Charging and discharging test system, charging and discharging test method and control device

Abstract

A charge / discharge test system, a charge / discharge test method, and a control device are provided to reduce power loss associated with the conversion of power charged into or discharged by a charge / discharge body. The charge / discharge system (1) comprises: an AC / DC converter (20) that converts a first power into a second DC power; a bidirectional DC / DC converter (30) connected at one end to the AC / DC converter (20) via a bus (BS) and at the other end to a charge / discharge body (BT) that is the object of the charge / discharge test, which converts the second DC power converted by the AC / DC converter (20) into a third DC power or converts the power discharged by the charge / discharge body (BT) into a second DC power; a capacitor (40) connected to the bus (BS); and a control device (10) that controls the operation of at least one of the AC / DC converter (20) and the bidirectional DC / DC converter (30).

Description

Technical Field

[0001] This disclosure relates to a charge-discharge testing system, a charge-discharge testing method, and a control device. Background Technology

[0002] In recent years, hybrid vehicles, plug-in hybrid vehicles, and electric vehicles have become increasingly popular. These vehicles are equipped with drive batteries. For example, Patent Document 1 discloses a technology related to a charge-discharge test system that connects multiple batteries for testing. In this charge-discharge test system, multiple circuits, including a bidirectional DC / DC converter and charge / discharge elements, are connected in parallel to a bus supplying DC power. In this charge-discharge test system, the charge / discharge element being tested charges or discharges power according to its own test plan, while the charge / discharge element not being tested charges or discharges power in a manner corresponding to the test of the charge / discharge element being tested. 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] However, in the method disclosed in Patent Document 1, when the power discharged by the charging / discharging body (which is the test object) is used to charge the charging / discharging body (which is not the test object), two power conversions based on a bidirectional DC / DC converter are performed, resulting in power loss associated with the conversion. Similarly, when the power discharged by the charging / discharging body (which is not the test object) is used to charge the charging / discharging body (which is the test object), two power conversions based on a bidirectional DC / DC converter are also performed, resulting in power loss associated with the conversion. Therefore, in the prior art, it is difficult to reduce the power loss associated with the conversion in the power distribution between the charging / discharging bodies in the charging / discharging test system. Solution for solving the problem

[0005] A charge / discharge test system for solving the above-mentioned problems includes: a converter that converts a first power into a second DC power; a bidirectional DC / DC converter, one end of which is connected to the converter via a bus, and the other end of which is connected to a charge / discharge body that is the object of the charge / discharge test, for converting the second DC power converted by the converter into a third DC power or converting the power discharged by the charge / discharge body into the second DC power; a capacitor connected to the bus; and a control device for controlling the operation of at least one of the converter and the bidirectional DC / DC converter.

[0006] A charge-discharge test method for solving the above-mentioned problems uses a computer in a control device that implements a charge-discharge test system to control the operation of at least one of a converter and a bidirectional DC / DC converter. The charge-discharge test system includes: a converter that converts a first power source into a second DC power source; a bidirectional DC / DC converter, one end of which is connected to the converter via a bus, and the other end of which is connected to a charge / discharge body that is the object of the charge-discharge test, converting the second DC power source converted by the converter into a third DC power source or converting the power discharged by the charge / discharge body into the second DC power source; and a capacitor connected to the bus.

[0007] The control device for solving the above-mentioned problem is a control device for a charge-discharge test system, wherein the charge-discharge test system comprises: a converter that converts a first power into a second DC power; a bidirectional DC / DC converter, one end of which is connected to the converter via a bus, and the other end of which is connected to a charge-discharge body that is the object of the charge-discharge test, for converting the second DC power converted by the converter into a third DC power or converting the power discharged by the charge-discharge body into the second DC power; and a capacitor connected to the bus, wherein the control device controls the operation of at least one of the converter and the bidirectional DC / DC converter. Invention Effects

[0008] According to this disclosure, for the electricity charged or discharged by the charging or discharging body, it is possible to reduce the power loss associated with the conversion. Attached Figure Description

[0009] Figure 1 This is a diagram illustrating an example of the structure of a charging and discharging system. Figure 2 This is a flowchart illustrating an example of a process performed in a control device. Figure 3 This is another example of the structure of a charging and discharging system. Figure 4 This is a diagram used to illustrate the switches installed on the busbar. Detailed Implementation

[0010] (Implementation Method) The following describes a specific implementation of the charge / discharge test system, charge / discharge test method, and control device, with reference to the accompanying drawings.

[0011] (Overall structure) like Figure 1 As shown, the charging and discharging system 1 includes a control device 10, an AC / DC converter 20, one or more bidirectional DC / DC converters 30, a capacitor 40, an electronic load 50, a voltage detection unit 60, and a bus BS.

[0012] AC / DC converter 20, for example, has one end connected to an AC power source E1 and another end connected to a bus BS. The AC power source E1 is, for example, mains power. The power supplied by AC power source E1 is, for example, AC power, specifically commercial 100V or commercial 200V AC power, etc. Based on the control of control device 10, AC / DC converter 20 converts the AC power supplied by AC power source E1 into a specified DC power and supplies this DC power to bus BS. The power supplied by AC power source E1 is an example of "first power". The specified DC power supplied by AC / DC converter 20 to bus BS is an example of "second DC power".

[0013] The bidirectional DC / DC converter 30 is connected, for example, at one end to the bus BS and at the other end to a charge / discharge device BT, which is the test object. The charge / discharge device BT is the test object used in the charge / discharge test conducted using the charge / discharge system 1. The charge / discharge device BT is, for example, a known type of secondary battery such as a lithium-ion battery, a nickel-metal hydride battery, or an all-solid-state battery (and also includes energy-storing devices such as high-capacity capacitors such as double-layer capacitors). Based on the control of the control device 10, the bidirectional DC / DC converter 30 converts the specified DC power supplied to the bus BS into DC power that the charge / discharge device BT can charge, and supplies this DC power to the charge / discharge device BT. Additionally, based on the control of the control device 10, the bidirectional DC / DC converter 30 converts the power discharged by the charge / discharge device BT into specified DC power, and supplies this DC power to the bus BS. The DC power converted by the bidirectional DC / DC converter 30 and the DC power that the charge / discharge device BT can charge is an example of "third DC power".

[0014] The charging / discharging system 1 includes a number of bidirectional DC / DC converters 30 corresponding to the number of charge / discharge bodies BT that can be tested by the charging / discharging system 1. In this embodiment, the case where the charging / discharging system 1 includes one bidirectional DC / DC converter 30 will be described. In the following description, the specified DC power supplied to the bus BS will be referred to as bus power, and the DC voltage generated by the bus BS will be referred to as bus voltage V.

[0015] A capacitor 40 is connected to the bus BS. The capacitor 40 is implemented using various known secondary batteries, such as lithium-ion batteries, nickel-metal hydride batteries, and all-solid-state batteries (and also includes energy-storing devices such as high-capacity capacitors like double-layer capacitors). The capacitor 40 charges the bus BS with electricity or discharges the charged electricity to the bus BS according to the state of the bus BS and its own charging / discharging state. The capacity of the capacitor 40 is determined, for example, based on the maximum output performance of the bidirectional DC / DC converter 30 provided by the charging / discharging system 1.

[0016] An electronic load 50 is connected to the busbar BS. The electronic load 50 operates under the control of the control device 10. The electronic load 50 functions as a simulated load that consumes power from the busbar. The electronic load 50 is an example of a "power consumption unit".

[0017] A voltage detection unit 60 for detecting the bus voltage V is provided on the bus BS. The voltage detection unit 60 detects the bus voltage V and outputs information indicating the detected bus voltage V to the control device 10. The control device 10 is implemented, for example, by a programmable logic controller (PLC). The control device 10 controls at least one of the AC / DC converter 20 and the bidirectional DC / DC converter 30 based on the bus voltage V detected by the voltage detection unit 60. Specifically, the control device 10 controls at least one of the AC / DC converter 20 and the bidirectional DC / DC converter 30 in a manner that maintains an appropriate bus voltage V on the bus BS.

[0018] More specifically, the control device 10 determines whether the charging / discharging system 1 is in any of six states based on the bus voltage V, and controls at least one of the AC / DC converter 20 and the bidirectional DC / DC converter 30 based on the determined state. The six states are, for example, a low voltage state, a high voltage state, a load operation recommendation state, a conversion stop recommendation state, a conversion suppression recommendation state, and a maximum conversion recommendation state. Details of each state are explained below.

[0019] (Regarding low voltage conditions) When the bus voltage V detected by the voltage detection unit 60 is less than the low-voltage abnormality voltage Ve, the control device 10 determines that the charging / discharging system 1 is in a low-voltage state. Here, there may be a situation where the AC / DC converter 20 cannot perform proper conversion operation for some reason. In this case, the AC / DC converter 20 becomes in a low-voltage abnormality. A low-voltage abnormality means that the voltage output by the AC / DC converter 20 is lower than the normal voltage. The low-voltage abnormality voltage Ve represents the output voltage of the AC / DC converter 20 when the low-voltage abnormality occurs. When the control device 10 determines that the charging / discharging system 1 is in a low-voltage state, it stops the charging / discharging system 1. Specifically, the control device 10 stops the operation of the AC / DC converter 20 and also stops the operation of the bidirectional DC / DC converter 30.

[0020] (Regarding high voltage conditions) When the bus voltage V detected by the voltage detection unit 60 is higher than the high voltage abnormality voltage Va, the control device 10 determines that the charging / discharging system 1 is in a high voltage state. The high voltage abnormality voltage Va is the operating voltage of the electronic load 50. Specifically, the high voltage abnormality voltage Va represents the bus voltage V in a state where even if the electronic load 50 consumes bus power, the bus voltage V cannot be reduced to an appropriate voltage. The high voltage abnormality voltage Va is, for example, a value preset based on the performance of the electronic load 50. When the control device 10 determines that the charging / discharging system 1 is in a high voltage state, it stops the operation of the bidirectional DC / DC converter 30. As a result, the operation of the bidirectional DC / DC converter 30 in converting the power associated with the discharge of the charging / discharging body BT and supplying it to the bus BS is stopped, thereby reducing the bus voltage V.

[0021] (Recommended working state for heavy workload) When the bus voltage V detected by the voltage detection unit 60 is lower than the high-voltage abnormality voltage Va and higher than the load operating voltage Vb, the control device 10 determines that the charging / discharging system 1 is in the recommended load operating state. The load operating voltage Vb represents the bus voltage V that decreases due to the consumption of bus power by the electronic load 50. The load operating voltage Vb is, for example, a value preset based on the performance of the electronic load 50. When the control device 10 determines that the charging / discharging system 1 is in the recommended load operating state, it activates the electronic load 50. As a result, the bus power is consumed by the electronic load 50, causing the bus voltage V to decrease. The load operating voltage Vb is an example of the "operating voltage of the power consumption unit".

[0022] (Regarding the conversion to a stopped recommended state) When the bus voltage V detected by the voltage detection unit 60 is less than the load operating voltage Vb but greater than the maximum output voltage Vc, the control device 10 determines that the charging / discharging system 1 is in a recommended switching stop state. The maximum output voltage Vc represents the maximum DC voltage output by the AC / DC converter 20. The maximum output voltage Vc is, for example, a value preset based on the performance of the AC / DC converter 20. When the control device 10 determines that the charging / discharging system 1 is in a recommended switching stop state, it stops the AC / DC converter 20. Furthermore, the control device 10 does not operate the electronic load 50 in the recommended switching stop state. As a result, the bus voltage V decreases due to the cessation of power supply from the AC / DC converter 20 and internal consumption within the charging / discharging system 1. The maximum output voltage Vc is an example of a "reference voltage".

[0023] Specifically, when the charging / discharging element BT is in a charging state, the bidirectional DC / DC converter 30 converts the power stored in the capacitor 40 and supplies the converted power to the charging / discharging element BT. At this time, if the bus voltage V of the bidirectional DC / DC converter 30 is high, the power conversion efficiency of the bidirectional DC / DC converter 30 will deteriorate. In the recommended state of conversion stop, the charging / discharging element BT is charged with a specified amount of power by stopping the AC / DC converter 20. As a result, the bus voltage V decreases as the bus power is consumed. Conversely, when the charging / discharging element BT is in a discharging state, the bidirectional DC / DC converter 30 converts the power discharged by the charging / discharging element BT and charges the capacitor 40 via the bus BS. At this time, since the bus voltage V of the bidirectional DC / DC converter 30 is high, the bidirectional DC / DC converter 30 is required to increase the voltage of the power output to the bus BS. Therefore, the power conversion efficiency of the bidirectional DC / DC converter 30 deteriorates. Consequently, as the capacitor 40 is charged with a specified amount of power, the bus power is consumed, causing the bus voltage V to decrease.

[0024] (Regarding the recommended state for conversion suppression) When the bus voltage V detected by the voltage detection unit 60 is less than the maximum output voltage Vc but greater than the normal output voltage Vd, the control device 10 determines that the charging / discharging system 1 is in a conversion suppression recommended state. The normal output voltage Vd represents the output voltage of the AC / DC converter 20 under normal conditions. The normal output voltage Vd is, for example, a value preset based on the performance of the AC / DC converter 20. When the control device 10 determines that the charging / discharging system 1 is in a conversion suppression recommended state, it suppresses the conversion operation of the AC / DC converter 20. Specifically, in the conversion suppression recommended state, the control device 10 controls the AC / DC converter 20 in a manner that makes the DC power output by the AC / DC converter 20 smaller than the DC power output by the AC / DC converter 20 under normal conditions. Furthermore, the control device 10 does not operate the electronic load 50 in the conversion suppression recommended state. As a result, the bus voltage V decreases due to the suppression of the power supply from the AC / DC converter 20 and internal consumption within the charging / discharging system 1. The normal output voltage Vd is an example of a "reference voltage".

[0025] Specifically, under the recommended conversion suppression state, capacitor 40 has completed charging the power discharged by the charging / discharging element BT. Therefore, when the charging / discharging element BT is in a charging state, the bidirectional DC / DC converter 30 converts the power supplied from the AC / DC converter 20 and supplies the converted power to the charging / discharging element BT. At this time, because the bus voltage V of the bidirectional DC / DC converter 30 is high, the power conversion efficiency of the bidirectional DC / DC converter 30 deteriorates. Therefore, as the charging / discharging element BT charges a predetermined amount of power to consume the bus power, the bus voltage V decreases. Furthermore, when the charging / discharging element BT is in a discharging state, the bidirectional DC / DC converter 30 converts the power discharged by the charging / discharging element BT and charges the capacitor 40 with the converted power via the bus BS. At this time, because the bus voltage V of the bidirectional DC / DC converter 30 is high, the bidirectional DC / DC converter 30 is required to increase the voltage of the power output to the bus BS. Therefore, the power conversion efficiency of the bidirectional DC / DC converter 30 deteriorates. Therefore, as the capacitor 40 is charged with a specified amount of power to consume the power of the bus, the bus voltage V decreases.

[0026] (Regarding the maximum conversion recommendation status) When the bus voltage V detected by the voltage detection unit 60 is lower than the normal output voltage Vd and is above the low voltage abnormality voltage Ve, the control device 10 determines that the charging / discharging system 1 is in the maximum conversion recommended state. When the control device 10 determines that the charging / discharging system 1 is in the maximum conversion recommended state, it controls the AC / DC converter 20 to output the maximum current that the AC / DC converter 20 can output. Furthermore, the control device 10 does not operate the electronic load 50 in the maximum conversion recommended state. As a result, the bus voltage V increases due to the maximum power supply from the AC / DC converter 20 and the internal consumption within the charging / discharging system 1.

[0027] Specifically, when the charging / discharging element BT is in a charging state, the bidirectional DC / DC converter 30 converts the power supplied from the AC / DC converter 20 and supplies the converted power to the charging / discharging element BT. At this time, the AC / DC converter 20 supplies sufficient power to the bus BS compared to the power charged to the charging / discharging element BT, thus increasing the bus voltage V. Furthermore, under the maximum conversion recommended state, the capacitor 40 has already discharged the power charged to the charging / discharging element BT. Therefore, when the charging / discharging element BT is in a discharging state, the bidirectional DC / DC converter 30 converts the power discharged by the charging / discharging element BT and charges the capacitor 40 via the bus BS. At this time, the bus BS receives sufficient power from the AC / DC converter 20 in addition to the power discharged by the charging / discharging element BT, thus increasing the bus voltage V.

[0028] (Regarding the processing performed in control device 10) Reference Figure 2 The series of processes performed by the control device 10 will be explained. Figure 2 The flowchart shown illustrates a process that is repeated at specified time intervals.

[0029] First, the control device 10 determines whether the bus voltage V detected by the voltage detection unit 60 is less than the voltage Ve when the voltage is abnormally low (step S100). If the control device 10 determines that the bus voltage V is less than the voltage Ve when the voltage is abnormally low (step S100; yes), it determines that the charging and discharging system 1 is in a low voltage state, stops the operation of the AC / DC converter 20 and stops the operation of the bidirectional DC / DC converter 30 (step S102), and ends the series of processes.

[0030] If the control device 10 determines that the bus voltage V is not lower than the voltage Ve when the voltage is low (step S100; no), it determines whether the bus voltage V is higher than the voltage Va when the voltage is high (step S104). If the control device 10 determines that the bus voltage V is higher than the voltage Va when the voltage is high (step S104; yes), it identifies that the charging / discharging system 1 is in a high-voltage state, stops the operation of the bidirectional DC / DC converter 30 (step S106), and ends the series of processes.

[0031] If the control device 10 determines that the bus voltage V is not above the voltage Va during a high voltage abnormality (step S104; no), it determines whether the bus voltage V is less than the voltage Va during a high voltage abnormality and is above the voltage Vb during load operation (step S108). If the control device 10 determines that the bus voltage V is less than the voltage Va during a high voltage abnormality and is above the voltage Vb during load operation (step S108; yes), it identifies the charging / discharging system 1 as being in the recommended load operation state, and causes the electronic load 50 to operate (step S110), ending the series of processes.

[0032] If the control device 10 determines that the bus voltage V does not meet the condition of being lower than the high voltage abnormality voltage Va and higher than the load operating voltage Vb (step S108; No), it determines whether the bus voltage V is lower than the load operating voltage Vb and higher than the maximum output voltage Vc (step S112). If the control device 10 determines that the bus voltage V is lower than the load operating voltage Vb and higher than the maximum output voltage Vc (step S112; Yes), it identifies the charging / discharging system 1 as being in the recommended conversion stop state, stops the AC / DC converter 20 (step S114), and ends the series of processes. In addition, in step S114, if the electronic load 50 is operating, the control device 10 stops the electronic load 50.

[0033] If the control device 10 determines that the bus voltage V is not less than the load operating voltage Vb and is greater than or equal to the maximum output voltage Vc (step S112; No), it determines whether the bus voltage V is less than the maximum output voltage Vc and is greater than or equal to the normal output voltage Vd (step S116). If the control device 10 determines that the bus voltage V is less than the maximum output voltage Vc and is greater than or equal to the normal output voltage Vd (step S116; Yes), it identifies that the charging / discharging system 1 is in the recommended conversion suppression state, suppresses the conversion operation of the AC / DC converter 20 (step S118), and ends the series of processes. In addition, in step S118, if the electronic load 50 is operating, the control device 10 stops the electronic load 50.

[0034] When the control device 10 determines that the bus voltage V is not less than the maximum output voltage Vc and is above the normal output voltage Vd (step S116; no), that is, when the bus voltage V is less than the normal output voltage Vd and is above the voltage Ve when the voltage is abnormally low, the control device 10 determines that the charging and discharging system 1 is in the maximum conversion recommended state, and controls the AC / DC converter 20 to output the maximum current that the AC / DC converter 20 can output (step S122), and ends a series of processes.

[0035] (Effects of the implementation method) According to the above implementation method, the following effects can be obtained. (1) The charging / discharging system 1 includes an AC / DC converter 20, a bidirectional DC / DC converter 30, a capacitor 40, and a control device 10. The AC / DC converter 20 converts alternating current (AC) power into a specified direct current (DC) power. One end of the bidirectional DC / DC converter 30 is connected to the AC / DC converter 20 via a bus BS, and the other end is connected to a charge / discharge element BT, which is the object of the charging / discharging test. The bidirectional DC / DC converter 30 converts the specified DC power converted by the AC / DC converter 20 into DC power that can be charged into the charge / discharge element BT. In addition, the bidirectional DC / DC converter 30 converts the power discharged by the charge / discharge element BT into a specified DC power. The capacitor 40 is connected to the bus BS. The control device 10 controls the operation of at least one of the AC / DC converter 20 and the bidirectional DC / DC converter 30.

[0036] Here, existing charging and discharging systems sometimes need to allocate the power input or output between the charging / discharging element BT connected to a bidirectional DC / DC converter and other charging / discharging elements connected to other bidirectional DC / DC converters. On the other hand, in this case, the power discharged by one charging / discharging element is used to charge other charging / discharging elements after undergoing two power conversions based on the bidirectional DC / DC converter, thus sometimes resulting in power losses associated with the conversion.

[0037] According to the structure of this embodiment, the power discharged by the charging / discharging element BT is used to charge the capacitor 40 after power conversion based on the bidirectional DC / DC converter 30, and the power discharged by the capacitor 40 is used to charge the charging / discharging element BT after power conversion based on the bidirectional DC / DC converter 30. Therefore, the power loss associated with the conversion can be reduced for the power charged or discharged by the charging / discharging element BT.

[0038] (2) An electronic load 50 that consumes the supplied power is connected to the busbar BS. When the busbar voltage V generated by the busbar BS is above the maximum output voltage Vc, which serves as the reference voltage for the busbar voltage V, or above the normal output voltage Vd, the control device 10 restricts the operation of the AC / DC converter 20 and prevents the electronic load 50 from operating. According to this structure, when the busbar voltage V is above the reference voltage, the charging and discharging system 1 can reduce the busbar voltage V and suppress the consumption of busbar power by the electronic load 50 by restricting the operation of the AC / DC converter 20 (e.g., stopping operation, suppressing operation, etc.).

[0039] (3) When the bus voltage V is less than the load operating voltage Vb and greater than the maximum output voltage Vc, the control device 10 stops the operation of the AC / DC converter 20. According to this structure, the charging and discharging system 1 consumes bus power by charging the charging and discharging body BT or the capacitor 40, thereby reducing the bus voltage V and thus appropriately maintaining the bus voltage V.

[0040] (4) When the bus voltage V is less than the maximum output voltage Vc but greater than the normal output voltage Vd, the control device 10 suppresses the conversion operation of the AC / DC converter 20. Specifically, the control device 10 controls the AC / DC converter 20 in a manner that makes the DC power output by the AC / DC converter 20 smaller than the DC power output by the AC / DC converter 20 under normal conditions. According to this structure, the charging and discharging system 1 consumes bus power by charging the charging and discharging body BT or the capacitor 40, thereby reducing the bus voltage V and appropriately maintaining the bus voltage V.

[0041] (5) When the bus voltage V generated by the bus BS is less than the normal output voltage Vd and is above the low voltage abnormality voltage Ve, the control device 10 operates the AC / DC converter 20 in such a way that the output of the AC / DC converter 20 is at its maximum current. According to this structure, the charging / discharging system 1 increases the bus voltage V by supplying sufficient power from the AC / DC converter 20 to the bus BS along with the power charged by the charging / discharging body BT, thereby appropriately maintaining the bus voltage V. Furthermore, the charging / discharging system 1 increases the bus voltage V by supplying sufficient power from the AC / DC converter 20 to the bus BS in addition to the power discharged by the charging / discharging body BT, thereby appropriately maintaining the bus voltage V.

[0042] (6) An electronic load 50 that consumes the supplied power is connected to the busbar BS. When the busbar voltage V generated by the busbar BS is abnormally high (voltage Va or higher), the control device 10 stops the operation of the bidirectional DC / DC converter 30. According to this structure, the charging and discharging system 1, by stopping the bidirectional DC / DC converter 30 from converting the power associated with the discharge of the charging and discharging body BT and supplying it to the busbar BS, reduces the busbar voltage V, thereby appropriately maintaining the busbar voltage V.

[0043] (7) When the bus voltage V generated by the bus BS is less than the voltage Ve during a low voltage abnormality, the control device 10 stops the AC / DC converter 20 and the bidirectional DC / DC converter 30. According to this structure, the charging and discharging system 1 can appropriately stop the operation of the charging and discharging system 1 when the AC / DC converter 20 is unable to perform proper conversion work for some reason.

[0044] The above-described embodiments can also be modified as follows. Furthermore, the above-described embodiments and the following variations can be combined with each other within the scope of technical non-contradiction. The charging and discharging system 1 may also include, for example, a DC / AC converter 70 that converts bus power into specified AC power. The specified AC power is, for example, commercial 100V or commercial 200V AC power.

[0045] exist Figure 3 An example of the structure of a charging / discharging system 1 equipped with two DC / AC converters 70-1 and 70-2 is shown. Additionally, Figure 3 The charging and discharging system 1 shown has two bidirectional DC / DC converters 30-1 and 30-2. A charging and discharging element BT is connected to the bidirectional DC / DC converter 30-1, and a charging and discharging element BT disposed in a constant temperature bath CT is connected to the bidirectional DC / DC converter 30-2.

[0046] One end of DC / AC converter 70-1 is connected to bus BS and the other end is connected to control device 10. DC / AC converter 70-1 supplies the converted AC power to control device 10. Control device 10 operates using the converted AC power. One end of DC / AC converter 70-2 is connected to bus BS and the other end is connected to thermostatic bath CT. The thermostatic bath CT operates using the converted AC power. Furthermore, the temperature inside the thermostatic bath CT is appropriately adjusted according to the test plan set for the internal charge / discharge device BT.

[0047] According to this structure, the charging and discharging system 1 can be powered from the bus power to operate the various structures (e.g., control device 10) of the charging and discharging system 1 or the various structures (e.g., thermostatic bath CT) used in the testing of the charging and discharging system 1.

[0048] In addition, charging and discharging system 1 can also replace Figure 3 The DC / AC converter 70 shown (or in addition to this) includes an AC / DC converter 20-2 (not shown). In this case, the AC / DC converter 20-2 is connected, for example, one end to an AC power source E1, and the other end to various structures included in the charging / discharging system 1 or used in the testing of the charging / discharging system 1. In this case, even if the AC / DC converter 20-2 cannot supply bus power to the bus BS under the aforementioned low voltage condition, it can still enable the AC power-using structures in the charging / discharging system 1 or used in the testing of the charging / discharging system 1 to continue operating.

[0049] like Figure 4 As shown, a switch SW1 can also be provided on the bus BS to switch the AC / DC converter 20 and the bidirectional DC / DC converter 30 to a connected state with electrical conduction or an unconnected state without electrical conduction. Switch SW1, for example, has a first terminal t1 and a second terminal t2. The second terminal t2 of switch SW1 is directly connected to the AC / DC converter 20. The first terminal t1 of switch SW1 is connected to the bidirectional DC / DC converter 30 via the bus BS. Additionally, a diode is provided in switch SW1. The anode of the diode is connected to the second terminal t2, and the cathode of the diode is connected to the first terminal t1. Switch SW1 uses, for example, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). Therefore, switch SW1 allows current to flow from the second terminal t2 to the first terminal t1 even in the unconnected state.

[0050] In this case, the control device 10 sets the switch SW1 to the connected state when the charging / discharging body BT is charging. Conversely, the control device 10 sets the switch SW1 to the disconnected state when the charging / discharging body BT is discharging. According to this structure, the charging / discharging system 1 can suppress the application of a high bus voltage V to the output terminal of the AC / DC converter 20 when the bus voltage V increases due to the discharge of the charging / discharging body BT during the discharging state.

[0051] In addition, such as Figure 4 As shown, a switch SW2 can also be installed on bus BS to switch capacitor 40 and bidirectional DC / DC converter 30 to a connected state with electrical conduction or a disconnected state without electrical conduction. Since switch SW2 has the same structure as switch SW1, its description is omitted. In this example, switch SW2 is located on bus BS between the connection point of capacitor 40 and electronic load 50 and bidirectional DC / DC converter 30. The second terminal t2 of switch SW2 is connected to capacitor 40 via bus BS. The first terminal t1 of switch SW2 is connected to bidirectional DC / DC converter 30 via bus BS. Switch SW2 also allows current to flow from the second terminal t2 to the first terminal t1 even in the disconnected state.

[0052] In this case, the control device 10 sets the switch SW2 to the unconnected state when the charging / discharging body BT is charging. Conversely, the control device 10 sets the switch SW2 to the connected state when the charging / discharging body BT is discharging. According to this structure, the charging / discharging system 1 can use the power discharged by the charging / discharging body BT to charge the capacitor 40 and use the power discharged by the capacitor 40 for other structures connected to the bus BS. These other structures include, for example, the various structures included in the charging / discharging system 1 (e.g., the control device 10) or the various structures used in the testing of the charging / discharging system 1 (e.g., the constant temperature bath CT (not shown)). Furthermore, in this case, structures not associated with the charging / discharging system 1 can also be connected to the bus BS. These structures, for example, operate using a specified DC power.

[0053] The AC / DC converter 20 included in the charging / discharging system 1 can be implemented using a bidirectional AC / DC converter. According to this structure, the bidirectional AC / DC converter can convert excess bus power into AC power and return this AC power to the AC power source E1 under high voltage conditions, recommended load operating conditions, and recommended conversion stop conditions. Here, within the facility where the charging / discharging system 1 is installed, other structures besides the charging / discharging system 1 may also utilize the AC power source E1. Therefore, the charging / discharging system 1 can supply AC power to these other structures utilizing the AC power source E1. Furthermore, the charging / discharging system 1 can sell AC power to the power operator providing the AC power source E1.

[0054] The charging / discharging system 1 can also replace the capacitor 40 and electronic load 50 (or in addition to these) and include a bidirectional AC / DC converter. In this case, one end of the bidirectional AC / DC converter is connected to the AC power source E1 and the other end is connected to the bus BS. In this case, when the capacitor 40 is charging and the electronic load 50 is operating, the control device 10 controls the bidirectional AC / DC converter to convert the bus power into AC power and return the AC power to the AC power source E1. Additionally, when the capacitor 40 is discharging, the control device 10 controls the bidirectional AC / DC converter to convert the AC power into a specified DC power. Furthermore, when the capacitor 40 is discharging, the control device 10 can also cause at least one of the AC / DC converter 20 and the bidirectional AC / DC converter to perform the power conversion from AC power to a specified DC power. According to this structure, the capacitor 40 and electronic load 50 can be omitted from the charging / discharging system 1.

[0055] The charging / discharging system 1 may also include a DC / DC converter between the AC / DC converter 20 and the bidirectional DC / DC converter 30. In this case, one end of the DC / DC converter is connected to the AC / DC converter 20 and the other end is connected to the bus BS. The DC / DC converter converts the DC power converted by the AC / DC converter 20 into a specified DC power (i.e., bus power). Here, the DC power converted by the AC / DC converter 20 is sometimes unsuitable as bus power. According to this structure, the DC power converted by the AC / DC converter 20 can be converted into appropriate bus power using the DC / DC converter. In this case, the DC power supplied by the AC / DC converter 20 is an example of "first power". The specified DC power supplied by the DC / DC converter to the bus BS is an example of "second DC power".

[0056] The control device 10 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 10 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-volatile storage medium such as an HDD (Hard Disk Drive) or flash memory, which is provided with the control device 10.

[0057] Alternatively, a resistor can be installed on the busbar BS instead of the electronic load 50. In this case, a switch is provided on the busbar BS to switch the busbar BS and the resistor to a connected state with electrical conduction or a disconnected state with no electrical conduction. The control device 10 controls the busbar BS and the resistor to be in a connected or disconnected state by controlling this switch. In this case, the control device 10 operating the electronic load 50 is the same as the control device 10 controlling the switch to the connected state. Similarly, the control device 10 stopping the electronic load 50 is the same as the control device 10 controlling the switch to the disconnected state. In this case, the resistor and switch together constitute an example of a "power consumption unit".

[0058] The capacitance of capacitor 40 can be determined not by the maximum output performance of bidirectional DC / DC converter 30, but (or on top of that) by the charge / discharge schedule for the charge / discharge body BT.

[0059] The expression “at least one of A and B” as used in this specification means “only A, only B, or both A and B”. Explanation of reference numerals in the attached figures

[0060] 1…charging and discharging system, 10…control device, 20, 20-1, 20-2…AC / DC converter, 30, 30-1, 30-2…bidirectional DC / DC converter, 40…capacitor, 50…electronic load, 60…voltage detection unit, 70, 70-1, 70-2…DC / AC converter, BS…bus, BT…charging and discharging element, CT…thermostatic bath, E1…AC power source, SW1, SW2…switches, V…bus voltage, Va…voltage during high voltage abnormality, Vb…voltage during load operation, Vc…maximum output voltage, Vd…normal output voltage, Ve…voltage during low voltage abnormality.

Claims

1. A charge / discharge testing system, comprising: The converter converts the first type of power into a second type of DC power. A bidirectional DC / DC converter, one end of which is connected to the converter via a bus, and the other end of which is connected to a charge / discharge body that is the object of the charge / discharge test, converts the second DC power converted by the converter into a third DC power or converts the power discharged by the charge / discharge body into the second DC power; A capacitor is connected to the busbar; as well as A control device controls the operation of at least one of the converter and the bidirectional DC / DC converter.

2. The charge / discharge testing system according to claim 1, wherein, A power consumption unit is connected to the busbar to consume the supplied power. When the bus voltage generated by the bus is higher than the reference voltage of the bus voltage, the control device limits the operation of the converter and prevents the power-consuming part from operating.

3. The charge / discharge testing system according to claim 2, wherein, The control device stops the operation of the converter when the bus voltage is less than the operating voltage (Vb) of the power consumption section and greater than the maximum output voltage of the converter.

4. The charge / discharge testing system according to claim 2, wherein, When the bus voltage is less than the maximum output voltage of the converter but greater than the normal output voltage of the converter, the control device makes the output current of the converter smaller than it is normally.

5. The charge / discharge testing system according to claim 1, wherein, The control device operates the converter so that its output is at maximum current when the bus voltage generated by the bus is less than the normal output voltage of the converter and greater than the output voltage of the converter during a low voltage anomaly.

6. The charge / discharge testing system according to claim 1, wherein, A power consumption unit is connected to the busbar to consume the supplied power. When the bus voltage generated by the bus is higher than the operating voltage of the power-consuming part, the control device stops the operation of the bidirectional DC / DC converter.

7. The charge / discharge testing system according to claim 1, wherein, When the bus voltage generated by the bus is less than the output voltage of the converter during a low voltage abnormality, the control device stops the converter and the bidirectional DC / DC converter.

8. The charge / discharge testing system according to claim 1, wherein, A switch is provided on the busbar, which is used to switch the converter and the bidirectional DC / DC converter to a connected state with electrical conduction or a disconnected state without electrical conduction. The control device sets the switch to the connected state when the charging / discharging body is charging, and sets the switch to the disconnected state when the charging / discharging body is discharging.

9. The charge / discharge testing system according to claim 1, wherein, A switch is provided on the busbar, which is used to switch the capacitor and the bidirectional DC / DC converter to a connected state with electrical conduction or a disconnected state with no electrical conduction. The control device sets the switch to the disconnected state when the charging / discharging body is charging, and sets the switch to the connected state when the charging / discharging body is discharging.

10. A charge-discharge testing method, wherein a computer used in the control device of the charge-discharge testing system controls the operation of at least one of a converter and a bidirectional DC / DC converter, wherein... The charge / discharge testing system includes: The converter converts the first power into a second DC power. The bidirectional DC / DC converter has one end connected to the converter via a bus, and the other end connected to a charging / discharging device that is the subject of the charge / discharge test. It converts the second DC power converted by the converter into a third DC power, or converts the power discharged by the charging / discharging device into the second DC power; and A capacitor is connected to the busbar.

11. A control device, which is a control device for a charge-discharge test system, wherein, The charge / discharge testing system includes: The converter converts the first type of power into a second type of DC power. A bidirectional DC / DC converter, one end connected to the converter via a bus, and the other end connected to a charge / discharge device subject to charge / discharge testing, converts the second DC power converted by the converter into a third DC power, or converts the power discharged by the charge / discharge device into the second DC power; and A capacitor is connected to the busbar. The control device controls the operation of at least one of the converter and the bidirectional DC / DC converter.

Images