Voltage sensor circuit
By designing a voltage sensor circuit consisting of a voltage divider capacitor, a filtering module, an operational amplifier module, and a signal conditioning module, the problem that voltage sensors in the existing technology cannot be miniaturized and modularized is solved, and high-precision voltage monitoring and fault location are achieved. It is suitable for power systems, industrial automation, and new energy fields.
Patent Information
- Application Number
- CN202510620997.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-14
- Publication Date
- 2025-09-05
AI Technical Summary
Existing electronic voltage sensors cannot meet the small modular requirements of power inspection meters, power grid monitoring, smart grids, electric vehicle battery management systems, and portable medical devices. This is mainly due to the contradiction between the electrode size and sensitivity of the signal sensing unit, the large coil size, the high impedance front end requiring high voltage power supply, and the large number of signal conditioning circuit components and the large PCB area occupied.
A voltage sensor circuit was designed, including a voltage divider capacitor, a filter module, an operational amplifier module, a signal conditioning module, and an output module. The voltage divider capacitor reduces the high-voltage input signal, the filter module filters out clutter and AC components, the operational amplifier module amplifies the signal, the signal conditioning module determines the output impedance and calibrates the phase difference, and the output module outputs the signal. The number of components is reduced to 11, achieving compact modularization.
The electronic voltage sensor is modularized to achieve a small size with an accuracy of less than 0.2%, which saves materials, is environmentally friendly and low-carbon, and can monitor high-voltage input signals in real time and perform fault location and grid regulation.
Smart Images
Figure CN120594909A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of sensor technology, and in particular to a voltage sensor circuit. Background Art
[0002] An electronic voltage sensor (EVS) is a device that uses electronic technology to measure voltage and is primarily used in power systems, industrial automation, new energy, and other fields. The voltage sensor circuit typically consists of a signal sensing unit, a high-impedance front end, a signal conditioning circuit, a digital-to-analog converter, and a power supply system. Due to the conflict between the electrode size and sensitivity of the signal sensing unit, the coil is large; the high-impedance front end requires a high-voltage power supply and relies on discrete JFETs, occupying over 40% of the PCB area; the signal conditioning circuit needs to handle multiple stages of amplification and bandpass filtering, requiring more than 20 passive components; and the power module accounts for over 30% of the PCB area. Therefore, existing electronic voltage sensors cannot meet the demands for small modularization in areas such as power inspection meters, power grid monitoring, smart grids, electric vehicle battery management systems, and portable medical devices. Summary of the Invention
[0003] In order to solve the above technical problems, an object of the present invention is to provide a voltage sensor circuit that can realize small modularization of an electronic voltage sensor.
[0004] The technical solution adopted by the present invention is: a voltage sensor circuit, including a voltage divider capacitor, a filter module, an operational amplifier module, a signal conditioning module and an output module, wherein:
[0005] The first end of the voltage-dividing capacitor is connected to the high-voltage input signal; the second end of the voltage-dividing capacitor is connected to the input end of the filtering module; the output end of the filtering module is connected to the input end of the operational amplifier module; the output end of the operational amplifier module is connected to the input end of the signal conditioning module; and the output end of the signal conditioning module is connected to the output module.
[0006] The signal conditioning module includes an eighth resistor, a ninth resistor and a nineteenth capacitor, the first end of the eighth resistor is connected to the output end of the operational amplifier; the second end of the eighth resistor is connected to the first end of the ninth resistor, the first end of the nineteenth capacitor, and the signal output interface of the output module; the second end of the ninth resistor and the second end of the nineteenth capacitor are grounded.
[0007] Furthermore, the filtering module includes a sixth resistor, a fifteenth capacitor, and a sixteenth capacitor, wherein:
[0008] The first end of the sixth resistor is connected to the second end of the voltage-dividing capacitor; the second end of the sixth resistor is connected to the first end of the fifteenth capacitor, the first end of the sixteenth capacitor, and the input end of the operational amplifier module; the second end of the fifteenth capacitor and the second end of the sixteenth capacitor are grounded.
[0009] Furthermore, the operational amplifier module includes an eighteenth capacitor, a fourth resistor, a fourteenth capacitor, a seventeenth capacitor, a seventh resistor, a fifth resistor and an operational amplifier, wherein:
[0010] The negative input gain adjustment pin of the operational amplifier is connected to the first end of the fourth resistor; the positive input gain adjustment pin of the operational amplifier is connected to the second end of the fourth resistor; the differential input negative pin of the operational amplifier is connected to the second end of the fifth resistor; the first end of the fifth resistor is grounded; the differential input positive pin of the operational amplifier is connected to the second end of the sixth resistor; the negative power supply pin of the operational amplifier is connected to the second end and the negative power supply of the eighteenth capacitor; the first end of the eighteenth capacitor is grounded; the positive power supply pin of the operational amplifier is connected to the first end and the positive power supply of the fourteenth capacitor; the second end of the fourteenth capacitor is grounded; the reference voltage input pin of the operational amplifier is connected to the first end of the seventeenth capacitor and the first end of the seventh resistor; the second end of the seventeenth capacitor and the second end of the seventh resistor are grounded; and the output pin of the operational amplifier is connected to the first end of the eighth resistor.
[0011] Furthermore, the fifteenth capacitor and the sixteenth capacitor form a multi-capacitor connected in parallel, which is used to filter out clutter and AC components in the high-voltage input signal.
[0012] Furthermore, the fourth resistor and the fifth resistor are operational amplifier adjustment resistors, which jointly adjust the gain of the operational amplifier.
[0013] Furthermore, the seventh resistor and the seventeenth capacitor form an RC parallel network for providing a midpoint voltage.
[0014] Furthermore, the ninth resistor and the nineteenth capacitor form an RC parallel network for determining output impedance and calibrating output phase difference.
[0015] Furthermore, the eighth resistor and the ninth resistor are used to adjust the output voltage amplitude.
[0016] Furthermore, the fourteenth capacitor and the eighteenth capacitor are filter capacitors, which are used to filter out clutter and AC components in the positive power supply and the negative power supply respectively.
[0017] The present invention provides a voltage sensor circuit that reduces the voltage of a high-voltage input signal using a voltage-dividing capacitor; removes noise and AC components from the reduced-voltage input signal using a filtering module; amplifies the filtered input signal using a signal amplification module to facilitate observation; and determines the circuit's output impedance using a signal conditioning module and calibrates the phase difference of the op amp's output signal, enabling monitoring of the high-voltage input signal. This voltage sensor circuit requires only 11 passive components, enabling compact modularization of electronic voltage sensors, achieving an accuracy of less than 0.2%, and significantly saving materials, resulting in environmentally friendly and low-carbon designs. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a structural schematic diagram of a voltage sensor circuit of the present invention;
[0019] Description of the accompanying drawings: C, voltage-dividing capacitor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor; R9, ninth resistor; C15, fifteenth capacitor; C16, sixteenth capacitor; C17, seventeenth capacitor; C18, eighteenth capacitor; C19, nineteenth capacitor; U5, operational amplifier; CN1, output module. DETAILED DESCRIPTION
[0020] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the embodiments of the present invention, and should not be construed as limiting the present invention.
[0021] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.
[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically defined.
[0023] In the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.
[0024] Reference Figure 1 A voltage sensor circuit includes a voltage divider capacitor C, a filter module, an operational amplifier module, a signal conditioning module, and an output module, wherein:
[0025] The first end of the voltage-dividing capacitor C is connected to the high-voltage input signal, and the voltage-dividing capacitor C is used to reduce the voltage of the high-voltage input signal. Otherwise, the 10KV, 50Hz high-voltage input signal used in the specific embodiment of the present invention will overvoltage and break down the operational amplifier, damaging circuit components; the second end of the voltage-dividing capacitor C is connected to the input end of the filtering module, and the noise and AC components in the input signal after the voltage is reduced are filtered out by the filtering module; the output end of the filtering module is connected to the input end of the operational amplifier module, and the filtered input signal is amplified to facilitate observation of the filtered input signal; the output end of the operational amplifier module is connected to the input end of the signal conditioning module, which is used to determine the output impedance of the circuit and calibrate the phase difference of the operational amplifier output signal; the output end of the signal conditioning module is connected to the output module to facilitate outputting the output signal to a display device.
[0026] As a preferred embodiment, the signal conditioning module includes an eighth resistor R8, a ninth resistor R9 and a nineteenth capacitor C19, wherein:
[0027] The first end of the eighth resistor R8 is connected to the output end of the operational amplifier U5; the second end of the eighth resistor R8 is connected to the first end of the ninth resistor R9, the first end of the nineteenth capacitor C19, and the signal output interface of the output module; the second end of the ninth resistor R9 and the second end of the nineteenth capacitor C19 are grounded. The ninth resistor R9 and the nineteenth capacitor C19 together form an RC parallel network for determining the output impedance and calibrating the output phase difference; the eighth resistor R8 and the ninth resistor R9 are used to adjust the output voltage amplitude.
[0028] As a preferred embodiment, the filtering module includes a sixth resistor R6, a fifteenth capacitor C15, and a sixteenth capacitor C16, wherein:
[0029] The first end of the sixth resistor R6 is connected to the second end of the voltage divider capacitor C. The second end of the sixth resistor R6 is connected to the first end of the fifteenth capacitor C15, the first end of the sixteenth capacitor C16, and the input end of the operational amplifier module. The second end of the fifteenth capacitor C15 and the second end of the sixteenth capacitor C16 are grounded. The sixth resistor R6 reduces current noise and common-mode noise, while also improving the stability and reliability of the circuit. The fifteenth capacitor C15 and the sixteenth capacitor C16 together form a multi-capacitor parallel connection for filtering out noise and AC components in the stepped-down input signal.
[0030] As a preferred embodiment, the operational amplifier module includes an eighteenth capacitor C18, a fourth resistor R4, a fourteenth capacitor C14, a seventeenth capacitor C17, a seventh resistor R7, a fifth resistor R5 and an operational amplifier U5, wherein:
[0031] The negative input gain adjustment pin RG- of the operational amplifier U5 is connected to the first end of the fourth resistor R4; the positive input gain adjustment pin RG+ of the operational amplifier U5 is connected to the second end of the fourth resistor R4; the differential input negative pin IN- of the operational amplifier U5 is connected to the second end of the fifth resistor R5; the first end of the fifth resistor R5 is grounded; the differential input positive pin IN+ of the operational amplifier U5 is connected to the second end of the sixth resistor R6; the negative power supply pin VS- of the operational amplifier U5 is connected to the second end of the eighteenth capacitor C18 and the negative power supply VEE; the first end of the eighteenth capacitor C18 is grounded; the positive power supply pin VS+ of the operational amplifier U5 is connected to the first end of the fourteenth capacitor C14 and the positive power supply VCC; the second end of the fourteenth capacitor C14 is grounded; the reference voltage input pin REF of the operational amplifier U5 is connected to the first end of the seventeenth capacitor C17 and the first end of the seventh resistor R7; the second end of the seventeenth capacitor C17 and the second end of the seventh resistor R7 are grounded; the output pin OUT of the operational amplifier U5 is connected to the first end of the eighth resistor R8. The fourth resistor R4 and the fifth resistor R5 are op amp adjustment resistors, which together adjust the gain of the operational amplifier. The seventh resistor R7 and the seventeenth capacitor C17 together form an RC parallel network for providing a midpoint voltage. The fourteenth capacitor C14 and the eighteenth capacitor C18 are filter capacitors, respectively used to filter out noise and AC components in the positive and negative power supplies.
[0032] As a preferred embodiment, the output module further includes a power port VCC and a ground port GND. In a specific embodiment of the present invention, the output module does not have to assume the signal conditioning function, but only outputs the output signal adjusted by the signal conditioning module. Therefore, in order to fully minimize the circuit structure, the output module and the power module are organically integrated. The output module can be a socket with an output interface, a power interface and a ground interface.
[0033] As a preferred embodiment, in order to further highlight the small modular features of the voltage sensor, the voltage divider capacitor C is set on the outside of the PCB board, and screw holes and copper screws are used as the connection medium between the voltage divider capacitor C and the filter module, further avoiding the impact of the large volume of the voltage divider capacitor C on the small modularity of the voltage sensor circuit.
[0034] In a specific embodiment of the present invention, the fifteenth capacitor and the sixteenth capacitor form a multi-capacitor parallel connection, the seventh resistor and the seventeenth capacitor form an RC parallel connection, and the ninth resistor and the nineteenth capacitor form an RC parallel connection. By using a multi-element parallel compensation method, the voltage sensor of the present invention can achieve an accuracy of less than 0.2%.
[0035] By using the voltage sensor of the present invention, when detecting the voltage stability of a high-voltage transmission line, the voltage sensor of the present invention is installed at a key node to collect voltage amplitude and phase information in real time; the output module is then used to transmit the voltage sensor data to a fuzzy PID controller to dynamically optimize the grid voltage regulation; in addition, the voltage sensor of the present invention captures the traveling wave signal generated by the fault, fuses it with the current sensor data, and calculates the distance to the fault point through a D-type or A-type traveling wave ranging algorithm to achieve fault location.
[0036] By using the voltage sensor of the present invention, when distributed energy is connected to the grid, the voltage sensor of the present invention is deployed at the distributed power grid connection point and key feeder nodes to monitor the voltage amplitude and fluctuation in real time. When the output power of the photovoltaic inverter suddenly changes, causing the local voltage to rise, the sensor data triggers the dynamic voltage restorer to inject a compensation voltage to suppress the voltage exceeding the limit and achieve coordinated voltage balance. In the wind power cluster grid connection scenario, the voltage sensor detects voltage frequency oscillation, and the power electronic damper generates a reverse damping voltage based on the voltage sensor feedback signal to stabilize the system and suppress grid oscillation.
[0037] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.
Claims
1. A voltage sensor circuit, characterized in that: It includes voltage divider capacitors, filter modules, operational amplifier modules, signal conditioning modules and output modules, among which: The first end of the voltage-dividing capacitor is connected to the high-voltage input signal; the second end of the voltage-dividing capacitor is connected to the input end of the filtering module; the output end of the filtering module is connected to the input end of the operational amplifier module; the output end of the operational amplifier module is connected to the input end of the signal conditioning module; and the output end of the signal conditioning module is connected to the output module. The signal conditioning module includes an eighth resistor, a ninth resistor and a nineteenth capacitor, the first end of the eighth resistor is connected to the output end of the operational amplifier; the second end of the eighth resistor is connected to the first end of the ninth resistor, the first end of the nineteenth capacitor, and the signal output interface of the output module; the second end of the ninth resistor and the second end of the nineteenth capacitor are grounded.
2. A voltage sensor circuit according to claim 1, characterized in that: The filtering module includes a sixth resistor, a fifteenth capacitor, and a sixteenth capacitor, wherein: The first end of the sixth resistor is connected to the second end of the voltage-dividing capacitor; the second end of the sixth resistor is connected to the first end of the fifteenth capacitor, the first end of the sixteenth capacitor, and the input end of the operational amplifier module; the second end of the fifteenth capacitor and the second end of the sixteenth capacitor are grounded.
3. The voltage sensor circuit according to claim 1, wherein: The operational amplifier module includes an eighteenth capacitor, a fourth resistor, a fourteenth capacitor, a seventeenth capacitor, a seventh resistor, a fifth resistor, and an operational amplifier, wherein: The negative input gain adjustment pin of the operational amplifier is connected to the first end of the fourth resistor; the positive input gain adjustment pin of the operational amplifier is connected to the second end of the fourth resistor; the differential input negative pin of the operational amplifier is connected to the second end of the fifth resistor; the first end of the fifth resistor is grounded; the differential input positive pin of the operational amplifier is connected to the second end of the sixth resistor; the negative power supply pin of the operational amplifier is connected to the second end and the negative power supply of the eighteenth capacitor; the first end of the eighteenth capacitor is grounded; the positive power supply pin of the operational amplifier is connected to the first end and the positive power supply of the fourteenth capacitor; the second end of the fourteenth capacitor is grounded; the reference voltage input pin of the operational amplifier is connected to the first end of the seventeenth capacitor and the first end of the seventh resistor; the second end of the seventeenth capacitor and the second end of the seventh resistor are grounded; and the output pin of the operational amplifier is connected to the first end of the eighth resistor.
4. A voltage sensor circuit according to any one of claims 1 to 3, characterized in that: The fifteenth capacitor and the sixteenth capacitor form a multi-capacitor connected in parallel, and are used to filter out clutter and AC components in the high-voltage input signal.
5. The voltage sensor circuit according to any one of claims 1 to 3, characterized in that: The fourth resistor and the fifth resistor are operational amplifier adjustment resistors, which jointly adjust the gain of the operational amplifier.
6. The voltage sensor circuit according to any one of claims 1 to 3, characterized in that: The seventh resistor and the seventeenth capacitor form an RC parallel network for providing a midpoint voltage.
7. The voltage sensor circuit according to any one of claims 1 to 3, characterized in that: The ninth resistor and the nineteenth capacitor form an RC parallel network, which is used to determine the output impedance and calibrate the output phase difference.
8. The voltage sensor circuit according to any one of claims 1 to 3, characterized in that: The eighth resistor and the ninth resistor are used to adjust the output voltage amplitude.
9. The voltage sensor circuit according to any one of claims 1 to 3, characterized in that: The fourteenth capacitor and the eighteenth capacitor are filter capacitors, which are used to filter out clutter and AC components in the positive power supply and the negative power supply respectively.