Rogowski coil and electric energy metering equipment

Abstract

The invention provides a Rogowski coil and electric energy metering equipment, and relates to the technical field of electric power measurement, the Rogowski coil comprises an annular coil, a signal coupling circuit and an MCU circuit, the annular coil is used for sensing the current of a to-be-measured power grid wire to obtain an AC measurement signal; the annular coil transmits an alternating current measurement signal to an external measurement device through a signal coupling circuit; the MCU circuit is used for storing precision error information of the annular coil, and is also used for transmitting the precision error information to an external measurement device, so that the external measurement device measures the current of the to-be-measured power grid wire based on the alternating current measurement signal and the precision error information; wherein the annular coil, the signal coupling circuit and the MCU circuit are integrally designed. By implementing the technical scheme provided by the invention, the effect of improving the measurement accuracy is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of electric power measurement, and in particular to a Rogowski coil and electric energy metering equipment. Background Art

[0002] As a non-invasive current sensor, Rogowski coil is widely used in power systems due to its simple structure, fast response speed, wide dynamic range and other advantages. Many existing Rogowski coils do not fully consider the accuracy error data during design and use, which leads to large deviations in the measurement results. Especially under the demand for high-precision measurements, this error is unacceptable. In some measurement schemes with high accuracy requirements, Rogowski coils need to be paired with specific external measurement devices. Even if some Rogowski coils provide accuracy error data, these data usually need to be manually queried and manually input into the external measurement equipment. This method is not only inefficient, but also difficult to adjust and optimize the measurement results in real time, affecting the accuracy and reliability of the measurement. Summary of the invention

[0003] In order to solve the above technical problems, the present application provides a Rogowski coil and an electric energy metering device.

[0004] In a first aspect, the present application provides a Rogowski coil, comprising: a toroidal coil, a signal coupling circuit and an MCU circuit, wherein the toroidal coil is used to sense the current of a power grid conductor to be measured to obtain an AC measurement signal; the toroidal coil transmits the AC measurement signal to an external measuring device through the signal coupling circuit; the MCU circuit is used to store accuracy error information of the toroidal coil, and the MCU circuit is also used to transmit the accuracy error information to the external measuring device, so that the external measuring device can measure the current of the power grid conductor to be measured based on the AC measurement signal and the accuracy error information; wherein the toroidal coil, the signal coupling circuit and the MCU circuit are an integrated design.

[0005] By adopting the above technical solution, the toroidal coil is used to sense the current of the power grid conductor to be measured and generate an AC measurement signal. The signal coupling circuit is responsible for transmitting the AC measurement signal to the external measurement device. At the same time, the MCU circuit stores the accuracy error information of the toroidal coil and transmits it to the external measurement device. In this way, the external measurement device can correct the measurement results according to these accuracy error information, thereby improving the accuracy of the measurement. The integrated design makes the structure of the entire system more compact and improves reliability and stability. The Rogowski coil of this technical solution can achieve high-precision current measurement.

[0006] Optionally, the signal coupling circuit is connected between the first end of the annular coil and the first external port of the Rogowski coil, and the second end of the annular coil is electrically connected to the second external port of the Rogowski coil, wherein the first external port of the Rogowski coil and the second external port of the Rogowski coil are electrically connected to an external measuring device to transmit the AC measurement signal to the external measuring device; when the external measuring device reads the accuracy error information from the MCU circuit, the external measuring device supplies power to the MCU circuit through the first external port of the Rogowski coil and the second external port of the Rogowski coil.

[0007] By adopting the above technical solution, the signal coupling circuit is connected between the first end of the ring coil and the first external port of the Rogowski coil, and the second end of the ring coil is electrically connected to the second external port of the Rogowski coil, ensuring that the AC measurement signal can be stably transmitted to the external measurement device. At the same time, the external measurement device can supply power to the MCU circuit through the first external port and the second external port of the Rogowski coil, thereby realizing the normal operation of the MCU circuit without the need for an external power supply, thereby improving the integration and reliability of the system. In addition, this design enables the precision error information to be reliably transmitted to the external measurement device, further improving the accuracy and stability of the measurement.

[0008] Optionally, the signal coupling circuit includes a filtering unit and a switching unit, wherein the filtering unit is used to filter the AC measurement signal, and the switching unit is used to transmit the filtered AC measurement signal to an external measuring device.

[0009] By adopting the above technical solution, the filtering unit can effectively remove high-frequency noise and other interference signals in the AC measurement signal, improve the purity of the signal, and thus improve the accuracy of the measurement; the switching unit ensures that the AC measurement signal after filtering can be reliably transmitted to the external measurement device, ensuring the stability and integrity of the signal.

[0010] Optionally, the filtering unit includes a first resistor and a first capacitor, and the switching unit includes a first MOS tube, wherein the first resistor is connected between the first end of the annular coil and the drain of the first MOS tube, and the first capacitor is connected in parallel with the first resistor; the source of the first MOS tube is electrically connected to the first external port of the Rogowski coil, and the gate of the first MOS tube is electrically connected to the ground terminal, wherein the first MOS tube is a depletion type MOS tube.

[0011] By adopting the above technical solution, the first resistor and the first capacitor in the filter unit form an RC filter, which can filter out high-frequency noise and ensure that the AC measurement signal transmitted to the external measurement device is more stable and reliable. At the same time, the first MOS tube in the switch unit, as a switch element, can transmit the filtered AC measurement signal to the external measurement device at an appropriate time, further improving the efficiency and accuracy of signal transmission. This technical solution significantly improves the measurement accuracy and stability of the Rogowski coil.

[0012] Optionally, the switch unit further includes a first diode and a second resistor, wherein the cathode of the first diode is electrically connected to the drain of the first MOS tube, and the anode of the first diode is electrically connected to the source of the first MOS tube through the second resistor.

[0013] By adopting the above technical solution, the switch unit in the signal coupling circuit is composed of a first MOS tube, a first diode and a second resistor. The first MOS tube is used as a switching element to control the transmission of the filtered AC measurement signal to the external measurement device. The first diode and the second resistor further improve the stability and reliability of the switch unit, prevent the reverse voltage from damaging the MOS tube, thereby ensuring the high efficiency and stability of signal transmission.

[0014] Optionally, the MCU circuit includes an energy storage unit and an MCU chip, wherein the input end of the energy storage unit is electrically connected to the first external port of the Roche coil and the second external port of the Roche coil, the output end of the energy storage unit is electrically connected to the power supply of the MCU chip, the output end of the MCU chip is electrically connected to the first external port of the Roche coil, the MCU chip transmits accuracy error information to an external measuring device through the first external port of the Roche coil, and the external measuring device is electrically connected to the Roche coil through the first external port of the Roche coil and the second external port of the Roche coil; wherein, when the external measuring device receives a target instruction, the external measuring device provides a first level signal to the first external port of the Roche coil through the first GPIO port and provides a second level signal to the second external port of the Roche coil through the second GPIO port, the energy storage unit converts the level signal provided by the external measuring device into energy for storage and supplies power to the MCU chip, so that the MCU chip transmits the accuracy error information to the external measuring device, and the target instruction is used to instruct to obtain the accuracy error information from the Roche coil.

[0015] By adopting the above technical solution, the energy storage unit can convert the level signal provided by the external measuring device into energy for storage and power the MCU chip, ensuring that the MCU chip can still work normally without an external power supply, and enhancing the adaptive ability of the system; the MCU chip receives the first level signal and the second level signal provided by the external measuring device through the first external port and the second external port of the Rogowski coil, and converts them into control signals, so that the precision error information can be transmitted to the external measuring device in time, reducing manual intervention and improving work efficiency, so that the external measuring device can be automatically calibrated based on the precision error information, avoiding the errors and inefficiencies caused by manual query and manual input in traditional methods, and further improving the accuracy and stability of the measurement. The purpose of automatic transmission of the precision error information of the Rogowski coil is achieved, so that the external measuring device can automatically calibrate the measurement results in time based on the precision error information, and improve the accuracy and reliability of the measurement.

[0016] Optionally, the energy storage unit includes a rectifier bridge and a second capacitor, and the MCU circuit also includes a third resistor and a first voltage-stabilizing diode, wherein the two input ends of the rectifier bridge are electrically connected to the first external port and the second external port of the Rogowski coil respectively, the second capacitor is connected between the first output end of the rectifier bridge and the second output end of the rectifier bridge, the first output end of the rectifier bridge is electrically connected to the power supply end of the MCU chip, and the second output end of the rectifier bridge is electrically connected to the ground end; the output end of the MCU chip is electrically connected to the positive electrode of the first voltage-stabilizing diode, and the negative electrode of the first voltage-stabilizing diode is electrically connected to the first external port of the Rogowski coil through the third resistor.

[0017] By adopting the above technical solution, the energy storage unit of the Rogowski coil can effectively convert the GPIO port level signal of the external measuring device into stable DC power and store it in the second capacitor, providing a reliable working power supply for the MCU chip. At the same time, the design of the rectifier bridge ensures that the MCU chip can be powered correctly regardless of the polarity of the communication signal provided by the external measuring device, thereby enhancing the stability and compatibility of the system. The protection circuit composed of the first voltage stabilizing diode and the third resistor further improves the safety of the system, prevents excessive voltage from damaging the MCU chip, and ensures the long-term stable operation of the entire system.

[0018] Optionally, when the external measuring device supplies power to the MCU chip through the first external port of the Rogowski coil and the second external port of the Rogowski coil, the signal coupling circuit is turned off; the MCU chip is used to determine the positive and negative polarity of the first external port of the Rogowski coil and the second external port of the Rogowski coil through the output end of the MCU chip, and when it is determined that the first external port of the Rogowski coil is positive and the second external port of the Rogowski coil is negative, the accuracy error information is sent to the external measuring device through the output end of the MCU chip; and when it is determined that the first external port of the Rogowski coil is negative and the second external port of the Rogowski coil is positive, the MCU chip refuses to send the accuracy error information to the external measuring device.

[0019] By adopting the above technical solution, when the external measuring device supplies power to the MCU chip, the signal coupling circuit is turned off, ensuring that the communication signal will not interfere with the normal current measurement process, and improving the stability and accuracy of the measurement; the MCU chip determines the positive and negative polarity of the first external port and the second external port of the Rogowski coil through its output terminal. This function effectively prevents data transmission errors or damage caused by wiring errors, and enhances the reliability and safety of the system; only when it is determined that the first external port of the Rogowski coil is positive and the second external port is negative, the MCU chip will send precision error information to the external measuring device, avoiding invalid or erroneous information transmission, and further improving the accuracy and efficiency of the measurement; at the same time, if it is determined that the first external port is negative and the second external port is positive, the MCU chip will refuse to send precision error information, thereby protecting the normal operation of the system. Accurate control and efficient management of the Rogowski coil when communicating with the external measuring device are achieved.

[0020] Optionally, the MCU chip includes a set of programming interfaces, and the precision error information is written through the set of programming interfaces.

[0021] By adopting the above technical solution, the MCU chip includes a set of programming interfaces, so that the precision error information can be written through the programming interface, which facilitates error calibration and updating, realizes programmable writing of precision error information, and improves the flexibility and adaptability of the Rogowski coil.

[0022] In a second aspect, the present application further provides an electric energy metering device, comprising the Rogowski coil as described in any of the above items.

[0023] In summary, one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 1. By storing the accuracy error information in the MCU circuit inside the Rogowski coil, the external measurement device can correct the measurement results according to the accuracy error information, thereby improving the accuracy of the measurement; 2. The purpose of automatic transmission of the accuracy error information of the Rogowski coil is realized, so that the external measuring device can automatically calibrate the measurement results in time based on the accuracy error information, thereby improving the accuracy and reliability of the measurement; 3. With the built-in polarity detection function, users can use the Rogowski coil to connect to external measurement devices with greater confidence, improving the product's ease of use and user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a structural block diagram of a Rogowski coil provided in an embodiment of the present application; Figure 2 This is a schematic diagram of the circuit principle of a Rogowski coil provided in an embodiment of the present application; Figure 3 is an example diagram of a Rogowski coil provided in an embodiment of the present application; Figure 4 is a cross-sectional view of a Rogowski coil provided in an embodiment of the present application; Figure 5 is a circuit diagram of an external testing device provided in an embodiment of the present application; Figure 6 It is a schematic diagram of the working process of the external testing device and the Rogowski coil provided in the embodiment of the present application.

[0025] Reference numerals: R1-first resistor, R2-second resistor, R3-third resistor, R4-fourth resistor, BR1-rectifier bridge, C1-first capacitor, C2-second capacitor, D1-first diode, D2-second diode, ZD1-first voltage regulator diode, Q1-first MOS tube, U1-MCU chip, K1-first analog switch, K2-second analog switch. DETAILED DESCRIPTION

[0026] In order to enable technicians in this field to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0027] In the description of the embodiments of the present application, words such as "for example" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "for example" or "for example" is intended to present related concepts in a specific way.

[0028] In the description of the embodiments of the present application, the term "plurality" means two or more. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. The terms "include", "comprise", "have" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0029] The present application provides a Rogowski coil, such as Figure 1 As shown, Figure 1 : is a structural block diagram of a Rogowski coil provided in an embodiment of the present application, the circuit comprises: a ring coil, a signal coupling circuit and an MCU circuit, wherein: The toroidal coil is used to sense the current of the power grid conductor to be measured and obtain an AC measurement signal; The toroidal coil transmits the AC measurement signal to the external measurement device through the signal coupling circuit; The MCU circuit is used to store the accuracy error information of the toroidal coil, and the MCU circuit is also used to transmit the accuracy error information to an external measuring device, so that the external measuring device can measure the current of the measured power grid conductor based on the AC measurement signal and the accuracy error information; Among them, the ring coil, signal coupling circuit and MCU circuit are integrated into one design.

[0030] In the above embodiment, the toroidal coil is used to sense the current of the power grid conductor to be measured and generate an AC measurement signal. The signal coupling circuit is responsible for transmitting the AC measurement signal to the external measurement device. At the same time, the MCU circuit stores the accuracy error information of the toroidal coil and transmits it to the external measurement device. In this way, the external measurement device can correct the measurement results according to the accuracy error information, thereby improving the accuracy of the measurement. The integrated design makes the structure of the entire system more compact and improves reliability and stability. The Rogowski coil of this embodiment can achieve high-precision current measurement.

[0031] In the design and use process of the Rogowski coil in the related art, the accuracy error data is not fully considered, resulting in a large deviation in the measurement results; this embodiment integrates the MCU circuit in the Rogowski coil to store and transmit the accuracy error information of the ring coil, so that the external measurement device can perform more accurate current measurement based on the AC measurement signal and the accuracy error information; the integrated design of the ring coil, signal coupling circuit and MCU circuit enables the Rogowski coil to communicate directly with the external measurement device without manual query and manual input of error data, simplifying the measurement process; the MCU circuit can automatically transmit the accuracy error information to the external measurement device, reducing manual operation, improving measurement efficiency, and allowing real-time adjustment and optimization of measurement results, enhancing the accuracy and reliability of the measurement. Since the Rogowski coil has integrated error information processing capabilities, it no longer needs to rely on a specific external measurement device, thereby improving its versatility and flexibility in different measurement scenarios. The integrated design of the ring coil, signal coupling circuit and MCU circuit makes the entire Rogowski coil structure more compact, easy to install and use, and also convenient for subsequent maintenance and upgrades.

[0032] In an optional embodiment, the signal coupling circuit is connected between the first end of the annular coil and the first external port of the Rogowski coil, and the second end of the annular coil is electrically connected to the second external port of the Rogowski coil, wherein the first external port of the Rogowski coil and the second external port of the Rogowski coil are electrically connected to an external measuring device to transmit the AC measurement signal to the external measuring device; when the external measuring device reads the accuracy error information from the MCU circuit, the external measuring device supplies power to the MCU circuit through the first external port of the Rogowski coil and the second external port of the Rogowski coil.

[0033] In the above embodiment, the signal coupling circuit is connected between the first end of the annular coil and the first external port of the Rogowski coil, and the second end of the annular coil is electrically connected to the second external port of the Rogowski coil, ensuring that the AC measurement signal can be stably transmitted to the external measurement device. At the same time, the external measurement device can supply power to the MCU circuit through the first external port and the second external port of the Rogowski coil, thereby realizing the normal operation of the MCU circuit without the need for an external power supply, thereby improving the integration and reliability of the system. In addition, this design enables the precision error information to be reliably transmitted to the external measurement device, further improving the accuracy and stability of the measurement.

[0034] In this embodiment, a signal coupling circuit is designed to connect the ring coil and the external measuring device, and the external measuring device is allowed to supply power to the MCU circuit through the external port of the Rogowski coil, thereby simplifying the power supply method. This method reduces the demand for an external power supply and reduces the complexity and cost of the system. Since it is no longer necessary to equip the MCU circuit with a separate power supply, the user does not need to worry about additional power management issues when using it, and the operation becomes simpler and more convenient. By integrating the data transmission and power supply functions into the same interface (i.e., the external port of the Rogowski coil), the coordination of data transmission and power supply is optimized. This method not only simplifies the system connection, but also improves the reliability and efficiency of data transmission. This enables the Rogowski coil to transmit data more accurately under high-precision measurement requirements, while reducing the risk of system failure.

[0035] In an optional embodiment, the signal coupling circuit includes a filtering unit and a switching unit, wherein the filtering unit is used to filter the AC measurement signal, and the switching unit is used to transmit the filtered AC measurement signal to an external measurement device.

[0036] In the above embodiment, the filtering unit can effectively remove high-frequency noise and other interference signals in the AC measurement signal, improve the purity of the signal, and thus improve the accuracy of the measurement; the switching unit ensures that the AC measurement signal after filtering can be reliably transmitted to the external measurement device, thereby ensuring the stability and integrity of the signal.

[0037] The AC measurement signal output by the ring coil may contain unnecessary components such as high-frequency noise and electromagnetic interference, which will affect the accuracy and stability of the signal and thus the accuracy of the measurement result. By introducing a filter unit to filter the AC measurement signal, the unnecessary components such as high-frequency noise and electromagnetic interference are effectively removed, thereby improving the accuracy and stability of the signal, which helps to ensure the accuracy and reliability of the measurement result. The introduction of the switch unit makes the signal transmission more controllable. The addition of the switch unit enables the system to control when to send the filtered signal to the external device as needed, increasing the flexibility in the signal processing process, thereby controlling the transmission timing or transmission path of the AC measurement signal. This flexibility helps to adapt to different measurement needs or requirements of external devices and improve the overall performance and adaptability of the system. By integrating filtering and switching functions inside the Rogowski coil, the demand for external filters and switching devices can be reduced, thereby reducing the overall cost of the system. At the same time, since the front end has been effectively pre-processed, the back-end processing burden of the external measurement device is reduced, which is conducive to accelerating the response speed and improving work efficiency. This integrated design also helps to simplify the system structure and improve the reliability and maintainability of the system.

[0038] In an optional embodiment, if Figure 2As shown, the filtering unit includes a first resistor R1 and a first capacitor C1, and the switching unit includes a first MOS tube Q1, wherein the first resistor R1 is connected between the first end of the ring coil and the drain of the first MOS tube Q1, and the first capacitor C1 is connected in parallel with the first resistor R1; the source of the first MOS tube Q1 is electrically connected to the first external port of the Rogowski coil, and the gate of the first MOS tube Q1 is electrically connected to the ground end, wherein the first MOS tube Q1 is a depletion type MOS tube.

[0039] In the above embodiment, the first resistor R1 and the first capacitor C1 in the filter unit form an RC filter, which can filter out high-frequency noise and ensure that the AC measurement signal transmitted to the external measurement device is more stable and reliable. At the same time, the first MOS tube Q1 in the switch unit, as a switch element, can transmit the filtered AC measurement signal to the external measurement device at an appropriate time, further improving the efficiency and accuracy of signal transmission. This embodiment significantly improves the measurement accuracy and stability of the Rogowski coil.

[0040] In this embodiment, the first resistor R1 and the first capacitor C1 are used as the main components of the filter unit, thereby simplifying the design of the filter circuit. This simple RC filter circuit is low in cost. A depletion-type MOS tube is used as the switch unit. Due to its special gate structure, the MOS tube can be turned on without the need for additional voltage control, thereby improving the response speed of the switch unit and realizing rapid transmission of the AC measurement signal. This design enables the Rogowski coil to accurately measure the AC signal and transmit it to the external measurement device.

[0041] In an optional embodiment, if Figure 2 As shown, the switch unit further includes a first diode D1 and a second resistor R2, wherein the cathode of the first diode D1 is electrically connected to the drain of the first MOS transistor Q1, and the anode of the first diode D1 is electrically connected to the source of the first MOS transistor Q1 through the second resistor R2.

[0042] In the above embodiment, the switch unit in the signal coupling circuit is composed of the first MOS tube Q1, the first diode D1 and the second resistor R2. The first MOS tube Q1 is used as a switch element to control the transmission of the filtered AC measurement signal to the external measurement device. The first diode D1 and the second resistor R2 further improve the stability and reliability of the switch unit, prevent the reverse voltage from damaging the MOS tube, and thus ensure the efficiency and stability of signal transmission. The addition of the first diode D1 and the second resistor R2 can also protect the MOS tube from being damaged due to excessive voltage or current.

[0043] In an optional embodiment, if Figure 2As shown, the MCU circuit includes an energy storage unit and an MCU chip U1, wherein the input end of the energy storage unit is electrically connected to the first external port of the Rogowski coil and the second external port of the Rogowski coil, the output end of the energy storage unit is electrically connected to the power supply of the MCU chip U1, the output end of the MCU chip U1 is electrically connected to the first external port of the Rogowski coil, the MCU chip U1 transmits the accuracy error information to the external measuring device through the first external port of the Rogowski coil, and the external measuring device is electrically connected to the Rogowski coil through the first external port of the Rogowski coil and the second external port of the Rogowski coil; wherein, when the external measuring device receives the target instruction, the external measuring device provides a first level signal to the first external port of the Rogowski coil through the first GPIO port and provides a second level signal to the second external port of the Rogowski coil through the second GPIO port, the energy storage unit converts the level signal provided by the external measuring device into energy for storage and supplies power to the MCU chip U1, so that the MCU chip U1 transmits the accuracy error information to the external measuring device, and the target instruction is used to instruct to obtain the accuracy error information from the Rogowski coil.

[0044] In the above embodiment, the energy storage unit can convert the level signal provided by the external measuring device into energy for storage, and supply power to the MCU chip U1, ensuring that the MCU chip U1 can still work normally without an external power supply, and enhancing the adaptive ability of the system; the MCU chip U1 receives the first level signal and the second level signal provided by the external measuring device through the first external port and the second external port of the Rogowski coil, and converts them into control signals, so that the accuracy error information can be transmitted to the external measuring device in time, reducing manual intervention and improving work efficiency, so that the external measuring device can automatically calibrate based on the accuracy error information, avoiding the errors and inefficiencies caused by manual query and manual input in traditional methods, and further improving the accuracy and stability of the measurement. The purpose of automatic transmission of the accuracy error information of the Rogowski coil is achieved, so that the external measuring device can automatically calibrate the measurement results in time based on the accuracy error information, and improve the accuracy and reliability of the measurement.

[0045] This embodiment converts the communication signal sent by the external measuring device into energy for storage through the energy storage unit, thereby improving the energy utilization efficiency and reducing energy waste. The MCU chip U1 can directly obtain energy from the level signal of the GPIO port of the external measuring device, thereby enhancing the self-sufficiency of the system and reducing the dependence on the external power supply. Since the MCU circuit can directly obtain energy from the level signal of the GPIO port of the external measuring device, the need for battery replacement is reduced, thereby reducing maintenance costs and system complexity. The MCU chip U1 uses the stored energy to transmit accuracy error information to the external measuring device, thereby optimizing data transmission efficiency and ensuring the timeliness and accuracy of the data.

[0046] In an optional embodiment, if Figure 2 As shown, the energy storage unit includes a rectifier bridge BR1 and a second capacitor C2, and the MCU circuit also includes a third resistor R3 and a first voltage-stabilizing diode ZD1, wherein the two input ends of the rectifier bridge BR1 are electrically connected to the first external port and the second external port of the Rogowski coil respectively, the second capacitor C2 is connected between the first output end of the rectifier bridge BR1 and the second output end of the rectifier bridge BR1, the first output end of the rectifier bridge BR1 is electrically connected to the power supply end of the MCU chip U1, and the second output end of the rectifier bridge BR1 is electrically connected to the ground end; the output end of the MCU chip U1 is electrically connected to the positive electrode of the first voltage-stabilizing diode ZD1, and the negative electrode of the first voltage-stabilizing diode ZD1 is electrically connected to the first external port of the Rogowski coil through the third resistor R3.

[0047] In the above embodiment, the energy storage unit of the Rogowski coil can effectively convert the level signal of the GPIO port of the external measuring device into stable DC power, and store it in the second capacitor C2, providing a reliable working power supply for the MCU chip U1. At the same time, the design of the rectifier bridge BR1 ensures that no matter what the polarity of the communication signal provided by the external measuring device is, the MCU chip U1 can be correctly powered, thereby enhancing the stability and compatibility of the system. The protection circuit composed of the first voltage stabilizing diode ZD1 and the third resistor R3 further improves the safety of the system, prevents excessive voltage from damaging the MCU chip U1, and ensures the long-term stable operation of the entire system. The combination of the rectifier bridge BR1 and the second capacitor C2 improves the efficiency of extracting and converting energy from the external measuring device, reduces energy loss, and improves the energy utilization efficiency of the system. The MCU chip U1 can also judge the positive and negative polarity of the first external port of the Rogowski coil and the second external port of the Rogowski coil through the output end of the MCU chip U1, and then determine whether to send accuracy error information to the external measuring device according to the positive and negative polarity.

[0048] In an optional embodiment, when the external measuring device supplies power to the MCU chip U1 through the first external port of the Rogowski coil and the second external port of the Rogowski coil, the signal coupling circuit is turned off; the MCU chip U1 is used to determine the positive and negative polarity of the first external port of the Rogowski coil and the second external port of the Rogowski coil through the output end of the MCU chip U1, and when it is determined that the first external port of the Rogowski coil is positive and the second external port of the Rogowski coil is negative, the accuracy error information is sent to the external measuring device through the output end of the MCU chip U1; and when it is determined that the first external port of the Rogowski coil is negative and the second external port of the Rogowski coil is positive, the MCU chip U1 refuses to send the accuracy error information to the external measuring device.

[0049] In the above embodiment, when the external measuring device supplies power to the MCU chip U1, the signal coupling circuit is turned off, ensuring that the communication signal will not interfere with the normal current measurement process, thereby improving the stability and accuracy of the measurement; the MCU chip U1 determines the positive and negative polarity of the first external port and the second external port of the Rogowski coil through its output terminal. This function effectively prevents data transmission errors or damage caused by wiring errors, thereby enhancing the reliability and safety of the system; only when it is determined that the first external port of the Rogowski coil is positive and the second external port is negative, the MCU chip U1 will send precision error information to the external measuring device, thereby avoiding invalid or erroneous information transmission, thereby further improving the accuracy and efficiency of the measurement; at the same time, if it is determined that the first external port is negative and the second external port is positive, the MCU chip U1 will refuse to send precision error information, thereby protecting the normal operation of the system. Accurate control and efficient management of the Rogowski coil when communicating with the external measuring device are achieved.

[0050] This embodiment determines the positive and negative polarity of the first external port and the second external port of the Rogowski coil through the output end of the MCU chip U1, and can automatically detect whether the connection polarity between the external measuring device and the Rogowski coil is correct; when it is determined that the connection polarity between the Rogowski coil and the external measuring device is correct, the MCU chip U1 sends the accuracy error information to the external measuring device through the output end; when it is determined that the connection polarity between the Rogowski coil and the external measuring device is wrong, the MCU chip U1 refuses to send the accuracy error information to the external measuring device, which avoids the transmission of erroneous data caused by misoperation and improves the overall performance and reliability of the system; the user does not need to check or confirm the connection polarity additionally, because the system can automatically identify and take corresponding measures, which simplifies the user's operation process and reduces the possibility of human error. Through the built-in polarity detection function, users can use the Rogowski coil to connect with the external measuring device more confidently, which improves the usability and user experience of the product. Through the automatic judgment and control of the MCU chip U1, the intelligence level of the entire Rogowski coil system is improved, so that the system can handle communication and data transmission tasks more intelligently.

[0051] In an optional embodiment, the MCU chip U1 includes a group of programming interfaces, and the precision error information is written through the group of programming interfaces.

[0052] In the above embodiment, the MCU chip U1 includes a set of programming interfaces, such as Figure 2PB0, PB1 and PB3 in the program interface allow the accuracy error information to be written through the programming interface, which facilitates error calibration and update, realizes programmable writing of accuracy error information, and improves the flexibility and adaptability of the Rogowski coil. Optionally, the accuracy error information can also be updated through a set of programming interfaces. Through the programming interface, the accuracy error information of the Rogowski coil can be easily updated, which improves the convenience of data update. The programming interface facilitates system maintenance and upgrades, allowing the system to be updated and maintained in a timely manner to adapt to changes in technological development and user needs.

[0053] The present application also provides an electric energy metering device, comprising the Rogowski coil described in any one of the aforementioned embodiments, and also comprising the aforementioned external measuring device.

[0054] The integrated design of the ring coil, signal coupling circuit and MCU circuit ensures the compactness and reliability of the measurement system. The MCU circuit stores the accuracy error information of the ring coil and transmits it to the external measurement device, so that the external measurement device can calibrate the measurement result based on the accuracy error information, thereby improving the accuracy of the electric energy metering device. The signal coupling circuit includes a filtering unit and a switching unit, which can effectively filter out noise, improve the purity of the signal, and further improve the measurement accuracy of the electric energy metering device.

[0055] It should be noted that the above-described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application will be described in detail below in conjunction with specific embodiments.

[0056] The embodiment of the present application provides a communication circuit applied to a Rogowski coil. The communication circuit realizes that the accuracy compensation information of the Rogowski coil is stored inside the Rogowski coil, and an external measuring device can obtain the error information of the Rogowski coil online, which has good flexibility.

[0057] Including signal coupling circuit and MCU circuit; (1) The Rogowski coil is unidirectionally connected to the external measuring device through the signal coupling circuit, and the AC measurement signal is unidirectionally output to the external measuring device; (2) The external measuring device is directly connected to the MCU circuit and reads the information stored in the MCU circuit through digital communication. The signal coupling circuit plays the role of unidirectional isolation of communication information; (3) Signal coupling circuit The output signal of the Rogowski coil is an AC measurement signal with a frequency of 45Hz~65Hz. The signal is connected to the first MOS tube Q1 (depletion type MOS tube) through the first capacitor C1. When METER+ and METER- of the external measurement device are used as input ports, the first MOS tube Q1 works in the on working state and connects the AC measurement signal to the external measurement device; METER+ and METER- refer to the ports of the external measuring device, which are connected to the first external port of the Rogowski coil (such as Figure 2 J2 in the figure) and the second external port of the Rogowski coil (such as Figure 2 J4 in the connection; (4) MCU circuit The accuracy error information stored in the MCU circuit is programmed and written into the MCU chip U1 through the TP1, TP2, and TP3 signals.

[0058] When METER+ and METER- of the external measuring device are used as output ports, they are connected to the rectifier bridge to convert the METER+ and METER- signals of the external measuring device into energy stored in the second capacitor C2. The MCU chip U1 is connected to the external measuring device through the first voltage stabilizing diode ZD1 and the third resistor R3 to send the accuracy error information stored in the MCU chip U1 to the external measuring device.

[0059] It should be noted that Figure 2 The toroidal coil is not shown. Figure 2 CT1 and CT2 represent the two output ends of the toroidal coil, which correspond to the first end and the second end of the toroidal coil, respectively. J1 and J3 represent the two ports of the circuit board, which includes the signal coupling circuit and the MCU circuit, that is, the AC voltage signal induced by the toroidal coil is input into the circuit board through the J1 and J3 ports. The circuit board and the toroidal coil are designed in an integrated manner to form a complete Rogowski coil, that is, the Rogowski coil only exposes the J2 and J4 ports to the outside, and is connected to an external measuring device. Figure 2 The second diode D2 and the fourth resistor R4 are also included. The second diode D2 can be used to indicate the connection between the external measuring device and the Rogowski coil (such as Figure 2 Are the METER+ and METER- in the table correct?

[0060] Figure 3 is an example diagram of a Rogowski coil provided in an embodiment of the present application. The circuit board composed of the signal coupling circuit and the MCU circuit is embedded in Figure 3 The dotted ellipse in Figure 4 The circuit board in the Rogowski coil is embedded in the Rogowski coil. From the outside, the entire Rogowski coil only has two wires connected to the external measuring device.

[0061] Figure 5 This is a circuit diagram of an external test device provided in an embodiment of the present application, which includes 2-way analog switches, such as K1 and K2, and also includes a CPU and an ADC.

[0062] Combine the following Figure 2 , Figure 5 and Figure 6 The working process of the external test device and the Rogowski coil is described, and the process includes the following steps: Step 1: The external measuring device receives instructions through human-computer interaction to read the accuracy error information of the Rogowski coil. Its CPU controls the first analog switch K1 to close through the S1 signal line and controls the second analog switch K2 to open through the S2 signal line. The digital signal interfaces D+ and D- of the CPU are connected to METER+ and METER- of the Rogowski coil. Step 2: The D+ signal of the external measuring device CPU is connected to the pin S of the depletion type MOS tube Q1 (corresponding to the first MOS tube Q1 mentioned above) of the Rogowski coil. If D+ is at a high level (pulled up to the power supply through a resistor), and the VGS of Q1 is a negative voltage, Q1 switches to the off state, and the CT1 signal of the ring coil cannot be transmitted to METER+. Step 3: The rectifier bridge of the Rogowski coil draws power from the METER+ and METER- signals, and the MCU software runs to determine the input level status of pin PB2; Step 4: Determine whether PB2 is high level; When the judgment result of the above step 4 is yes, proceed to step 5-1; when the judgment result of the above step 4 is no, proceed to step 5-2; Step 5-1: The MCU of the Rogowski coil outputs a 1Hz PWM signal through the pin PB1, controlling the light-emitting diode D2 to flash once every 1 second, indicating that the wiring of METER+ and METER- is correct; then proceed to step 6-1; Step 5-2: The MCU of the Rogowski coil outputs a 0.5Hz PWM signal through pin PB1, controlling the light-emitting diode D2 to flash once every 2 seconds, indicating that the wiring of METER+ and METER- is wrong; then go to step 6-2; Step 6-1: The MCU of the Rogowski coil outputs a digital signal of the accuracy error through the pin PB2, and the CPU of the external measurement device obtains the accuracy error information of the Rogowski coil through the D+ and D- signal lines; then proceed to step 7; Step 6-2: The CPU of the external measuring device cannot receive the accuracy error information of the Rogowski coil through the D+ and D- signal lines, and prompts that the external Rogowski coil is faulty through human-computer interaction; Step 7: After the external measuring device reads the accuracy error information of the Rogowski coil, its CPU controls the analog switch K1 to open through the S1 signal line, and controls the analog switch K2 to close through the S2 signal line, and the analog signal interfaces A+ and A- of the ADC are connected to METER+ and METER- of the Rogowski coil; Step 8: The MCU of the Rogowski coil loses D+ / D- power supply, the software stops running, the S level of the signal coupling circuit Q1 pin is low, and the VGS of Q1 is 0 level, then Q1 switches to the on state, and the signals CT1 and CT2 sampled by the ring coil are transmitted to METER+ and METER-; Step 9: The CPU of the external measuring device controls the ADC to measure the A+ and A- signals through SPI serial communication to obtain the current information collected by the ring coil. The CPU performs error compensation on the measured current information based on the accuracy error information obtained in step 6-1 to obtain more accurate measured current information. This step is executed cyclically.

[0063] The embodiments of the present application have at least the following technical effects: 1) the communication circuit is embedded in the Rogowski coil, and an external measuring device can obtain the accuracy error information of the Rogowski coil online; 2) the communication circuit and the annular coil output multiplexed signal line, which can be used to obtain information online, and can also be used without supporting an external test device for online compensation; 3) the MCU circuit draws power from the signal line, does not need a separate power supply, and has a low cost of use.

[0064] It should be noted that: when the device provided in the above embodiment realizes its function, only the division of the above functional modules is used as an example. In actual application, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the device and method embodiments provided in the above embodiment belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0065] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0066] The above is only an exemplary embodiment of the present disclosure and cannot be used to limit the scope of the present disclosure. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the disclosure of the specification and practice, those skilled in the art will easily think of other embodiments of the present disclosure.

[0067] This application is intended to cover any modifications, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary technical means in the technical field not recorded in the present disclosure.

Claims

1. A Rogowski coil, characterized in that: include: Ring coil, signal coupling circuit and MCU circuit, among which, The annular coil is used to sense the current of the power grid conductor to be measured to obtain an AC measurement signal; The annular coil transmits the AC measurement signal to an external measurement device through the signal coupling circuit; The MCU circuit is used to store the accuracy error information of the toroidal coil, and the MCU circuit is also used to transmit the accuracy error information to the external measuring device, so that the external measuring device can measure the current of the grid conductor to be measured based on the AC measurement signal and the accuracy error information; Among them, the ring coil, the signal coupling circuit and the MCU circuit are integrated into one design.

2. The Rogowski coil according to claim 1, characterized in that: The signal coupling circuit is connected between the first end of the annular coil and the first external port of the Rogowski coil, and the second end of the annular coil is electrically connected to the second external port of the Rogowski coil, wherein the first external port of the Rogowski coil and the second external port of the Rogowski coil are electrically connected to the external measuring device to transmit the AC measuring signal to the external measuring device; When the external measuring device reads the accuracy error information from the MCU circuit, the external measuring device supplies power to the MCU circuit through the first external connection port of the Rogowski coil and the second external connection port of the Rogowski coil.

3. The Rogowski coil according to claim 1, characterized in that: The signal coupling circuit includes a filtering unit and a switching unit, wherein the filtering unit is used to filter the AC measurement signal, and the switching unit is used to transmit the filtered AC measurement signal to the external measurement device.

4. The Rogowski coil according to claim 3, characterized in that: The filtering unit includes a first resistor and a first capacitor, and the switch unit includes a first MOS tube, wherein: The first resistor is connected between the first end of the annular coil and the drain of the first MOS transistor, and the first capacitor is connected in parallel with the first resistor; The source of the first MOS tube is electrically connected to the first external port of the Rogowski coil, and the gate of the first MOS tube is electrically connected to the ground terminal, wherein the first MOS tube is a depletion type MOS tube.

5. The Rogowski coil according to claim 4, characterized in that: The switch unit further includes a first diode and a second resistor, wherein a cathode of the first diode is electrically connected to a drain of the first MOS tube, and an anode of the first diode is electrically connected to a source of the first MOS tube through the second resistor.

6. The Rogowski coil according to claim 1, characterized in that: The MCU circuit includes an energy storage unit and an MCU chip, wherein: The input end of the energy storage unit is electrically connected to the first external port of the Rogowski coil and the second external port of the Rogowski coil, the output end of the energy storage unit is electrically connected to the power supply of the MCU chip, the output end of the MCU chip is electrically connected to the first external port of the Rogowski coil, the MCU chip transmits the accuracy error information to the external measuring device through the first external port of the Rogowski coil, and the external measuring device is electrically connected to the Rogowski coil through the first external port of the Rogowski coil and the second external port of the Rogowski coil; Wherein, when the external measuring device receives the target instruction, the external measuring device provides a first level signal to the first external port of the Rogowski coil through the first GPIO port and provides a second level signal to the second external port of the Rogowski coil through the second GPIO port, the energy storage unit converts the level signal provided by the external measuring device into energy for storage and supplies power to the MCU chip, so that the MCU chip transmits the accuracy error information to the external measuring device, and the target instruction is used to instruct to obtain the accuracy error information from the Rogowski coil.

7. The Rogowski coil according to claim 6, characterized in that: The energy storage unit includes a rectifier bridge and a second capacitor, and the MCU circuit also includes a third resistor and a first voltage regulator diode, wherein: The two input ends of the rectifier bridge are electrically connected to the first external port of the Rogowski coil and the second external port of the Rogowski coil respectively, the second capacitor is connected between the first output end of the rectifier bridge and the second output end of the rectifier bridge, the first output end of the rectifier bridge is electrically connected to the power supply end of the MCU chip, and the second output end of the rectifier bridge is electrically connected to the ground end; The output end of the MCU chip is electrically connected to the anode of the first voltage stabilizing diode, and the cathode of the first voltage stabilizing diode is electrically connected to the first external port of the Rogowski coil through the third resistor.

8. The Rogowski coil according to claim 6, characterized in that: When the external measuring device supplies power to the MCU chip through the first external port of the Rogowski coil and the second external port of the Rogowski coil, the signal coupling circuit is turned off; the MCU chip is used to determine the positive and negative polarities of the first external port of the Rogowski coil and the second external port of the Rogowski coil through the output end of the MCU chip, and when it is determined that the first external port of the Rogowski coil is positive and the second external port of the Rogowski coil is negative, the accuracy error information is sent to the external measuring device through the output end of the MCU chip; And when it is determined that the first external port of the Rogowski coil is negative and the second external port of the Rogowski coil is positive, the MCU chip refuses to send the accuracy error information to the external measuring device.

9. The Rogowski coil according to claim 6, characterized in that: The MCU chip includes a set of programming interfaces, and the precision error information is written through the set of programming interfaces.

10. An electric energy metering device, characterized in that: The method comprises the Rogowski coil according to any one of claims 1 to 9.

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