Signal identification circuit, battery management system and battery pack

Abstract

The embodiment of the invention provides a signal identification circuit, a battery management system and a battery pack. The signal identification circuit comprises a signal detection sub-circuit; the negative voltage generation sub-circuit is electrically connected with the signal detection sub-circuit; the controller is electrically connected with the signal detection sub-circuit; the output end of the control sub-circuit is electrically connected with the signal detection sub-circuit, and the input end of the control sub-circuit is configured to access P + of the battery pack or P-of the battery pack; the signal identification circuit is configured as follows: in response to the access of the control sub-circuit to the positive electrode output terminal, the signal detection sub-circuit generates an identification signal, and the controller confirms that the battery pack is installed in place; in response to the control sub-circuit accessing the cathode output terminal, the signal detection sub-circuit generates an identification signal, and the controller confirms that the battery pack is installed in place.

Description

Technical Field

[0001] The present application relates to the technical field of battery management systems, and in particular to a signal recognition circuit, a battery management system, and a battery pack. Background Art

[0002] The battery pack's BMS (Battery Management System) needs to accurately identify the presence signal when the battery pack is installed to confirm whether the battery pack is installed in place. When the presence signal is identified, the battery pack's charging and discharging is controlled to supply power to the electrical equipment. If the presence signal is not identified, the battery pack is controlled to prohibit charging and discharging of the battery pack to ensure power safety.

[0003] There are two ways to confirm whether the battery pack is properly installed: one is to detect the signal at the P+ (positive output point) of the battery pack, and the other is to detect the signal at the P- (negative output point) of the battery pack. In the prior art, when detecting whether the battery pack is properly installed, when the signal at the P+ point is required, the detection circuit used is a positive voltage signal detection circuit because P+ outputs a positive voltage; when the signal at the P- point is required, the detection circuit used is a ground signal detection circuit because P- outputs a ground voltage.

[0004] Regarding the detection of whether the battery pack is installed in place, different customers have different requirements for detecting P- and P+. This leads to the need to design different BMS hardware circuits in the battery pack production process to meet the requirements of different customers. This not only increases production costs, but also makes it easy for the detection circuit to be installed incorrectly. For example, the ground signal detection circuit is installed on P+, or the positive voltage signal detection circuit is installed on P-, which further increases the battery pack production cost. Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a signal recognition circuit, a battery management system and a battery pack to reduce the production cost of the battery pack.

[0006] An embodiment of the present application provides a signal identification circuit, comprising: a signal detection subcircuit; a negative voltage generation subcircuit electrically connected to the signal detection subcircuit and configured to provide a negative voltage to the signal detection subcircuit; a controller electrically connected to the signal detection subcircuit; and a control subcircuit, the output end of which is electrically connected to the signal detection subcircuit and the input end of which is configured to be connected to the positive output terminal or the negative output terminal of the battery pack. The signal identification circuit is configured such that: in response to the control subcircuit being connected to the positive output terminal, the signal detection subcircuit generates an identification signal, and the controller confirms that the battery pack is properly installed; in response to the control subcircuit being connected to the negative output terminal, the signal detection subcircuit generates an identification signal, and the controller confirms that the battery pack is properly installed.

[0007] In one possible embodiment, the control subcircuit is configured as follows: in response to the input end of the control subcircuit being electrically connected to the positive output terminal, the control subcircuit controls the signal detection subcircuit to enter the on state; in response to the input end of the control subcircuit being electrically connected to the negative output terminal, the control subcircuit controls the signal detection subcircuit to enter the on state; in response to the input end of the control subcircuit being left floating, the control subcircuit controls the signal detection subcircuit to enter or maintain the off state; the signal detection subcircuit is configured to output the identification signal in the on state, and output other signals different from the identification signal in the off state.

[0008] In one possible embodiment, the output end of the control subcircuit is electrically connected to the first input end of the signal detection subcircuit, and the output end of the negative voltage of the negative voltage generating subcircuit is electrically connected to the second input end of the signal detection subcircuit; the control subcircuit and the signal detection subcircuit are configured as follows: when the input end of the control subcircuit is suspended, the current value between the first input end and the second input end of the signal detection subcircuit is limited to below a preset turn-on current value, so as to control the detection subcircuit to enter or maintain an off state, and the detection subcircuit outputs other signals different from the identification signal; when the input end of the control subcircuit is electrically connected to the positive output terminal or the negative output terminal, the current value between the first input end and the second input end of the signal detection subcircuit is pulled above the preset turn-on current value, so as to control the signal detection subcircuit to enter an on state, and the signal detection subcircuit outputs the identification signal.

[0009] In one possible embodiment, the control subcircuit includes: a first switch, a first resistor, and a second resistor; the second end of the first switch is electrically connected to the first end of the second resistor, the second end of the second resistor is electrically connected to the signal detection subcircuit, the control end of the first switch is electrically connected to the first end of the first resistor, and the second end of the first resistor is grounded; wherein the second end of the second resistor is the output end of the control subcircuit, and the first end of the first switch is the input end of the control subcircuit.

[0010] In a possible implementation, the control subcircuit further includes: a first voltage-stabilizing diode; the anode of the first voltage-stabilizing diode is electrically connected to the first end of the first resistor and the control end of the first switch, respectively; and the cathode of the first voltage-stabilizing diode is electrically connected to the first end of the first switch.

[0011] In one possible embodiment, the control subcircuit includes: a second switch, a third switch, a third resistor, and a fourth resistor; the second end of the second switch is electrically connected to the first end of the fourth resistor, the second end of the fourth resistor is electrically connected to the signal detection subcircuit, the control end of the second switch is electrically connected to the second end of the third switch, the control end of the third switch is electrically connected to the first end of the third resistor, the first end of the third switch is circuit-connected to the first end of the second switch, and the second end of the third resistor is grounded; wherein the second end of the fourth resistor is the output end of the control subcircuit, and the first end of the second switch is the input end of the control subcircuit.

[0012] In one possible embodiment, the control subcircuit further includes: a second voltage-stabilizing diode; the anode of the second voltage-stabilizing diode is electrically connected to the first end of the third resistor and the control end of the third switch, and the cathode of the second voltage-stabilizing diode is electrically connected to the first end of the third switch and the first end of the second switch.

[0013] In one possible embodiment, the signal detection subcircuit includes: a photoelectric coupler, a fifth resistor, and a first power supply; the photoelectric coupler includes a light-emitting diode and a photosensitivity switch, the first end of the photosensitivity switch is connected to the second end of the fifth resistor, the first end of the fifth resistor is connected to the positive electrode of the first power supply, and the first end of the photosensitivity switch is connected to the negative electrode of the first power supply; wherein, the cathode of the light-emitting diode is the second input end of the signal detection subcircuit, the anode of the light-emitting diode is the first input end of the signal detection subcircuit, and the second end of the fifth resistor is the output end of the signal detection subcircuit.

[0014] In a possible embodiment, the negative voltage generating sub-circuit includes: a second power supply, a driver, a fifth switch, a sixth switch, a first capacitor, a second capacitor, a fourth diode, a fifth diode, a sixth resistor and a seventh resistor; the anode of the second power supply is connected to the first end of the fifth switch, and the cathode of the second power supply is respectively connected to the second end of the sixth switch, the second end of the driver, the cathode of the fifth diode, and the second end of the second capacitor; the first end of the driver is connected to the control end of the fifth switch through the sixth resistor; the first end of the driver is connected to the control end of the sixth switch through the seventh resistor; the second end of the fifth switch is respectively connected to the first end of the sixth switch and the first end of the first capacitor; the second end of the first capacitor is respectively connected to the cathode of the fourth diode and the anode of the fifth diode; the anode of the fourth diode is connected to the first end of the second capacitor; the driver is used to output a pulse width modulated PWM voltage signal; wherein, the first end of the second capacitor is the output end of the negative voltage generating sub-circuit.

[0015] An embodiment of the present application provides a battery management system, comprising the signal recognition circuit described in any one of the embodiments of the present application.

[0016] An embodiment of the present application provides a battery pack, including a battery module and the battery management system described in the embodiment of the present application.

[0017] An embodiment of the present application provides an electrical device, including a load and the battery pack described in the embodiment of the present application.

[0018] Beneficial effects of the embodiments of the present application:

[0019] The signal recognition circuit provided in the embodiment of the present application includes: a signal detection subcircuit; a negative voltage generating subcircuit electrically connected to the signal detection subcircuit and configured to provide a negative voltage to the signal detection subcircuit; a controller electrically connected to the signal detection subcircuit; a control subcircuit, whose output end is electrically connected to the signal detection subcircuit and whose input end is configured to be connected to the positive output terminal of the battery pack or the negative output terminal of the battery pack; the signal recognition circuit is configured to: in response to the control subcircuit being connected to the positive output terminal, the signal detection subcircuit generates an identification signal, and the controller confirms that the battery pack is installed in place; in response to the control subcircuit being connected to the negative output terminal, the signal detection subcircuit generates an identification signal, and the controller confirms that the battery pack is installed in place. In the embodiment of the present application, the battery BMS design architecture is optimized. Whether detecting the negative output terminal P- or the positive output terminal P+, the same signal recognition circuit can be used to detect whether the battery pack is installed in place, making the design simpler and more universal, simplifying the hardware circuit design requirements of the battery pack, reducing the situation of incorrect installation of the detection circuit, and reducing the manufacturing cost of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0021] FIG1( a ) is a schematic diagram of detecting the positive output point P+ of a battery pack in the related art;

[0022] FIG1( b ) is a schematic diagram of detecting the negative output point P- of a battery pack in the related art;

[0023] Figure 2 A schematic diagram of a signal recognition circuit in an embodiment of the present application;

[0024] Figure 3 This is a first schematic diagram of a control subcircuit in a signal recognition circuit according to an embodiment of the present application;

[0025] Figure 4 This is a second schematic diagram of the control subcircuit in the signal recognition circuit of an embodiment of the present application;

[0026] Figure 5 This is a third schematic diagram of a control subcircuit in the signal recognition circuit according to an embodiment of the present application;

[0027] Figure 6 This is a fourth schematic diagram of a control subcircuit in a signal recognition circuit according to an embodiment of the present application;

[0028] Figure 7 A schematic diagram of a signal detection subcircuit in a signal recognition circuit according to an embodiment of the present application;

[0029] Figure 8 This is a schematic diagram of a negative voltage generating sub-circuit in a signal recognition circuit according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and in detail describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field based on this application are within the scope of protection of this application.

[0031] The battery pack is installed in place means that the battery pack is correctly installed in the electrical equipment. In the related art, there are two ways to confirm whether the battery pack is installed in place, see Figure 1 (a), one is to detect the signal of P+ (positive output point) of the battery pack. The other is to detect the signal of P- (negative output point) of the battery pack, as shown in Figure 1 (b). In the related art, when detecting whether the battery pack is installed in place, when it is required to detect the signal of the P+ point, because the output of P+ is a positive voltage, the detection circuit used is a positive voltage signal detection circuit; and when it is required to detect the signal of the P- point, because the output of P- is a ground voltage, the detection circuit used is a ground signal detection circuit, wherein the in-place signal recognition end is the access point of the signal recognition circuit.

[0032] Regarding the detection of whether the battery pack is installed in place, different customers have different requirements for detecting P- and P+. This leads to the need to design different BMS hardware circuits in the battery pack production process to meet the requirements of different customers, resulting in different versions of the BMS circuit board. This not only increases production costs, but also makes it easy for the detection circuit to be installed incorrectly. For example, the ground signal detection circuit is installed on P+, or the positive voltage signal detection circuit is installed on P-, which further increases the battery pack production cost.

[0033] The present application provides a signal recognition circuit, a battery management system, and a battery pack, which can detect the positive output point P+ or the negative output point P- of the battery pack, thereby reducing the production cost of the battery pack. The following is a detailed description:

[0034] The present application embodiment provides a signal recognition circuit, see Figure 2 ,include:

[0035] Signal detection subcircuit 101;

[0036] The negative voltage generating sub-circuit 102 is electrically connected to the signal detecting sub-circuit 101 and is configured to provide a negative voltage to the signal detecting sub-circuit 101;

[0037] The controller 103 is electrically connected to the signal detection sub-circuit 101;

[0038] The control sub-circuit 104 has an output end electrically connected to the signal detection sub-circuit 101 and an input end configured to be connected to the positive output terminal P+ of the battery pack or the negative output terminal P- of the battery pack;

[0039] The signal recognition circuit is configured as follows:

[0040] In response to the control subcircuit 104 being connected to the positive output terminal, the signal detection subcircuit 101 generates an identification signal, and the controller 103 confirms that the battery pack is properly installed;

[0041] In response to the control sub-circuit 104 being connected to the negative output terminal, the signal detection sub-circuit 101 generates an identification signal, and the controller 103 confirms that the battery pack is installed in place.

[0042] The input end of the control subcircuit 104 is connected to the point to be detected. When the battery pack is installed in place, the input end of the control subcircuit 104 is connected to the positive output terminal of the battery pack or the negative output terminal of the battery pack; when the battery pack is not installed in place, the input end of the control subcircuit 104 is left floating. In one example, as shown in Figures 1(a) and 1(b), when the battery pack is not installed in place, the electrode of the point to be detected has no input, that is, the input end of the control subcircuit 104 is left floating. When the battery pack is installed in place, the P+ of the battery pack is electrically connected to the positive input terminal of the electrical device, the P- of the battery pack is electrically connected to the negative input terminal of the electrical device, the electrode of the point to be detected is electrically connected to the in-place feedback terminal of the electrical device, and the in-place feedback terminal of the electrical device is electrically connected to its own positive input terminal or negative input terminal. Therefore, when the battery pack is installed in place, the input end of the control subcircuit 104 is connected to the positive output terminal of the battery pack or the negative output terminal of the battery pack.

[0043] The output terminal of the control subcircuit 104 is electrically connected to the first input terminal of the signal detection subcircuit 101, and the negative voltage output terminal of the negative voltage generating subcircuit 102 is electrically connected to the second input terminal of the signal detection subcircuit 101. The negative voltage generating subcircuit 102 provides a negative voltage to the signal detection subcircuit 101. When the voltage signal of the positive output terminal or the voltage signal of the negative output terminal is input to the input terminal of the control subcircuit 104, the signal detection subcircuit 101 generates an identification signal under the combined action of the negative voltage generating subcircuit 102 and the control subcircuit 104. In some embodiments of the present application, the negative voltage has a negative value.

[0044] The controller 103 can be an MCU (Microcontroller Unit), SoC (System on Chip) or FPGA (Field Programmable Gate Array), etc. The controller 103 is electrically connected to the signal detection subcircuit 101. When the controller 103 receives the identification signal from the signal detection subcircuit 101, the controller 103 confirms that the battery pack is installed in place.

[0045] The signal recognition circuit in the embodiment of the present application can detect the positive output terminal or the negative output terminal of the battery pack without setting up two circuits, which simplifies the circuit design for identifying whether the battery pack is connected to an electrical device and reduces the manufacturing cost of the battery pack. At the same time, there will be no situation where the detection circuit is installed incorrectly, thereby improving the safety of the battery pack.

[0046] In one possible implementation, the control subcircuit 104 is configured to:

[0047] In response to the input end of the control sub-circuit 104 being electrically connected to the positive output terminal, the control sub-circuit 104 controls the signal detection sub-circuit 101 to enter a conducting state;

[0048] In response to the input end of the control sub-circuit 104 being electrically connected to the negative output terminal, the control sub-circuit 104 controls the signal detection sub-circuit 101 to enter a conducting state;

[0049] In response to the input terminal of the control sub-circuit 104 being suspended, the control sub-circuit 104 controls the signal detection sub-circuit 101 to enter or maintain an off state;

[0050] The signal detection sub-circuit 101 is configured to output an identification signal in an on state, and output a signal other than the identification signal in an off state.

[0051] When the input terminal of the control subcircuit 104 receives a voltage signal from the positive output terminal of the battery pack, or a voltage signal from the negative output terminal of the battery pack, the control subcircuit 104 controls the signal detection subcircuit 101 to enter the on state. When the signal detection subcircuit 101 is in the on state, the signal detection subcircuit 101 outputs an identification signal. When the input terminal of the control subcircuit 104 is floating (open circuit), the control subcircuit 104 controls the signal detection subcircuit 101 to enter or maintain the off state, and the signal detection subcircuit 101 outputs a signal other than the identification signal. Specifically, if the signal detection subcircuit 101 was in the off state at the previous moment, then when the input terminal of the control subcircuit 104 is floating, the control subcircuit 104 controls the signal detection subcircuit 101 to remain in the off state. If the signal detection subcircuit 101 was in the on state at the previous moment, then when the input terminal of the control subcircuit 104 is floating, the control subcircuit 104 controls the signal detection subcircuit 101 to enter the off state. When the controller 103 receives the identification signal from the signal detection subcircuit 101 , the controller 103 confirms that the battery pack is properly installed; when the controller 103 receives other signals from the signal detection subcircuit 101 , the controller 103 confirms that the battery pack is not properly installed.

[0052] In an embodiment of the present application, when the input end of the control subcircuit 104 receives a voltage signal from the positive output terminal or the negative output terminal, the signal detection subcircuit 101 can be turned on to generate an identification signal. There is no need to set up two detection circuits for P+ and P-, which reduces the manufacturing cost of the circuit and thus reduces the manufacturing cost of the battery pack.

[0053] In one possible implementation, the output terminal of the control subcircuit 104 is electrically connected to the first input terminal of the signal detection subcircuit 101, and the negative voltage output terminal of the negative voltage generating subcircuit 102 is electrically connected to the second input terminal of the signal detection subcircuit 101;

[0054] The control sub-circuit 104 and the signal detection sub-circuit 101 are configured as follows:

[0055] When the input terminal of the control sub-circuit 104 is left floating, the current value between the first input terminal and the second input terminal of the signal detection sub-circuit 101 is limited to below a preset turn-on current value, so as to control the detection sub-circuit 101 to enter or maintain an off state, and the detection sub-circuit 101 outputs a signal other than the identification signal;

[0056] When the input end of the control sub-circuit 104 is electrically connected to the positive output terminal or the negative output terminal, the current value between the first input end and the second input end of the signal detection sub-circuit 101 is pulled up to above the preset turn-on current value, and the signal detection sub-circuit 101 is controlled to enter the on state, and the signal detection sub-circuit 101 outputs an identification signal.

[0057] In some embodiments, the voltage value of the negative voltage provided by the negative voltage generating subcircuit 102 is set according to the preset turn-on current value of the signal detection subcircuit 101, that is, the negative voltage needs to meet the following requirements: when the input end of the control subcircuit 104 is suspended, the current generated by the negative voltage between the first input end and the second input end of the signal detection subcircuit 101 is less than the preset turn-on current value; when the input end of the control subcircuit 104 is connected to the voltage signal of P+ or P-, the current generated by the negative voltage and P+ / P- between the first input end and the second input end of the signal detection subcircuit 101 is not less than the preset turn-on current value.

[0058] The preset turn-on current value is the on-current of the detection subcircuit 101. When the control subcircuit 104 is connected to the voltage signal of the positive output terminal of the battery pack, or is connected to the voltage signal of the negative output terminal, under the joint action of the P+ / P- voltage signal and the above-mentioned negative voltage, the current value of the current generated is greater than or equal to the preset turn-on current value, the signal detection subcircuit 101 is turned on, and an identification signal is output; when the input end of the control subcircuit 104 is floating, the current value of the current generated by the above-mentioned negative voltage is less than the preset turn-on current value, the signal detection subcircuit 101 is in a disconnected state, and outputs other signals different from the identification signal.

[0059] In an embodiment of the present application, when the voltage signal of the positive output terminal or the negative output terminal is connected to the input end of the control subcircuit 104, the current generated between the first input end and the second input end of the signal detection subcircuit 101 is not less than the preset turn-on current value, and the signal detection subcircuit 101 is turned on; when the input end of the control subcircuit 104 is floating, the current generated between the first input end and the second input end of the signal detection subcircuit 101 is less than the preset turn-on current value, and the signal detection subcircuit 101 is disconnected. The conduction control of the signal detection subcircuit 101 is achieved by current control. Whether detecting the negative output terminal P- or the positive output terminal P+, the same signal recognition circuit can be used to detect whether the battery pack is installed in place, which optimizes the battery BMS design architecture, makes the design simpler and more universal, simplifies the hardware circuit design requirements of the battery pack, reduces the situation of detection circuit installation errors, and reduces the manufacturing cost of the battery pack.

[0060] In one possible implementation, see Figure 3 , the control sub-circuit 104 includes:

[0061] A first switch Q1, a first resistor R1, and a second resistor R2;

[0062] The second end of the first switch Q1 is electrically connected to the first end of the second resistor R2, the second end of the second resistor R2 is electrically connected to the signal detection sub-circuit 101, the control end of the first switch Q1 is electrically connected to the first end of the first resistor R1, and the second end of the first resistor R1 is grounded;

[0063] The second end of the second resistor R2 is the output end of the control sub-circuit 104 , and the first end of the first switch Q1 is the input end of the control sub-circuit 104 .

[0064] The first switch Q1 can be an NPN transistor or an NMOS (N-Metal-Oxide-Semiconductor, N-type transistor), etc. The resistance values ​​of the first resistor R1 and the second resistor R2 can be customized according to actual conditions, and both need to meet the following conditions: when the first end of the first switch Q1 is open, that is, when the input end of the control sub-circuit 104 is floating, R1 and R2 limit the current value of the negative voltage to below the preset turn-on current value; when the first end of the first switch Q1 is connected to the P+ or P- voltage signal, the current value generated when the P+ / P- voltage signal and the negative voltage act on R2 at the same time is not less than the preset turn-on current value, and will not burn the signal detection sub-circuit 101. In one example, the first resistor R1 and the second resistor R2 can be resistors with a resistance of megohms. When the control sub-circuit 104 is connected to the voltage signal of the negative output terminal of the battery pack, the first switch Q1 is turned on, the current generated in the circuit is greater than or equal to the preset turn-on current value, the signal detection sub-circuit 101 is turned on, and an identification signal is output; when the control sub-circuit 104 is connected to the voltage signal of the positive output terminal of the battery pack, the first switch Q1 is turned on, the current generated in the circuit is greater than or equal to the preset turn-on current value, the signal detection sub-circuit 101 is turned on, and an identification signal is output. Since the resistance of the second resistor R2 is large, the current in the circuit is a smaller current value greater than or equal to the preset turn-on current value, which reduces the situation where the signal detection sub-circuit 101 is damaged by excessive current; when the input end of the control sub-circuit 104 is floating, the first switch Q1 operates in a non-saturated state, the current generated by the resistor R1 is less than the preset turn-on current value, the signal detection sub-circuit 101 is in a disconnected state, and outputs other signals different from the identification signal.

[0065] When the input terminal of the control subcircuit 104 is left floating, the first resistor R1 limits the current in the circuit to below a preset turn-on current value, turning the signal detection subcircuit 101 off. When the control subcircuit 104 receives a voltage signal from the negative or positive output terminal of the battery pack, the current generated by the first resistor R1 and the second resistor R2 is greater than or equal to the preset turn-on current value, turning the signal detection subcircuit 101 on. The control subcircuit 104 has a simple structure and is easy to implement, which reduces the manufacturing cost of the circuit, thereby reducing the manufacturing cost of the battery pack.

[0066] In one embodiment, see Figure 4 , the control sub-circuit 104 further includes: a first voltage stabilizing diode D1;

[0067] An anode of the first zener diode D1 is electrically connected to the first end of the first resistor R1 and the control end of the first switch Q1 , and a cathode of the first zener diode D1 is electrically connected to the first end of the first switch Q1 .

[0068] The breakdown voltage of the first voltage zener diode D1 is greater than the maximum voltage of the battery pack when it is working. During normal operation, the first voltage zener diode D1 will not be broken down when the control sub-circuit 104 is connected to the voltage signal of the positive output terminal or the negative output terminal of the battery pack; when there is a surge voltage, the first voltage zener diode D1 may be broken down. After the first voltage zener diode D1 is broken down, the voltage is divided by the first resistor R1. The resistance of the first resistor R1 is in the megohm level, which can reduce the damage caused by the surge voltage to the first switch Q1 and the signal detection circuit 101, and improve the service life of the circuit.

[0069] In one embodiment, see Figure 5 , the control sub-circuit 104 includes: a second switch Q2, a third switch Q3, a third resistor R3, and a fourth resistor R4;

[0070] A second end of the second switch Q2 is electrically connected to a first end of a fourth resistor R4, a second end of the fourth resistor R4 is electrically connected to the signal detection sub-circuit 101, a control end of the second switch Q2 is electrically connected to a second end of a third switch Q3, a control end of the third switch Q3 is electrically connected to a first end of the third resistor R3, a first end of the third switch Q3 is circuit-connected to the first end of the second switch Q2, and a second end of the third resistor R3 is grounded;

[0071] The second end of the fourth resistor R4 is the output end of the control sub-circuit 104 , and the first end of the second switch Q2 is the input end of the control sub-circuit 104 .

[0072] The second switch Q2 and the third switch Q3 may be switch transistors such as BJT (Bipolar Transistor), FET (Field Effect Transistor), or triode. The third resistor R3 and the fourth resistor R4 are resistors with a resistance in the megohm range. When the control sub-circuit 104 is connected to the voltage signal of the negative output terminal of the battery pack, the second switch Q2 and the third switch Q3 are turned on, the current in the circuit is greater than the preset turn-on current value, the signal detection sub-circuit 101 is turned on, and an identification signal is output. When the control sub-circuit 104 is connected to the voltage signal of the positive output terminal of the battery pack, the second switch Q2 and the third switch Q3 are turned on, the current in the circuit is greater than the preset turn-on current value, the signal detection sub-circuit 101 is turned on, and an identification signal is output. Due to the large resistance of the fourth resistor R4, the current in the circuit is a smaller current value greater than or equal to the preset turn-on current value, thereby reducing the possibility of damage to the signal detection sub-circuit 101 due to excessive current. When the input terminal of the control sub-circuit 104 is left floating, the second switch Q2 and the third switch Q3 are turned on, and the voltage divided by the third resistor R3 generates an extremely small current. The current in the signal detection sub-circuit 101 is less than the preset turn-on current value, the signal detection sub-circuit 101 is in a disconnected state, and outputs a signal other than the identification signal.

[0073] In one embodiment, see Figure 6 , the control sub-circuit 104 further includes: a second voltage stabilizing diode D2;

[0074] The anode of the second zener diode D2 is electrically connected to the first end of the third resistor R3 and the control end of the third switch Q3 , and the cathode of the second zener diode D2 is electrically connected to the first end of the third switch Q3 and the first end of the second switch Q2 .

[0075] The breakdown voltage of the second voltage stabilizing diode D2 is greater than the maximum voltage of the battery pack during operation. During normal operation, the second voltage stabilizing diode D2 will not be broken down when the control sub-circuit 104 is connected to the voltage signal of the positive output terminal or the negative output terminal of the battery pack. When a surge voltage exists, the second voltage stabilizing diode D2 may be broken down. After the second voltage stabilizing diode D2 is broken down, the voltage is divided by the third resistor R3. The resistance of the third resistor R3 is in the megohm range, which can reduce the damage caused by the surge voltage to the second switch Q2, the third switch Q3 and the signal detection circuit 101, thereby improving the service life of the circuit.

[0076] In one possible implementation, see Figure 7 , the signal detection sub-circuit 101 includes:

[0077] Optocoupler OC, fifth resistor R5, first power supply V1;

[0078] The optocoupler OC includes a light-emitting diode D3 and a photoswitch Q4. The first end of the photoswitch Q4 is connected to the second end of the fifth resistor R5. The first end of the fifth resistor R5 is connected to the positive electrode of the first power supply V1. The second end of the photoswitch Q4 is connected to the negative electrode of the first power supply V1.

[0079] The cathode of the light-emitting diode D3 is the second input terminal of the signal detection subcircuit 101 , the anode of the light-emitting diode D3 is the first input terminal of the signal detection subcircuit 101 , and the second terminal of the fifth resistor R5 is the output terminal of the signal detection subcircuit 101 .

[0080] Before the photoswitch Q4 turns on, the voltage at the second terminal of the fifth resistor R5 is equal to the anode voltage of the first power supply V1. The conduction current of the LED D3 is the predetermined turn-on current. When the control subcircuit 104 receives a voltage signal from the positive or negative output terminal of the battery pack, it generates a conduction current greater than or equal to the predetermined turn-on current, turning on the LED D3 and emitting light, thereby turning on the photoswitch Q4. The voltage at the second terminal of the fifth resistor R5 (the first terminal of the photoswitch Q4) is pulled low, and the voltage detected by the controller 103 decreases, indicating that the controller 103 has received an identification signal. When the input terminal of the control subcircuit 104 is left floating, the current flowing through the LED D3 is insufficient to turn on the LED, and the photoswitch Q4 turns off. The controller 103 then receives a signal other than the identification signal (the voltage at the positive terminal of the first power supply V1).

[0081] The absolute value of the negative voltage provided by the negative voltage generating subcircuit 102 should be greater than the voltage drop of the light-emitting diode D3. In one example, the negative voltage provided by the negative voltage generating subcircuit 102 is -2.5V, the voltage drop of the light-emitting diode D3 is 1V, and the anode potential of the light-emitting diode D3 is maintained at -1.5V. When the input end of the control subcircuit 104 is connected to the voltage signal of the positive output terminal of the battery pack, the positive voltage of the positive output terminal is at least partially applied to the light-emitting diode D3, and the current flowing through the light-emitting diode D3 increases. The light-emitting diode D3 is turned on, and the photoswitch Q4 is turned on accordingly. When the input end of the control sub-circuit 104 is connected to the voltage signal of the negative output terminal of the battery pack, the 0V voltage of the negative output terminal is at least partially applied to the light-emitting diode D3, the current flowing through the light-emitting diode D3 increases, the light-emitting diode D3 is turned on, and the photoswitch Q4 is turned on accordingly. When the input end of the control sub-circuit 104 is left floating, the light-emitting diode D3 is not turned on, the photoswitch Q4 is not turned on, and the signal detection sub-circuit 101 is in the disconnected state.

[0082] The controller 103 can determine whether the battery pack is properly installed by obtaining the identification signal output by the signal detection subcircuit 101 or other signals different from the identification signal. The circuit structure is simple, and the manufacturing cost of the battery pack is reduced.

[0083] In one possible implementation, see Figure 8 , the negative pressure generating sub-circuit 102 includes:

[0084] A second power source V2, a driver 105, a fifth switch Q5, a sixth switch Q6, a first capacitor C1, a second capacitor C2, a fourth diode D4, a fifth diode D5, a sixth resistor R6, and a seventh resistor R7;

[0085] The positive electrode of the second power supply V2 is connected to the first end of the fifth switch Q5, and the negative electrode of the second power supply V2 is respectively connected to the second end of the sixth switch Q6, the second end of the driver 105, the cathode of the fifth diode D5, and the second end of the second capacitor C2; the first end of the driver 105 is connected to the control end of the fifth switch Q5 via the sixth resistor R6; the first end of the driver 105 is connected to the control end of the sixth switch Q6 via the seventh resistor R7; the second end of the fifth switch Q5 is respectively connected to the first end of the sixth switch Q6 and the first end of the first capacitor C1; the second end of the first capacitor C1 is respectively connected to the cathode of the fourth diode D4 and the anode of the fifth diode D5; and the anode of the fourth diode D4 is connected to the first end of the second capacitor C2.

[0086] The driver 105 is used to output a PWM (pulse width modulation) voltage signal;

[0087] The first end of the second capacitor C2 is the output end of the negative voltage generating sub-circuit 102 .

[0088] The driver 105 can be part of the controller 103 or provided separately, as long as it can output a PWM voltage signal. The fifth switch Q5 and the sixth switch Q6 are of opposite types. For example, if the fifth switch Q5 is an N-type switch, the sixth switch Q6 is a P-type switch; for example, if the fifth switch Q5 is a P-type switch, the sixth switch Q6 is an N-type switch. The driver 105 outputs a PWM signal with alternating high and low levels, causing the fifth switch Q5 and the sixth switch Q6 to turn on at different times. This, by charging and discharging the first capacitor C1 and the second capacitor C2, causes the negative voltage generating sub-circuit 102 to output the aforementioned negative voltage.

[0089] The negative voltage generating subcircuit 102 is intended to generate a negative voltage. The embodiment of the present application provides the above-mentioned negative voltage generating subcircuit. It is understandable that in other embodiments, the negative voltage subcircuit also includes other structures.

[0090] An embodiment of the present application provides a battery management system, comprising the signal recognition circuit described in any one of the embodiments of the present application.

[0091] The battery management system is used to monitor the battery status and prevent the battery from overcharging and over-discharging to extend the battery life.

[0092] An embodiment of the present application provides a battery pack, including a battery module and a battery management system in an embodiment of the present application.

[0093] The battery pack provided in the embodiment of the present application is provided with electrodes of P+, P- and the point to be detected. When the battery pack is not installed in place, the electrode of the point to be detected has no input, that is, the input end of the control sub-circuit is suspended. When the battery pack is installed in place, the P+ electrode is electrically connected to the positive input terminal of the electrical equipment, the P- electrode is electrically connected to the negative input terminal of the electrical equipment, the electrode of the point to be detected is electrically connected to the in-situ feedback terminal of the electrical equipment, and the in-situ feedback terminal of the electrical equipment is electrically connected to its own positive input terminal or negative input terminal, which is equivalent to: when the battery pack is installed in place, the input end of the control sub-circuit is connected to the positive output terminal of the battery pack or the negative output terminal of the battery pack. There will be no situation where the detection circuit is installed incorrectly, which improves the safety of the battery pack.

[0094] The present invention provides an electrical device including a load and a battery pack according to the present invention. In some embodiments, the electrical device includes an electric vehicle, such as an electric two-wheeled vehicle or an electric three-wheeled vehicle, wherein the load includes a motor in the electric vehicle.

[0095] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0096] Each embodiment in this specification is described in a related manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0097] The above description is merely a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application.

Claims

1. A signal recognition circuit, characterized in that: include: signal detection subcircuit; a negative voltage generating subcircuit, electrically connected to the signal detecting subcircuit and configured to provide a negative voltage to the signal detecting subcircuit; a controller, electrically connected to the signal detection subcircuit; a control subcircuit, the output end of which is electrically connected to the signal detection subcircuit, and the input end of which is configured to be connected to the positive output terminal of the battery pack or the negative output terminal of the battery pack; The signal recognition circuit is configured to: In response to the control subcircuit being connected to the positive output terminal, the signal detection subcircuit generates an identification signal, and the controller confirms that the battery pack is properly installed; In response to the control subcircuit being connected to the negative output terminal, the signal detection subcircuit generates an identification signal, and the controller confirms that the battery pack is installed in place.

2. The identification circuit according to claim 1, characterized in that The control subcircuit is configured to: In response to the input end of the control subcircuit being electrically connected to the positive output terminal, the control subcircuit controls the signal detection subcircuit to enter a conducting state; In response to the input end of the control subcircuit being electrically connected to the negative output terminal, the control subcircuit controls the signal detection subcircuit to enter a conducting state; In response to the input terminal of the control subcircuit being suspended, the control subcircuit controls the signal detection subcircuit to enter or maintain an off state; The signal detection sub-circuit is configured to output the identification signal in an on state, and output a signal different from the identification signal in an off state.

3. The identification circuit according to claim 2, characterized in that The output end of the control subcircuit is electrically connected to the first input end of the signal detection subcircuit, and the negative voltage output end of the negative voltage generating subcircuit is electrically connected to the second input end of the signal detection subcircuit; The control subcircuit and the signal detection subcircuit are configured as follows: When the input terminal of the control subcircuit is suspended, the current value between the first input terminal and the second input terminal of the signal detection subcircuit is limited to below a preset turn-on current value, so as to control the detection subcircuit to enter or maintain an off state, and the detection subcircuit outputs a signal other than the identification signal; When the input end of the control subcircuit is electrically connected to the positive output terminal or the negative output terminal, the current value between the first input end and the second input end of the signal detection subcircuit is pulled up to above the preset turn-on current value, the signal detection subcircuit is controlled to enter the on state, and the signal detection subcircuit outputs the identification signal.

4. The identification circuit according to any one of claims 1 to 3, characterized in that: The control subcircuit comprises: a first switch, a first resistor, and a second resistor; The second end of the first switch is electrically connected to the first end of the second resistor, the second end of the second resistor is electrically connected to the signal detection sub-circuit, the control end of the first switch is electrically connected to the first end of the first resistor, and the second end of the first resistor is grounded; The second end of the second resistor is the output end of the control sub-circuit, and the first end of the first switch is the input end of the control sub-circuit.

5. The identification circuit according to claim 4, characterized in that: The control subcircuit further includes: a first voltage stabilizing diode; An anode of the first zener diode is electrically connected to a first end of the first resistor and a control end of the first switch, respectively, and a cathode of the first zener diode is electrically connected to a first end of the first switch.

6. The identification circuit according to any one of claims 1 to 3, characterized in that: The control subcircuit includes: a second switch, a third switch, a third resistor, and a fourth resistor; The second end of the second switch is electrically connected to the first end of the fourth resistor, the second end of the fourth resistor is electrically connected to the signal detection sub-circuit, the control end of the second switch is electrically connected to the second end of the third switch, the control end of the third switch is electrically connected to the first end of the third resistor, the first end of the third switch is circuit-connected to the first end of the second switch, and the second end of the third resistor is grounded; The second end of the fourth resistor is the output end of the control sub-circuit, and the first end of the second switch is the input end of the control sub-circuit.

7. The identification circuit according to claim 6, characterized in that: The control subcircuit further includes: a second voltage stabilizing diode; The anode of the second zener diode is electrically connected to the first end of the third resistor and the control end of the third switch, and the cathode of the second zener diode is electrically connected to the first end of the third switch and the first end of the second switch.

8. The identification circuit according to any one of claims 3 to 7, characterized in that: The signal detection subcircuit comprises: a photocoupler, a fifth resistor, and a first power supply; The photoelectric coupler includes a light-emitting diode and a photosensitive switch, wherein a first end of the photosensitive switch is connected to the second end of the fifth resistor, a first end of the fifth resistor is connected to the positive electrode of the first power supply, and a first end of the photosensitive switch is connected to the negative electrode of the first power supply; The cathode of the light-emitting diode is the second input terminal of the signal detection subcircuit, the anode of the light-emitting diode is the first input terminal of the signal detection subcircuit, and the second terminal of the fifth resistor is the output terminal of the signal detection subcircuit.

9. The identification circuit according to any one of claims 3 to 7, characterized in that: The negative pressure generating sub-circuit comprises: a second power supply, a driver, a fifth switch, a sixth switch, a first capacitor, a second capacitor, a fourth diode, a fifth diode, a sixth resistor, and a seventh resistor; An anode of the second power supply is connected to a first end of the fifth switch, and a cathode of the second power supply is respectively connected to a second end of the sixth switch, a second end of the driver, a cathode of the fifth diode, and a second end of the second capacitor; a first end of the driver is connected to a control end of the fifth switch via the sixth resistor; a first end of the driver is connected to a control end of the sixth switch via the seventh resistor; a second end of the fifth switch is respectively connected to a first end of the sixth switch and a first end of the first capacitor; a second end of the first capacitor is respectively connected to a cathode of the fourth diode and an anode of the fifth diode; and an anode of the fourth diode is connected to a first end of the second capacitor; The driver is used to output a pulse width modulation (PWM) voltage signal; Wherein, the first end of the second capacitor is the output end of the negative voltage generating sub-circuit.

10. A battery management system, characterized in that: The invention comprises the signal recognition circuit according to any one of claims 1 to 9.

11. A battery pack, characterized in that: It comprises a battery module and the battery management system according to claim 10.

12. An electrical device, characterized in that: Comprising a load and the battery pack according to claim 11.

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