj is within the upper limit determination range and the voltage rise ΔVj(+) is greater than the allowable rise ΔVp(+). In other words, the control device 20 performs forced discharge processing when it anticipates that the voltage of the non-test battery 12 will reach the upper limit voltage Vmax.

[0056] (The function of the second implementation method) like Figure 12 As shown, when the forced charging condition (Vj≤V3, ΔVp(-)<ΔVj(-)) is met during the execution of the power sharing process, the control device 20 interrupts the power sharing process and performs forced charging. Conversely, when the forced discharging condition (V4≤Vj, ΔVp(+)<ΔVj(+)) is met during the execution of the power sharing process, the control device 20 interrupts the power sharing process and performs forced discharging. Therefore, the determination voltage Vj will fluctuate in a balanced manner between the lower limit voltage Vmin and the upper limit voltage Vmax.

[0057] The effects of the second embodiment will be explained. (2-1) According to the charge-discharge test system 10, it is possible to effectively suppress the non-test battery 12 from reaching the upper limit voltage Vmax or the lower limit voltage Vmin. As a result, the proportion of power sharing is further increased, thus enabling further energy saving of the charge-discharge test system 10.

[0058] (2-2) It can suppress the non-test battery 12 from becoming over-discharged or over-charged. As a result, it can extend the lifespan of the non-test battery 12. (2-3) The allowable drop ΔVp(-) is set to the following value: the closer it is to the judgment voltage Vj of the lower limit voltage Vmin, the smaller the allowable drop ΔVp(-), thereby more effectively suppressing the non-test battery 12 from reaching the lower limit voltage Vmin.

[0059] (2-4) The allowable rise ΔVp(+) is set to the following value: the closer the voltage Vj is to the upper limit voltage Vmax, the smaller the allowable rise ΔVp(+), thereby more effectively suppressing the non-test battery 12 from reaching the upper limit voltage Vmax.

[0060] (Third Implementation) Reference Figures 13-15 A third embodiment of the charge-discharge test system, charge-discharge test method, and procedure will be described. Furthermore, the difference between the charge-discharge test system, charge-discharge test method, and procedure of the third embodiment and those of the first and second embodiments lies in that the control device 20 performs a forced condition setting process. Therefore, in the third embodiment, the forced condition setting process will be described in detail, and the same reference numerals will be used to denote parts that are the same as in the first and second embodiments to omit detailed descriptions.

[0061] like Figure 13 As shown, in the facility where the charge / discharge test system 10 is installed, the power supplied to other devices 5 via the AC bus 3 often varies depending on the time of day. In the charge / discharge test system 10 of the third embodiment, the power supply from the AC power source 4 to the entire facility is smoothed. Specifically, forced charging is prioritized during off-peak hours when the supplied power W is below the peak value W1, thereby actively supplying power from the AC bus 3 to the charge / discharge test system 10. In addition, forced discharging is prioritized during peak hours when the supplied power W is above the peak value W2, thereby actively feeding back power from the charge / discharge test system 10 to the AC bus 3.

[0062] like Figure 14 As shown, in the charge / discharge test system 10, supply status information 30, indicating the power supply status from the AC bus 3 to other devices 5, is input to the control device 20. For example, the current total power consumption is input to the control device 20 in real time from a higher-level power monitor that monitors the power consumption of other devices 5 as supply status information 30. Additionally, for example, before the charge / discharge test, the control device 20 is input with information pre-generated based on the monitoring results of the higher-level power monitor, corresponding to a time period and the total power consumption as supply status information 30. Furthermore, the control device 20 repeatedly executes forced condition setting processing based on the supply status information 30 in parallel with forced voltage boosting processing.

[0063] like Figure 15 As shown, in the forced condition setting process, the control device 20 obtains the supplied power W based on the supply status information 30 (step S501). Next, the control device 20 compares the obtained supplied power W with the non-peak W1 and the peak W2 (step S502).

[0064] When the supplied power W is above the non-peak value W1 and below the peak value W2 (step S502: Yes), the control device 20 temporarily terminates the forced condition setting process. If the supplied power W is less than the non-peak W1 (step S502: W < W1), the control device 20 sets the charging-related forced conditions in a manner that prioritizes the forced charging of the non-test battery 12 (step S503). Furthermore, the control device 20 temporarily terminates the forced condition setting process at the end of step S503.

[0065] Step S503 will be described in detail. For example, the control device 20 performing the first forced boost process sets a voltage greater than the forced charging voltage V1 as the forced charging voltage for the forced charging condition. For example, the control device 20 performing the second forced boost process sets a voltage greater than the lower limit threshold voltage V3 as the lower limit threshold voltage for the forced charging condition and sets a drop smaller than the allowable drop ΔVp(-) as the allowable drop for the forced charging condition. For example, the control device 20 sets the forced condition to perform only forced charging process as the forced process in the forced boost process.

[0066] If the supplied power W is greater than the peak value W2 (step S502: W2 < W), the control device 20 sets the forced conditions related to discharge in a manner that prioritizes the forced discharge of the non-test battery 12 (step S504). Furthermore, the control device 20 temporarily terminates the forced condition setting process at the end of step S504.

[0067] Step S504 will be described in detail. For example, the control device 20 performing the first forced boost process sets a voltage smaller than the forced discharge voltage V2 as the forced discharge voltage for the forced discharge condition. For example, the control device 20 performing the second forced boost process sets a voltage smaller than the upper limit threshold voltage V4 as the upper limit threshold voltage for the forced charging condition and sets a rise smaller than the allowable rise amount ΔVp(+) as the allowable rise amount for the forced charging condition. For example, the control device 20 sets the forced condition to perform only forced discharge processing as the forced processing in the forced boost process.

[0068] The function and effects of the third embodiment are explained. (3-1) In the charge / discharge test system 10, forced conditions are set based on the supply status information 30. Therefore, forced charging is prioritized when the power supply W is during off-peak hours. Conversely, forced discharging is prioritized when the power supply W is during peak hours. As a result, the power supply from the AC power source 4 to the entire facility can be smoothed.

[0069] The first to third embodiments can be implemented with modifications as follows. The first to third embodiments and the following modifications can be combined and implemented with each other within the scope of technical non-contradiction.

[0070] The control device 20 can also perform a first forced boost process and a second forced boost process. With this structure, it is possible to more reliably prevent the non-test battery 12 from entering an over-discharged or over-charged state.

[0071] The control device 20 can also perform forced boosting processing by setting the forced condition to forced charging condition and the forced processing to forced charging processing. The control device 20 can also perform forced voltage boosting by setting the forced condition to forced discharge condition and the forced processing to forced discharge processing. Explanation of reference numerals in the attached figures

[0072] 3… AC bus, 4… AC power source, 5… Equipment, 10… Charge and discharge test system, 11… Test battery, 12… Non-test battery, 13… Bidirectional AC / DC converter, 14… First bidirectional DC / DC converter, 15… Second bidirectional DC / DC converter, 16… DC bus, 20… Control device, 30… Supply status information.

Claims

1. A charge / discharge testing system, comprising: A bidirectional AC / DC converter, with one end connected to the AC bus and the other end connected to the DC bus; The first bidirectional DC / DC converter has one end connected to the DC bus and the other end connected to the test battery, which is a secondary battery and is the object of the charge and discharge test. A second bidirectional DC / DC converter, one end of which is connected to the DC bus, and the other end of which is connected to a non-test battery (a secondary battery not subject to the charge / discharge test); and The control device, during the charge-discharge test, controls the operation of the first bidirectional DC / DC converter and the second bidirectional DC / DC converter in a manner that allows power sharing between the test battery and the non-test battery via the DC bus, and controls the operation of the bidirectional AC / DC converter based on whether there is excess or insufficient power in the DC bus. The control device performs: The determination voltage acquisition process acquires the determination voltage, which is the voltage of the non-test battery. Voltage determination processing, determining whether the mandatory conditions set for the determined voltage are met; and Forced processing, in the event that the forced condition is met, controls the operation of the second bidirectional DC / DC converter in a manner that makes the forced condition not met, to perform forced discharge or forced charging of the non-test battery.

2. The charge / discharge testing system according to claim 1, wherein, The mandatory conditions include the mandatory charging condition where the determination voltage reaches the mandatory charging voltage. The control device maintains the non-test battery in a charging state during the forced processing until the determination voltage reaches the discharge start voltage.

3. The charge / discharge testing system according to claim 1, wherein, The mandatory conditions include the mandatory discharge condition where the determination voltage reaches the mandatory discharge voltage. The control device maintains the non-test battery in a discharged state during the forced processing until the determination voltage reaches the charging start voltage.

4. The charge / discharge testing system according to claim 1, wherein, The mandatory conditions include: Forced discharge conditions, wherein the determination voltage is a value within the upper limit determination range, and the increase in the determination voltage per unit time is greater than the allowable increase; and Under forced charging conditions, the determination voltage is a value within the lower limit determination range, and the decrease in the determination voltage per unit time is greater than the allowable decrease. In the forced processing, the control device maintains the non-test battery in a discharging state until the determination voltage reaches the charging start voltage when the forced discharge condition is met, and maintains the non-test battery in a charging state until the determination voltage reaches the discharge start voltage when the forced charging condition is met.

5. The charge / discharge testing system according to claim 1, wherein, The control device performs forced condition setting processing. In the forced condition setting process, the power supply status from the AC bus to other devices is obtained. When the power supply status is at its peak, the forced condition is set in a manner that prioritizes the forced discharge of the non-test battery. When the power supply status is at its off-peak, the forced condition is set in a manner that prioritizes the forced charging of the non-test battery.

6. A charge-discharge test method, which is a charge-discharge test method for a charge-discharge test system, wherein, The charge / discharge testing system includes: A bidirectional AC / DC converter, with one end connected to the AC bus and the other end connected to the DC bus; The first bidirectional DC / DC converter has one end connected to the DC bus and the other end connected to the test battery, which is a secondary battery and is the object of the charge and discharge test. A second bidirectional DC / DC converter, one end of which is connected to the DC bus, and the other end of which is connected to a non-test battery (a secondary battery not subject to the charge / discharge test); and The control device, during the charge-discharge test, controls the operation of the first bidirectional DC / DC converter and the second bidirectional DC / DC converter in a manner that allows power sharing between the test battery and the non-test battery via the DC bus, and controls the operation of the bidirectional AC / DC converter based on whether there is excess or insufficient power in the DC bus. The charge / discharge test method causes the control device to perform the following operations: Obtain the determination voltage as the voltage of the non-test battery; Determine whether the mandatory conditions set for the determination voltage are met; and If the forced condition is met, the operation of the second bidirectional DC / DC converter is controlled to force discharge or force charge the non-test battery, so that the forced condition is not met.

7. A program, applicable to a charge / discharge test system, wherein, The charge / discharge testing system includes: A bidirectional AC / DC converter, with one end connected to the AC bus and the other end connected to the DC bus; The first bidirectional DC / DC converter has one end connected to the DC bus and the other end connected to the test battery, which is a secondary battery and is the object of the charge and discharge test. A second bidirectional DC / DC converter, one end of which is connected to the DC bus, and the other end of which is connected to a non-test battery (a secondary battery not subject to the charge / discharge test); and The control device, during the charge-discharge test, controls the operation of the first bidirectional DC / DC converter and the second bidirectional DC / DC converter in a manner that allows power sharing between the test battery and the non-test battery via the DC bus, and controls the operation of the bidirectional AC / DC converter based on whether there is excess or insufficient power in the DC bus. The program causes the control device to execute: The determination voltage acquisition process acquires the determination voltage, which is the voltage of the non-test battery. Voltage determination processing, determining whether the mandatory conditions set for the determined voltage are met; and Forced processing involves controlling the operation of the second bidirectional DC / DC converter to force discharge or force charge the non-test battery when the forced condition is met, so that the forced condition is not met.

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