Positive and negative voltage acquisition circuit of single-power ADC system

Abstract

The utility model provides a positive and negative voltage acquisition circuit for a single-power ADC system. The positive and negative voltage acquisition circuit comprises a main controller, an analog-to-digital conversion circuit, a signal amplification circuit, a biasing circuit and a filter circuit. The connector is connected with the signal amplification circuit and is used for transmitting the RCV signal; the signal amplification circuit is connected with the biasing circuit and is used for adjusting the amplitude of the signal; the biasing circuit is connected with the filter circuit and is used for eliminating interference to obtain an ideal sampling signal; the filter circuit is connected with the analog-to-digital conversion circuit and is used for converting the analog quantity into digital information collected by the main controller; and the main controller performs reading through a bus and is used for realizing closed-loop control. According to the utility model, bipolar signals are modulated into unipolar signals through circuit design, so that the integrity of the signals is ensured. Tiny signals are amplified to a proper amplitude, and the signal acquisition precision is improved. A mainstream single-power ADC chip is adopted, and compared with a dual-power ADC chip, the design cost is greatly reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of voltage signal collection, in particular, especially relates to a single power supply ADC system gathers positive and negative voltage circuit. BACKGROUND

[0002] In the all-vanadium redox flow battery control system, the accurate collection of RCV and OCV is crucial for the control of the whole system and ensures the stable operation of the system.

[0003] In the battery system, RCV and OCV represent the error and open circuit voltage under normal conditions, respectively.

[0004] RCV (Regular Conditions Voltage) refers to the error obtained by measuring the battery under normal conditions, reflecting the precision level of the project under normal conditions. It can not only be used to compare the precision of different methods, instruments, operators, etc. under normal conditions, but also is the basis for determining the target value and allowable error range in the battery system.

[0005] OCV (Open Circuit Voltage) refers to the voltage of the battery under no open circuit state, i.e. the voltage of the battery when it is not connected to an external circuit or load. It represents the potential difference of the battery in the static state and is usually used to evaluate the internal state and health condition of the battery.

[0006] In the battery management system (BMS), the accurate collection of these two voltages is of great significance. In most cases, RCV is a small voltage output with polarity, and for single power control system, it is necessary to do complex modulation to collect positive and negative voltages to ensure that the input signal of the final analog-to-digital converter is within the reference voltage range. INVENTION CONTENTS

[0007] According to the technical problems mentioned in the above background technology, a single power supply ADC system for collecting positive and negative voltage circuit is provided.

[0008] The technical means adopted by the utility model are as follows:

[0009] A single power supply ADC system for collecting positive and negative voltage circuit, comprising:

[0010] A main controller, an analog-to-digital conversion circuit, a signal amplification circuit, a bias circuit and a filter circuit;

[0011] The connector is connected with the signal amplification circuit and is used for transmitting RCV signal;

[0012] The signal amplification circuit is connected with the bias circuit and is used for adjusting the amplitude of the signal;

[0013] The bias circuit is connected with the filter circuit, and is used for eliminating interference to obtain a desired sampling signal.

[0014] The filter circuit is connected with the analog-digital conversion circuit, and is used for converting an analog quantity into digital information collected by the main controller.

[0015] The main controller reads through bus reading, and is used for realizing closed-loop control.

[0016] Further, the signal amplification circuit comprises a first-stage differential amplifier and a second-stage differential amplifier.

[0017] Further, the analog-digital conversion circuit is connected with the main controller, and the main controller reads the voltage amplitude of the ADC input signal through bus reading.

[0018] Further, the amplitude of the input signal is ±200 mV.

[0019] Further, the filter circuit is a Sallen-key topology, and the cutoff frequency of the filter circuit is 10 kHz.

[0020] Further, the first-stage differential amplifier comprises resistors R199, R205, R208 and R205.

[0021] After the signal amplification circuit is modulated by the first-stage differential amplifier, the voltage amplification multiple is:

[0022]

[0023] Wherein, R199, R205, R208 and R205 respectively represent resistance values.

[0024] The second-stage differential amplifier comprises resistors R210, R211 and R209.

[0025] After the signal amplification circuit is modulated by the second-stage differential amplifier, the voltage amplification multiple is:

[0026]

[0027] Wherein, R199, R205, R208 and R205 respectively represent resistance values.

[0028] Further, the bias circuit adjusts the amplitude of the signal to be:

[0029]

[0030] Wherein, R207 and R195 respectively represent resistance values; and V3 represents a voltage value at a previous moment.

[0031] Compared with the prior art, the utility model has the advantages that:

[0032] The utility model discloses a circuit design is modulated as unipolar signal to bipolar signal, guarantees the integrality of signal.

[0033] The utility model amplifies the small signal to the suitable amplitude, improves the collection accuracy of signal.

[0034] The utility model discloses the mainstream single power supply ADC chip is adopted, compared with dual power supply ADC chip, greatly reduces the design cost. DRAWINGS

[0035] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, the following will be to the embodiment or prior art description needed to use the drawing do with a simple introduction, obviously, the following description in the drawing is some embodiments of the utility model, for those skilled in the art, under the premise of not paying the creative labor, can also obtain other drawings according to these drawings.

[0036] Figure 1 It is the utility model circuit topology diagram.

[0037] Figure 2 It is the utility model circuit principle diagram. DETAILED DESCRIPTION

[0038] It should be noted that, in the case of no conflict, the embodiment in the utility model and the features in the embodiment can be combined with each other. The following will be described in detail with reference to the drawings and in combination with the embodiment.

[0039] In order to make the purpose, technical scheme and advantage of the embodiment of the utility model more clear, the following will be combined with the drawing in the embodiment of the utility model, and the technical scheme in the embodiment of the utility model is clearly and completely described, obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiment. The following description of at least one exemplary embodiment is actually only illustrative, but not as any limitation on the utility model and its application or use. Based on the embodiment in the utility model, all other embodiments obtained by those skilled in the art without creative labor are within the scope of the utility model protection.

[0040] It is to be understood that the terms so far as the language goes are used herein only to describe specific embodiments and not intended to limit the example embodiments according to the present application. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components, and / or combinations thereof.

[0041] The relative arrangement of parts and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application unless otherwise specifically stated. At the same time, it should be clear that the sizes of the various parts shown in the drawings are not drawn in accordance with the actual proportional relationship for the convenience of description. The technology, methods and devices known to those skilled in the related art can not be discussed in detail, but should be considered as part of the authorized description under appropriate circumstances. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so further discussion is not needed in subsequent drawings once an item is defined in one drawing.

[0042] In the description of the present application, it should be understood that the orientation words such as "front, rear, upper, lower, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate and imply that the indicated device or element must have a specific orientation or be constructed and operated in a specific orientation, therefore it cannot be understood as a limitation on the scope of protection of the present application: the orientation words "inner, outer" refer to the inner and outer of the contour of each component itself.

[0043] 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.

[0044] 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 cannot be construed as limiting the scope of protection of this utility model.

[0045] like Figure 1 As shown, this utility model provides a single-supply ADC system for acquiring positive and negative voltages, including: a main controller, an analog-to-digital conversion circuit, a signal amplification circuit, a bias circuit, and a filter circuit.

[0046] The connector connects to the signal amplification circuit for transmitting RCV signals; the signal amplification circuit connects to the bias circuit for adjusting the signal amplitude; the bias circuit connects to the filter circuit for eliminating interference and obtaining an ideal sampling signal; the filter circuit connects to the analog-to-digital converter circuit for converting analog quantities into digital information acquired by the main controller; the main controller reads data via the bus to achieve closed-loop control.

[0047] Preferably, the signal amplification circuit of this application includes: a first-stage differential amplifier and a second-stage differential amplifier. The first-stage differential amplifier includes: resistors R199, R205, R208, and R205;

[0048] After modulation by the first-stage differential amplifier, the voltage amplification factor of the signal amplification circuit is:

[0049]

[0050] Where R199, R205, R208, and R205 represent the resistance values, respectively;

[0051] The second-stage differential amplifier includes resistors R210, R211, and R209.

[0052] The voltage amplification factor of the signal amplification circuit after modulation by the second differential amplifier is:

[0053]

[0054] wherein R199, R205, R208, and R205 represent resistance values, respectively.

[0055] Preferably, the analog-to-digital conversion circuit is connected to the main controller, and the main controller reads the voltage amplitude of the ADC input signal through the bus. The amplitude of the input signal is ±200mV.

[0056] In the present application, the filter circuit is a Sallen-key topology, and the cutoff frequency of the filter circuit is 10kHz.

[0057] Preferably, the bias circuit adjusts the amplitude of the signal to:

[0058]

[0059] wherein R207 and R195 represent resistance values, respectively; and V3 represents the voltage value at the previous moment.

[0060] Embodiment:

[0061] Figure 2 In the present application, the ADC chip U26 is connected to the main controller, and the main controller reads the voltage amplitude of the ADC input signal through the bus.

[0062] The amplitude of the RCV signal input from the connector CN11 is ±200mV, and after modulation by the differential amplification circuit composed of the amplifiers U24A and U24B and the resistance-capacitance device, the voltage is amplified to V2, and the amplification factor is:

[0063]

[0064] V2=5*V1;

[0065] After processing by the U24C amplification circuit, the voltage is further amplified to V 3， The amplification factor is:

[0066]

[0067] V3=4*V2; the overall transfer function is V3=20*V1. The signal amplitude is amplified to ±4V, and the signal and the reference voltage are matched by resistance division, and a bias voltage is added to raise the negative half of the signal voltage to above 0V:

[0068]

[0069] Wherein, R207, R195 respectively represent resistance resistance value;V3 represents voltage value of previous time. The amplitude of V4 signal is modulated to 0~+4V, which has been controlled in the reference voltage 4.1V of ADC chip, and the chip can correctly process the signal.

[0070] In order to ensure the accuracy of signal acquisition, a level filter is added to remove the interference and high frequency components on the signal, and the filter adopts Sallen-key topology, and the low-pass filter is set to have a cutoff frequency of 10kHz. The operational amplifier is configured as a voltage follower model.

[0071] In this way, the signal meeting the sampling amplitude range can be sent into the ADC chip, and the main controller can monitor the change of RCV signal in real time through the bus, and the reference RCV voltage value can accurately control the whole battery system.

[0072] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the utility model, and not to limit them;Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features;And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A circuit for acquiring positive and negative voltages in a single-supply ADC system, characterized in that, include: Main controller, analog-to-digital converter circuit, signal amplifier circuit, bias circuit, and filter circuit; The connector is connected to the signal amplification circuit for transmitting RCV signals; The signal amplification circuit is connected to the bias circuit and is used to adjust the amplitude of the signal; The bias circuit is connected to the filter circuit to eliminate interference and obtain an ideal sampling signal; The filter circuit is connected to the analog-to-digital converter circuit and is used to convert analog signals into digital information collected by the main controller. The main controller reads data via a bus to achieve closed-loop control.

2. The circuit for acquiring positive and negative voltages in a single-supply ADC system according to claim 1, characterized in that, The signal amplification circuit includes a first-stage differential amplifier and a second-stage differential amplifier.

3. The circuit for acquiring positive and negative voltages in a single-supply ADC system according to claim 1, characterized in that, The analog-to-digital converter circuit is connected to the main controller, and the main controller reads the voltage amplitude of the ADC input signal through the bus.

4. The single-supply ADC system for acquiring positive and negative voltages according to claim 3, characterized in that, The amplitude of the input signal is ±200mV.

5. The circuit for acquiring positive and negative voltages in a single-supply ADC system according to claim 1, characterized in that, The filter circuit is a Sallen-key topology, and the cutoff frequency of the filter circuit is 10kHz.

6. The circuit for acquiring positive and negative voltages in a single-supply ADC system according to claim 2, characterized in that, The first stage differential amplifier includes: resistors ; After modulation by the first-stage differential amplifier, the voltage amplification factor of the signal amplification circuit is: ； in, These represent the resistance values; The second-stage differential amplifier includes: resistors ,resistance and resistance ; After modulation by the second-stage differential amplifier, the voltage amplification factor of the signal amplification circuit is: ； in, These represent the resistance values.

7. The circuit for acquiring positive and negative voltages in a single-supply ADC system according to claim 1, characterized in that, The bias circuit adjusts the amplitude of the signal. for: ； in, These represent the resistance values; This represents the voltage value at the previous moment.

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