Battery charging and discharging system and its charging test method and discharging test method

Abstract

This invention provides a battery charging and discharging system, as well as charging and discharging test methods thereof. [Solution] The battery charging and discharging system includes a bidirectional power supply and a bypass module. The bidirectional power supply charges the battery by providing a charging current during the charging operation. The bypass module includes a first current path and a second current path connected in parallel. The first current path includes a first resistor unit and the battery coupled to the first resistor unit, and the second current path includes a second resistor unit. The charging current is the sum of a first charging current flowing through the first current path and a second charging current flowing through the second current path. The impedances of the first and second resistor units are adjusted to gradually increase and gradually decrease, respectively, so that the current value of the first charging current gradually decreases from a first current value to zero, and at the same time, the current value of the second charging current gradually decreases from zero to a second current value.

Description

Technical Field

[0001] The present invention relates to a battery charging and discharging system, its charging test method, and its discharging test method. In particular, when performing a battery charging operation or a discharging operation, by adjusting the impedance of resistance units on two current paths in a bypass module, it relates to a system for changing the flowing current, its charging test method, and its discharging test method.

Background Art

[0002] In the production process of batteries, in order to ensure the quality of products, two programs of formation and testing must be carried out. Formation is a process of charging the battery to activate it after the battery assembly is completed, and testing is a process of repeatedly charging and discharging the battery to check whether the capacity and charge-discharge performance of the battery reach the standard requirements after the formation of the battery is completed.

[0003] The conventional formation and testing method for single batteries has the following problems. When using a single battery charging and discharging device, only one battery can be formed or tested at a time, and the production efficiency is too low. If multiple battery charging and discharging devices are used to speed up the productization and testing programs, the cost is high and the floor area is large. In addition, the conventional formation and testing method for single batteries has the drawback that since the voltage is too low, it is difficult for the electrical energy of the battery during discharge to be fed back to the power supply, resulting in low power consumption. Therefore, in recent years, batch charging and discharging of multiple batteries using a series charging architecture has become the mainstream.

[0004] However, due to the differences between individual batteries, the batteries cannot complete charging and discharging simultaneously. Therefore, in order to avoid the risks of overcharging and over-discharging of the batteries, a bypass module must be adopted in the series charging architecture so that the batteries that have completed charging and discharging are switched, the charging and discharging current bypasses these batteries, and charging and discharging continue only for other batteries that have not completed charging and discharging. However, the surge current generated during the switching may damage circuit elements and batteries.

Summary of the Invention

[0005] The present invention provides a battery charge / discharge system comprising: a bidirectional power supply for providing a charging current to charge a battery during a charging operation; a first current path and a second current path coupled in parallel between the ends of the bidirectional power supply; the first current path comprising a first resistor unit and a battery coupled to the first resistor unit; and the second current path comprising a bypass module including a second resistor unit; wherein the charging current is the sum of a first charging current flowing through the first current path and a second charging current flowing through the second current path; the impedance of the first resistor unit is adjusted to gradually increase, and at the same time, the impedance of the second resistor unit is adjusted to gradually decrease, thereby providing a battery charge / discharge system in which the current value of the first charging current gradually decreases from a first current value to zero, and at the same time, the current value of the second charging current gradually decreases from zero to a second current value.

[0006] In some embodiments, the first current value and the second current value are both equal to the charging current value.

[0007] In some embodiments, during a discharge operation, a bidirectional power supply provides a discharge demand command to the battery, and the battery outputs a discharge current in response to the discharge demand command, the discharge current being the sum of a first discharge current flowing through a first current path and a second discharge current flowing through a second current path, the impedance of the first resistance unit being adjusted to gradually increase, and at the same time, the impedance of the second resistance unit being adjusted to gradually decrease, thereby causing the current value of the first discharge current to gradually decrease from a third current value to zero, and at the same time, the current value of the second discharge current to gradually decrease from zero to a fourth current value.

[0008] In some embodiments, the third current value and the fourth current value are both equal to the discharge current value.

[0009] In some embodiments, the first resistor unit includes a first transistor and a second transistor connected in series, and the second resistor unit includes a third transistor and a fourth transistor connected in series.

[0010] In some embodiments, the first resistor unit is a first variable resistor, and the second resistor unit is a second variable resistor.

[0011] The present invention provides a charging test method for a battery charging and discharging system, which is used in a battery charging and discharging system having a bidirectional power supply and a bypass module, wherein the bypass module is coupled between both ends of the bidirectional power supply and includes a first current path and a second current path arranged in parallel, the first current path includes a first resistor unit and a battery coupled to the first resistor unit, and the second current path includes a second resistor unit, the method comprising: the bidirectional power supply charging the battery in a charging operation by providing a charging current which is the sum of a first charging current flowing through the first current path and a second charging current flowing through the second current path; and gradually increasing the impedance of the first resistor unit and simultaneously gradually decreasing the impedance of the second resistor unit, thereby causing the current value of the first charging current to gradually decrease from a first current value to zero, and simultaneously causing the current value of the second charging current to gradually decrease from zero to a second current value.

[0012] In some embodiments, the first current value and the second current value in the charging test method are both equal to the charging current value.

[0013] The present invention provides a discharge test method for a battery charge / discharge system used in a battery charge / discharge system having a bidirectional power supply and a bypass module, wherein the bypass module is coupled between the ends of the bidirectional power supply and includes a first current path and a second current path arranged in parallel, the first current path includes a first resistor unit and a battery coupled to the first resistor unit, and the second current path includes a second resistor unit, the method comprising: the bidirectional power supply providing a discharge demand command to the battery; the battery responding to the discharge demand command by outputting a discharge current which is the sum of a first discharge current flowing through the first current path and a second discharge current flowing through the second current path; and gradually increasing the impedance of the first resistor unit and simultaneously gradually decreasing the impedance of the second resistor unit, thereby causing the current value of the first discharge current to gradually decrease from a first current value to zero, and simultaneously causing the current value of the second discharge current to gradually decrease from zero to a second current value.

[0014] In some embodiments, the first current value and the second current value in the discharge test method are both equal to the discharge current value.

[0015] Therefore, the main objective of this disclosure is to provide a battery charging and discharging method that adjusts the switching timing based on the characteristics of the transistor and avoids open circuits and battery short circuits in the series charging architecture. [Brief explanation of the drawing]

[0016] When reading the drawings in conjunction with this invention, the aspects of one embodiment of the present invention should be best understood from the following detailed description. However, based on industry standards, each feature is not drawn proportionally. The size of each feature may be arbitrarily increased or decreased to clarify the discussion. [Figure 1] This is a schematic diagram of a battery charging and discharging system according to one embodiment of the present invention. [Figure 2] This is a flowchart of a charging test method used in a battery charging and discharging system according to one embodiment of the present invention. [Figure 3]This is a schematic diagram of a battery charging and discharging system according to one embodiment of the present invention. [Figure 4A] This is a schematic diagram corresponding to different time points in a charging test of a battery charging and discharging system as shown in Figure 3, according to one embodiment of the present invention. [Figure 4B] This is a schematic diagram corresponding to different time points in a charging test of a battery charging and discharging system as shown in Figure 3, according to one embodiment of the present invention. [Figure 4C] This is a schematic diagram corresponding to different time points in a charging test of a battery charging and discharging system as shown in Figure 3, according to one embodiment of the present invention. [Figure 5] This is a flowchart of a discharge test method for a battery charge / discharge system according to one embodiment of the present invention. [Figure 6A] This is a schematic diagram corresponding to different time points in a discharge test of a battery charge / discharge system as shown in Figure 3, according to one embodiment of the present invention. [Figure 6B] This is a schematic diagram corresponding to different time points in a discharge test of a battery charge / discharge system as shown in Figure 3, according to one embodiment of the present invention. [Figure 6C] This is a schematic diagram corresponding to different time points in a discharge test of a battery charge / discharge system as shown in Figure 3, according to one embodiment of the present invention. [Figure 7] This is a schematic diagram of a battery charging and discharging system according to another embodiment of the present invention. [Figure 8A] This is a schematic diagram corresponding to different time points in a charging test of a battery charging and discharging system as shown in Figure 7, according to one embodiment of the present invention. [Figure 8B] This is a schematic diagram corresponding to different time points in a charging test of a battery charging and discharging system as shown in Figure 7, according to one embodiment of the present invention. [Figure 8C] This is a schematic diagram corresponding to different time points in a charging test of a battery charging and discharging system as shown in Figure 7, according to one embodiment of the present invention. [Figure 9A] This is a schematic diagram corresponding to different time points in a charging test of a battery charging / discharging system as shown in Figure 7, according to another embodiment of the present invention. [Figure 9B]Schematic diagrams corresponding to different time points in the charging test of a battery charging and discharging system as shown in FIG. 7 according to another embodiment of the present invention. [Figure 9C] Schematic diagrams corresponding to different time points in the charging test of a battery charging and discharging system as shown in FIG. 7 according to another embodiment of the present invention. [Figure 10A] Schematic diagrams corresponding to different time points in the discharging test of a battery charging and discharging system as shown in FIG. 7 according to an embodiment of the present invention. [Figure 10B] Schematic diagrams corresponding to different time points in the discharging test of a battery charging and discharging system as shown in FIG. 7 according to an embodiment of the present invention. [Figure 10C] Schematic diagrams corresponding to different time points in the discharging test of a battery charging and discharging system as shown in FIG. 7 according to an embodiment of the present invention. [Figure 10D] Schematic diagrams corresponding to different time points in the discharging test of a battery charging and discharging system as shown in FIG. 7 according to an embodiment of the present invention. [Figure 11A] Schematic diagrams corresponding to different time points in the discharging test of a battery charging and discharging system as shown in FIG. 7 according to another embodiment of the present invention. [Figure 11B] Schematic diagrams corresponding to different time points in the discharging test of a battery charging and discharging system as shown in FIG. 7 according to another embodiment of the present invention. [Figure 11C] Schematic diagrams corresponding to different time points in the discharging test of a battery charging and discharging system as shown in FIG. 7 according to another embodiment of the present invention. [Figure 11D] Schematic diagrams corresponding to different time points in the discharging test of a battery charging and discharging system as shown in FIG. 7 according to another embodiment of the present invention.

Mode for Carrying Out the Invention

[0017] Please refer to Figure 1. Figure 1 is a schematic diagram of a battery charging and discharging system 10 according to one embodiment of the present invention. The battery charging and discharging system 10 includes a bypass module 110, a bypass module 120, and a bidirectional power supply 130. As shown in the embodiment in Figure 1, the bypass modules 110 and 120 are connected in series between the ends of the bidirectional power supply 130.

[0018] The bypass module 110 includes parallel current paths P1 and P2. Current path P1 includes a resistor unit 111 and a battery 113 coupled to the resistor unit 111. Current path P2 includes a resistor unit 112.

[0019] Similarly, the bypass module 120 includes parallel current paths P3 and P4. Current path P3 includes a resistor unit 121 and a battery 123 coupled to the resistor unit 121. Current path P4 includes a resistor unit 122.

[0020] In some embodiments, the battery charge / discharge system 10 is used to test the charge / discharge performance of batteries 113 and 123 by performing charge and discharge operations on batteries 113 and 123 via bypass modules 110 and 120 and a bidirectional power supply 130.

[0021] In some embodiments, the battery charge / discharge system 10 operates batteries 113 and 123, respectively, by switching the charge / discharge current transmission paths of bypass modules 110 and 120. For example, in some embodiments, the battery charge / discharge system 10 transmits a charging current Ic through resistor units 111 and 121, and simultaneously charges batteries 113 and 123. If battery 113 becomes fully charged but battery 123 does not, the battery charge / discharge system 10 switches the current transmission path of bypass module 110 so that the charging current Ic flows through resistor unit 112 instead of resistor unit 111, in order to avoid damage to battery 113 due to overcharging. Then, battery 113 may be removed or other operations may be performed. In other words, with the above configuration, battery 123 can maintain its original charge state without its charging operation being affected by the disconnection of battery 113 from the system. The discharge operation of batteries 113 and 123 by the battery charge / discharge system 10 is similar to the charging operation and will not be described here.

[0022] Please refer to Figure 2. Figure 2 is a flowchart of the charge test method 200 used in a battery charge / discharge system according to one embodiment of the present invention. The charge test method 200 refers to steps S201 and S202 described below in the embodiments of Figures 3 and 4A to 4C. In some embodiments, the charge test method 200 is also used in a battery charge / discharge system 70 as shown in Figure 7.

[0023] Please refer to Figure 3. Figure 3 is a schematic diagram of a battery charging / discharging system 30 according to one embodiment of the present invention. In some embodiments, the battery charging / discharging system 30 is configured in relation to the battery charging / discharging system 10, for example, in Figure 1.

[0024] As shown in the embodiment of Figure 3, resistor units 111 and 112 are variable resistors Rt11 and Rt12, respectively, and resistor units 121 and 122 are variable resistors Rt21 and Rt22, respectively. In some embodiments, the variable resistors Rt11, Rt12, Rt21, and Rt22 each have a variable impedance in response to signals S1 to S4. In some embodiments, the battery charge / discharge system 10 includes a controller (not shown) that generates control signals S1 to S4 based on the operation setting for the battery in the system (such as charging or discharging), and changes the transmission path of the charge / discharge current by adjusting the impedance of the variable resistors Rt11, Rt12, and Rt21.

[0025] Please refer to Figures 2 to 4C simultaneously. Figures 4A to 4C are schematic diagrams corresponding to different time points in a charging test of a battery charging / discharging system 30 as shown in Figure 3, according to one embodiment of the present invention.

[0026] Taking the bypass module 110 as an example, in step S201, the bidirectional power supply 130 charges the battery 113 by providing a charging current Ic, which is the sum of the charging current Ic1 flowing through the current path P1 and the charging current Ic2 flowing through the current path P2, during the charging operation of the bidirectional power supply 130.

[0027] Specifically, as shown in Figure 4A, the variable resistor Rt11 has a low impedance (e.g., close to 0), and the variable resistor Rt12 has a very high impedance (e.g., close to an open circuit), so that the charging current Ic flows through the current path P1 as the charging current Ic1 and charges the battery 113.

[0028] Then, when the battery 113 is charged to the point where it needs to be disconnected from the charging current, based on step S202, the impedance of the variable resistor Rt11 is gradually increased and at the same time the impedance of the variable resistor Rt12 is gradually decreased, so that the current value of the charging current Ic1 gradually decreases from the first current value to zero, and at the same time the current value of the charging current Ic2 gradually decreases from zero to the second current value, that is, the charging current Ic shown in Figure 4C flows through the current path P2 as the charging current Ic2. In embodiments where some batteries 113 are fully charged to the point where they need to be disconnected from the charging current, both the first current value and the second current value are equal to the current value of the charging current Ic.

[0029] Compared to some charging test methods that employ a hard handover method that simultaneously turns off two current paths and then rapidly turns on both current paths simultaneously, the above configuration of the present invention allows the battery 113 to gradually cut off the charging current and slowly disengage from the charging circuit, thereby suppressing the occurrence of a very large surge current (inrush current) at the moment of switching, avoiding damage to devices on the circuit, and thereby improving the reliability of each device in the battery charging and discharging system.

[0030] Please refer to Figure 5. Figure 5 is a flowchart of a discharge test method 500 used in a battery charge / discharge system according to one embodiment of the present invention. The discharge test method 500 refers to steps S501 to S503 described below in the embodiments of Figures 1 and 6A to 6C. In some embodiments, the discharge test method 500 is also used in the battery charge / discharge system 70 shown in Figure 7.

[0031] For example, based on step S501, the bidirectional power supply 130 provides a discharge demand command to the battery 113. Then, in step S502, the battery 113 outputs a discharge current Idis in response to the discharge demand command, and the discharge current Idis is the sum of the discharge current Idis1 flowing through current path P1 and the discharge current Idis2 flowing through current path P2.

[0032] As shown in Figure 6A, the variable resistor Rt11 has a low impedance, and the variable resistor Rt12 has a very high impedance, thereby making the discharge current Idis the discharge current Idis1 flowing through the current path P1.

[0033] Then, when battery 113 is discharged to the point where it needs to be disconnected from the discharge current, based on step S503, the impedance of variable resistor Rt11 is gradually increased and at the same time the impedance of variable resistor Rt12 is gradually decreased, as shown in Figure 6B, so that the current value of discharge current Idis1 gradually decreases from the third current value to zero, and at the same time the current value of discharge current Idis2 gradually decreases from zero to the fourth current value, i.e., the discharge current Idis shown in Figure 6C flows through the current path P2 as discharge current Idis2. In embodiments where some batteries 113 are completely discharged to the point where they need to be disconnected from the discharge current, the third current value and the fourth current value are both equal to the current value of discharge current Idis.

[0034] In other embodiments, resistor units 111-112 and 121-122 are implemented with transistors. See Figure 7, which is a schematic diagram of a battery charge / discharge system 70 according to another embodiment of the present invention. In some embodiments, the battery charge / discharge system 70 is configured in relation to, for example, the battery charge / discharge system 10 in Figure 1.

[0035] As shown in Figure 7, in the battery charge / discharge system 70, resistor unit 111 includes transistors M11 and M12 connected in series. Resistor unit 112 includes transistors M21 and M22 connected in series. Resistor unit 121 includes transistors M31 and M32 connected in series. Resistor unit 122 includes transistors M41 and M42 connected in series. In some embodiments, transistors M11 and M12, M21 and M22, M31 and M32, and M41 and M42 are N-type metal oxide semiconductor field-effect transistors (MOSFETs).

[0036] In detail, the sources of transistors M11 and M12 are coupled to each other. The drain of transistor M12 is coupled to one end of battery 113. The drains of transistors M11 and M12 are coupled to each other and to the bidirectional power supply 130. The sources of transistors M21 and M22 are coupled to each other. The drain of transistor M22 is coupled to the other end of battery 113 and to the bypass module 120. Similarly, the sources of transistors M31 and M32 are coupled to each other. The drain of transistor M32 is coupled to one end of battery 123. The drains of transistors M31 and M41 are coupled to each other and to the bypass module 110. The sources of transistors M41 and M42 are coupled to each other. The drain of transistor M42 is coupled to the other end of battery 123 and to the bidirectional power supply 130.

[0037] The battery charging and discharging system 70 further includes drive circuits 611-612, 621-622, 631-632, and 641-642. In some embodiments, drive circuits 611-612 control transistors M11 and M12 by generating signals S11-S12 in response to signals CS11-CS12, respectively. Similarly, drive circuits 621-622 control transistors M21 and M22 by generating signals S21-S22 in response to signals CS21-CS22, respectively; drive circuits 631-632 control transistors M31 and M32 by generating signals S31-S32 in response to signals CS31-CS32, respectively; and drive circuits 641-642 control transistors M41 and M42 by generating signals S41-S42 in response to signals CS41-CS42, respectively.

[0038] In some embodiments, the battery charging / discharging system 70 includes a controller (not shown) for generating control signals CS11-CS12, CS21-CS22, CS31-CS32 and CS41-CS42 based on the operating settings for the battery in the system (charging, discharging, etc.). Drive circuits 611-612, 621-622, 631-632 and 641-642 are used to generate signals S11-S12, S21-S22, S31-S32 and S41-S42 for the resistance of adjustable transistors required at a particular time by delaying and modulating the corresponding signals among CS11-CS12, CS21-CS22, CS31-CS32 and CS41-CS42, thereby changing the transmission path of the charging / discharging current in the battery charging / discharging system 70. In some embodiments, the drive circuits 611-612, 621-622, 631-632, and 641-642 may be implemented with any suitable delay circuit.

[0039] Please refer to Figures 8A to 8C. Figures 8A to 8C are schematic diagrams corresponding to a charging test of a battery charging / discharging system 70 as shown in Figure 7, according to one embodiment of the present invention.

[0040] Taking the bypass module 110 as an example, the bidirectional power supply 130 charges the battery 113 by providing a charging current Ic during the charging operation. The charging current Ic is the sum of the charging current Ic1 flowing through the current path P1 and the charging current Ic2 flowing through the current path P2.

[0041] Specifically, as shown in Figure 8A, transistors M11 and M12 have low impedance because they are ON, and transistors M21 and M22 have very high impedance because they are OFF. As a result, the charging current Ic flows through the current path P1 as charging current Ic1 and charges the battery 113.

[0042] Then, when the battery 113 is charged to the point where it needs to be disconnected from the charging current, the decreasing potentials of signals S11 and S12 adjust the conduction state of transistors M11 and M12, and as shown in Figure 8B, the impedance of transistors M11 and M12 gradually increases, and the current value of the charging current Ic1 gradually decreases from the first current value to zero. At the same time, the rising potentials of signals S21 and S22 adjust the conduction state of transistors M21 and M22, and the impedance of transistors M11 and M12 gradually decreases, and the current value of the charging current Ic2 gradually increases from zero to the second current value, that is, the charging current Ic shown in Figure 8C flows through the current path P2 as the charging current Ic2. In embodiments where some batteries 113 are fully charged to the point where they need to be disconnected from the charging current, both the first current value and the second current value are equal to the current value of the charging current Ic.

[0043] By utilizing the configuration according to the present invention described above, during the process of disconnecting the battery from the charging current, the impedance of the two current paths of the bypass module 110 is suppressed, reducing the charging current Ic, which is then reduced by the surge current generated by the switching of transistors M11 and M12 and transistors M21 and M22, thereby shortening this transient state.

[0044] Conversely, some methods simultaneously switch the charging current transmission path by turning off both paths of the charging module, and also use a high-frequency switching speed to switch the transistor to avoid excessive current interruptions. However, this hard handover generates a very large surge current in the charging circuit at the moment of switching, for example, 300 amperes. This can cause damage to devices on the circuit, such as the power supply, the switching transistor, and the battery. Compared to the above methods, the configuration according to the present invention can suppress the surge current to a level of 1 ampere or less. In this way, the reliability of each device in the battery charging and discharging system is greatly improved.

[0045] In some embodiments, if the charge quality of the battery 113 does not reach a standard level after a charging operation has been performed on the battery 113 and after transistors M11~M12 in the resistor unit 111 have been turned off, and recharging is necessary, the battery charge / discharge system 70 recharges the battery 113 by switching the charging current Ic transmitted through the current path P2 to the charging current Ic transmitted through the current path P1, as shown in the embodiments of Figures 9A~9C.

[0046] Please refer to Figures 9A to 9C. Figures 9A to 9C are schematic diagrams corresponding to a charging test of a battery charging / discharging system 70 as shown in Figure 7, according to another embodiment of the present invention.

[0047] At the start, as shown in Figure 9A, when transistors M21 and M22 are turned on and transistors M11 and M12 are turned off, the charging current Ic flows through the current path P2 as the charging current Ic2.

[0048] In the embodiments shown in Figures 9B and 9C, the impedances of transistors M21 and M22 gradually increase, and the current value of the charging current Ic2 gradually decreases from a first current value to zero. Simultaneously, the impedances of transistors M11 and M12 gradually decrease, and the current value of the charging current Ic1 gradually decreases from zero to a second current value. As a result, the charging current Ic shown in Figure 9C flows through the current path P1 as the charging current Ic1, recharging the battery 113.

[0049] Please refer to Figures 10A to 10D. Figures 10A to 10D are schematic diagrams corresponding to a discharge test of a battery charge / discharge system 70 as shown in Figure 7, according to one embodiment of the present invention.

[0050] Taking the bypass module 110 as an example, the bidirectional power supply 130 provides a discharge demand command to the battery 113. In response to the discharge demand command, the battery 113 outputs a discharge current Idis, which is the sum of the discharge current Idis1 flowing through current path P1 and the discharge current Idis2 flowing through current path P2.

[0051] As shown in Figure 10A, transistors M11 and M12 are turned on, while transistors M21 and M22 are turned off, thereby making the discharge current Idis1 flowing through the current path P1.

[0052] Then, when battery 113 is discharged to the point where it needs to be disconnected from the discharge current, first, as shown in Figures 10B to 10C, transistors M11 and M12 are gradually turned off, increasing the impedance of transistors M11 and M12, so that the current value of discharge current Idis1 gradually decreases from the third current value to zero. At the same time, transistor M22 is gradually turned on in response to signal S22 having an upward potential, decreasing the impedance of transistor M22, and transistor M21 flows discharge current Idis2 through its parasitic diode in response to signal S21 having a low potential. Subsequently, in Figure 10D, in response to signal S21 changing to a high potential via transistor M21, the current value of discharge current Idis2 gradually increases from zero to the fourth current value, and discharge current Idis flows through the current path P2 as discharge current Idis2.

[0053] Similar to the embodiment of the charging operation, by utilizing the configuration according to the present invention described above, the discharge current Idis is significantly reduced by suppressing the two sets of impedances of the bypass module 110, thereby reducing the surge current (inrush current) generated by the switching of transistors M11 and M12 and transistors M21 and M22, and shortening this transient state.

[0054] Furthermore, in order to avoid a short circuit in the battery 113 due to switching during discharge, compared to the charging operation, transistor M21 is controlled (Figure 10D) before the switching operation of the discharge current Idis is completed, and this is treated as a diode operation.

[0055] In some embodiments, if the discharge quality of the battery 113 does not reach the standard after the battery 113 has been discharged and transistors M11-M12 in the resistor unit 111 have been turned off, it is necessary to recharge it. The battery charge / discharge system 70 switches from transmitting the discharge current Idis via the current path P2 to re-discharging the battery 113 and transmitting the discharge current Idis via the current path P1, as shown in the embodiments of Figures 11A-11D.

[0056] Please refer to Figures 11A to 11D. Figures 11A to 11D are schematic diagrams corresponding to a discharge test of a battery charge / discharge system 70 as shown in Figure 7, according to another embodiment of the present invention.

[0057] At the start, as shown in Figure 11A, when transistors M21 and M22 are turned on and transistors M11 and M12 are turned off, the discharge current Idis flows through the current path P2 as the discharge current Idis2.

[0058] Then, as shown in Figure 11B, by keeping transistor M21 ON and using transistor M22 to respond to a low-potential signal S22, the discharge current Idis2 flows through its parasitic diode. Subsequently, as shown in Figures 11C to 11D, transistors M11 and M12 are gradually turned ON, lowering the impedance of transistors M11 and M12, so that the current value of the discharge current Idis1 gradually increases from zero to a third current value, and transistors M21 and M22 are gradually turned OFF, raising the impedance of transistors M21 and M22, so that the current value of the discharge current Idis2 gradually decreases from a fourth current value to zero, and the battery 113 re-discharges and transmits the discharge current Idis through the current path P1.

[0059] Figures 1 to 11D are given for illustrative purposes. Various other embodiments shown in Figures 1 to 11D are within the scope of the invention. For example, in some embodiments, the battery charging and discharging system may include two or more bypass modules coupled in series with each other and have operating modes similar to those shown in Figures 1 to 11D.

[0060] In some embodiments of the present invention, the transistor in Figure 7 may be a P-type transistor, and the battery charging and discharging system uses the inversion signals shown in Figures 8A to 11D (for example, CS11 to CS12, CS21 to CS22, CS31 to CS32, CS41 to CS42 and the signals generated by them in correspondence with the transistors) in a corresponding manner to achieve the charging and discharging operations shown in Figures 8A to 11D.

[0061] As described above, the battery charging and discharging system and its operating method according to the present invention cleverly generate two sets of impedances corresponding to two current transmission paths by controlling the resistance change of the resistor unit in the bypass module, suppressing excessive surge currents that occur when switching transmission paths, further improving the reliability of each element in the battery charging and discharging system, and improving work efficiency.

[0062] Having outlined the features of several embodiments, those skilled in the art will be able to better understand the aspects of one embodiment of the present invention. Those skilled in the art should understand that one embodiment of the present invention can be readily used as a basis for designing or modifying other processes and structures to carry out the same objectives and / or achieve the same advantages of the embodiments described herein. Those skilled in the art should recognize that such equivalent structures do not depart from the spirit and scope of one embodiment of the present invention, and that various changes, substitutions and modifications can be made in one embodiment of the present invention without departing from the spirit and scope of one embodiment of the present invention. [Explanation of Symbols]

[0063] 10: Battery charging and discharging system 110: Bypass Module 111: Resistor Unit 112: Resistor Unit 113:Battery 120: Bypass Module 121: Resistor Unit 122: Resistor Unit 123:Battery 130: Bidirectional power supply P1-P4: Current path 200: Charging test method for battery charging and discharging systems S201-S202: Step 30: Battery charging and discharging system S1-S4: Signal Rt11-Rt12: Variable resistors Rt21-Rt22: Variable resistors IC: Charging current Ic1: Charging current Ic2: Charging current r1-r2: Impedance Ropen: Open circuit impedance Idis:Discharge current Idis1:Discharge current Idis2:Discharge current 500: Discharge test method for battery charging and discharging systems S501-S503: Step 70: Battery charging and discharging system S11-S12: Signal S21-S22: Signal S31-S32: Signal S41-S42: Signal CS11-CS12: Signal CS21-CS22: Signal CS31-CS32: Signal CS41-CS42: Signal M11-M12: Transistors M21-M22: Transistors M31-M32: Transistors M41-M42: Transistors

Claims

1. A battery charging and discharging system, In the charging operation, a bidirectional power supply for providing charging current to charge the battery, The bidirectional power supply includes a first current path and a second current path coupled in parallel between both ends of the aforementioned bidirectional power supply, the first current path includes a first resistor unit and the battery coupled to the first resistor unit, and the second current path includes a bypass module including the second resistor unit. Equipped with, The charging current is the sum of a first charging current flowing through the first current path and a second charging current flowing through the second current path, the impedance of the first resistor unit is adjusted to gradually increase, and at the same time, the impedance of the second resistor unit is adjusted to gradually decrease, thereby causing the current value of the first charging current to gradually decrease from a first current value to zero, and at the same time, the current value of the second charging current to gradually decrease from zero to a second current value.

2. The battery charging and discharging system according to claim 1, wherein both the first current value and the second current value are equal to the current value of the charging current.

3. In a discharge operation, the bidirectional power supply is further used to provide a discharge demand command to the battery, the battery outputs a discharge current in response to the discharge demand command, the discharge current is the sum of a first discharge current flowing through the first current path and a second discharge current flowing through the second current path, the impedance of the first resistor unit is adjusted to gradually increase, and at the same time, the impedance of the second resistor unit is adjusted to gradually decrease, thereby causing the current value of the first discharge current to gradually decrease from a third current value to zero, and at the same time, the current value of the second discharge current to gradually decrease from zero to a fourth current value, according to claim 1.

4. The battery charging and discharging system according to claim 3, wherein both the third current value and the fourth current value are equal to the discharge current value.

5. The first resistor unit includes a first transistor and a second transistor connected in series, The battery charging and discharging system according to claim 1, wherein the second resistor unit includes a third transistor and a fourth transistor connected in series.

6. The battery charging and discharging system according to claim 1, wherein the first resistor unit is a first variable resistor, and the second resistor unit is a second variable resistor.

7. A battery charge / discharge system having a bidirectional power supply and a bypass module, wherein the bypass module is coupled between the ends of the bidirectional power supply and includes a first current path and a second current path arranged in parallel, the first current path includes a first resistor unit and a battery coupled to the first resistor unit, and the second current path includes a second resistor unit, a charge test method for the battery charge / discharge system, The bidirectional power supply charges the battery by providing a charging current that is the sum of a first charging current flowing through the first current path and a second charging current flowing through the second current path during a charging operation. The impedance of the first resistor unit is gradually increased, and at the same time, the impedance of the second resistor unit is gradually decreased, thereby causing the current value of the first charging current to gradually decrease from the first current value to zero, and at the same time, the current value of the second charging current to gradually decrease from zero to the second current value. A charging test method for a battery charging and discharging system, including the battery charging and discharging system.

8. The charging test method according to claim 7, wherein both the first current value and the second current value are equal to the current value of the charging current.

9. A discharge test method for a battery charge / discharge system having a bidirectional power supply and a bypass module, wherein the bypass module is coupled between the ends of the bidirectional power supply and includes a first current path and a second current path arranged in parallel, the first current path includes a first resistor unit and a battery coupled to the first resistor unit, and the second current path includes a second resistor unit, The bidirectional power supply provides a discharge demand command to the battery, The battery outputs a discharge current that is the sum of a first discharge current flowing through the first current path and a second discharge current flowing through the second current path in response to the discharge demand command. The impedance of the first resistor unit is gradually increased, and at the same time, the impedance of the second resistor unit is gradually decreased, thereby causing the current value of the first discharge current to gradually decrease from the first current value to zero, and at the same time, the current value of the second discharge current to gradually decrease from zero to the second current value. A discharge test method for a battery charge / discharge system, including the battery charge / discharge system.

10. The discharge test method according to claim 9, wherein both the first current value and the second current value are equal to the current value of the discharge current.

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