A non-contact self-calibration current-voltage combined sensor and calibration system

Abstract

The present application relates to the technical field of power transformers, and aims to provide a contactless self-calibration current-voltage combination sensor and a calibration system, wherein the sensor comprises a current sensor, a voltage sensor, a signal processing circuit, a control circuit, a temperature measurement circuit and a self-test circuit; the self-test circuit comprises a self-test coil, a self-test power supply, a self-test wire and a self-test controller, wherein the self-test coil is nested in a shielding shell and connected to the self-test power supply for supplying power to the self-test power supply, the self-test wire passes through an inner hole of the shielding shell and is connected to the self-test power supply, the self-test controller is connected to the self-test power supply and the control circuit for detecting the power of the self-test power supply; the control circuit is connected to a master control device, and the self-test signal output by the signal processing circuit after the self-test circuit is started is uploaded to the master control device, and the output value of the combination sensor is calibrated according to the temperature signal output by the temperature measurement circuit and the self-test calibration information output by the master control device.

Description

Technical Field

[0001] The present application relates to the technical field of power transformers, and in particular to a non-contact self-calibration current-voltage combination sensor and a calibration system. Background Art

[0002] Power sensor is a common electrical component that plays the role of electric energy metering in power systems. The measurement accuracy and reliability of power sensors are closely related to the safety and economy of power systems.

[0003] In the related art, power sensors mainly include current sensors and voltage sensors, which detect the current and voltage in the circuit respectively, and are independent sensors. At the same time, due to the different wiring methods of current sensors and voltage sensors, current sensors and voltage sensors also need to be detected separately during use.

[0004] The utility model patent with publication number CN221378143U discloses a non-contact self-calibration current and voltage integrated sensor, including a current sensor, a voltage sensor and a signal processing device. The current sensor includes a ring-shaped iron core coil, which is nested in a shielding shell and connected to the signal processing circuit. The voltage sensor includes a ring-shaped capacitive screen, which is connected to the signal processing circuit, and the signal processing circuit is connected to the self-calibration combined metering unit.

[0005] The above utility model patent discloses a sensor structure that combines a current sensor and a voltage sensor into one, but how to improve the measurement accuracy of the sensor needs to be solved urgently. Summary of the invention

[0006] The purpose of the present application is to provide a non-contact self-calibration current-voltage combination sensor and a calibration system to improve the measurement accuracy of the combination sensor.

[0007] The above application objectives of this application are achieved through the following technical solutions:

[0008] In a first aspect, the present application provides a non-contact self-calibration current-voltage combination sensor that adopts the following technical solution.

[0009] A non-contact self-calibration current and voltage combination sensor, the sensor comprising a current sensor, a voltage sensor, a signal processing circuit, a control circuit, a temperature measurement circuit and a self-test circuit;

[0010] The current sensor comprises a ring-shaped iron core coil, which is nested in a shielding shell and connected to a signal processing circuit;

[0011] The voltage sensor comprises a capacitor ring, which is fixed to the inner hole wall of the shielding shell and connected to the signal processing circuit;

[0012] A temperature measuring circuit, used for detecting the temperature of the combined sensor;

[0013] The signal processing circuit is connected to the voltage sensor and the current sensor, and transmits the monitoring signals of the voltage sensor and the current sensor to the control circuit;

[0014] A self-test circuit includes a self-test coil, a self-test power supply, a self-test wire and a self-test controller, wherein the self-test coil is nested in a shielding shell and connected to the self-test power supply to supply power to the self-test power supply, the self-test wire passes through an inner hole of the shielding shell and is connected to the self-test power supply, and the self-test controller is connected to the self-test power supply and a control circuit to detect the power of the self-test power supply;

[0015] The control circuit is connected to the main control device, and uploads the self-test signal output by the signal processing circuit after the self-test circuit is started to the main control device, and calibrates the output value of the combined sensor according to the temperature signal output by the temperature measurement circuit and the self-test calibration information output by the main control device.

[0016] In a preferred embodiment, the annular iron core coil and the self-test coil are separated and fixed in the shielding shell by insulating glue.

[0017] In a preferred embodiment, the control circuit compensates the detection data output by the signal processing circuit according to the detection data of the temperature measurement circuit, and then calibrates the detection data according to the self-test calibration information.

[0018] In a preferred embodiment, the capacitor ring is formed by wrapping a shielded copper mesh, and both ends of the capacitor ring are provided with test terminals, and the self-test wire is connected to the test terminals.

[0019] In a preferred embodiment, the signal processing circuit includes a signal amplifying circuit, which is configured with at least two stages of amplification and adjusts the amplification stage of the signal amplifying circuit in response to the self-test start signal output by the control circuit.

[0020] In a second aspect, the present application provides a calibration system that adopts the following technical solution.

[0021] A calibration system applied to the above-mentioned combined sensor, the system comprising:

[0022] A signal receiving module, used for receiving a preparation signal output by the self-test circuit and a self-test calibration signal and a power-off signal output by the master control device;

[0023] The processing module responds to the power-off signal and the ready signal to output a self-test start signal to the self-test circuit to drive the self-test circuit to start, and obtains the self-test signal output by the signal processing circuit after outputting the self-test start signal; after receiving the self-test signal, the processing module transmits the self-test signal to the master control device, and calibrates the output value of the combined sensor according to the temperature signal output by the temperature measurement circuit and the self-test calibration signal fed back by the master control device.

[0024] In a preferred embodiment, the processing module comprises:

[0025] The start control unit outputs a self-test start signal when receiving a power-off signal and a ready signal at the same time;

[0026] A self-test receiving unit, connected to the signal processing circuit, responding to the self-test driving signal to switch the signal processing circuit to a self-test mode, and receiving a self-test signal output by the signal processing circuit;

[0027] A data transmission unit, used to upload the self-test signal to the master control device and receive a self-test calibration signal fed back by the master control device;

[0028] The output calibration unit is used to calibrate the output value of the combined sensor according to the self-test calibration signal and the temperature signal.

[0029] In a preferred embodiment, a plurality of self-test wires are arranged, and the start control unit drives the self-test circuit to energize through each self-test wire in turn according to a self-test start signal.

[0030] In a preferred embodiment, the capacitor ring is wrapped by a shielded copper mesh, and both ends of the capacitor ring are configured with test terminals. At least one self-test wire among the self-test wires passing through the inner hole of the shielding shell is connected to the test terminals, and passes through the inner hole of the shielding shell through the capacitor ring. The start control unit cuts off or closes the connection between the capacitor ring and the signal processing circuit according to the self-test start signal.

[0031] In a preferred embodiment, the processing module is connected to a self-test switch, and after receiving a switch signal output by the self-test switch, responds to a power-off signal and a ready signal to output a self-test start signal to the self-test circuit.

[0032] In summary, the present application includes the following beneficial technical effects: when the self-test controller detects that the power of the self-test power supply reaches a preset value, it outputs a preparation signal to the control circuit; when the power cable is powered off, the master control device outputs a power-off signal to the control circuit. When the self-test switch is triggered, the control circuit receives the preparation signal and the power-off signal at the same time, and the control circuit outputs a self-test start signal to the self-test circuit, the self-test circuit starts, and controls each self-test wire and the shielded copper mesh to be powered on in turn. During the self-test circuit startup process, the control circuit receives the self-test signal output by the signal processing circuit, and uploads the self-test signal to the master control device. The master control device obtains the calibration value of the combined sensor based on the self-test signal and feeds back the self-test calibration information to the control circuit. The control circuit calibrates the output value of the combined sensor in turn through the temperature signal and the self-test calibration information. Due to the setting of the self-test circuit, the calibration of the output value of the combined sensor is realized, thereby improving the accuracy of the combined sensor detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the application of the combined sensor in the embodiment of the present application.

[0034] Figure 2 It is a schematic diagram of the structure of the combined sensor in the embodiment of the present application.

[0035] Figure 3 It is a topological diagram of the combined sensor system in the embodiment of the present application.

[0036] Figure 4 It is a system topology diagram of the self-test circuit in the embodiment of the present application.

[0037] Figure 5 This is a structural diagram of the isolation and fixation of the current sensor and the self-test wire in an embodiment of the present application.

[0038] Explanation of the accompanying drawings: 1. combined sensor; 2. current and voltage indicator; 11. shell; 111. inner hole; 12. cover plate; 21. current sensor; 22. voltage sensor; 23. signal processing circuit; 24. control circuit; 25. temperature measurement circuit; 26. self-test circuit; 261. self-test coil; 262. self-test power supply; 263. self-test wire; 264. self-test controller. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings to Figures 1 to 5 , the technical solutions in the embodiments of the present application are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0040] In addition, the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article, unless otherwise specified, generally means that the associated objects before and after are in an "or" relationship.

[0041] The present application provides a non-contact self-calibration current and voltage combination sensor, the combination sensor 1 is applied to the field of high-voltage power distribution, especially to the voltage and current detection of three-phase high-voltage electricity. Figure 1 The combination sensors 1 are composed of three sensors in a group, which are used to detect the current and voltage in the three-phase cable respectively. The output lines of the three combination sensors 1 are connected to the current and voltage indicator 2, and the current and voltage indicator 2 displays the detected current and voltage. Generally, the current and voltage indicator 2 is configured in the master control device.

[0042] Reference Figure 2 and Figure 3 The current-voltage combination sensor 1 includes a current sensor 21, a voltage sensor 22, a signal processing circuit 23, a control circuit 24, and a temperature measurement circuit 25. The current sensor 21 and the voltage sensor 22 are combined and arranged in a shielding shell, and the shielding shell is provided with an inner hole 111. The cable passes through the shielding shell through the inner hole 111 of the shielding shell, and the current sensor 21 and the voltage sensor 22 detect the voltage and current of the cable.

[0043] The current sensor 21 is configured as a ring-shaped iron core coil, that is, the coil is wound around a ring-shaped iron core to form the current sensor 21, and the ring-shaped iron core coil is nested in the shielding shell. The shielding shell includes a shell 11 and a cover plate 12, and the inner hole 111 is formed by an annular wall in the shell 11, and the ring-shaped iron core coil is nested outside the annular wall, and the annular iron core coil is cast in the shell 11 by insulating glue, and then the cover plate 12 is fixedly connected to the shell 11 by fixing screws. The voltage sensor 22 includes a capacitor ring, which is wrapped by a shielding copper mesh, and the capacitor ring is fixed to the wall of the inner hole 111 of the shielding shell. The cable passes through the inner hole 111. When the cable is powered on, the current sensor 21 and the voltage sensor 22 detect the current and voltage of the cable through the principle of electromagnetic induction.

[0044] The signal processing circuit 23 is disposed in the shielding shell, and is connected to the current sensor 21 and the voltage sensor 22, and is used to receive the current signal and the voltage signal detected by the current sensor 21 and the voltage sensor 22, and filter and amplify the current signal and the voltage signal, that is, the signal processing circuit 23 includes an amplifier circuit. The amplifier circuit is composed of an integrated operational amplifier.

[0045] The temperature measuring circuit 25 is used to detect the temperature of the combined sensor 1 and output a temperature signal to the control circuit 24 . The control circuit 24 calibrates and compensates the output value of the combined sensor 1 according to the temperature signal.

[0046] Based on the above-mentioned combined sensor 1, in the application process, the current and voltage signals have inaccurate measurement values ​​after calibration and compensation, but the inaccurate measurement cannot be discovered in time. Based on this, the applicant has made the following improvements to the combined sensor 1.

[0047] Reference Figure 2-Figure 4 The combined sensor 1 further includes a self-test circuit 26, which includes a self-test coil 261, a self-test power supply 262, a self-test wire 263 and a self-test controller 264. The self-test coil 261 is nested in the shielding shell, the self-test power supply 262 is arranged outside the shielding shell, and the self-test wire 263 passes through the inner hole 111 of the shielding shell. During the normal power-on process of the cable, the self-test coil 261 generates an induced current to charge the self-test power supply 262, and the self-test power supply 262 is a battery that can store the power output by the self-test coil 261. During the power-off calibration process of the combined sensor 1, the self-test wire 263 is powered by the self-test power supply 262, so that the current sensor 21 and the voltage sensor 22 can detect the voltage and current generated by the power-on of the self-test wire 263. Since the configuration of the self-test wire 263 and the self-test power supply 262 is controllable, the voltage and current generated by the power-on of the self-test wire 263 are controllable, thereby providing a data basis for the calibration of the combined sensor 1.

[0048] In a preferred example, the annular iron core coil and the self-test coil 261 are separated and fixed in the shielding shell by insulating glue.

[0049] When the self-test wire 263 is powered on, the signal processing circuit 23 receives the current signal and the voltage signal output by the current sensor 21 and the voltage sensor 22, and outputs the self-test signal accordingly. The self-test controller 264 is connected to the control circuit 24, and the control circuit 24 uploads the self-test signal output by the signal processing circuit 23 during the power-on process of the self-test wire 263 to the master control device, which can display the voltage value and the current value corresponding to the self-test signal, so as to compare the theoretical voltage and the theoretical current generated after the self-test coil 261 is powered on to analyze and obtain the measurement deviation of the current combination sensor 1, and then feed back the self-test calibration signal to calibrate the output value of the combination sensor 1.

[0050] In a preferred example, the self-test calibration signal fed back by the master control device can be manually controlled feedback or automatically fed back by the master control device. In this example, the master control device outputs the self-test calibration signal based on the calibration data output by the staff, thereby ensuring the accuracy of the output value of the combination sensor 1.

[0051] Furthermore, when the control circuit 24 calibrates the output value of the combined sensor 1, the control circuit 24 compensates the detection data output by the signal processing circuit 23 according to the detection data of the temperature measurement circuit 25, and then calibrates the detection data according to the self-test calibration information.

[0052] Furthermore, both ends of the capacitor ring are provided with test terminals, and the self-test wires 263 are provided with multiple ones, at least one of the multiple self-test wires 263 is connected to the test terminal, the test terminal is connected to the shielded copper mesh in the capacitor ring, and the self-test power supply 262 forms a conductive path with the capacitor ring through the terminal. When the self-test circuit 26 is started, it is energized only through the self-test wire 263, and it can also be energized through the capacitor ring.

[0053] In a preferred example, each of the self-test wires 263 is configured with a line switch, and the line switch sequentially controls each self-test wire 263 and the capacitor loop to be energized through the line switch when the self-test circuit 26 is started. A capacitor switch is connected between the output end of the capacitor loop and the signal processing circuit 23. When the self-test circuit 26 is started, the capacitor switch is disconnected, thereby disconnecting the connection between the capacitor loop and the signal processing circuit 23, thereby testing the detection accuracy of the current sensor 21.

[0054] In a preferred example, the combination sensor 1 further includes a self-test switch, and a worker starts the self-test of the combination sensor 1 through the self-test switch.

[0055] The working principle of the combined sensor 1 described in the present application is as follows: when the self-test controller 264 detects that the power of the self-test power supply 262 reaches a preset value, it outputs a preparation signal to the control circuit 24; when the power cable is powered off, the master control device outputs a power-off signal to the control circuit 24. When the self-test switch is triggered, the control circuit 24 receives the preparation signal and the power-off signal at the same time, and the control circuit 24 outputs a self-test start signal to the self-test circuit 26, the self-test circuit 26 starts, and sequentially controls each self-test wire 263 and the shielding copper mesh to be powered on. During the startup process of the self-test circuit 26, the control circuit 24 receives the self-test signal output by the signal processing circuit 23, and uploads the self-test signal to the master control device. The master control device obtains the calibration value of the combined sensor 1 according to the self-test signal and feeds back the self-test calibration information to the control circuit 24. The control circuit 24 sequentially calibrates the output value of the combined sensor 1 through the temperature signal and the self-test calibration information. Due to the setting of the self-test circuit 26, the calibration of the output value of the combined sensor 1 is realized, thereby improving the detection accuracy of the combined sensor 1.

[0056] In another embodiment, the present application also provides a calibration system, which is applied to the combined sensor 1. The calibration system includes: a signal receiving module, which is used to receive a preparation signal output by the self-test circuit 26 and a self-test calibration signal and a power-off signal output by the master control device; a processing module, which outputs a self-test start signal to the self-test circuit 26 in response to the power-off signal and the preparation signal to drive the self-test circuit 26 to start, and obtains the self-test signal output by the signal processing circuit 23 after outputting the self-test start signal; after receiving the self-test signal, the processing module transmits the self-test signal to the master control device, and calibrates the output value of the combined sensor 1 according to the temperature signal output by the temperature measuring circuit 25 and the self-test calibration signal fed back by the master control device.

[0057] The processing module includes a start control unit, which outputs a self-test start signal when receiving a power-off signal and a ready signal at the same time. The start control unit cuts off or closes the connection between the capacitor loop and the signal processing circuit 23 according to the self-test start signal; a self-test receiving unit, which is connected to the signal processing circuit 23, switches the signal processing circuit 23 to a self-test mode in response to a self-test drive signal, and receives a self-test signal output by the signal processing circuit 23; a data transmission unit, which is used to upload the self-test signal to the master control device and receive a self-test calibration signal fed back by the master control device; and an output calibration unit, which is used to calibrate the output value of the combined sensor 1 according to the self-test calibration signal and the temperature signal.

[0058] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the calibration system described above is a component of the control circuit 24, and the functions implemented by the calibration system are the functions implemented by the control circuit 24, which will not be repeated here.

[0059] In the several examples provided in the present application, the disclosed structure may be one or more. For example, in one example, the self-test wire 263 is not connected to the capacitor ring, and in another example, at least one of the self-test wires 263 is connected to the capacitor ring. For another example, the combination sensor 1 is not equipped with a self-test switch, and the control circuit 24 receives a ready signal and a power-off signal at the same time, then the control circuit 24 outputs a self-test start signal to the self-test circuit 26, thereby completing an automated self-test.

Claims

1. A non-contact self-calibration current-voltage combination sensor, characterized in that: The sensor comprises a current sensor (21), a voltage sensor (22), a signal processing circuit (23), a control circuit (24), a temperature measurement circuit (25) and a self-test circuit (26); The current sensor (21) comprises a ring-shaped iron core coil, which is nested in a shielding shell and connected to a signal processing circuit (23); The voltage sensor (22) comprises a capacitor ring, which is fixed to the wall of the inner hole (111) of the shielding shell and connected to the signal processing circuit (23); A temperature measuring circuit (25) for detecting the temperature of the combined sensor (1); The signal processing circuit (23) is connected to the voltage sensor (22) and the current sensor (21), and transmits monitoring signals of the voltage sensor (22) and the current sensor (21) to the control circuit (24); A self-test circuit (26), comprising a self-test coil (261), a self-test power supply (262), a self-test wire (263) and a self-test controller (264); the self-test coil (261) is nested in a shielding shell and connected to the self-test power supply (262) for supplying power to the self-test power supply (262); the self-test wire (263) passes through an inner hole (111) of the shielding shell and is connected to the self-test power supply (262); the self-test controller (264) is connected to the self-test power supply (262) and a control circuit (24) for detecting the amount of electricity in the self-test power supply (262); The capacitor ring is formed by wrapping a shielded copper mesh, and both ends of the capacitor ring are provided with test terminals. A plurality of self-test wires (263) are provided, and at least one of the plurality of self-test wires (263) is connected to the test terminal. The test terminal is connected to the shielded copper mesh in the capacitor ring, and the self-test power supply (262) forms a conductive path with the capacitor ring through the terminal. The control circuit (24) is connected to the master control device, and uploads the self-test signal output by the signal processing circuit (23) to the master control device after the self-test circuit (26) is started, and calibrates the output value of the combined sensor (1) according to the temperature signal output by the temperature measuring circuit (25) and the self-test calibration information output by the master control device.

2. A non-contact self-calibration current-voltage combination sensor according to claim 1, characterized in that: The annular iron core coil and the self-test coil (261) are separated and fixed in the shielding shell by insulating glue.

3. A non-contact self-calibration current-voltage combination sensor according to claim 1, characterized in that: The control circuit (24) compensates the detection data output by the signal processing circuit (23) according to the detection data of the temperature measurement circuit (25), and then calibrates the detection data according to the self-test calibration information.

4. A non-contact self-calibration current-voltage combination sensor according to claim 1, characterized in that: The signal processing circuit (23) comprises a signal amplifying circuit, which is configured with at least two stages of amplification and adjusts the amplification stage of the signal amplifying circuit in response to the self-check start signal output by the control circuit (24).

5. A calibration system for the combined sensor according to any one of claims 1 to 4, characterized in that: The system comprises: A signal receiving module, used for receiving a preparation signal output by the self-test circuit (26) and a self-test calibration signal and a power-off signal output by the master control device; The processing module outputs a self-test start signal to the self-test circuit (26) in response to the power-off signal and the preparation signal to drive the self-test circuit (26) to start, and obtains the self-test signal output by the signal processing circuit (23) after outputting the self-test start signal; after receiving the self-test signal, the processing module transmits the self-test signal to the master control device, and calibrates the output value of the combined sensor (1) according to the temperature signal output by the temperature measuring circuit (25) and the self-test calibration signal fed back by the master control device; The self-test circuit (26) is started and controls each self-test wire (263) and the shielding copper mesh to be energized in turn.

6. The calibration system according to claim 5, characterized in that The processing module comprises: The start control unit outputs a self-test start signal when receiving a power-off signal and a ready signal at the same time; A self-test receiving unit connected to the signal processing circuit (23), responding to a self-test driving signal to switch the signal processing circuit (23) to a self-test mode, and receiving a self-test signal output by the signal processing circuit (23); A data transmission unit, used to upload the self-test signal to the master control device and receive a self-test calibration signal fed back by the master control device; An output calibration unit is used to calibrate the output value of the combined sensor (1) according to the self-test calibration signal and the temperature signal.

7. The calibration system according to claim 6, characterized in that A plurality of self-test wires (263) are arranged, and the start control unit drives the self-test circuit (26) to energize each self-test wire (263) in turn according to a self-test start signal.

8. The calibration system according to claim 7, characterized in that The capacitor ring is formed by wrapping a shielded copper mesh, and both ends of the capacitor ring are configured with test terminals. At least one of the self-test wires (263) passing through the inner hole (111) of the shielding shell is connected to the test terminal, and the capacitor ring passes through the inner hole (111) of the shielding shell. The start control unit cuts off or closes the connection between the capacitor ring and the signal processing circuit (23) according to the self-test start signal.

9. The calibration system according to claim 5, characterized in that: The processing module is connected to a self-test switch and, after receiving a switch signal output by the self-test switch, responds to a power-off signal and a preparation signal to output a self-test start signal to a self-test circuit (26).

Images