Nickel-hydrogen battery management system and voltage sampling circuit thereof

Abstract

This utility model discloses a nickel-metal hydride battery management system and its voltage sampling circuit. The voltage sampling circuit includes N batteries connected in series, N pairs of signal coupling devices, and a control device. Each pair of signal coupling devices corresponds to one battery. Each pair of signal coupling devices includes a first signal coupling device and a second signal coupling device. The output terminal of the first signal coupling device is connected to the positive terminal of the corresponding battery and a voltage divider resistor, respectively. The output terminal of the second signal coupling device is connected to the negative terminal of the corresponding battery and a voltage divider resistor, respectively. The control device is configured to output control signals to the signal coupling devices and receive the voltage divider signals from the voltage divider resistors. Through the arrangement of the signal coupling devices, batteries, and voltage divider circuit, voltage sampling of a single battery can be achieved, thereby realizing voltage sampling of the nickel-metal hydride battery.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, specifically, it relates to a nickel-metal hydride battery management system and its voltage sampling circuit. Background Technology

[0002] With the increasing application of nickel-metal hydride (NiMH) batteries in new scenarios such as backup power for rail transit, offshore wind power generation, and aviation containers, there is a need to develop BMS (Battery Management System) solutions based on NiMH batteries to ensure the safe and reliable operation of these systems. Initially, the development of dedicated BMS chips was considered, but the market only offers dedicated BMS chips for lithium batteries, whose voltage sampling range is typically designed according to the voltage of lithium batteries, ranging from 0-6V. However, in NiMH batteries, the typical voltage of a minimum battery pack is 6V or 12V, so existing lithium battery dedicated BMS chips cannot meet the voltage sampling requirements of NiMH batteries.

[0003] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0004] This invention proposes a nickel-metal hydride battery management system and its voltage sampling circuit to solve the technical problem that existing lithium battery BMS dedicated chips cannot sample the high voltage of nickel-metal hydride batteries.

[0005] To achieve the above-mentioned utility model / design objectives, the present utility model adopts the following technical solution:

[0006] A nickel-metal hydride battery voltage sampling circuit, the circuit comprising:

[0007] N batteries connected in series;

[0008] N pairs of signal coupling devices, each pair of signal coupling devices corresponds to one battery. Each pair of signal coupling devices includes a first signal coupling device and a second signal coupling device. The output terminal of the first signal coupling device is connected to the positive terminal of the corresponding battery and a voltage divider resistor, respectively. The output terminal of the second signal coupling device is connected to the negative terminal of the corresponding battery and a voltage divider resistor, respectively.

[0009] The control device is configured to output a control signal to the signal coupling device and receive the voltage divider signal from the voltage divider resistor.

[0010] The nickel-metal hydride battery voltage sampling circuit described above includes a decoder, which is connected to the control device and the signal coupling device. The control device outputs a control signal to the decoder.

[0011] The nickel-metal hydride battery voltage sampling circuit described above includes an analog signal digitization device connected to the voltage divider resistor and the control device.

[0012] In the nickel-metal hydride battery voltage sampling circuit described above, the signal coupling device is an optocoupler.

[0013] In the nickel-metal hydride battery voltage sampling circuit described above, the voltage divider resistor includes a first resistor and a second resistor. The first resistor is connected to the output terminal of the second signal coupling device, and the second resistor is connected to the output terminal of the first signal coupling device. A voltage divider signal is output between the first resistor and the second resistor.

[0014] The nickel-metal hydride battery voltage sampling circuit described above includes an analog signal digitization device, which is a differential analog-to-digital converter (ADC). The input terminal of the differential ADC is connected to both ends of a second resistor.

[0015] A nickel-metal hydride battery management system, the system including the voltage sampling circuit described above.

[0016] Compared with existing technologies, the advantages and positive effects of this invention are as follows: The nickel-metal hydride battery voltage sampling circuit of this invention includes N batteries connected in series, N pairs of signal coupling devices, and a control device. Each pair of signal coupling devices corresponds to one battery. Each pair of signal coupling devices includes a first signal coupling device and a second signal coupling device. The output terminal of the first signal coupling device is connected to the positive terminal of the corresponding battery and a voltage divider resistor, respectively. The output terminal of the second signal coupling device is connected to the negative terminal of the corresponding battery and a voltage divider resistor, respectively. The control device is configured to output control signals to the signal coupling devices and receive the voltage divider signals from the voltage divider resistors. Through the arrangement of the signal coupling devices, batteries, and voltage divider circuit, voltage sampling of a single battery can be achieved, thereby realizing voltage sampling of the nickel-metal hydride battery.

[0017] The nickel-metal hydride battery management system of this invention can achieve voltage sampling through the aforementioned nickel-metal hydride battery voltage sampling circuit.

[0018] Other features and advantages of this utility model will become clearer after reading the detailed embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1This is a circuit diagram of a nickel-metal hydride battery voltage sampling circuit according to a specific embodiment of this utility model.

[0021] Figure 2 This is a truth table for a decoder in a specific embodiment of this utility model. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0024] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. In the description of the embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0025] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0026] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0027] A nickel-metal hydride battery voltage sampling circuit includes N batteries connected in series, N pairs of signal coupling devices, and a control device.

[0028] N batteries connected in series are arranged in series to provide the voltage after the series connection.

[0029] N pairs of signal coupling devices, each pair of signal coupling devices corresponds to one battery. Each pair of signal coupling devices includes a first signal coupling device and a second signal coupling device. The output terminal of the first signal coupling device is connected to the positive terminal of the corresponding battery and a voltage divider resistor, respectively. The output terminal of the second signal coupling device is connected to the negative terminal of the corresponding battery and a voltage divider resistor, respectively.

[0030] The control device is configured to output a control signal to a signal coupling device and receive the voltage divider signal from the voltage divider resistor.

[0031] exist Figure 1 In one example, the nickel-metal hydride battery consists of three cells connected in series and three pairs of signal coupling devices.

[0032] The three batteries connected in series are battery B1, battery B2, and battery B3.

[0033] The three signal coupling devices include a first signal coupling device and a second signal coupling device, respectively.

[0034] The voltage divider resistor includes a first resistor R1 and a second resistor R2, which are connected in series. The first resistor R1 is connected to the output terminal of the second signal coupling device, and the second resistor R2 is connected to the output terminal of the first signal coupling device. A voltage divider signal is output between the first resistor R1 and the second resistor R2.

[0035] Battery B1 corresponds to the first signal coupling device 11 and the second signal coupling device 12. The output terminal of the first signal coupling device 11 is connected to the positive terminal B1+ of battery B1 and the second resistor R2. The output terminal of the second signal coupling device 12 is connected to the negative terminal B1- of battery B1 and the first resistor R1.

[0036] Battery B2 corresponds to the first signal coupling device 21 and the second signal coupling device 22. The output terminal of the first signal coupling device 21 is connected to the positive terminal B2+ of battery B2 and the second resistor R2. The output terminal of the second signal coupling device 22 is connected to the negative terminal B2- of battery B2 and the first resistor R1.

[0037] Battery B3 corresponds to the first signal coupling device 31 and the second signal coupling device 32. The output terminal of the first signal coupling device 31 is connected to the positive terminal B3+ of battery B3 and the second resistor R2. The output terminal of the second signal coupling device 32 is connected to the negative terminal B3- of battery B3 and the first resistor R1.

[0038] In some embodiments, the signal coupling device is an optocoupler. When the battery voltage is not being sampled, the optocoupler is in an off state, resulting in low power consumption and increased battery life.

[0039] The first signal coupling device 11 is an optocoupler 11, and the second signal coupling device 12 is an optocoupler 12.

[0040] The first signal coupling device 21 is an optocoupler 21, and the second signal coupling device 22 is an optocoupler 22.

[0041] The first signal coupling device 31 is an optocoupler 31, and the second signal coupling device 32 is an optocoupler 32.

[0042] In some embodiments, the sampling circuit includes a decoder, which is connected to a control device MCU and a signal coupling device, and the control device MCU outputs a control signal to the decoder.

[0043] The truth table of the decoder is as follows Figure 2 As shown, the MCU outputs high and low levels to the decoder input ports S0, S1, and S2, and adjusts the high and low levels of the output ports Y0, Y1, and Y2 to ultimately achieve sampling switching for different batteries.

[0044] In some embodiments, the sampling circuit includes an analog signal digitization device (ADC), which is connected to a voltage divider resistor and a control device (MCU). An optocoupler can physically disconnect the battery and the ADC, resulting in low power loss.

[0045] In some embodiments, the analog signal digitization device is a differential analog-to-digital converter (ADC), and the input of the differential analog-to-digital converter (ADC) is connected to both ends of the second resistor R2.

[0046] When sampling the voltage of battery B1, the MCU first controls ports S0, S1, and S2 to output low level, low level, low level, and the decoder output ports Y0, Y1, and Y2 will output low level, high level, high level. Next, the LEDs inside optocouplers 11 and 12 are turned on, while the LEDs inside optocouplers 21, 22, 31, and 32 are turned off. This turns on the internal switches of optocouplers 11 and 12, connecting the positive terminal B1+ and negative terminal B1- of battery B1 to the differential ADC channel. The ADC samples the voltage and transmits the sampling result to the MCU, thus obtaining the voltage of battery B1.

[0047] The principles of sampling batteries B2 and B3 are similar to those of sampling battery B1, and will not be explained further here.

[0048] The nickel-metal hydride battery voltage sampling circuit solves the problem that lithium battery-specific BMS chips cannot sample the high voltage of nickel-metal hydride batteries; it also solves the problem of low sampling channel scalability of lithium battery-specific BMS chips; it only requires setting two voltage divider resistors, and matching different battery voltages only requires adjusting the resistance values ​​of resistors R1 and R2, resulting in a small number of resistors to adjust.

[0049] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by this utility model.

Claims

1. A nickel-metal hydride battery voltage sampling circuit, characterized in that, The circuit includes: N batteries connected in series; N pairs of signal coupling devices, each pair of signal coupling devices corresponds to one battery. Each pair of signal coupling devices includes a first signal coupling device and a second signal coupling device. The output terminal of the first signal coupling device is connected to the positive terminal of the corresponding battery and a voltage divider resistor, respectively. The output terminal of the second signal coupling device is connected to the negative terminal of the corresponding battery and a voltage divider resistor, respectively. The control device is configured to output a control signal to the signal coupling device and receive the voltage divider signal from the voltage divider resistor.

2. The nickel-metal hydride battery voltage sampling circuit according to claim 1, characterized in that, The sampling circuit includes a decoder, which is connected to the control device and the signal coupling device. The control device outputs a control signal to the decoder.

3. The nickel-metal hydride battery voltage sampling circuit according to claim 1, characterized in that, The sampling circuit includes an analog signal digitization device, which is connected to the voltage divider resistor and the control device.

4. The nickel-metal hydride battery voltage sampling circuit according to claim 1, characterized in that, The signal coupling device is an optocoupler.

5. The nickel-metal hydride battery voltage sampling circuit according to claim 1, characterized in that, The voltage divider resistor includes a first resistor and a second resistor. The first resistor is connected to the output terminal of the second signal coupling device, and the second resistor is connected to the output terminal of the first signal coupling device. A voltage divider signal is output between the first resistor and the second resistor.

6. The nickel-metal hydride battery voltage sampling circuit according to claim 1, characterized in that, The sampling circuit includes an analog signal digitization device, which is a differential analog-to-digital converter, and the input terminal of the differential analog-to-digital converter is connected to both ends of a second resistor.

7. A nickel-metal hydride battery management system, characterized in that, The system includes the voltage sampling circuit according to any one of claims 1-6.

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