A voltage sampling circuit for a series battery pack

Abstract

The utility model provides a kind of voltage sampling circuit for series battery pack, comprising: signal processing part and power isolation part;Signal processing part includes: the sampling circuit of multichannel electrode, multiplexer circuit, ADC conversion circuit and digital isolation circuit;Power isolation part includes: reference voltage circuit, 5V isolation power module and 9V isolation power module;The battery voltage of series battery pack is input to the input end of the sampling circuit of multichannel electrode, and the output end of the sampling circuit of multichannel electrode is connected with multiplexer circuit;The output end of multiplexer circuit is connected with the input end of ADC conversion circuit;The output end of ADC conversion circuit is connected with the input end of digital isolation circuit;The output end of digital isolation circuit is connected with the input end of multiplexer circuit;Reference voltage circuit is connected with ADC conversion circuit.The utility model circuit is simple, and it has the advantages of small, low cost.

Description

Technical Field

[0001] This invention relates to the technical field of automatic control and data acquisition in the new energy industry, and more particularly to a voltage sampling circuit for series battery packs. Background Technology

[0002] A battery, as an energy storage device, converts electrical energy into chemical energy for storage and releases it through chemical reactions when needed. The core of this process lies in the chemical reaction between the electrolyte and electrode materials inside the battery. In the renewable energy sector, battery energy storage systems can balance the output of unstable energy sources such as wind and solar power, improving grid stability and reliability. Battery voltage measurement is mainly used for:

[0003] 1. Determining the remaining battery power: As an energy storage device, the amount of power a battery has directly affects its lifespan and performance. By measuring the battery voltage, you can accurately determine the remaining battery power, thus deciding whether to replace or recharge it.

[0004] 2. Checking Battery Status: The battery's lifespan and status directly affect its performance and overall lifespan. Measuring battery voltage allows you to check its status, determining whether it's functioning correctly and whether replacement is necessary.

[0005] 3. Prevent battery undervoltage: Battery undervoltage can seriously affect battery life and safety. By measuring battery voltage, undervoltage problems can be detected early, allowing for appropriate measures to improve battery life and safety.

[0006] Currently, there are many battery voltage measurement schemes. The selection of a measurement scheme should take into account the accuracy, speed and cost of the measurement, as well as the issues of sampling signal distortion and high and low voltage interference isolation. Summary of the Invention

[0007] In view of the technical problems mentioned in the background section, a voltage sampling circuit for series-connected battery packs is provided. This invention employs a floating ground measurement method, directly measuring the potential signal across the terminals of the battery under test. This signal enters a differential amplifier, extracts the voltage difference, and sends it to an AD converter.

[0008] The technical means employed in this invention are as follows:

[0009] A voltage sampling circuit for a series battery pack includes: a signal processing unit and a power isolation unit;

[0010] The signal processing unit includes: a sampling circuit with multi-channel electrodes, a multiplexer circuit, an ADC conversion circuit, and a digital isolation circuit; the power isolation unit includes: a reference voltage circuit, a 5V isolation power supply module, and a 9V isolation power supply module.

[0011] The battery voltage of the series-connected battery pack is input to the input terminal of the sampling circuit of the multi-channel electrode. The output terminal of the sampling circuit of the multi-channel electrode is connected to the multiplexer circuit. The output terminal of the multiplexer circuit is connected to the input terminal of the ADC conversion circuit. The output terminal of the ADC conversion circuit is connected to the input terminal of the digital isolation circuit. The output terminal of the digital isolation circuit is connected to the input terminal of the multiplexer circuit. The reference voltage circuit is connected to the ADC conversion circuit.

[0012] Furthermore, the ADC conversion circuit provides VREF to the reference voltage circuit.

[0013] Furthermore, the 5V isolated power supply module is connected to a 5V power supply to provide stable power to the ADC conversion circuit and the multiplexer circuit.

[0014] Furthermore, the 9V isolated power supply module is connected to a 24V power supply to provide stable power to the sampling circuit of the multi-channel electrode.

[0015] Furthermore, the sampling circuit of the multi-channel electrode achieves multiple-to-one selection through a U10 chip multiplexer.

[0016] Furthermore, the ADC conversion circuit converts the analog signal into a readable data stream, making the voltage quantization readable.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] Compared with other voltage measurement circuits, the voltage sampling circuit provided by this utility model has the advantages of simple circuit, small price increase and low cost. Combined with isolation technology, it reduces the impact of the measurement circuit on the consistency of the battery pack. Therefore, the battery measurement circuit provided by this utility model patent has great practical value. Attached Figure Description

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

[0020] Figure 1 This is a circuit topology diagram of the present invention.

[0021] Figure 2 The circuit principle of this invention Figure 1 .

[0022] Figure 3 The circuit principle of this invention Figure 2 .

[0023] Figure 4 The circuit principle of this invention Figure 3 .

[0024] Figure 5 The circuit principle of this invention Figure 4 .

[0025] Figure 6 The circuit principle of this invention Figure 5 . Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0030] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0031] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0032] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0033] like Figure 1-6As shown, this utility model provides a voltage sampling circuit for a series battery pack, including a signal processing unit and a power isolation unit. The signal processing unit includes a multi-channel electrode sampling circuit, a multiplexer circuit, an ADC conversion circuit, and a digital isolation circuit; the power isolation unit includes a reference voltage circuit, a 5V isolated power supply module, and a 9V isolated power supply module.

[0034] The battery voltage of the series-connected battery pack is input to the input terminal of the sampling circuit of the multi-channel electrode. The output terminal of the sampling circuit of the multi-channel electrode is connected to the multiplexer circuit. The output terminal of the multiplexer circuit is connected to the input terminal of the ADC conversion circuit. The output terminal of the ADC conversion circuit is connected to the input terminal of the digital isolation circuit. The output terminal of the digital isolation circuit is connected to the input terminal of the multiplexer circuit. The reference voltage circuit is connected to the ADC conversion circuit.

[0035] In a preferred embodiment, in this application, the ADC conversion circuit provides VREF to the reference voltage circuit. A 5V isolated power supply module connected to a 5V power supply provides stable power to the ADC conversion circuit and the multiplexer circuit. A 9V isolated power supply module connected to a 24V power supply provides stable power to the sampling circuit of the multi-channel electrodes.

[0036] like Figure 2 As shown, the battery position signal input from connector CN7 / 8 / 9 / 10 has an amplitude of approximately 100V. After V1 is modulated by a differential amplifier circuit consisting of discrete resistors and capacitors and amplifier U7 / 8 / 9 / 10A, the voltage is amplified to V2, with an amplification factor of:

[0037]

[0038] V2 = 0.027 * V1;

[0039] To ensure the accuracy of signal acquisition, a filter stage was added. The filter circuit consists of discrete resistors and capacitors and amplifiers U7 / 8 / 9 / 10B, filtering out interference and high-frequency components from the signal. The filter adopts a Sallen-key topology, with the low-pass filter having a cutoff frequency set at 10kHz. The operational amplifiers are configured as voltage follower models.

[0040] In this application, the sampling circuit for the multi-channel electrodes achieves one-to-many selection via a U10 chip multiplexer. Each acquired voltage value is polled by controlling the pins. The U38 chip implements the ADC function, converting the analog signal into a readable data stream, making the voltage quantized and readable. An independent reference voltage VREF is also provided for the ADC module; the U37 reference voltage generator can provide a +4.1V voltage with an accuracy of 0.05%, ensuring that the ADC conversion is not affected by voltage fluctuations caused by the operation of other components in the system, thus guaranteeing reading accuracy.

[0041] To minimize the impact on other batteries in the battery pack, the power supply of the above measurement circuit needs to be isolated from the control power supply. This requires the use of a digital isolator and an isolated power supply module. U39 provides a ±9V isolated power supply to the entire sampling circuit to maintain the amplifier's operation, while U36 provides the operating voltage for other AD chips and multiplexers.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A voltage sampling circuit for a series-connected battery pack, characterized in that, include: Signal processing unit and power isolation unit; The signal processing unit includes: a sampling circuit with multi-channel electrodes, a multiplexer circuit, an ADC conversion circuit, and a digital isolation circuit; the power isolation unit includes: a reference voltage circuit, a 5V isolation power supply module, and a 9V isolation power supply module. The battery voltage of the series-connected battery pack is input to the input terminal of the sampling circuit of the multi-channel electrode. The output terminal of the sampling circuit of the multi-channel electrode is connected to the multiplexer circuit. The output terminal of the multiplexer circuit is connected to the input terminal of the ADC conversion circuit. The output terminal of the ADC conversion circuit is connected to the input terminal of the digital isolation circuit. The output terminal of the digital isolation circuit is connected to the input terminal of the multiplexer circuit. The reference voltage circuit is connected to the ADC conversion circuit.

2. The voltage sampling circuit for a series battery pack according to claim 1, characterized in that, The ADC conversion circuit provides VREF to the reference voltage circuit.

3. A voltage sampling circuit for a series battery pack according to claim 1, characterized in that, The 5V isolated power supply module is connected to a 5V power supply to provide stable power to the ADC conversion circuit and the multiplexer circuit.

4. A voltage sampling circuit for a series battery pack according to claim 1, characterized in that, The 9V isolated power supply module is connected to a 24V power supply to provide stable power to the sampling circuit of the multi-channel electrode.

5. A voltage sampling circuit for a series battery pack according to claim 1, characterized in that, The sampling circuit of the multi-channel electrode achieves multiple-choice selection through a U10 chip multiplexer.

6. A voltage sampling circuit for a series battery pack according to claim 1, characterized in that, The ADC conversion circuit converts analog signals into a readable data stream, making voltage quantization readable.

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