A Rogowski coil and an energy metering device

Abstract

This application provides a Rogowski coil and an energy metering device, relating to the field of power measurement technology. The Rogowski coil includes a loop coil, a signal coupling circuit, and an MCU circuit. The loop coil senses the current in the conductor of the power grid under test, obtaining an AC measurement signal. The loop coil transmits the AC measurement signal to an external measuring device via the signal coupling circuit. The MCU circuit stores the accuracy error information of the loop coil and also transmits this accuracy error information to the external measuring device, enabling the external measuring device to measure the current in the conductor of the power grid under test based on the AC measurement signal and the accuracy error information. The loop coil, signal coupling circuit, and MCU circuit are integrated into a single design. Implementing the technical solution provided in this application improves the accuracy of measurements.

Description

Technical Field

[0001] This application relates to the field of power measurement technology, specifically to a Rogowski coil and an energy metering device. Background Technology

[0002] Rogowski coils, as non-invasive current sensors, are widely used in power systems due to their simple structure, fast response speed, and wide dynamic range. However, many existing Rogowski coils do not adequately consider accuracy error data during design and use, leading to significant deviations in measurement results. This error is unacceptable, especially under high-precision measurement requirements. In some high-precision measurement schemes, Rogowski coils need to be paired with specific external measuring devices. Even if some Rogowski coils provide accuracy error data, this data usually needs to be manually queried and entered into the external measuring equipment. This method is not only inefficient but also makes it difficult to adjust and optimize the measurement results in real time, affecting the accuracy and reliability of the measurement. Summary of the Invention

[0003] To address the aforementioned technical problems, this application provides a Rogowski coil and an energy metering device.

[0004] In a first aspect, this application provides a Rogowski coil, comprising: a loop coil, a signal coupling circuit, and an MCU circuit, wherein the loop coil is used to sense the current in the conductor of the power grid under test to obtain an AC measurement signal; the loop coil transmits the AC measurement signal to an external measuring device through the signal coupling circuit; the MCU circuit is used to store the accuracy error information of the loop 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 in the conductor of the power grid under test based on the AC measurement signal and the accuracy error information; wherein the loop coil, the signal coupling circuit, and the MCU circuit are integrated into a single design.

[0005] By adopting the above technical solution, the loop coil is used to sense the current in the conductor of the power grid under test, generating an AC measurement signal. The signal coupling circuit is responsible for transmitting the AC measurement signal to the external measuring device. Simultaneously, the MCU circuit stores the accuracy error information of the loop coil and transmits it to the external measuring device. In this way, the external measuring device can correct the measurement results based on this accuracy error information, thereby improving the measurement accuracy. The integrated design makes the entire system structure more compact, improving reliability and stability. The Rogowski coil in this technical solution can achieve high-precision current measurement.

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

[0007] By adopting the above technical solution, the signal coupling circuit is connected between the first end of the loop coil and the first external port of the Rogowski coil, and the second end of the loop 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 measuring device. Simultaneously, the external measuring device can supply power to the MCU circuit through the first and second external ports of the Rogowski coil, thereby enabling the MCU circuit to operate normally without an external power supply, improving the system's integration and reliability. Furthermore, this design allows accuracy error information to be reliably transmitted to the external measuring device, further enhancing 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 measuring 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 MOSFET. The first resistor is connected between the first end of the loop coil and the drain of the first MOSFET, and the first capacitor is connected in parallel with the first resistor. The source of the first MOSFET is electrically connected to the first external port of the Rogowski coil, and the gate of the first MOSFET is electrically connected to the ground terminal. The first MOSFET is a depletion-type MOSFET.

[0011] By adopting the above technical solution, the first resistor and the first capacitor in the filtering unit form an RC filter, which can filter out high-frequency noise and ensure that the AC measurement signal transmitted to the external measuring device is more stable and reliable. Simultaneously, the first MOSFET in the switching unit acts as a switching element, enabling the transmission of the filtered AC measurement signal to the external measuring device at appropriate times, 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 switching 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 MOSFET, and the anode of the first diode is electrically connected to the source of the first MOSFET through the second resistor.

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

[0014] Optionally, the MCU circuit includes an energy storage unit and an MCU chip. The input terminal of the energy storage unit is electrically connected to the first external port and the second external port of the Rogowski coil. The output terminal of the energy storage unit is electrically connected to the power supply of the MCU chip. The output terminal of the MCU chip is electrically connected to the first external port of the Rogowski coil. The MCU chip transmits accuracy error information to an external measuring device through the first external port of the Rogowski coil. The external measuring device is electrically connected to the Rogowski coil through the first and second external ports of the Rogowski coil. When the external measuring device receives a target instruction, it provides a first level signal to the first external port of the Rogowski coil through a first GPIO port and a second level signal to the second external port of the Rogowski coil through a second GPIO port. The energy storage unit converts the level signals provided by the external measuring device into energy for storage and powers the MCU chip, enabling the MCU chip to transmit the accuracy error information to the external measuring device. The target instruction is used to instruct the MCU chip to obtain the accuracy error information from the Rogowski 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 operate normally without an external power supply and enhancing the system's adaptability. The MCU chip receives the first and second level signals provided by the external measuring device through the first and second external ports of the Rogowski coil and converts them into control signals, enabling the timely transmission of accuracy error information to the external measuring device. This reduces manual intervention, improves work efficiency, and allows the external measuring device to automatically calibrate based on the accuracy error information, avoiding the errors and inefficiencies caused by manual querying and input in traditional methods, further improving the accuracy and stability of the measurement. This achieves the goal of automatically transmitting the accuracy error information of the Rogowski coil, enabling the external measuring device to automatically calibrate the measurement results in a timely manner based on this accuracy error information, thus improving the accuracy and reliability of the measurement.

[0016] Optionally, the energy storage unit includes a rectifier bridge and a second capacitor. The MCU circuit also includes a third resistor and a first Zener diode. The two input terminals 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 terminal and the second output terminal of the rectifier bridge. The first output terminal of the rectifier bridge is electrically connected to the power supply terminal of the MCU chip, and the second output terminal of the rectifier bridge is electrically connected to the ground terminal. The output terminal of the MCU chip is electrically connected to the positive terminal of the first Zener diode, and the negative terminal of the first Zener 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 Rogowski coil energy storage unit 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 operating power supply for the MCU chip. Simultaneously, the rectifier bridge design ensures that the MCU chip is correctly powered regardless of the polarity of the communication signal provided by the external measuring device, enhancing system stability and compatibility. The protection circuit composed of the first Zener diode and the third resistor further improves system safety, preventing excessive voltage from damaging the MCU chip and ensuring the long-term stable operation of the entire system.

[0018] Optionally, when an external measuring device supplies power to the MCU chip through the first external port and the second external port of the Rogowski coil, the signal coupling circuit is turned off. The MCU chip is used to determine the polarity of the first and second external ports of the Rogowski coil through its output terminal. If the first external port of the Rogowski coil is positive and the second external port is negative, the MCU chip sends accuracy error information to the external measuring device through its output terminal. If the first external port of the Rogowski coil is negative and the second external port is positive, the MCU chip refuses to send 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, thus improving the stability and accuracy of the measurement. The MCU chip determines the polarity of the first and second external ports of the Rogowski coil through its output terminal. This function effectively prevents data transmission errors or damage caused by wiring mistakes, enhancing the reliability and security of the system. Only when the first external port of the Rogowski coil is determined to be positive and the second external port to be negative will the MCU chip send accuracy 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 the first external port is determined to be negative and the second external port to be positive, the MCU chip will refuse to send accuracy error information, thereby protecting the normal operation of the system. This achieves precise control and efficient management of the Rogowski coil when communicating with external measuring devices.

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

[0021] By adopting the above technical solution, the MCU chip includes a set of programming interfaces, which allows precision error information to be written through the programming interfaces, facilitating error calibration and updates, realizing programmable writing of precision error information, and improving the flexibility and adaptability of the Rogowski coil.

[0022] Secondly, this application also provides an energy metering device, including the Rogowski coil described in any of the preceding claims.

[0023] In summary, one or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0024] 1. By storing the accuracy error information in the MCU circuit inside the Rogowski coil, the external measuring device can correct the measurement results based on this accuracy error information, thereby improving the accuracy of the measurement;

[0025] 2. It achieves the goal of automatically transmitting the accuracy error information of the Rogowski coil, enabling external measuring devices to automatically calibrate the measurement results in a timely manner based on this accuracy error information, thereby improving the accuracy and reliability of the measurement;

[0026] 3. With the built-in polarity detection function, users can more confidently connect Rogowski coils to external measuring devices, improving the product's ease of use and user experience. Attached Figure Description

[0027] Figure 1 This is a structural block diagram of a Rogowski coil provided in an embodiment of this application;

[0028] Figure 2 This is a schematic diagram of the circuit principle of a Rogowski coil provided in an embodiment of this application;

[0029] Figure 3 This is an example diagram of a Rogowski coil provided in an embodiment of this application;

[0030] Figure 4 This is a cross-sectional view of a Rogowski coil provided in an embodiment of this application;

[0031] Figure 5 This is a circuit diagram of an external testing device provided in an embodiment of this application;

[0032] Figure 6 This is a schematic diagram of the working process of the external testing device and the Rogowski coil provided in the embodiments of this application.

[0033] Figure label:

[0034] 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 Zener diode, Q1 - First MOSFET, U1 - MCU chip, K1 - First analog switch, K2 - Second analog switch. Detailed Implementation

[0035] To enable those skilled in the art 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 with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0036] In the description of the embodiments of this application, the words "for example" or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design that is described as "for example" or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design options. Rather, the use of the words "for example" or "for instance" is intended to present the relevant concepts in a specific manner.

[0037] In the description of the embodiments of this application, the term "multiple" means two or more. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0038] This application provides a Rogowski coil, such as Figure 1 As shown, Figure 1 This is a block diagram of a Rogowski coil provided in an embodiment of this application. The circuit includes: a loop coil, a signal coupling circuit, and an MCU circuit, wherein...

[0039] A loop coil is used to sense the current in the conductor of the power grid under test to obtain an AC measurement signal;

[0040] The loop coil transmits the AC measurement signal to the external measuring device through a signal coupling circuit;

[0041] The MCU circuit is used to store the accuracy error information of the loop coil. 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 power grid conductor under test based on the AC measurement signal and the accuracy error information.

[0042] The loop coil, signal coupling circuit, and MCU circuit are integrated into a single design.

[0043] In the above embodiment, the loop coil is used to sense the current in the conductor of the power grid under test, generating an AC measurement signal. The signal coupling circuit is responsible for transmitting the AC measurement signal to the external measuring device. Simultaneously, the MCU circuit stores the accuracy error information of the loop coil and transmits it to the external measuring device. In this way, the external measuring device can correct the measurement results based on this accuracy error information, thereby improving the measurement accuracy. The integrated design makes the entire system structure more compact, improving reliability and stability. The Rogowski coil in this embodiment can achieve high-precision current measurement.

[0044] In related technologies, Rogowski coils often fail to adequately consider accuracy error data during design and use, leading to significant deviations in measurement results. This embodiment integrates an MCU circuit into the Rogowski coil to store and transmit the coil's accuracy error information, enabling external measuring devices to perform more accurate current measurements based on AC measurement signals and accuracy error information. The integrated design of the coil, signal coupling circuit, and MCU circuit allows the Rogowski coil to communicate directly with external measuring devices, eliminating the need for manual querying and input of error data, thus simplifying the measurement process. The MCU circuit automatically transmits accuracy error information to the external measuring device, reducing manual operation, improving measurement efficiency, and allowing real-time adjustment and optimization of measurement results, enhancing measurement accuracy and reliability. Because the Rogowski coil integrates error information processing capabilities, it no longer relies on specific external measuring devices, thereby improving its versatility and flexibility in different measurement scenarios. The integrated design of the coil, signal coupling circuit, and MCU circuit makes the entire Rogowski coil structure more compact, easier to install and use, and also facilitates subsequent maintenance and upgrades.

[0045] In an optional embodiment, a signal coupling circuit is connected between the first end of the loop coil and the first external port of the Rogowski coil, and the second end of the loop coil is electrically connected to the second external port of the Rogowski coil. The first and second external ports of the Rogowski coil are electrically connected to an external measuring device to transmit AC measurement signals to the external measuring device. When the external measuring device reads accuracy error information from the MCU circuit, the external measuring device supplies power to the MCU circuit through the first and second external ports of the Rogowski coil.

[0046] In the above embodiment, the signal coupling circuit is connected between the first end of the loop coil and the first external port of the Rogowski coil, and the second end of the loop 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 measuring device. Simultaneously, the external measuring device can supply power to the MCU circuit through the first and second external ports of the Rogowski coil, thereby enabling the MCU circuit to operate normally without an external power supply, improving the system's integration and reliability. Furthermore, this design allows accuracy error information to be reliably transmitted to the external measuring device, further enhancing the accuracy and stability of the measurement.

[0047] This embodiment connects the loop coil to the external measuring device through a signal coupling circuit, allowing the external measuring device to supply power to the MCU circuit via the Rogowski coil's external port. This simplifies the power supply method, reduces the need for an external power supply, and lowers system complexity and cost. Since a separate power supply for the MCU circuit is no longer required, users do not need to worry about additional power management issues, making operation simpler and more convenient. By integrating data transmission and power supply functions onto the same interface (i.e., the Rogowski coil's external port), the coordination between data transmission and power supply is optimized. This not only simplifies system connections 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.

[0048] 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 measuring device.

[0049] In the above embodiments, the filtering unit can effectively remove high-frequency noise and other interference signals from 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 measuring device, ensuring the stability and integrity of the signal.

[0050] The AC measurement signal output from the loop coil may contain unwanted components such as high-frequency noise and electromagnetic interference. These interference components can affect the accuracy and stability of the signal, thus impacting the precision of the measurement results. By introducing a filtering unit to filter the AC measurement signal, unwanted components such as high-frequency noise and electromagnetic interference are effectively removed, thereby improving the accuracy and stability of the signal. This helps ensure the accuracy and reliability of the measurement results. The introduction of a switching unit makes signal transmission more controllable. The addition of a switching unit allows the system to control when to send the filtered signal to external devices as needed, increasing the flexibility in the signal processing process. This allows control over the timing or path of AC measurement signal transmission, which helps adapt to different measurement requirements or the requirements of external devices, improving the overall performance and adaptability of the system. By integrating filtering and switching functions within the Rogowski coil, the need for external filters and switching devices can be reduced, thereby lowering the overall system cost. At the same time, since effective signal preprocessing has been performed at the front end, the back-end processing burden of external measuring devices is reduced, which helps to speed up response and improve work efficiency. This integrated design also helps to simplify the system structure and improve the system's reliability and maintainability.

[0051] In an optional embodiment, such as Figure 2As shown, the filter unit includes a first resistor R1 and a first capacitor C1, and the switching unit includes a first MOSFET Q1. The first resistor R1 is connected between the first end of the loop coil and the drain of the first MOSFET Q1, and the first capacitor C1 is connected in parallel with the first resistor R1. The source of the first MOSFET Q1 is electrically connected to the first external port of the Rogowski coil, and the gate of the first MOSFET Q1 is electrically connected to the ground terminal. The first MOSFET Q1 is a depletion-type MOSFET.

[0052] In the above embodiment, the first resistor R1 and the first capacitor C1 in the filtering unit form an RC filter, which can filter out high-frequency noise and ensure that the AC measurement signal transmitted to the external measuring device is more stable and reliable. Simultaneously, the first MOSFET Q1 in the switching unit acts as a switching element, enabling the transmission of the filtered AC measurement signal to the external measuring device at appropriate times, further improving the efficiency and accuracy of signal transmission. This embodiment significantly improves the measurement accuracy and stability of the Rogowski coil.

[0053] This embodiment simplifies the design of the filter circuit by using the first resistor R1 and the first capacitor C1 as the main components of the filter unit. This simple RC filter circuit is inexpensive. The depletion-type MOSFET is used as the switching unit. Due to its special gate structure, the MOSFET can be turned on without additional voltage control, thereby improving the response speed of the switching unit and enabling fast transmission of AC measurement signals. This design allows the Rogowski coil to accurately measure AC signals and transmit them to external measuring devices.

[0054] In an optional embodiment, such as Figure 2 As shown, the switching unit also 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 MOSFET Q1, and the anode of the first diode D1 is electrically connected to the source of the first MOSFET Q1 through the second resistor R2.

[0055] In the above embodiment, the switching unit in the signal coupling circuit consists of a first MOSFET Q1, a first diode D1, and a second resistor R2. The first MOSFET Q1 acts as a switching element, controlling the transmission of the filtered AC measurement signal to the external measuring device. The first diode D1 and the second resistor R2 further improve the stability and reliability of the switching unit, preventing reverse voltage from damaging the MOSFET, thereby ensuring the high efficiency and stability of signal transmission. The addition of the first diode D1 and the second resistor R2 also protects the MOSFET, preventing it from being damaged by excessive voltage or current.

[0056] In an optional embodiment, such as Figure 2As shown, the MCU circuit includes an energy storage unit and an MCU chip U1. The input terminal of the energy storage unit is electrically connected to the first external port and the second external port of the Rogowski coil. The output terminal of the energy storage unit is electrically connected to the power supply of the MCU chip U1. The output terminal of the MCU chip U1 is electrically connected to the first external port of the Rogowski coil. The MCU chip U1 transmits accuracy error information to an external measuring device through the first external port of the Rogowski coil. The external measuring device is electrically connected to the Rogowski coil through the first and second external ports of the Rogowski coil. When the external measuring device receives a target instruction, it provides a first level signal to the first external port of the Rogowski coil through a first GPIO port and a second level signal to the second external port of the Rogowski coil through a second GPIO port. The energy storage unit converts the level signals provided by the external measuring device into energy for storage and powers the MCU chip U1, enabling the MCU chip U1 to transmit the accuracy error information to the external measuring device. The target instruction is used to instruct the MCU chip U1 to obtain the accuracy error information from the Rogowski coil.

[0057] In the above embodiments, the energy storage unit can convert the level signal provided by the external measuring device into energy for storage and power the MCU chip U1, ensuring that the MCU chip U1 can still operate normally without an external power supply, thus enhancing the system's adaptability. The MCU chip U1 receives the first and second level signals provided by the external measuring device through the first and second external ports of the Rogowski coil, and converts them into control signals. This allows the accuracy error information to be transmitted to the external measuring device in a timely manner, reducing manual intervention and improving work efficiency. It enables the external measuring device to automatically calibrate based on the accuracy error information, avoiding the errors and inefficiencies caused by manual querying and input in traditional methods, further improving the accuracy and stability of the measurement. This achieves the goal of automatically transmitting the accuracy error information of the Rogowski coil, allowing the external measuring device to automatically calibrate the measurement results in a timely manner based on this accuracy error information, thereby improving the accuracy and reliability of the measurement.

[0058] This embodiment converts the communication signals sent by the external measuring device into energy for storage through an energy storage unit, improving energy utilization efficiency and reducing energy waste. The MCU chip U1 can directly obtain energy from the level signals of the GPIO port of the external measuring device, enhancing the system's self-sufficiency and reducing dependence on external power sources. Since the MCU circuit can directly obtain energy from the level signals of the GPIO port of the external measuring device, the need for battery replacement is reduced, thereby lowering maintenance costs and system complexity. The MCU chip U1 uses the stored energy to transmit accuracy error information to the external measuring device, optimizing data transmission efficiency and ensuring the timeliness and accuracy of the data.

[0059] In an optional embodiment, such as Figure 2 As shown, the energy storage unit includes a rectifier bridge BR1 and a second capacitor C2. The MCU circuit also includes a third resistor R3 and a first Zener diode ZD1. The two input terminals 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 terminal and the second output terminal of the rectifier bridge BR1. The first output terminal of the rectifier bridge BR1 is electrically connected to the power supply terminal of the MCU chip U1, and the second output terminal of the rectifier bridge BR1 is electrically connected to the ground terminal. The output terminal of the MCU chip U1 is electrically connected to the positive terminal of the first Zener diode ZD1, and the negative terminal of the first Zener diode ZD1 is electrically connected to the first external port of the Rogowski coil through the third resistor R3.

[0060] 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 operating power supply for the MCU chip U1. Simultaneously, the design of the rectifier bridge BR1 ensures that the MCU chip U1 is correctly powered regardless of the polarity of the communication signal provided by the external measuring device, enhancing the system's stability and compatibility. The protection circuit composed of the first Zener diode ZD1 and the third resistor R3 further improves the system's safety, preventing excessive voltage from damaging the MCU chip U1 and ensuring 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 system's energy utilization efficiency. The MCU chip U1 can also determine the polarity of the first and second external ports of the Rogowski coil through its output terminal, and then determine whether to send accuracy error information to the external measuring device based on the polarity.

[0061] In an optional embodiment, when an external measuring device supplies power to the MCU chip U1 through the first external port 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 polarity of the first external port and the second external port of the Rogowski coil through its output terminal. If the first external port of the Rogowski coil is positive and the second external port of the Rogowski coil is negative, the MCU chip U1 sends accuracy error information to the external measuring device through its output terminal. If 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 accuracy error information to the external measuring device.

[0062] 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 does not interfere with the normal current measurement process, thus improving the stability and accuracy of the measurement. The MCU chip U1 determines the polarity of the first and second external ports of the Rogowski coil through its output terminal. This function effectively prevents data transmission errors or damage caused by wiring mistakes, enhancing the reliability and security 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 will the MCU chip U1 send accuracy 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 U1 will refuse to send accuracy error information, thereby protecting the normal operation of the system. This achieves precise control and efficient management of the Rogowski coil when communicating with the external measuring device.

[0063] This embodiment uses the output of the MCU chip U1 to determine the polarity of the first and second external ports of the Rogowski coil, automatically detecting whether the connection polarity between the external measuring device and the Rogowski coil is correct. If the connection polarity is correct, the MCU chip U1 sends accuracy error information to the external measuring device via its output. If the connection polarity is incorrect, the MCU chip U1 refuses to send accuracy error information, avoiding erroneous data transmission due to misoperation and improving the overall performance and reliability of the system. Users do not need to additionally check or confirm the connection polarity, as the system automatically identifies and takes appropriate measures, simplifying the user's operation and reducing the possibility of human error. The built-in polarity detection function allows users to connect the Rogowski coil to external measuring devices with greater confidence, improving product usability and user experience. The automatic judgment and control by the MCU chip U1 enhances the intelligence level of the entire Rogowski coil system, enabling it to handle communication and data transmission tasks more intelligently.

[0064] In an optional embodiment, the MCU chip U1 includes a set of programming interfaces through which accuracy error information is written.

[0065] In the above embodiments, the MCU chip U1 includes a set of programming interfaces, such as... Figure 2The PB0, PB1, and PB3 interfaces allow for the writing of accuracy error information via a programming interface, facilitating error calibration and updates. This enables programmable writing of accuracy error information, improving the flexibility and adaptability of the Rogowski coil. Optionally, the accuracy error information can also be updated via a set of programming interfaces. These interfaces facilitate easy updating of the Rogowski coil's accuracy error information, enhancing data update convenience. The programming interfaces also provide convenience for system maintenance and upgrades, enabling timely system updates and maintenance to adapt to technological advancements and changing user needs.

[0066] This application also provides an energy metering device, including the Rogowski coil described in any of the foregoing embodiments, and also including the aforementioned external measuring device.

[0067] The integrated design of the loop 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 loop coil and transmits it to the external measuring device, allowing the external measuring device to calibrate the measurement results based on this accuracy error information, thus improving the accuracy of the power metering equipment. The signal coupling circuit includes a filtering unit and a switching unit, which can effectively filter out noise, improve signal purity, and further enhance the measurement accuracy of the power metering equipment.

[0068] It should be noted that the embodiments described above are only some embodiments of this application, and not all embodiments. The present application will be described in detail below with reference to specific embodiments.

[0069] This application provides a communication circuit for Rogowski coils. This communication circuit enables the Rogowski coil's accuracy compensation information to be stored inside the Rogowski coil, allowing external measuring devices to acquire the error information of the Rogowski coil online, thus offering good flexibility.

[0070] This includes signal coupling circuits and MCU circuits;

[0071] (1) The Rogowski coil is unidirectionally connected to the external measuring device through the signal coupling circuit, and outputs the AC measuring signal unidirectionally to the external measuring device;

[0072] (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.

[0073] (3) Signal coupling circuit

[0074] The Rogowski coil output signal is an AC measurement signal with a frequency of 45Hz~65Hz. The signal is connected to the first MOSFET Q1 (depletion-type MOSFET) through the first capacitor C1. When the METER+ and METER- of the external measuring device are used as input ports, the first MOSFET Q1 is in the on state, connecting the AC measurement signal to the external measuring device.

[0075] METER+ and METER- refer to the ports of the external measuring device, which are connected to the first external port of the Rogowski coil (e.g., ...). Figure 2 J2 in the middle) and the second external port of the Rogowski coil (such as ... Figure 2 J4) connection;

[0076] (4) MCU circuit

[0077] The precision error information stored in the MCU circuit is programmed and written into the MCU chip U1 through the TP1, TP2, and TP3 signals.

[0078] When the 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 Zener diode ZD1 and the third resistor R3 to send the accuracy error information stored in the MCU chip U1 to the external measuring device.

[0079] It should be noted that, Figure 2 The toroidal coil is not shown. Figure 2 In this diagram, CT1 and CT2 represent the two output terminals of the loop coil, corresponding to the first and second ends of the loop coil, respectively. J1 and J3 represent the two ports of the circuit board, which includes the aforementioned signal coupling circuit and MCU circuit. The AC voltage signal induced by the loop coil is input into the circuit board through ports J1 and J3. The circuit board and the loop coil are integrated into a single design, forming a complete Rogowski coil. Only ports J2 and J4 of this Rogowski coil are exposed externally for connection to external measuring devices. Figure 2 It also includes a second diode D2 and a fourth resistor R4. The second diode D2 can be used to indicate the wiring between the external measuring device and the Rogowski coil (e.g., Figure 2 Are METER+ and METER- correct?

[0080] Figure 3 This is an example diagram of a Rogowski coil provided in an embodiment of this application. The circuit board consisting of the signal coupling circuit and the MCU circuit described above is embedded in... Figure 3 The dashed elliptical part in the middle corresponds to Figure 4The circuit board is embedded inside the Rogowski coil. From the outside, the entire Rogowski coil appears to have only two wires connecting to the external measuring device.

[0081] Figure 5 This is a circuit diagram of an external testing device provided in an embodiment of this application. The diagram includes two analog switches, such as K1 and K2, as well as a CPU and an ADC.

[0082] The following is combined with Figure 2 , Figure 5 and Figure 6 The operation of the external testing device and the Rogowski coil is described, and the process includes the following steps:

[0083] Step 1: The external measuring device receives instructions through human-machine 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 CPU's digital signal interfaces D+ and D- are connected to the METER+ and METER- of the Rogowski coil.

[0084] Step 2: The D+ signal of the external measuring device CPU is connected to pin S of the depletion-type MOSFET Q1 (corresponding to the first MOSFET Q1 mentioned above) of the Rogowski coil. When D+ is high (pulled up to the power supply through a resistor), and VGS of Q1 is negative, Q1 switches to the off state, and the CT1 signal of the loop coil cannot be transmitted to METER+.

[0085] Step 3: The rectifier bridge of the Rogowski coil draws power from the METER+ and METER- signals. The MCU software runs and determines the input level status of pin PB2.

[0086] Step 4: Determine if PB2 is at a high level;

[0087] If the result of step 4 above is yes, proceed to step 5-1; if the result of step 4 above is no, proceed to step 5-2.

[0088] Step 5-1: The MCU of the Rogowski coil outputs a 1Hz PWM signal through pin PB1, which controls the LED D2 to flash once every 1 second, indicating that METER+ and METER- are connected correctly; then proceed to step 6-1;

[0089] Step 5-2: The MCU of the Rogowski coil outputs a 0.5Hz PWM signal through pin PB1, controlling the LED D2 to flash once every 2 seconds to indicate that METER+ and METER- are wired incorrectly; then proceed to step 6-2.

[0090] Step 6-1: The MCU of the Rogowski coil outputs a digital signal of accuracy error through pin PB2. The CPU of the external measuring device obtains the accuracy error information of the Rogowski coil through the D+ and D- signal lines; then proceed to step 7.

[0091] 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 a fault in the external Rogowski coil through human-machine interaction;

[0092] 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. The analog signal interfaces A+ and A- of the ADC are connected to the METER+ and METER- of the Rogowski coil.

[0093] Step 8: When the MCU of the Rogowski coil loses the D+ / D- power supply, the software stops running, the S level of the Q1 pin of the signal coupling circuit is low, and the VGS of Q1 is 0, so Q1 switches to the on state, and the signals CT1 and CT2 sampled by the loop coil are transmitted to METER+ and METER-.

[0094] Step 9: The CPU of the external measuring device controls the ADC to measure the A+ and A- signals via SPI serial communication to obtain the current information collected by the loop coil. Based on the accuracy error information obtained in step 6-1, the CPU performs error compensation on the measured current information to obtain more accurate measured current information. This step is executed cyclically.

[0095] The embodiments of this application have at least the following technical effects: 1) The communication circuit is embedded inside the Rogowski coil, and the external measuring device can obtain the accuracy error information of the Rogowski coil online; 2) The communication circuit and the loop coil output multiplexed signal line can be used for online information acquisition, and can also be used with external testing devices that do not support online compensation; 3) The MCU circuit draws its own power from the signal line, does not require a separate power supply, and has low operating costs.

[0096] It should be noted that the above embodiments of the apparatus are only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus and method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0097] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0098] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Other embodiments of this disclosure will be readily apparent to those skilled in the art upon consideration of the specification and practical application.

[0099] This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art that are not described in this disclosure.

Claims

1. A Rogowski coil, characterized in that, include: The circuit includes a loop coil, a signal coupling circuit, and an MCU circuit. The loop coil is used to sense the current in the conductor of the power grid under test to obtain an AC measurement signal; The loop coil transmits the AC measurement signal to an external measuring device through the signal coupling circuit. The MCU circuit is used to store the accuracy error information of the loop coil. 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 under test based on the AC measurement signal and the accuracy error information. The ring coil, the signal coupling circuit, and the MCU circuit are integrated into a single design. The MCU circuit includes an energy storage unit and an MCU chip. The input terminal of the energy storage unit is electrically connected to a first external port and a second external port of the Rogowski coil. The output terminal of the energy storage unit is electrically connected to the power supply of the MCU chip. The output terminal 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 an external measuring device through the first external port of the Rogowski coil. The external measuring device is electrically connected to the Rogowski coil through the first and second external ports. When the external measuring device receives a target instruction, it provides a first level signal to the first external port of the Rogowski coil through a first GPIO port and a second level signal to the second external port of the Rogowski coil through a second GPIO port. The energy storage unit converts the level signals provided by the external measuring device into energy for storage and powers the MCU chip, enabling the MCU chip to transmit the accuracy error information to the external measuring device. The target instruction is used to instruct the acquisition of the accuracy error information from the Rogowski coil. The signal coupling circuit includes a filtering unit and a switching unit. 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 measuring device. The filtering unit includes a first resistor and a first capacitor, and the switching unit includes a first MOSFET. The first resistor is connected between the first end of the loop coil and the drain of the first MOSFET, and the first capacitor is connected in parallel with the first resistor. The source of the first MOSFET is electrically connected to the first external port of the Rogowski coil, and the gate of the first MOSFET is electrically connected to ground. The first MOSFET is a depletion-mode MOSFET. Wherein, the first MOSFET is in the on state when the energy storage unit is not powered to transmit the AC measurement signal to the external measuring device, and the first MOSFET is in the off state when the energy storage unit is powered to isolate the AC measurement signal; The signal coupling circuit is connected between the first end of the loop coil and the first external port of the Rogowski coil, and the second end of the loop coil is electrically connected to the second external port of the Rogowski coil. The first and second external ports of the Rogowski coil are electrically connected to the 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 and second external ports of the Rogowski coil. When the external measuring device supplies power to the MCU chip through the first external port and the second external port of the Rogowski coil, the signal coupling circuit is turned off. The MCU chip is used to determine the polarity of the first and second external ports of the Rogowski coil through its output terminal. If the first external port of the Rogowski coil is positive and the second external port of the Rogowski coil is negative, the MCU chip sends the accuracy error information to the external measuring device through its output terminal. If 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.

2. The Rogowski coil according to claim 1, characterized in that, The switching 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 transistor, and the anode of the first diode is electrically connected to the source of the first MOS transistor through the second resistor.

3. The Rogowski coil according to claim 1, characterized in that, The energy storage unit includes a rectifier bridge and a second capacitor, and the MCU circuit further includes a third resistor and a first Zener diode. The two input terminals 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 terminal and the second output terminal of the rectifier bridge. The first output terminal of the rectifier bridge is electrically connected to the power supply terminal of the MCU chip, and the second output terminal of the rectifier bridge is electrically connected to the ground terminal. The output terminal of the MCU chip is electrically connected to the positive terminal of the first Zener diode, and the negative terminal of the first Zener diode is electrically connected to the first external port of the Rogowski coil through the third resistor.

4. The Rogowski coil according to claim 3, characterized in that, The MCU chip includes a set of programming interfaces, through which the precision error information is written.

5. An electricity metering device, characterized in that, Includes the Rogowski coil as described in any one of claims 1 to 4.

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