A power supply failure detection circuit for an energy storage battery

Abstract

The application discloses a power supply fault detection circuit of an energy storage battery. The power supply fault detection circuit comprises a direct-current power supply, a first resistor, a second resistor, a third resistor and a control device; the direct-current power supply is used for providing a detection power supply; the first resistor and the second resistor are connected in series between the direct-current power supply and a ground end, a connection point of the first resistor and the second resistor is connected with one end of the third resistor, and the other end of the third resistor is used for connecting a power supply end; the control device is provided with a detection end and a first control end, the detection end is connected with the connection point of the first resistor and the second resistor, and the first control end is used for connecting a switching device to control the on-off state of the switching device; and the control device is used for generating a first switching control signal according to the relative relationship between a detection voltage inputted by the detection end and a preset range, so as to control the on-off state of the switching device. In the case of connecting a load, the detection circuit provided by the application will not fail, and the reliability of the energy storage battery fault detection can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, in particular to a power supply fault detection circuit of an energy storage battery. BACKGROUND

[0002] With the development of energy storage technology, the application scenarios of energy storage batteries are more and more, and the energy storage safety is more and more important.

[0003] The existing energy storage battery adopts a fault detection circuit as shown in the figure, which can accurately identify the short circuit fault of the energy storage battery in the case that the power supply end is not connected with a load, and then control the switch device to be disconnected, so as to prevent the safety accidents caused by overcurrent fault. Figure 1

[0004] However, the connection of the power supply end of the energy storage battery with a load will cause the existing fault detection circuit to be invalid, and the fault detection reliability is low. SUMMARY

[0005] The present application provides a power supply fault detection circuit of an energy storage battery, which can detect the fault of the energy storage battery, and the detection circuit will not be invalid in the case of connecting with a load, thereby improving the reliability of the fault detection of the energy storage battery.

[0006] In a first aspect, an embodiment of the present application provides a power supply fault detection circuit of an energy storage battery. The energy storage battery comprises a battery module, a switch device and a power supply end, the battery module is connected with the power supply end through the switch device, and the power supply end is used for connecting with a load;

[0007] The power supply fault detection circuit comprises a direct current power supply, a first resistor, a second resistor, a third resistor and a control device.

[0008] The direct current power supply is used for providing a detection power supply.

[0009] The first resistor and the second resistor are connected in series between the direct current power supply and a ground end, one end of the third resistor is connected with the connection point of the first resistor and the second resistor, and the other end of the third resistor is used for connecting the power supply end.

[0010] The control device is provided with a detection end and a first control end, the detection end is connected with the connection point of the first resistor and the second resistor, the first control end is used for connecting the switch device to control the on-off state of the switch device, and the control device is used for generating a first switch control signal according to the relative relationship between the detection voltage input by the detection end and a preset range, so as to control the on-off state of the switch device.

[0011] ​Optionally, the power supply fault detection circuit of the energy storage battery further comprises a switch unit connected between the second resistor and the ground terminal.

[0012] The control device further comprises a second control terminal connected to the switch unit, and the control device is further configured to generate a second switch control signal according to the on-off state of the switch device to control the on-off state of the switch unit, wherein the on-off state of the switch device is consistent with the on-off state of the switch unit.

[0013] Optionally, the switch unit comprises a transistor.

[0014] Optionally, the control device is configured to determine that the energy storage battery has not occurred overcurrent fault when the detection voltage is within a first preset range, and output the first switch control signal comprising the on information to keep the switch device on.

[0015] Optionally, the first preset range comprises a first preset value.

[0016] The control device is further configured to determine that the energy storage battery has not been connected to a load when the detection voltage is equal to the first preset value, wherein the first preset value is equal to V dd *R2 / (R1+R2), V dd R1 is a first resistor, and R2 is a second resistor.

[0017] Optionally, the first preset range further comprises a second preset range.

[0018] The control device is further configured to determine that the energy storage battery has been connected to a load when the detection voltage is within the second preset range.

[0019] Optionally, the control device is further configured to determine the resistance of the load according to the detection voltage, the supply voltage of the battery module, the first resistor, the second resistor and a third resistor when it is determined that the energy storage battery has been connected to the load.

[0020] Optionally, the control device is configured to determine that the energy storage battery has occurred short circuit fault when the detection voltage is within a third preset range, and output the first switch control signal comprising the off information to control the switch device to be off.

[0021] In a second aspect, the embodiments of the present application further provide a battery management system, which comprises the power supply fault detection circuit of any of the first aspect.

[0022] In a third aspect, the embodiment of the present application further provides a storage battery, which comprises the battery management system, the battery module, the switching device and the power supply end as described in the second aspect, and the battery management system is connected with the battery module, the switching device and the power supply end respectively.

[0023] The storage battery, the battery management system and the power failure detection circuit provided by the present application are provided with a direct current power supply, a first resistor, a second resistor, a third resistor and a control device, the first resistor and the second resistor are connected in series between the direct current power supply and a ground end, a connection point of the first resistor and the second resistor is connected with the power supply end through the third resistor, and the connection point of the first resistor and the second resistor is also connected with a detection end of the control device, a first control end of the control device is connected with the switching device, the switching device can be controlled to be turned on or turned off according to the relative relationship between the voltage inputted by the detection end and a preset range, the detection of the power failure of the storage battery is realized, the circuit structure is simple and will not fail in the case that the load is connected, and the reliability of the failure detection of the storage battery is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a schematic diagram of the composition of the prior art storage battery and the failure detection circuit;

[0025] Figure 2 It is a structural schematic diagram of the storage battery and the power failure detection circuit provided by the embodiment of the present application;

[0026] Figure 3 It is another structural schematic diagram of the storage battery and the power failure detection circuit provided by the embodiment of the present application;

[0027] Figure 4 It is still another structural schematic diagram of the storage battery and the power failure detection circuit provided by the embodiment of the present application;

[0028] Figure 5 It is a schematic diagram of the composition of the battery management system provided by the embodiment of the present application;

[0029] Figure 6 It is a structural schematic diagram of the storage battery provided by the embodiment of the present application. DETAILED DESCRIPTION

[0030] The present application will be further described in detail below in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all the structures.

[0031] As described in the background, referring to Figure 1 , in Figure 1In the prior art fault detection circuit, the base of the transistor is connected with the power supply end of the energy storage battery. In the case of short circuit fault of the energy storage battery, the base voltage of the transistor is pulled up, and the transistor is turned on. The MCU (also known as microcontroller) can detect the collector voltage of the transistor, and judge whether the short circuit fault occurs according to the collector voltage. However, the inventor has found through research that this fault detection circuit can only be applied to the case where the power supply end is not connected with a load. Once the power supply end is connected with a load, the transistor will be turned on, and at this time, the MCU continuously monitors that the collector voltage is equal to the ground voltage, so that it cannot truly detect whether the load is short-circuited, and the fault detection fails.

[0032] To solve the above problems, an energy storage battery power supply fault detection circuit is provided in the embodiments of the present application. Figure 2 The structure of the energy storage battery and the power supply fault detection circuit thereof provided in the embodiments of the present application is shown in Figure 2 The energy storage battery 100 includes a battery module 101, a switching device 102 and a power supply end 103. The battery module 100 is connected with the power supply end 103 through the switching device 102, and the power supply end 103 is used for connecting an external load. The power supply fault detection circuit 104 includes a direct current power supply V dd , a first resistor R1, a second resistor R2, a third resistor R3 and a control device 105. The direct current power supply V dd is used for providing a detection power supply. The first resistor R1 and the second resistor R2 are connected in series between the direct current power supply V dd and a ground end GND, one end of the third resistor R3 is connected with the connection point of the first resistor R1 and the second resistor R2, and the other end of the third resistor R3 is used for connecting the power supply end 103. The control device 105 is provided with a detection end a and a first control end b. The detection end a is connected with the connection point of the first resistor R1 and the second resistor R2, and the first control end b is used for connecting the switching device 102 to control the on-off state of the switching device 102. The control device 105 is used for generating a first switch control signal according to the relative relationship between the detection voltage input through the detection end a and a preset range, and outputting the first switch control signal through the first control end b.

[0033] Specifically, the battery module 101 refers to the cell assembly in the energy storage battery 100. For example, the battery module 101 can include at least one cell connected in series. The switching device 102 refers to a switching assembly arranged between the battery module and the power supply end, which can control the on-off of the discharge circuit of the battery module. For example, the switching device 102 includes at least one of a transistor and a relay, and is arranged between the negative electrode 1- of the battery module 101 and the negative electrode 2- of the power supply end 103. The power supply end 103 refers to the external power supply port of the energy storage battery 100, which can be connected with a load and supply power to the load.

[0034] The direct current power supply Vdd A detection power supply is provided for the detection resistor and the control device 105 in the power supply fault detection circuit 104. A DC power supply V dd , whose original source is not shown in the figure, is exemplarily provided by the battery module 101 and a proper voltage reduction circuit. dd The voltage level of the detection power supply V dd is lower than that of the output power supply of the battery module 101. The voltage level of the detection power supply V dd may be 3.3V or 5V. The third resistor R3 has one end connected to the connection point of the first resistor R1 and the second resistor R2 and the other end connected to the power supply end 103. Exemplarily, the other end of the third resistor R3 is connected to the negative pole 2- of the power supply end 103. As the power supply end 103 is connected to the load and the state of the energy storage battery 100 changes, the voltage at the connection point of the first resistor R1 and the second resistor R2 also changes. The control device 105 can determine whether the energy storage battery 100 has a short circuit fault according to whether the detection voltage V adc at the detection end a is within a preset range, and further control the switching device 102 to be turned off in the case of a short circuit fault to prevent damage to the battery cell and the circuit caused by the short circuit. The preset range can be set according to the short circuit experimental data of the energy storage battery 100. Exemplarily, the preset range can include the voltage detection value at the connection point of the first resistor R1 and the second resistor R2 when the energy storage battery 100 has a short circuit.

[0035] Exemplarily, in the case of a short circuit fault, the resistance value of the load RL connected to the power supply end 103 is approximately equal to 0. At this time, the detection voltage V adc is equal to the short circuit voltage V 短 , V 短 = V dd *[(R2 / / R3) / (R1+R2 / / R3)]+V p *[(R1 / / R2) / (R1+R2 / / R3)], where R1 / / R2 is the parallel resistance of the first resistor and the second resistor, equal to 1 / (1 / R1+1 / R2), R2 / / R3 is the parallel resistance of the second resistor and the third resistor, equal to 1 / (1 / R1+1 / R2), and V p is the voltage of the power supply provided by the battery module. Therefore, the control device 105 can determine that the energy storage battery has a short circuit fault when the detection voltage V adc at the detection end a is equal to V 短 , and further output a first switching control signal including a closing signal from the first control end to control the switching device to be turned off, thereby cutting off the short circuit loop of the energy storage battery and preventing damage to the battery cell caused by the short circuit fault.

[0036] The power supply fault detection circuit of the energy storage battery provided in the embodiment is provided with a direct current power supply, a first resistor, a second resistor, a third resistor and a control device, the first resistor and the second resistor are connected in series between the direct current power supply and a ground terminal, the connection point of the first resistor and the second resistor is connected with the power supply terminal through the third resistor, the connection point of the first resistor and the second resistor is also connected with the detection terminal of the control device, the first control terminal of the control device is connected with the switching device, the on-off of the switching device can be controlled according to the relative relationship between the voltage inputted by the detection terminal and the preset range, the detection of the power supply fault of the energy storage battery is realized, the circuit structure is simple, and in the case that the load is connected, the high impedance of the load will not affect the judgment of the control device, the power supply fault judgment will not fail, and the reliability of the energy storage battery fault detection is improved.

[0037] Optionally, Figure 3 Another energy storage battery and its power supply fault detection circuit structure schematic diagram provided in the embodiment are provided, and on the basis of the foregoing embodiment, the power supply fault detection circuit 104 further comprises a switching unit Q connected between the second resistor R2 and the ground terminal GND. The control device 105 is further provided with a second control terminal c, the second control terminal c is further connected with the switching unit Q, and the control device 105 is further used for generating a second switching control signal according to the on-off state of the switching device 102 and outputting the second switching control signal through the second control terminal c, so as to control the on-off state of the switching unit Q.

[0038] Specifically, the switching unit Q refers to a switching component for controlling the start-stop of the detection function of the fault detection circuit 104, and can include a transistor. The second control terminal c of the control device 105 is connected with the switching unit Q. The control device 105 can adjust the voltage level of the second switching control signal outputted by the second control terminal c according to the on-off state of the switching device 102, so as to control the conduction and shutdown of the switching unit Q, wherein the first control terminal b and the second control terminal c can be interlocked. The control device 105 can also generate a first switching control signal according to the control signal inputted by the user, so as to control the on-off of the switching device 102. For example, before the user needs to disable the energy storage battery 100 for a long time, the user can input a control signal containing shutdown information to the control device 105 by clicking a button, and the control device 105 generates a first switching control signal according to the control signal to control the switching device 102 to be turned off, so as to suspend the power supply function of the energy storage battery 100.

[0039] For example, before the energy storage battery 100 is powered on or in the case of short-circuit shutdown, the switching device 102 is in the off state. At this time, the control device can output a second switching control signal containing shutdown information according to the off state of the switching device 102, so as to control the switching unit Q to be turned off, thereby reducing the power consumption of the power supply fault detection circuit 104.

[0040] The power supply fault detection circuit of the energy storage battery provided in the embodiment is provided with a switching unit, and the control device is provided with a second control end. The control device can control the on-off state of the switching unit according to the on-off state of the switching device, so as to realize the closing of the power supply fault detection function after the energy storage battery is powered off, and reduce the power consumption of the power supply fault detection circuit.

[0041] Optionally, Figure 4 Another energy storage battery and a structure schematic diagram of a power supply fault detection circuit thereof provided in the embodiment are provided on the basis of the foregoing embodiment, and the foregoing description is continued with reference to Figure 4 The switching unit Q can be an NPN triode. The control device 105 can adjust the voltage level of the second switching control signal outputted, so as to make the on-off state of the NPN triode consistent with the switching device 102.

[0042] Optionally, the foregoing embodiment is provided on the basis of, and the foregoing description is continued with reference to Figure 4 The control device 105 is configured to determine that the energy storage battery 100 does not occur overcurrent fault in a case where the detection voltage is in a first preset range, and output a first switching control signal including opening information, so as to keep the switching device 102 conducting.

[0043] Specifically, the first preset range can be determined according to the short circuit experiment of the energy storage battery 100. The voltage values in the first preset range can all be less than the short circuit voltage, which refers to the voltage value detected by the detection end in the case where the energy storage battery occurs short circuit. Exemplarily, if the short circuit voltage is 50V, the first preset range can be less than 20V. The control device 105 can determine that the energy storage battery 100 occurs overcurrent fault in a case where the detection voltage is in the first preset voltage, and further output a first switching control signal including opening information, so as to keep the switching device 102 conducting.

[0044] Exemplarily, the first preset range includes a first preset value and a second preset range, and the first preset value is equal to V dd V represents the voltage value of the detection power supply, R1 is a first resistor, and R2 is a second resistor. The control device 105 is further configured to determine that the energy storage battery 100 is not connected to a load in a case where the detection voltage is equal to the first preset value.

[0045] The second preset range is a preset range greater than the first preset value and less than the short circuit voltage. The control device 105 is further configured to determine that the energy storage battery 100 is connected to a load in a case where the detection voltage is in the second preset range. Further, in the case where the energy storage battery 100 is connected to a load and does not occur short circuit, the detection voltage can be represented by a first formula, which is wherein V p is the power supply voltage of the battery module, R Lis the resistance of the load. The control device is further configured to calculate the resistance R of the load by bringing the supply voltage V of the battery module, the first resistance R1, the second resistance R2 and the third resistance R3 into a first formula in a case where it is determined that the energy storage battery has been connected to the load adc , the supply voltage V of the battery module p , the first resistance R1, the second resistance R2 and the third resistance R3 into a first formula to calculate the resistance R of the load L , and to determine the size of the load of the energy storage battery 100.

[0046] The supply fault detection circuit of the energy storage battery provided in the embodiment can determine that the energy storage battery has a short circuit fault in a case where the detection voltage is within a first preset range, and the first preset range includes a first preset value and a second preset range. The control device can determine that the energy storage battery has not been connected to the load in a case where the detection voltage is equal to the first preset value, and can determine that the energy storage battery has been connected to the load in a case where the detection voltage is within the second preset range. The size of the load is calculated according to the specific value of the detection voltage, the load connected to the energy storage battery is analyzed and detected, and the user can adjust the size of the connected load according to the load condition, thereby further improving the power supply safety of the energy storage battery.

[0047] Optionally, on the basis of the foregoing embodiments, the supply fault detection circuit of the energy storage battery provided in the embodiment can further comprise a control device 105. Figure 4 The control device 105 is configured to determine that the energy storage battery 100 has a short circuit fault in a case where the detection voltage is within a third preset range, and to output a first switch control signal comprising a shutdown signal to control the switch device 102 to shut down.

[0048] Specifically, the third preset range is a short circuit voltage range for identifying a short circuit fault, which is determined according to a short circuit experiment of the energy storage battery. The third preset range can include that the detection voltage is equal to the short circuit voltage. For example, in the short circuit experiment, if the short circuit voltage of the connection point of the first resistance and the second resistance is equal to 50 V, the third preset range can be set to be greater than 48 V.

[0049] The supply fault detection circuit of the energy storage battery provided in the embodiment can determine that the energy storage battery has a short circuit fault in the third preset range, output a first switch control signal comprising a shutdown signal to control the switch device to shut down, prevent damage to the battery cell caused by the short circuit fault, and further improve the reliability of the energy storage battery.

[0050] The embodiment of the present application further provides a battery management system. Figure 5 The embodiment of the present application further provides a battery management system. Figure 5 The battery management system 500 comprises the supply fault detection circuit 104 in any embodiment of the present application. The battery management system 500 refers to a component for managing and controlling the energy storage battery according to the state parameters of the energy storage battery, also known as BMS.

[0051] The embodiment of the present application also provides a storage battery. Figure 6 A structural diagram of a storage battery provided by the embodiment of the present application is shown in Figure 6 The storage battery 100 comprises the battery management system 500, the battery module 101, the switching device 102 and the power supply end 103, and the battery management system 500 is connected with the battery module 101, the switching device 102 and the power supply end 103 respectively.

[0052] The storage battery, the battery management system and the power supply fault detection circuit provided by the embodiment are provided with a direct current power supply, a first resistor, a second resistor, a third resistor and a control device, the first resistor and the second resistor are connected in series between the direct current power supply and a ground end, a connection point of the first resistor and the second resistor is connected with the power supply end through the third resistor, the connection point of the first resistor and the second resistor is also connected with a detection end of the control device, a first control end of the control device is connected with the switching device, the switching device can be controlled to be on or off according to the relative relationship between the voltage inputted by the detection end and a preset range, the detection of the power supply fault of the storage battery is realized, the circuit structure is simple and will not fail in the case that the load is connected, and the reliability of the storage battery fault detection is improved.

[0053] It should be noted that the above only describes the preferred embodiments of the present application and the applied technical principles. Those skilled in the art should understand that the present application is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, re-adjustments, combinations and substitutions without departing from the protection scope of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments, and more other equivalent embodiments can be included without departing from the concept of the present application, and the scope of the present application is determined by the appended claims.

Claims

1. A power supply fault detection circuit for an energy storage battery, characterized in that, The energy storage battery includes a battery module, a switching device, and a power supply terminal. The battery module is connected to the power supply terminal via the switching device, and the power supply terminal is used to connect an external load. The power supply fault detection circuit includes: a DC power supply, a first resistor, a second resistor, a third resistor, and a control device; The DC power supply is used to provide power for detection. The first resistor and the second resistor are connected in series between the DC power supply and the ground terminal. The connection point of the first resistor and the second resistor is connected to one end of the third resistor, and the other end of the third resistor is used to connect to the power supply terminal. The control device is provided with a detection terminal and a first control terminal. The detection terminal is connected to the connection point of the first resistor and the second resistor. The first control terminal is used to connect the switching device to control the on / off state of the switching device. The control device is used to generate a first switch control signal according to the relative relationship between the detection voltage connected to the detection terminal and a preset range to control the on / off state of the switching device. The power supply fault detection circuit of the energy storage battery can still detect short circuits when a load is connected.

2. The power supply fault detection circuit for the energy storage battery according to claim 1, characterized in that, Also includes: A switching unit, wherein the switching unit is connected between the second resistor and the ground terminal; The control device further includes a second control terminal, which is also connected to the switching unit. The control device is also used to generate a second switch control signal according to the on / off state of the switching device to control the on / off state of the switching unit, wherein the on / off state of the switching device is consistent with that of the switching unit.

3. The power supply fault detection circuit for the energy storage battery according to claim 2, characterized in that, The switching unit includes a transistor.

4. The power supply fault detection circuit for the energy storage battery according to any one of claims 1-3, characterized in that, The control device is used to determine that the energy storage battery has not experienced an overcurrent fault when the detected voltage is within a first preset range, and outputs the first switch control signal including turn-on information to keep the switch device on.

5. The power supply fault detection circuit for the energy storage battery according to claim 4, characterized in that, The first preset range includes the first preset value; The control device is further configured to determine, when the detected voltage is equal to the first preset value, that the energy storage battery is not connected to a load, wherein the first preset value is equal to V. dd *R2 / (R1+R2), V dd R1 is the voltage value of the detection power supply, R2 is the first resistor, and R1 is the second resistor.

6. The power supply fault detection circuit for the energy storage battery according to claim 4, characterized in that, The first preset range also includes a second preset range; The control device is also used to determine that the energy storage battery has been connected to the load when the detected voltage is within the second preset range.

7. The power supply fault detection circuit for the energy storage battery according to claim 6, characterized in that, The control device is also used to determine the resistance of the load based on the detected voltage, the power supply voltage of the battery module, the first resistor, the second resistor, and the third resistor when it is determined that the energy storage battery has been connected to a load.

8. The power supply fault detection circuit for an energy storage battery according to any one of claims 1-3, characterized in that, The control device is used to determine that the energy storage battery has a short circuit fault when the detected voltage is within a third preset range, and outputs the first switch control signal including shutdown information to control the switching device to turn off.

9. A battery management system, characterized in that, Includes the power supply fault detection circuit as described in any one of claims 1-8.

10. An energy storage battery, characterized in that, The system includes the battery management system, battery module, switching device, and power supply terminal as described in claim 9, wherein the battery management system is connected to the battery module, the switching device, and the power supply terminal, respectively.

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