CN218938462U - A DC power supply voltage sampling component for feeder terminal devices - Google Patents

Abstract

The utility model belongs to the technical field of measuring instruments, and in particular relates to a DC power supply voltage sampling component used on a feeder terminal device. The DC power supply voltage sampling component comprises: a voltage divider module, a filter module, a first operational amplifier module, and Isolate the input module and the voltage follower module; the voltage divider module samples the voltage signal of the DC power supply to divide the voltage signal; the filter module filters out the low-frequency ripple interference of the power supply in the voltage signal; the first operational amplifier module amplifies the voltage signal to send Input the isolated input module; after the voltage signal is electrically isolated by the isolated input module, the voltage follower module outputs the buffered voltage signal to the single-chip microcomputer; the utility model can ensure the linearity of the input and output under the condition of effective isolation by setting the isolated input module, And the performance is good, the circuit is simple, and effectively solves the electrical isolation problem between the analog signal and the single-chip microcomputer. The driving stage and the buffer stage adopt a combined operational amplifier, which can improve the linearity.

Description

A DC power supply voltage sampling component for feeder terminal device

technical field

The utility model belongs to the technical field of measuring instruments, in particular to a DC power supply voltage sampling component used on a feeder terminal device.

Background technique

The feeder terminal device has the functions of remote control, remote signaling, and fault detection, and communicates with the main station of distribution automation to provide the operation status of the distribution system and various parameters, that is, the information required for monitoring and control, including switch status, power parameters, phase-to-phase faults, and grounding. Fault and fault parameters, and execute the command issued by the power distribution master station, adjust and control the power distribution equipment, and realize the functions of fault location, fault isolation and fast restoration of power supply in non-faulty areas. In order to meet the above requirements, the feeder terminal device needs to be in the working state all the time. When the external power supply is disconnected, the feeder terminal device needs to be put into the battery immediately. If the DC power supply voltage sampling circuit part does not work accurately, it will cause some malfunctions.

In existing DC power supply voltage sampling circuits, resistance voltage dividers or voltage sensors are often used to realize DC power supply voltage sampling. The disadvantage of the resistor divider sampling circuit is that it cannot be isolated and its linearity is poor. If the power supply fails, it will damage the subsequent single-chip microcomputer chip and cause a large loss. The voltage sensor sampling circuit is costly, bulky, and occupies a large PCB area.

Therefore, there is an urgent need to develop a new DC power supply voltage sampling component for feeder terminal devices to solve the above problems.

Utility model content

The purpose of the utility model is to provide a DC power supply voltage sampling component used on a feeder terminal device.

In order to solve the above-mentioned technical problems, the utility model provides a DC power supply voltage sampling assembly used on the feeder terminal device, which includes: a voltage divider module, a filter module, a first operational amplifier module, an isolated input module and a voltage follower module; wherein the input end of the voltage divider module is connected to the DC power supply output by the AC power supply module, and the output end of the voltage follower module is connected to the single-chip microcomputer; the voltage divider module is suitable for sampling the voltage signal of the DC power supply to the voltage The signal is divided into voltages; the filter module is suitable for filtering out the low-frequency ripple interference of the power supply in the voltage signal; the first operational amplifier module is suitable for amplifying the voltage signal to send it to the isolated input module; the voltage signal is passed through the isolated After the input module is electrically isolated, the voltage follower module outputs the buffered voltage signal to the single-chip microcomputer.

Further, the voltage dividing module includes: a voltage dividing circuit; the voltage dividing circuit is adapted to sample the voltage signal of the DC power supply and divide the voltage signal.

Further, a first voltage-dividing resistor and a second voltage-dividing resistor are set in the voltage-dividing circuit, and the voltage signal is divided by the first voltage-dividing resistor and the second voltage-dividing resistor.

Further, the filter module includes: a filter circuit; the filter circuit is suitable for filtering low-frequency ripple interference of the power supply in the voltage signal.

Further, a first filter capacitor is set in the filter circuit, and the voltage signal passes through the filter capacitor to filter out low-frequency ripple interference of the power supply.

Further, the first op-amp module includes: a first op-amp circuit; the first op-amp circuit is adapted to amplify a voltage signal to send it to the isolated input module.

Further, a first operational amplifier is provided in the first operational amplifier circuit to perform operational amplification on the voltage signal.

Further, the isolated input module includes: an isolated input circuit; the isolated input circuit is suitable for electrically isolating voltage signals.

Further, the isolated input circuit includes: a linear optocoupler; a light emitting tube, a feedback photodiode and an output photodiode are arranged inside the linear optocoupler, when the first pin and the second pin of the linear optocoupler When passing through the driving current If, to emit infrared light; the infrared light is irradiated on the feedback photodiode and the output photodiode, and the feedback photodiode absorbs part of the luminous flux to generate the control current I1; the control current I1 is suitable for adjusting the driving current If to compensate The nonlinearity of the luminous tube: the output photodiode generates an output current I2 that is linearly proportional to the servo luminous flux emitted by the luminous tube, so as to electrically isolate the voltage signal.

Further, the voltage follower module includes: a voltage follower; the voltage follower buffers the voltage signal to send the voltage signal to the single-chip microcomputer.

The beneficial effect of the utility model is that the utility model can ensure the linearity of the input and output under the condition of effective isolation by setting the isolation input module, and the linearity is good, the circuit is simple, and the electrical isolation problem between the analog signal and the single-chip microcomputer is effectively solved , The driver stage and the buffer stage use combined operational amplifiers, which can improve the linearity.

Other features and advantages of the present invention will be set forth in the following description, and partly become apparent from the description, or can be learned by implementing the present invention.

In order to make the above-mentioned purpose, features and advantages of the present invention more comprehensible, preferred embodiments are specifically cited below, together with the accompanying drawings, and are described in detail as follows.

Description of drawings

In order to more clearly illustrate the specific implementation of the utility model or the technical solutions in the prior art, the accompanying drawings that need to be used in the description of the specific implementation or the prior art will be briefly introduced below. Obviously, the following descriptions The accompanying drawings are some implementations of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without any creative work.

Fig. 1 is the circuit diagram of the DC power supply voltage sampling assembly used on the feeder terminal device of the present utility model;

Fig. 2 is the circuit diagram of the voltage divider module and filter module of the present utility model;

Fig. 3 is the circuit diagram of the first operational amplifier module of the present utility model;

Fig. 4 is the circuit diagram of the isolated input module of the present utility model;

Fig. 5 is a circuit diagram of the voltage follower module of the present invention.

In the picture:

R2, the first voltage divider resistor; R5, the second voltage divider resistor; C7, the first filter capacitor; U2, the first operational amplifier; U1, linear optocoupler; L, light-emitting tube; PD1, feedback photodiode; PD2, output Photodiode; U3, voltage follower.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model. rather than all examples. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Example 1

In this embodiment, as shown in Fig. 1 to Fig. 5, this embodiment provides a DC power supply voltage sampling assembly used on a feeder terminal device, which includes: a voltage divider module, a filter module, a first An operational amplifier module, an isolated input module, and a voltage follower module; wherein the input end of the voltage divider module is connected to the DC power output of the AC power supply module, and the output end of the voltage follower module is connected to a single-chip microcomputer; the voltage divider module is suitable for sampling The voltage signal of the DC power supply is used to divide the voltage signal; the filter module is suitable for filtering the low-frequency ripple interference of the power supply in the voltage signal; the first operational amplifier module is suitable for amplifying the voltage signal to send it to the isolated An input module; after the voltage signal is electrically isolated by the isolation input module, the voltage follower module outputs the buffered voltage signal to the single-chip microcomputer.

In this embodiment, this embodiment can ensure the linearity of the input and output under the condition of effective isolation by setting the isolated input module, and the linearity is good, the circuit is simple, and the problem of electrical isolation between the analog signal and the single-chip microcomputer is effectively solved. Stage and buffer stage adopt combined operational amplifier, which can improve the linearity.

In this embodiment, the voltage dividing module includes: a voltage dividing circuit; the voltage dividing circuit is adapted to sample a voltage signal of a DC power supply and divide the voltage signal.

In this embodiment, a first voltage dividing resistor R2 and a second voltage dividing resistor R5 are provided in the voltage dividing circuit, and the voltage signal is divided by the first voltage dividing resistor R2 and the second voltage dividing resistor R5.

In this embodiment, the filter module includes: a filter circuit; the filter circuit is suitable for filtering low-frequency ripple interference of a power supply in a voltage signal.

In this embodiment, a first filter capacitor C7 is set in the filter circuit, and the voltage signal passes through the filter capacitor to filter out low-frequency ripple interference of the power supply.

In this embodiment, VIN is the DC power output by the AC power supply module, and the voltage signal after being divided by the first voltage dividing resistor R2 and the second voltage dividing resistor R5 is within the input range of the operational amplifier of the first operational amplifier module. A filter capacitor C7 is used to filter out the low-frequency ripple interference of the power supply.

In this embodiment, the first operational amplifier module includes: a first operational amplifier circuit; the first operational amplifier circuit is adapted to amplify a voltage signal to send it to the isolated input module.

In this embodiment, a first operational amplifier U2 is provided in the first operational amplifier circuit to perform operational amplification on voltage signals.

In this embodiment, the first operational amplifier U2 functions to improve the driving capability, the capacitor C1 is to improve the stability of the first operational amplifier U2, and the capacitors C2 and C3 are power filter capacitors of the first operational amplifier U2.

In this embodiment, the isolated input module includes: an isolated input circuit; the isolated input circuit is suitable for electrically isolating voltage signals.

In this embodiment, the isolated input circuit includes: a linear optocoupler U1; a light-emitting tube L, a feedback photodiode PD1 and an output photodiode PD2 are arranged inside the linear optocoupler U1, when the linear optocoupler U1 When the driving current If passes through the first pin and the second pin, infrared light is emitted; the infrared light is irradiated on the feedback photodiode PD1 and the output photodiode PD2, and the feedback photodiode PD1 absorbs part of the luminous flux to generate a control current I1; the control current I1 is suitable for adjusting the driving current If to compensate the nonlinearity of the light-emitting tube L; the output photodiode PD2 generates an output current I2 that is linearly proportional to the servo luminous flux emitted by the light-emitting tube L, so as to electrically isolate the voltage signal.

In this embodiment, the resistor R4 is used to adjust the driving current If of the light-emitting tube L in the linear optocoupler U1, and the current on the resistor R3 is the control current I1 of the feedback photodiode PD1 in the linear optocoupler U1.

In this embodiment, the voltage follower module includes: a voltage follower U3; the voltage follower U3 buffers the voltage signal, so as to send the voltage signal to the single-chip microcomputer.

In this embodiment, the voltage follower U3 and peripheral circuits can provide system stability, further isolate the signal acquisition terminal and the ADC input terminal of the single-chip microcomputer, and also reduce the interference of the ADC sampling of the single-chip microcomputer to the power supply input terminal.

In this embodiment, the resistor R6 satisfies the impedance matching of the ADC input end of the subsequent single-chip microcomputer, and the capacitor C8 is used to filter out low-frequency interference.

In summary, the utility model can ensure the linearity of input and output under the condition of effective isolation by setting the isolation input module, and the linearity is good, the circuit is simple, and the problem of electrical isolation between the analog signal and the single-chip microcomputer is effectively solved. , The buffer stage adopts a combined operational amplifier, which can improve the linearity.

Each device selected in this application (not specifying the parts of specific structure) is a general standard part or a part known to those skilled in the art, and its structure and principle are all known to those skilled in the art through technical manuals or through conventional experimental methods informed. Moreover, the software programs involved in this application are all prior art, and this application does not involve making any improvements to the software programs.

In the description of the embodiments of the present utility model, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, Or integrally connected; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present utility model in specific situations.

In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" The orientation or positional relationship indicated by etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, use a specific The azimuth structure and operation, therefore can not be construed as the limitation of the present utility model. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods may be implemented in other ways. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some communication interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit.

Inspired by the above ideal embodiment according to the utility model, through the above description content, relevant staff can completely make various changes and modifications within the scope of not deviating from the technical idea of the utility model. The technical scope of this utility model is not limited to the content in the description, but must be determined according to the scope of the claims.

Claims (10)

1. A DC power supply voltage sampling assembly used on a feeder terminal device, characterized in that it comprises: A voltage divider module, a filter module, a first operational amplifier module, an isolated input module and a voltage follower module connected in sequence; wherein The input end of the voltage divider module is connected to the DC power supply output by the AC power supply module, and the output end of the voltage follower module is connected to the single-chip microcomputer; The voltage dividing module is suitable for sampling the voltage signal of the DC power supply to divide the voltage signal; The filtering module is suitable for filtering low-frequency ripple interference of the power supply in the voltage signal; The first operational amplifier module is suitable for amplifying voltage signals to be sent to the isolated input module; After the voltage signal is electrically isolated by the isolation input module, the voltage follower module outputs the buffered voltage signal to the single-chip microcomputer. 2. The DC power supply voltage sampling assembly used on the feeder terminal device as claimed in claim 1, characterized in that, The voltage dividing module includes: a voltage dividing circuit; The voltage divider circuit is suitable for sampling the voltage signal of the DC power supply and dividing the voltage signal. 3. The DC power supply voltage sampling assembly used on the feeder terminal device as claimed in claim 2, characterized in that, A first voltage-dividing resistor and a second voltage-dividing resistor are set in the voltage-dividing circuit, and the voltage signal is divided by the first voltage-dividing resistor and the second voltage-dividing resistor. 4. The DC power supply voltage sampling assembly used on the feeder terminal device as claimed in claim 1, characterized in that, The filtering module includes: a filtering circuit; The filtering circuit is suitable for filtering low-frequency ripple interference of the power supply in the voltage signal. 5. The DC power supply voltage sampling assembly used on the feeder terminal device as claimed in claim 4, characterized in that, A first filter capacitor is set in the filter circuit, and the voltage signal passes through the filter capacitor to filter out low-frequency ripple interference of the power supply. 6. The DC power supply voltage sampling assembly used on the feeder terminal device as claimed in claim 1, characterized in that, The first operational amplifier module includes: a first operational amplifier circuit; The first operational amplifier circuit is suitable for amplifying a voltage signal to send it to the isolated input module. 7. The DC power supply voltage sampling assembly used on the feeder terminal device according to claim 6, characterized in that, A first operational amplifier is provided in the first operational amplifier circuit to perform operational amplification on the voltage signal. 8. The DC power supply voltage sampling assembly used on the feeder terminal device according to claim 1, characterized in that, The isolated input module includes: an isolated input circuit; The isolated input circuit is adapted to electrically isolate voltage signals. 9. The DC power supply voltage sampling assembly used on the feeder terminal device according to claim 8, characterized in that, The isolated input circuit includes: a linear optocoupler; The inside of the linear optocoupler is provided with a light-emitting tube, a feedback photodiode and an output photodiode, and when the first pin and the second pin of the linear optocoupler pass a driving current If, to emit infrared light; The infrared light is irradiated on the feedback photodiode and the output photodiode, and the feedback photodiode absorbs part of the luminous flux to generate the control current I1; The control current I1 is suitable for adjusting the driving current If to compensate the nonlinearity of the light-emitting tube; The output photodiode generates an output current I2 that is linearly proportional to the servo luminous flux emitted by the light emitting tube, so as to electrically isolate the voltage signal. 10. The DC power supply voltage sampling assembly used on the feeder terminal device according to claim 1, characterized in that, The voltage follower module includes: a voltage follower; The voltage follower buffers the voltage signal so as to send the voltage signal to the single-chip microcomputer.

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