Oscillation suppression circuit, battery pack and energy storage device

Abstract

The present application provides an oscillation suppression circuit, a battery pack and an energy storage device. The oscillation suppression circuit includes: a switch circuit, a suppression circuit and a control circuit, wherein the switch circuit and the suppression circuit are connected in series at both ends of the battery body and are connected to the upper switch tube and the lower switch tube; the control circuit is connected to the switch circuit, and the control circuit is used to control the switch circuit to be turned on when the upper switch tube is disconnected or the lower switch tube is disconnected, so that the suppression circuit suppresses the oscillation voltage generated by the disconnection of the upper switch tube or the lower switch tube, thereby preventing damage to the upper switch tube and the lower switch tube, avoiding failure of the upper switch tube and the lower switch tube, and reducing the risk of short circuit of the positive and negative electrodes of the battery body.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and in particular to an oscillation suppression circuit, a battery pack and an energy storage device. Background Art

[0002] Energy storage equipment can be composed of multiple battery packs, battery management systems (BMS), controllers and other hardware. Among them, multiple battery packs in energy storage equipment are generally connected in series to form energy storage equipment to operate, thereby avoiding the current sharing problem caused by parallel connection.

[0003] The energy storage device in the related art realizes the switching of the battery pack into and out of the series system by controlling the on and off of the upper switch tube and the lower switch tube that constitute the half-bridge topology. Since the upper switch tube and the lower switch tube are only used as switches for switching the circuit on and off, it is impossible to achieve zero voltage switch (Zero Voltage Switch, ZVS) and zero current switch (Zero Current Switch, ZCS). When the upper switch tube and the lower switch tube are switched on and off, the parasitic capacitor and the parasitic inductor in the switch tube exchange energy with each other, causing LC resonance at both ends of the switch tube, and then causing the voltage at both ends of the switch tube to oscillate at high frequency. The amplitude of the oscillating voltage exceeds the stress of the switch tube, which can easily cause the switch tube to fail and pass directly, and there is a risk of short circuit at the positive and negative poles of the battery pack. Utility Model Content

[0004] In view of this, the present application provides an oscillation suppression circuit, a battery pack and an energy storage device, which can effectively suppress the oscillation voltage generated by the disconnection of the upper switch tube or the lower switch tube.

[0005] In a first aspect, the present application provides an oscillation suppression circuit for a battery pack, wherein at least two battery packs are connected in series to form a battery module of an energy storage device, the battery pack comprising a battery body, an upper switch tube and a lower switch tube, wherein a first end of the battery body is connected to a first end of the upper switch tube, a second end of the upper switch tube is connected to a first end of the lower switch tube, and a second end of the lower switch tube is connected to a second end of the battery body; when the upper switch tube is turned on and the lower switch tube is turned off, the battery body switches into the energy storage device; when the upper switch tube is turned off and the lower switch tube is turned on, the battery body switches out of the energy storage device; the oscillation suppression circuit comprises: a switch circuit, a suppression circuit and a control circuit, wherein the switch circuit and the suppression circuit are connected in series at two ends of the battery body and are connected to the upper switch tube and the lower switch tube; the control circuit is connected to the switch circuit, and the control circuit is used to control the switch circuit to switch on when the upper switch tube is turned off or the lower switch tube is turned off, so that the suppression circuit suppresses the oscillation voltage generated by the disconnection of the upper switch tube or the disconnection of the lower switch tube.

[0006] In one embodiment, the suppression circuit includes an anti-reverse diode, a first capacitor and a first resistor; wherein the anode of the anti-reverse diode is connected to the first end of the battery body and the first end of the upper switch tube, the cathode of the anti-reverse diode is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the second end of the battery body and the second end of the lower switch tube through the switching circuit, and the first capacitor is used to absorb the oscillation voltage when the switching circuit is turned on; the first resistor is connected in parallel with the first capacitor.

[0007] In one embodiment, the suppression circuit also includes a second capacitor, a first end of the second capacitor is connected to the first end of the battery body and the first end of the upper switch tube, a second end of the second capacitor is connected to the second end of the battery body and the second end of the lower switch tube through the switch circuit, and the second capacitor is used to absorb the oscillation voltage when the switch circuit is turned on.

[0008] In one embodiment, the suppression circuit further includes a second resistor connected between the second end of the first capacitor and the switch circuit.

[0009] In one embodiment, the switching circuit includes a first switching tube, a first end of the first switching tube is connected to the second end of the first capacitor, a second end of the first switching tube is connected to the second end of the battery body and the second end of the lower switching tube, and a controlled end of the first switching tube is connected to a control circuit, and the control circuit is used to control the first switching tube to be turned on when the upper switching tube is disconnected or the lower switching tube is disconnected.

[0010] In one embodiment, the switching circuit includes a first switching tube and a second switching tube, wherein the first end of the first switching tube is connected to the second resistor, the second end of the first switching tube is connected to the second end of the battery body and the second end of the lower switching tube, and the controlled end of the first switching tube is connected to the control circuit; the first end of the second switching tube is connected to the second end of the second capacitor, the second end of the second switching tube is connected to the second end of the battery body and the second end of the lower switching tube, and the controlled end of the second switching tube is connected to the control circuit; the control circuit is used to control the first switching tube and / or the second switching tube to be turned on when the upper switching tube or the lower switching tube is disconnected.

[0011] In one embodiment, the control circuit is used to: when the upper switch tube is turned on and the lower switch tube is turned off, control the first switch tube to be turned on, and after a first preset time, control the first switch tube to be turned off and control the second switch tube to be turned on; when the upper switch tube is turned off and the lower switch tube is turned on, control the second switch tube to remain in the on state, and after a second preset time, control the second switch tube to be turned off.

[0012] In one embodiment, the control circuit is used to: when the upper switch tube is turned on and the lower switch tube is turned off, control the first switch tube to be turned on, after a first preset time period, control the first switch tube to be turned off and control the second switch tube to be turned on, after a second preset time period, control the second switch tube to be turned off; when the upper switch tube is turned off and the lower switch tube is turned on, control the first switch tube to be turned on, after the first preset time period, control the first switch tube to be turned off and control the second switch tube to be turned on, after the second preset time period, control the second switch tube to be turned off.

[0013] The second aspect of the present application provides a battery pack. The battery pack includes a battery body, an upper switch tube, a lower switch tube, and the oscillation suppression circuit as described above, at least two battery packs are connected in series to form a battery module of an energy storage device, the first end of the battery body is connected to the first end of the upper switch tube, the second end of the upper switch tube is connected to the first end of the lower switch tube, and the second end of the lower switch tube is connected to the second end of the battery body; when the upper switch tube is turned on and the lower switch tube is turned off, the battery body is cut into the energy storage device; when the upper switch tube is turned off and the lower switch tube is turned on, the battery body is cut out of the energy storage device.

[0014] The third aspect of the present application provides an energy storage device, which includes a power conversion device and at least two battery packs connected in series, the battery packs being as described in the second aspect above, wherein both ends of the battery packs connected in series are connected to the power conversion device.

[0015] Compared with the prior art, this application has at least the following advantages:

[0016] In the present application, the switch circuit and the suppression circuit of the oscillation suppression circuit are connected in series at both ends of the battery body. When the upper switch tube is disconnected or the lower switch tube is disconnected, that is, when the battery body is cut out of or cut into the energy storage device, the control circuit controls the switch circuit to be turned on, so that the suppression circuit is connected to the battery pack. The suppression circuit suppresses the oscillation voltage, thereby preventing damage to the upper switch tube and the lower switch tube, avoiding failure of the upper switch tube and the lower switch tube and directly connecting, and reducing the risk of short circuit of the positive and negative poles of the battery body. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic block diagram of an energy storage device.

[0018] Figure 2 It is a schematic diagram of the circuit structure of the energy storage device provided in the embodiment of the present application.

[0019] Figure 3 It is a connection diagram of the oscillation suppression circuit provided in the embodiment of the present application and the battery body, the upper switch tube and the lower switch tube.

[0020] Figure 4 It is a schematic diagram of the circuit structure of the battery pack provided in an embodiment of the present application.

[0021] Figure 5 It is a schematic diagram of the circuit structure of a battery pack provided in another embodiment of the present application.

[0022] Figure 6 It is a voltage waveform diagram at both ends of the upper switch tube and the lower switch tube when the battery pack of the embodiment of the present application is switched into the energy storage device.

[0023] Figure 7 It is a voltage waveform diagram at both ends of the upper switch tube and at both ends of the lower switch tube when the battery pack of the embodiment of the present application is cut out of the energy storage device.

[0024] Figure 8 It is a schematic diagram of an energy storage device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application. In the absence of conflict, the following different embodiments and features in the embodiments can be combined with each other.

[0026] It should be noted that when a device is referred to as being “connected to” another device, it may be directly connected to the other device or may be indirectly connected (with an intervening device).

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0028] Energy storage devices can be composed of multiple battery packs, battery management units, controllers and other hardware. Among them, multiple battery packs in energy storage devices are generally connected in series to form energy storage devices to operate, thereby avoiding the current sharing problem caused by parallel connection.

[0029] See also Figure 1 , Figure 1 The schematic block diagram of the energy storage device 100 provided in the embodiment of the present application is shown. The energy storage device 100 includes at least two battery packs 110 connected in series, and the two ends of each battery pack 110 connected in series are used to connect to the load 200, so as to serve as the battery module of the energy storage device 100 to power the load 200.

[0030] The battery pack 110 includes a battery body 111, an upper switch tube S11, and a lower switch tube S12. The first end of the battery body 111 is connected to the first end of the upper switch tube S11, the second end of the upper switch tube S11 is connected to the first end of the lower switch tube S12, and the second end of the lower switch tube S12 is connected to the second end of the battery body 111. The first end of the battery body 111 may be the positive electrode of the battery body 111, and the second end of the battery body 111 may be the negative electrode of the battery body 111, or vice versa.

[0031] When the upper switch tube S11 is turned on and the lower switch tube S12 is turned off, the battery body 111 switches into the energy storage device 100. When the upper switch tube S11 is turned off and the lower switch tube S12 is turned on, the battery body 111 switches out of the energy storage device 100. It can be understood that the on and off of the upper switch tube S11 and the lower switch tube S12 can be controlled by the battery management system of the battery pack 110. Among them, the upper switch tube S11 and the lower switch are MOS tubes.

[0032] See also Figure 2 , Figure 2 FIG. 1 shows a schematic diagram of the circuit structure of an energy storage device 100 formed by two battery packs 110 connected in series in an embodiment of the present application. Figure 2 As shown, there is a parasitic resistor R on the power wire connected to the battery body 111. BUS and parasitic inductor L BUS There is also a parasitic resistor R on the wires connecting the two battery packs 110 in series. c and parasitic inductor L c There is a parasitic resistor R between the pins of the upper switch tube S11 and the lower switch tube S12 and the PCB circuit board traces. p and parasitic inductor L p , and the upper switch tube S11 and the lower switch tube S12 have parasitic capacitors C gd , C gs and C ds In actual application, the wires or copper bars connecting the battery pack 110 in series and the PCB circuit board routing in the battery pack 110 will increase the parasitic inductance and parasitic capacitor of the series loop of the battery pack 110 .

[0033] In some embodiments, in order to improve working efficiency and reliability, a plurality of upper switch tubes S11 connected in parallel and a plurality of lower switch tubes S12 connected in parallel are provided in the battery pack 110. At this time, the parasitic parameters in the entire circuit are relatively large. At the moment when the upper switch tube S11 is disconnected (correspondingly, the lower switch tube S12 is turned on, and the battery pack 110 is cut out of the energy storage device 100) or the lower switch tube S12 is disconnected (correspondingly, the upper switch tube S11 is turned on, and the battery pack 110 is cut into the energy storage device 100), the circuit of the battery pack 110 is in a transient process (the circuit changes from one stable state to another). The voltage and current in the battery pack 110 circuit suddenly change, but the parasitic inductor suppresses the current sudden change, and the parasitic capacitor suppresses the voltage sudden change. The parasitic inductor and the parasitic capacitor exchange energy with each other, and LC resonance will occur at both ends of the upper switch tube S11 or the lower switch tube S12, causing the voltage at both ends of the switch tube to oscillate at high frequency. The amplitude of the oscillating voltage may exceed the maximum on-state voltage of the upper switch tube S11 and the lower switch tube S12 (when the upper switch tube S11 and the lower switch tube S12 are MOS tubes, the maximum on-state voltage is the maximum V ds Voltage), which will damage the upper switch tube S11 and the lower switch tube S12, and easily cause the upper switch tube S11 and the lower switch tube S12 to fail and directly connect, and there is a risk of short circuit between the positive and negative electrodes of the battery body 111.

[0034] Therefore, the embodiment of the present application proposes an oscillation suppression circuit 112 for a battery pack, which can effectively suppress the oscillation voltage generated by the disconnection of the upper switch tube S11 or the lower switch tube S12, thereby preventing damage to the upper switch tube S11 and the lower switch tube S12, avoiding failure of the upper switch tube S11 and the lower switch tube S12 and directly connecting, thereby reducing the risk of short circuit between the positive and negative electrodes of the battery body 111.

[0035] See also Figure 3 , which is a schematic diagram of a connection between the oscillation suppression circuit 112 of an embodiment of the present application and the battery body 111, the upper switch tube S11 and the lower switch tube S12, that is, a schematic block diagram of the battery pack 110 provided in an embodiment of the present application.

[0036] like Figure 3 As shown, the oscillation suppression circuit 112 includes a switch circuit 1120, a suppression circuit 1121 and a control circuit 1122. The switch circuit 1120 and the suppression circuit 1121 are connected in series at both ends of the battery body 111, and are connected to the upper switch tube S11 and the lower switch tube S12. The control circuit 1122 is connected to the switch circuit 1120, and the control circuit 1122 is used to control the switch circuit 1120 to be turned on when the upper switch tube S11 is disconnected or the lower switch tube S12 is disconnected, so that the suppression circuit 1121 suppresses the oscillation voltage generated by the disconnection of the upper switch tube S11 or the disconnection of the lower switch tube S12.

[0037] In the embodiment of the present application, when the upper switch tube S11 is disconnected or the lower switch tube S12 is disconnected, that is, when the battery body 111 is cut out of or cut into the energy storage device 100, the control circuit 1122 controls the switch circuit 1120 to be turned on, so that the suppression circuit 1121 is connected to the battery pack 110. The suppression circuit 1121 suppresses the oscillation voltage, thereby preventing damage to the upper switch tube S11 and the lower switch tube S12, avoiding failure of the upper switch tube S11 and the lower switch tube S12, and reducing the risk of short circuit of the positive and negative electrodes of the battery body 111.

[0038] Among them, the control circuit 1122 may include, for example, a microcontroller unit (MCU), a battery management system (BMS), and other control devices. When the control circuit 1122 includes a microcontroller unit that is independent of the battery management system of the battery pack 110, the microcontroller unit may be connected to the battery management system in communication to receive the status information of the upper switch tube S11 and the lower switch tube S12 in real time, and then be able to confirm whether the upper switch tube S11 and the lower switch tube S12 are disconnected, that is, whether the battery pack 110 is switched in or out of the energy storage device 100, and then control the switch circuit 1120 to be turned on accordingly. Of course, the control circuit 1122 may also include the battery management system of the battery pack 110, so that the battery management system controls the switch circuit 1120 to be turned on while controlling the upper switch tube S11 to be disconnected or the lower switch tube S12 to be disconnected.

[0039] It can be understood that when the upper switch tube S11 or the lower switch tube S12 is disconnected, the battery pack 110 circuit is in a transient process. After a period of time (milliseconds), the oscillating voltage in the circuit will gradually decrease and stabilize. The control circuit 1122 can control the switch circuit 1120 to be disconnected after the switch circuit 1120 is turned on for a period of time, and then control the switch circuit 1120 to be turned on again when the upper switch tube S11 or the lower switch tube S12 is turned off next time. Among them, the time for controlling the switch circuit 1120 to be turned on can be set according to specific circuit parameters (such as the duration of the oscillating voltage generated when the upper and lower switches are disconnected), and the embodiment of the present application does not limit this.

[0040] In some embodiments, a filter circuit can be connected in parallel at both ends of the upper switch tube S11 and at both ends of the lower switch tube S12, respectively. The filter circuit includes a filter resistor R0 and a filter capacitor C0 connected in series. The filter circuit can filter the oscillating voltage generated when the upper switch tube S11 and the lower switch tube S12 are turned on and off to a certain extent.

[0041] Please also read Figure 4, the suppression circuit 1121 of the embodiment of the present application may include an anti-reverse diode D1, a first capacitor C1 and a first resistor R1. Among them, the anode of the anti-reverse diode D1 is connected to the first end of the battery body 111 and the first end of the upper switch tube S11, the cathode of the anti-reverse diode D1 is connected to the first end of the first capacitor C1, and the second end of the first capacitor C1 is connected to the second end of the battery body 111 and the second end of the lower switch tube S12 through the switch circuit 1120. The first capacitor C1 is used to absorb the oscillation voltage when the switch circuit 1120 is turned on. The first resistor R1 is connected in parallel with the first capacitor C1.

[0042] Specifically, the first end of the battery body 111 is the positive electrode of the battery body 111, the second end of the battery body 111 is the negative electrode of the battery body 111, the upper switch tube S11 and the lower switch tube S12 are MOS tubes, the first ends of the upper switch tube S11 and the lower switch tube S12 are drain electrodes, and the second ends of the upper switch tube S11 and the lower switch tube S12 are source electrodes. That is, the anode of the anti-reverse diode D1 is connected to the positive electrode of the battery body 111 and the drain electrode of the upper switch tube S11, and the second end of the first capacitor C1 is connected to the negative electrode of the battery body 111 and the source electrode of the lower switch tube S12 through the switch circuit 1120.

[0043] In this embodiment, the anti-reverse diode D1, the first capacitor C1 and the first resistor R1 together constitute an RCD absorption circuit. When the switch circuit 1120 is turned on, the RCD absorption circuit composed of the anti-reverse diode D1, the first capacitor C1 and the first resistor R1 is connected to the battery pack 110, connected in parallel with the battery body 111, and connected in series between the drain of the upper switch tube S11 and the source of the lower switch tube S12. The oscillating voltage generated by the disconnection of the upper switch tube S11 or the lower switch tube S12 is absorbed by the first capacitor C1 through the anti-reverse diode D1, thereby achieving the suppression of the oscillating voltage. The anti-reverse diode D1 can prevent the first capacitor C1 from reversely charging the battery body 111 when the oscillating voltage absorbed by the first capacitor C1 is too large, causing the voltage across the two ends to be greater than the voltage of the battery body 111.

[0044] Since the oscillation frequency of the oscillating voltage generated by the disconnection of the upper switch tube S11 or the lower switch tube S12 can reach several hundred kHz, it is a high-frequency oscillation signal. In some specific examples, the anti-reverse diode D1 can be set to a Schottky diode. The Schottky diode has a short reverse recovery time and a high operating frequency, which can be more conducive to the suppression of the oscillating voltage by the suppression circuit 1121.

[0045] The first capacitor C1 can be set as an electrolytic capacitor. The electrolytic capacitor has a large capacitance and a low price, and can effectively absorb the oscillation voltage and reduce the cost of the suppression circuit 1121. The different capacitance values ​​of the electrolytic capacitor will affect the amplitude of the oscillation voltage. The larger the capacitance value of the electrolytic capacitor, the better the absorption capacity of the oscillation voltage, and thus the smaller the amplitude of the oscillation voltage. Therefore, the first capacitor C1 with a suitable capacitance can be set according to the size of the oscillation voltage generated by the switching of the upper switch tube S11 and the lower switch tube S12 in the battery pack 110. For example, it can be set to 600uF, 1200uF, 2700uF, etc.

[0046] The first resistor R1 can provide a discharge circuit for the first capacitor C1 when the switch circuit 1120 is disconnected, and release the voltage absorbed by the first capacitor C1, so that the first capacitor C1 can still maintain a good voltage absorption capability when the upper switch tube S11 or the lower switch tube S12 is disconnected next time. The resistance value of the first resistor R1 can be set according to actual needs, for example, it can be set to 5KΩ, 10KΩ, 15KΩ, etc.

[0047] In some embodiments, the suppression circuit 1121 may also include a second capacitor C2, wherein a first end of the second capacitor C2 is connected to a first end of the battery body 111 and a first end of the upper switch tube S11, and a second end of the second capacitor C2 is connected to a second end of the battery body 111 and a second end of the lower switch tube S12 through the switch circuit 1120, and the second capacitor C2 is used to absorb the oscillation voltage when the switch circuit 1120 is turned on.

[0048] Specifically, a first end of the second capacitor C2 is connected to the positive electrode of the battery body 111 and the drain of the upper switch tube S11 , and a second end of the second capacitor C2 is connected to the negative electrode of the battery body 111 and the source of the lower switch tube S12 through the switch circuit 1120 .

[0049] By adding the second capacitor C2, when the upper switch tube S11 or the lower switch tube S12 is turned off, the first capacitor C1 and the second capacitor C2 absorb the oscillation voltage together, which can further enhance the suppression effect of the suppression circuit 1121 on the oscillation voltage.

[0050] In some specific examples, the second capacitor C2 can be set as a ceramic capacitor. The capacitance of the second capacitor C2 is less than the capacitance of the first capacitor C1. The absorption effect of the oscillating voltage can also be changed by adjusting the capacitance of the second capacitor C2. Therefore, the second capacitor C2 with a suitable capacitance can be set according to the size of the oscillating voltage generated by the switching of the upper switch tube S11 and the lower switch tube S12 in the battery pack 110. For example, it can be set to 50uF, 10uF, 20uF, etc.

[0051] Further, the suppression circuit 1121 may also include a second resistor R2, which is connected between the second end of the second capacitor C2 and the switch circuit 1120. The second resistor R2 may be used to limit the instantaneous current generated when the first capacitor C1 and the second capacitor C2 absorb the oscillating voltage. The resistance value of the second resistor R2 may be set according to actual needs, for example, it may be set to 20Ω, 25Ω, 30Ω, etc.

[0052] The second resistor R2 and the second capacitor C2 together form an RC absorption circuit. When the switch circuit 1120 is turned on, the RC absorption circuit formed by the second resistor R2 and the second capacitor C2 and the RCD absorption circuit formed by the anti-reverse diode D1, the first capacitor C1 and the first resistor R1 jointly absorb the oscillation voltage generated by the disconnection of the upper switch tube S11 or the lower switch tube S12.

[0053] In some embodiments, Figure 4 As shown, the control circuit 1122 may further include a third resistor R3, which is connected in parallel to both ends of the anti-reverse diode D1. When the voltage across the first capacitor C1 is higher than the voltage of the battery body 111, resulting in an excessively high reverse voltage, the third resistor R3 may provide a discharge for the reverse current generated by the anti-reverse diode D1, thereby protecting the anti-reverse diode D1 and preventing damage to the anti-reverse diode D1. The resistance value of the third resistor R3 may be set according to actual needs, for example, it may be set to 50Ω, 100Ω, 150Ω, and the like.

[0054] Please refer again Figure 4 The switch circuit 1120 in the embodiment of the present application may include a first switch tube Q1. The first end of the first switch tube Q1 is connected to the second end of the first capacitor C1, the second end of the first switch tube Q1 is connected to the second end of the battery body 111 and the second end of the lower switch tube S12, and the controlled end of the first switch tube Q1 is connected to the control circuit 1122. The control circuit 1122 is used to control the first switch tube Q1 to be turned on when the upper switch tube S11 is disconnected or the lower switch tube S12 is disconnected.

[0055] Specifically, when the upper switch tube S11 is turned on and the lower switch tube S12 is turned off, that is, when the battery pack 110 is switched into the energy storage device 100, the control circuit 1122 controls the first switch tube Q1 to be turned on, and the first capacitor C1 and the second capacitor C2 absorb the oscillating voltage generated by the switching on of the battery pack 110. At this time, the oscillating voltage is mainly absorbed by the first capacitor C1, and the second capacitor C2 serves as an auxiliary absorption capacitor. Subsequently, the control circuit 1122 controls the first switch tube Q1 to remain in the on state, until the upper switch tube S11 is turned off and the lower switch tube S12 is turned on, that is, when the battery pack 110 is switched out of the energy storage device 100, the control circuit 1122 still controls the first switch tube Q1 to remain in the on state, and the first capacitor C1 and the second capacitor C2 continue to absorb the oscillating voltage generated by the switching out of the battery pack 110. At this time, since the first capacitor C1 has absorbed the oscillation voltage generated when the battery pack 110 is cut in when the battery pack 110 is cut out, the remaining capacity of the first capacitor C1 is small, and the oscillation voltage is mainly absorbed by the second capacitor C2, and the first capacitor C1 serves as an auxiliary absorption capacitor. After a certain period of time (for example, 150ms, 200ms, 300ms, etc.) after the battery pack 110 is cut out, the control circuit 1122 controls the first switch tube Q1 to disconnect, so as to cut the oscillation suppression circuit 112 out of the battery pack 110, and the voltage absorbed by the first capacitor C1 and the second capacitor C2 is discharged through the first resistor R1, so that the capacitance of the first capacitor C1 and the second capacitor C2 is restored. When the battery pack 110 is cut into the energy storage device 100 next time, the first switch tube Q1 is controlled to be turned on, so that the first capacitor C1 and the second capacitor C2 in the oscillation suppression circuit 112 can maintain a good absorption effect on the oscillation voltage.

[0056] In some other specific examples, the on-off control of the first switch tube Q1 by the control circuit 1122 may also be:

[0057] When the upper switch tube S11 is turned on and the lower switch tube S12 is turned off, that is, when the battery pack 110 is switched into the energy storage device 100, the control circuit 1122 controls the first switch tube Q1 to be turned on, and the first capacitor C1 and the second capacitor C2 absorb the oscillation voltage generated by the switching on of the battery pack 110. After a certain period of time after the switching on of the battery pack 110, the control circuit 1122 controls the first switch tube Q1 to be turned off to switch the oscillation suppression circuit 112 out of the battery pack 110. The voltage absorbed by the first capacitor C1 and the second capacitor C2 is discharged through the first resistor R1 to restore the capacitance of the first capacitor C1 and the second capacitor C2. When the battery pack 110 is switched out of the energy storage device 100, the first capacitor C1 and the second capacitor C2 in the oscillation suppression circuit 112 can maintain a good absorption effect on the oscillation voltage.

[0058] When the upper switch tube S11 is disconnected and the lower switch tube S12 is turned on, that is, when the battery pack 110 is cut out of the energy storage device 100, the control circuit 1122 controls the first switch tube Q1 to be turned on, and the first capacitor C1 and the second capacitor C2 absorb the oscillation voltage generated by the battery pack 110 being cut out. After a certain period of time has passed since the battery pack 110 was cut out, the control circuit 1122 controls the first switch tube Q1 to be disconnected to cut the oscillation suppression circuit 112 out of the battery pack 110. The voltage absorbed by the first capacitor C1 and the second capacitor C2 is discharged through the first resistor R1 to restore the capacitance of the first capacitor C1 and the second capacitor C2. When the battery pack 110 is cut into the energy storage device 100 next time, the first capacitor C1 and the second capacitor C2 in the oscillation suppression circuit 112 can maintain a good absorption effect on the oscillation voltage.

[0059] It should be understood that the embodiments of the present application do not limit the specific structures of the switch circuit 1120, the suppression circuit 1121 and the control circuit 1122, as long as the switch circuit 1120, the suppression circuit 1121 and the control circuit 1122 can achieve the corresponding functions.

[0060] See also Figure 5 , Figure 5 Detailed circuit diagrams of the battery pack 110 in other embodiments are shown. Figure 5 and Figure 4 The main difference lies in the switching circuit 1120.

[0061] like Figure 5 As shown, the switch circuit 1120 may include a first switch tube Q1 and a second switch tube Q2. The first end of the first switch tube Q1 is connected to the second resistor R2, the second end of the first switch tube Q1 is connected to the second end of the battery body 111 and the second end of the lower switch tube S12, and the controlled end of the first switch tube Q1 is connected to the control circuit 1122.

[0062] The first end of the second switch tube Q2 is connected to the second end of the second capacitor C2 , the second end of the second switch tube Q2 is connected to the second end of the battery body 111 and the second end of the lower switch tube S12 , and the controlled end of the second switch tube Q2 is connected to the control circuit 1122 .

[0063] Specifically, the second end of the first switch tube Q1 and the second end of the second switch tube Q2 are connected to the negative electrode of the battery body 111 and the source electrode of the lower switch tube S12 .

[0064] The control circuit 1122 is used for controlling the first switch tube Q1 and / or the second switch tube Q2 to be turned on when the upper switch tube S11 is turned off or the lower switch tube S12 is turned off.

[0065] In this embodiment, the switch circuit 1120 implements the suppression circuit 1121 switching in or out of the battery pack 110 through the first switch tube Q1 and the second switch tube Q2. When one of the switch tubes is damaged, the other switch tube can continue to work, which can improve the reliability of the oscillation suppression circuit 112.

[0066] In some specific examples, when the upper switch tube S11 is turned on and the lower switch tube S12 is turned off, the control circuit 1122 controls the first switch tube Q1 to be turned on. After a first preset time, the control circuit 1122 controls the first switch tube Q1 to be turned off and controls the second switch tube Q2 to be turned on.

[0067] When the upper switch tube S11 is turned off and the lower switch tube S12 is turned on, the control circuit 1122 controls the second switch tube Q2 to remain turned on. After a second preset time period, the control circuit 1122 controls the second switch tube Q2 to turn off.

[0068] Specifically, when the upper switch tube S11 is turned on and the lower switch tube S12 is turned off, that is, when the battery pack 110 is cut into the energy storage device 100, the control circuit 1122 controls the first switch tube Q1 to be turned on, and the first capacitor C1 plays a major role in absorbing the oscillating voltage generated by the battery pack 110 being cut in, and the second capacitor C2 assists in absorbing the oscillating voltage. After a first preset time (set according to the duration of the oscillating voltage generated when the upper switch tube S11 is turned on and the lower switch tube S12 is turned off, for example, it can be set to 150ms, 200ms, 300ms, etc.), the voltage in the battery pack 110 circuit tends to be stable, and the control circuit 1122 controls the first switch tube Q1 to be turned off and the second switch tube Q2 to be turned on, so that the second resistor R2 is cut out of the battery pack 110, thereby reducing the resistance value in the suppression circuit, which can reduce the loss of the battery pack 110, that is, reduce the loss of the energy storage device 100.

[0069] Then, the control circuit 1122 controls the second switch tube Q2 to remain in the on state, and when the upper switch tube S11 is turned off and the lower switch tube S12 is turned on, that is, when the battery pack 110 is cut out of the energy storage device 100, the control circuit 1122 still controls the first switch tube Q1 to remain in the on state, and the first capacitor C1 and the second capacitor C2 continue to absorb the oscillation voltage generated by the battery pack 110 being cut out. At this time, since the first capacitor C1 has absorbed the oscillation voltage generated when the battery pack 110 is cut in when the battery pack 110 is cut out, the remaining capacity of the first capacitor C1 is small, and the oscillation voltage is mainly absorbed by the second capacitor C2, and the first capacitor C1 assists in absorbing the oscillation voltage. After the battery pack 110 is cut out and a second preset time has passed, the control circuit 1122 controls the second switch tube Q2 to disconnect, so as to cut the oscillation suppression circuit 112 out of the battery pack 110, and the voltage absorbed by the first capacitor C1 and the second capacitor C2 is discharged through the first resistor R1, so that the first capacitor C1 and the second capacitor C2 in the oscillation suppression circuit 112 can maintain a good absorption effect on the oscillation voltage.

[0070] In this way, the control circuit 1122 controls the first switch tube Q1 and the second switch tube Q2 to be turned off according to the on-off timing of the upper switch tube S11 and the lower switch tube S12, which can have a better absorption effect on the oscillating voltage.

[0071] The second preset time length may be the same as or different from the first preset time length, and may be set according to the duration of the oscillating voltage generated when the upper switch tube S11 and the lower switch tube S12 are turned off.

[0072] In some other specific examples, when the upper switch tube S11 is turned on and the lower switch tube S12 is turned off, the control circuit 1122 controls the first switch tube Q1 to be turned on. After a first preset time, the control circuit 1122 controls the first switch tube Q1 to be turned off and controls the second switch tube Q2 to be turned on. After a second preset time, the control circuit 1122 controls the second switch tube Q2 to be turned off.

[0073] When the upper switch tube S11 is turned off and the lower switch tube S12 is turned on, the control circuit 1122 controls the first switch tube Q1 to be turned on. After the first preset time, the control circuit 1122 controls the first switch tube Q1 to be turned off and controls the second switch tube Q2 to be turned on. After the second preset time, the control circuit 1122 controls the second switch tube Q2 to be turned off.

[0074] Specifically, when the upper switch tube S11 is turned on and the lower switch tube S12 is turned off, that is, when the battery pack 110 is switched into the energy storage device 100, the control circuit 1122 controls the first switch tube Q1 to be turned on, and the first capacitor C1 plays a major role in absorbing the oscillating voltage generated by the switching on of the battery pack 110, and the second capacitor C2 assists in absorbing the oscillating voltage. After the first preset time, the control circuit 1122 controls the first switch tube Q1 to be turned off and controls the second switch tube Q2 to be turned on, and the first capacitor C1 and the second capacitor C2 continue to absorb the oscillating voltage. At this time, the second resistor R2 is switched out of the battery pack 110, which can reduce the resistance value in the suppression circuit, thereby reducing the loss of the battery pack 110, that is, reducing the loss of the energy storage device 100. After the second switch tube Q2 is turned on for the second preset time, the control circuit 1122 controls the second switch tube Q2 to be turned off to cut the oscillation suppression circuit 112 out of the battery pack 110, and the voltage absorbed by the first capacitor C1 and the second capacitor C2 is discharged through the first resistor R1 to restore the capacitance of the first capacitor C1 and the second capacitor C2. When the battery pack 110 is cut out of the energy storage device 100, the first capacitor C1 and the second capacitor C2 in the oscillation suppression circuit 112 can maintain a good absorption effect on the oscillation voltage.

[0075] When the upper switch tube S11 is disconnected and the lower switch tube S12 is turned on, that is, when the battery pack 110 is switched out of the energy storage device 100, the on-off control of the first switch tube Q1 and the second switch tube Q2 by the control circuit 1122 is the same as when the battery pack 110 is switched into the energy storage device 100, that is, the first switch tube Q1 is first controlled to be turned on for a first preset time, and then the first switch tube Q1 is controlled to be disconnected and the second switch tube Q2 is controlled to be turned on for a second preset time, and then the second switch tube Q2 is controlled to be disconnected. For details, see the description of when the battery pack 110 is switched into the energy storage device 100, which will not be repeated here.

[0076] It can be understood that, in this example, the sum of the first preset time length and the second preset time length can be set according to the duration of the oscillating voltage generated by the switching on and off of the upper switch tube S11 and the lower switch tube S12, wherein the sum of the first preset time length and the second preset time length can be greater than the duration.

[0077] Please also read Figures 3 to 5 , an embodiment of the present application also provides a battery pack 110.

[0078] like Figures 3 to 5As shown, the battery pack 110 includes a battery body 111, an upper switch tube S11, a lower switch tube S12, and an oscillation suppression circuit 112 as described above. At least two battery packs 110 are connected in series to form a battery module of the energy storage device 100. The first end of the battery body 111 is connected to the first end of the upper switch tube S11, the second end of the upper switch tube S11 is connected to the first end of the lower switch tube S12, and the second end of the lower switch tube S12 is connected to the second end of the battery body 111. When the upper switch tube S11 is turned on and the lower switch tube S12 is turned off, the battery body 111 is cut into the energy storage device 100. When the upper switch tube S11 is turned off and the lower switch tube S12 is turned on, the battery body 111 is cut out of the energy storage device 100.

[0079] The oscillation suppression circuit 112 can be referred to in the above Figures 3 to 5 The relevant description in the illustrated embodiment will not be repeated here.

[0080] See also Figure 6 and Figure 7 , Figure 6 The voltage waveform diagram across the upper switch tube S11 and across the lower switch tube S12 when the battery pack 110 according to the embodiment of the present application is switched into the energy storage device 100 is shown. Figure 7 The voltage waveforms at both ends of the upper switch tube S11 and the lower switch tube S12 are shown when the battery pack 110 of the embodiment of the present application is cut out of the energy storage device 100. Among them, waveform A is the voltage waveform at both ends of the upper switch tube S11, and waveform B is the voltage waveform at both ends of the lower switch tube S12.

[0081] according to Figure 6 and Figure 7 It can be seen that when the battery pack 110 provided with the oscillation suppression circuit 112 in the embodiment of the present application switches in and out of the energy storage device 100, the oscillation amplitude and oscillation frequency of the voltage across the upper switch tube S11 and the lower switch tube S12 are very small, thereby preventing damage to the upper switch tube S11 and the lower switch tube S12, avoiding failure of the upper switch tube S11 and the lower switch tube S12 and reducing the risk of short circuit of the positive and negative electrodes of the battery body 111.

[0082] Please also read Figure 8 The present application also provides an energy storage device 100, including a power conversion device 120 and at least two battery packs 110 connected in series, the battery pack 110 is as described above (such as Figures 3 to 5 ), wherein both ends of each battery pack 110 connected in series are connected to a power conversion device 120.

[0083] The power conversion device 120 is used as a load device of the energy storage device 100. The power conversion device 120 is used to convert the electric energy output by the energy storage device 100 and provide it to the external load to supply power to the external load. Figures 2 to 5 The relevant description will not be repeated here.

[0084] Since the oscillation suppression circuit 112 in the battery pack 110 can effectively suppress the oscillation voltage generated by the disconnection of the upper switch tube S11 or the lower switch tube S12, it can avoid the upper switch tube S11 and the lower switch tube S12 from failing directly, thereby reducing the short circuit risk of the positive and negative electrodes of the battery body 111, and can improve the reliability and safety of the energy storage device 100 when the battery pack 110 is switched in and out.

[0085] It can be understood that in some embodiments, both ends of the battery packs 110 connected in series can also be directly connected to an external load to supply power to the external load.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person of ordinary skill in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. An oscillation suppression circuit of a battery pack, at least two of the battery packs are connected in series to form a battery module of an energy storage device, the battery pack comprises a battery body, an upper switch tube and a lower switch tube, the first end of the battery body is connected to the first end of the upper switch tube, the second end of the upper switch tube is connected to the first end of the lower switch tube, and the second end of the lower switch tube is connected to the second end of the battery body; when the upper switch tube is turned on and the lower switch tube is turned off, the battery body is cut into the energy storage device; when the upper switch tube is turned off and the lower switch tube is turned on, the battery body is cut out of the energy storage device; It is characterized in that The oscillation suppression circuit comprises: a switch circuit, a suppression circuit and a control circuit, wherein: The switch circuit and the suppression circuit are connected in series at two ends of the battery body, and are connected to the upper switch tube and the lower switch tube; The control circuit is connected to the switch circuit, and is used to control the switch circuit to be turned on when the upper switch tube is disconnected or the lower switch tube is disconnected, so that the suppression circuit suppresses the oscillation voltage generated by the disconnection of the upper switch tube or the lower switch tube.

2. The oscillation suppression circuit according to claim 1, characterized in that: The suppression circuit includes an anti-reverse diode, a first capacitor and a first resistor; wherein, the anode of the anti-reverse diode is connected to the first end of the battery body and the first end of the upper switch tube, the cathode of the anti-reverse diode is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the second end of the battery body and the second end of the lower switch tube through the switch circuit, and the first capacitor is used to absorb the oscillating voltage when the switch circuit is turned on; the first resistor is connected in parallel with the first capacitor.

3. The oscillation suppression circuit according to claim 2, characterized in that: The suppression circuit also includes a second capacitor, a first end of the second capacitor is connected to the first end of the battery body and the first end of the upper switch tube, a second end of the second capacitor is connected to the second end of the battery body and the second end of the lower switch tube through the switch circuit, and the second capacitor is used to absorb the oscillating voltage when the switch circuit is turned on.

4. The oscillation suppression circuit according to claim 3, characterized in that: The suppression circuit also includes a second resistor connected between the second end of the second capacitor and the switching circuit.

5. The oscillation suppression circuit according to any one of claims 2 to 4, characterized in that: The switching circuit includes a first switching tube, a first end of the first switching tube is connected to the second end of the first capacitor, a second end of the first switching tube is connected to the second end of the battery body and the second end of the lower switching tube, and a controlled end of the first switching tube is connected to the control circuit, and the control circuit is used to control the first switching tube to be turned on when the upper switching tube is disconnected or the lower switching tube is disconnected.

6. The oscillation suppression circuit according to claim 4, characterized in that: The switch circuit includes a first switch tube and a second switch tube, wherein: The first end of the first switch tube is connected to the second resistor, the second end of the first switch tube is connected to the second end of the battery body and the second end of the lower switch tube, and the controlled end of the first switch tube is connected to the control circuit; The first end of the second switch tube is connected to the second end of the second capacitor, the second end of the second switch tube is connected to the second end of the battery body and the second end of the lower switch tube, and the controlled end of the second switch tube is connected to the control circuit; The control circuit is used for controlling the first switch tube and / or the second switch tube to be turned on when the upper switch tube is turned off or the lower switch tube is turned off.

7. The oscillation suppression circuit according to claim 6, characterized in that: The control circuit is used for: When the upper switch tube is turned on and the lower switch tube is turned off, the first switch tube is controlled to be turned on, and after a first preset time period, the first switch tube is controlled to be turned off and the second switch tube is controlled to be turned on; When the upper switch tube is turned off and the lower switch tube is turned on, the second switch tube is controlled to remain in the on state, and after a second preset time period, the second switch tube is controlled to be turned off.

8. The oscillation suppression circuit according to claim 6, characterized in that: The control circuit is used for: When the upper switch tube is turned on and the lower switch tube is turned off, the first switch tube is controlled to be turned on, and after a first preset time, the first switch tube is controlled to be turned off and the second switch tube is controlled to be turned on, and after a second preset time, the second switch tube is controlled to be turned off; When the upper switch tube is turned off and the lower switch tube is turned on, the first switch tube is controlled to be turned on. After the first preset time period, the first switch tube is controlled to be turned off and the second switch tube is controlled to be turned on. After the second preset time period, the second switch tube is controlled to be turned off.

9. A battery pack, characterized in that: The battery pack includes a battery body, an upper switch tube, a lower switch tube and an oscillation suppression circuit as described in any one of claims 1 to 8, at least two of the battery packs are connected in series to form a battery module of an energy storage device, the first end of the battery body is connected to the first end of the upper switch tube, the second end of the upper switch tube is connected to the first end of the lower switch tube, and the second end of the lower switch tube is connected to the second end of the battery body; when the upper switch tube is turned on and the lower switch tube is turned off, the battery body is cut into the energy storage device; when the upper switch tube is turned off and the lower switch tube is turned on, the battery body is cut out of the energy storage device.

10. An energy storage device, characterized in that: It comprises a power conversion device and at least two battery packs connected in series, the battery pack being as described in claim 9, wherein both ends of each battery pack connected in series are connected to the power conversion device.

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