Zero-flux coil on-off detection device

Abstract

A zero-flux coil on-off detection device disclosed by the present invention comprises an excitation power supply module, a transmitting coil, a receiving coil and a signal processing module, the excitation power supply module is electrically connected with the transmitting coil, and the excitation power supply module is used for providing a stable current for the transmitting coil, so that the transmitting coil generates a magnetic field; the transmitting coil is arranged on one side of the track and is parallel to the zero-flux coil, the signal processing module is electrically connected with the receiving coil, the receiving coil is arranged on the other side of the track and is parallel to the zero-flux coil connected with the transmitting coil side through a hinge line, and the signal processing module is used for detecting whether the transmitting coil and the receiving coil move synchronously or not when the transmitting coil and the receiving coil move synchronously. And receiving the output voltage of the coil. According to the invention, the on-off detection of the zero-flux coil can be realized, and serious consequences caused by the disconnection fault of the zero-flux coil can be effectively prevented.

Description

Technical Field

[0001] This invention relates to the field of zero flux coil continuity detection technology, and more specifically, to a zero flux coil continuity detection device. Background Technology

[0002] Superconducting electric levitation trains, with their advantages of strong levitation self-stability and large levitation gap, have become one of the important technical routes for high-speed maglev systems. Their basic principle lies in the interaction between the onboard superconducting magnet and the ground-based levitation coil, generating levitation and guiding forces, while simultaneously interacting with the ground-based propulsion coil to provide traction and braking forces. Due to their unique figure-eight structure, the levitation coil is also known as a figure-eight coil or a zero-flux coil. Figure 1 As shown, the topology of the superconducting electric levitation system based on zero-flux coils consists of a ground-based zero-flux coil array and an onboard superconducting coil. Each zero-flux coil comprises two independent loops, arranged in a figure-eight configuration. There is no electrical connection between coils on the same side, while the mirror-symmetrical zero-flux coils on both sides of the track are electrically connected via hinge lines to enhance the system's guiding stiffness.

[0003] Given the large number and long distances the ground coils are laid along the track, there is a potential risk of circuit breakage due to unpredictable factors during long-term outdoor operation. For example... Figure 2 As shown, there are five possible open circuit fault points in the superconducting electric suspension system unit module, corresponding to five fault modes: open circuit in the upper circuit of the left zero flux coil; open circuit in the lower circuit of the left zero flux coil; open circuit in the upper circuit of the right zero flux coil; open circuit in the lower circuit of the right zero flux coil; and open circuit in the hinge wire.

[0004] It should be particularly noted that an open-circuit fault in the levitation coil will inevitably cause abnormal fluctuations in the system's levitation force and guiding force. In mild cases, this can lead to increased train vibration; in severe cases, it can cause train instability or even collision with the tracks. Therefore, effectively detecting the continuity of the levitation coil is a problem that needs to be solved. Summary of the Invention

[0005] To address the aforementioned problems, this invention innovatively provides a zero-flux coil continuity detection device, which can detect the continuity of a zero-flux coil and effectively prevent serious consequences caused by a zero-flux coil disconnection fault.

[0006] To achieve the above-mentioned technical objectives, this invention discloses a zero-flux coil continuity detection device, comprising an excitation power supply module, a transmitting coil, a receiving coil, and a signal processing module. The excitation power supply module is electrically connected to the transmitting coil and provides a stable current to the transmitting coil to generate a magnetic field. The transmitting coil is arranged on one side of the track and parallel to the zero-flux coil. The signal processing module is electrically connected to the receiving coil, which is arranged on the other side of the track and parallel to the zero-flux coil connected to the transmitting coil side via a hinge line. The signal processing module is used to detect the output voltage of the receiving coil when the transmitting coil and the receiving coil move synchronously.

[0007] Furthermore, the present invention provides a zero flux coil continuity detection device, wherein the excitation power supply module includes a battery, a filter, a soft-start circuit, and a phase-shifting full-bridge circuit. The output terminal of the battery is connected to the input terminal of the filter, the output terminal of the filter is connected to the input terminal of the soft-start circuit, the output terminal of the soft-start circuit is connected to the input terminal of the phase-shifting full-bridge circuit, and the output terminal of the phase-shifting full-bridge circuit is connected to the transmitting coil.

[0008] Furthermore, the present invention provides a zero flux coil continuity detection device, wherein a compensation capacitor is connected between the phase-shifting full-bridge circuit and the transmitting coil.

[0009] Furthermore, the present invention provides a zero flux coil continuity detection device, wherein the soft-start circuit includes a first switch, a second switch, a current-limiting resistor, and a buffer capacitor. The first terminal of the first switch is connected to the positive output terminal of the filter, the second terminal of the first switch is connected to the first terminal of the current-limiting resistor, and the second terminal of the current-limiting resistor is connected to the positive input terminal of the phase-shifted full-bridge circuit. The first terminal of the second switch is connected to the positive output terminal of the filter, and the second terminal of the second switch is connected to the positive input terminal of the phase-shifted full-bridge circuit. The first terminal of the buffer capacitor is connected to the positive input terminal of the phase-shifted full-bridge circuit, and the second terminal of the buffer capacitor is connected to both the negative output terminal of the filter and the negative input terminal of the phase-shifted full-bridge circuit.

[0010] Furthermore, the present invention provides a zero flux coil continuity detection device, which further includes a main control module connected to the excitation power supply module. The main control module includes a first sampling circuit, a frequency detection circuit, an RMS value detection circuit, and a first digital signal processor. The first sampling circuit, the frequency detection circuit, and the RMS value detection circuit are all connected to the first digital signal processor.

[0011] Furthermore, in the present invention, a zero flux coil continuity detection device is provided, wherein the first digital signal processor is also connected to a microcontroller via a communication circuit, and the microcontroller is connected to a digital tube driving circuit.

[0012] Furthermore, the present invention provides a zero flux coil continuity detection device, wherein the signal processing module includes an envelope detection circuit, a second sampling circuit, and a second digital signal processor. The envelope detection circuit is connected to a receiving coil, and the second digital signal processor is connected to the envelope detection circuit through the second sampling circuit. The envelope detection circuit converts the alternating voltage of the receiving coil into a voltage analog signal reflecting the amplitude, and the second sampling circuit converts the voltage analog signal into a voltage digital signal that can be received by the second digital signal processor. The second digital signal processor determines the continuity state of the zero flux coil based on the voltage digital signal.

[0013] Furthermore, the present invention provides a zero flux coil continuity detection device, wherein the second digital signal processor is connected to an industrial control computer via Ethernet, and the second digital signal processor uploads the voltage digital signal and the continuity status of the zero flux coil to the industrial control computer via Ethernet.

[0014] Furthermore, the present invention provides a zero flux coil continuity detection device, wherein the transmitting coil is wound with insulated copper Litz wire.

[0015] Furthermore, the present invention provides a zero flux coil continuity detection device, wherein the receiving coil is a PCB coil.

[0016] Compared with existing technologies, the advantages of this invention are as follows: By setting up an excitation power supply module, a transmitting coil, a receiving coil, and a signal processing module, the excitation power supply module and the transmitting coil are electrically connected. The excitation power supply module provides a stable current to the transmitting coil, causing the transmitting coil to generate a magnetic field. The transmitting coil is arranged on one side of the track, parallel to the zero flux coil. The signal processing module is electrically connected to the receiving coil, which is arranged on the other side of the track, parallel to the zero flux coil connected to the transmitting coil side via a hinge line. The signal processing module detects the output voltage of the receiving coil when the transmitting and receiving coils move synchronously, thus constructing a zero flux coil continuity detection device capable of detecting the continuity of the zero flux coil, effectively preventing serious consequences caused by a zero flux coil disconnection fault. In practical use, the transmitting and receiving coils are installed on the vehicle, and the transmitting and receiving coils are respectively arranged on both sides of the track. A magnetic field is generated by supplying current to the transmitting coil through the excitation power module. As the vehicle moves forward, an induced current is generated in the zero-flux coil on the transmitting side. This induced current flows through the hinge wire into the zero-flux coil on the receiving side, where it generates a magnetic field. Changes in this magnetic field produce an induced electromotive force (EMF). When an open circuit occurs at different locations within a unit module, the equivalent circuit of the unit module changes, causing a change in the current flowing into the zero-flux coil on the receiving side. This ultimately leads to a change in the induced EMF of the receiving coil, resulting in a change in the output voltage across the receiving coil. The on / off state of the zero-flux coil can be determined based on the magnitude of this output voltage. Attached Figure Description

[0017] Figure 1 A schematic diagram of the topology of a superconducting electric levitation system with a zero flux coil; Figure 2 This is a schematic diagram of the unit module structure of a superconducting electric suspension system; Figure 3 This is a structural block diagram of a zero flux coil continuity detection device according to the present invention; Figure 4 This is a schematic diagram illustrating the usage state of the zero flux coil continuity detection device of the present invention during the detection process; Figure 5 This is a schematic diagram of the connection structure between the excitation power supply and the transmitting coil in a zero flux coil continuity detection device of the present invention; Figure 6 This is a schematic diagram of the connection structure between the receiving coil and the signal processing module in a zero flux coil continuity detection device of the present invention; Figure 7 This is a photograph of the transmitting coil in the zero flux coil continuity detection device of the present invention. Figure 8 This is a photograph of the receiving coil in the zero flux coil continuity detection device of the present invention. Detailed Implementation

[0018] The following is a detailed explanation and description of a zero-flux coil continuity detection device according to the present invention, with reference to the accompanying drawings.

[0019] like Figure 3 As shown, this invention discloses a zero-flux coil continuity detection device. It comprises an excitation power module, a transmitting coil, a receiving coil, and a signal processing module. The excitation power module and the transmitting coil are electrically connected, providing a stable current to the transmitting coil to generate a magnetic field. The transmitting coil is positioned on one side of a track, parallel to the zero-flux coil. The signal processing module is electrically connected to the receiving coil, which is positioned on the other side of the track, parallel to the zero-flux coil connected to the transmitting coil via a hinge line. The signal processing module detects the output voltage of the receiving coil when the transmitting and receiving coils move synchronously. This constitutes a zero-flux coil continuity detection device capable of detecting the continuity of the zero-flux coil, effectively preventing serious consequences caused by a zero-flux coil disconnection fault.

[0020] like Figure 4 As shown, in practical use, the transmitting and receiving coils are mounted on the vehicle, with the transmitting and receiving coils positioned on opposite sides of the track. A current is supplied to the transmitting coil via the excitation power module to generate a magnetic field. As the vehicle moves forward, an induced current is generated in the zero-flux coil on the transmitting side. This induced current flows through the hinge wire into the zero-flux coil on the receiving side, where it generates a magnetic field. Changes in this magnetic field produce an induced electromotive force (EMF). When an open circuit occurs at different locations within a unit module, the equivalent circuit of the unit module changes, causing a change in the current flowing into the zero-flux coil on the receiving side. This ultimately leads to a change in the induced EMF of the receiving coil, resulting in the output voltage across the receiving coil. The on / off state of the zero-flux coil can be determined based on the magnitude of this output voltage.

[0021] Based on actual experimental data, the continuity of the zero-flux coil and the location of the fault point can be determined according to the output voltage of the receiving coil. Experimental verification shows that when the output voltage of the receiving coil is 14.5V, the zero-flux coil is in a continuous state (i.e., normal state); when the output voltage is 1.08V, the upper circuit of the left zero-flux coil is determined to be open; when the output voltage is 20.5V, the lower circuit of the left zero-flux coil is determined to be open; when the output voltage is 0.4V, the upper circuit of the right zero-flux coil is determined to be open; when the output voltage is 19.5V, the lower circuit of the right zero-flux coil is determined to be open; and when the output voltage is 0.28V, the hinge wire is determined to be open. These voltage values ​​are typical values; actual measured values ​​may fluctuate within a small range around these values.

[0022] like Figure 5 As shown, the excitation power supply module in this invention includes a battery, a filter, a soft-start circuit, and a phase-shifted full-bridge circuit. The output terminal of the battery is connected to the input terminal of the filter, the output terminal of the filter is connected to the input terminal of the soft-start circuit, the output terminal of the soft-start circuit is connected to the input terminal of the phase-shifted full-bridge circuit, and the output terminal of the phase-shifted full-bridge circuit is connected to the transmitting coil. The filter uses an EMI filter to suppress electromagnetic interference. The soft-start circuit prevents large current from impacting subsequent circuits. The phase-shifted full-bridge circuit controls the phase shift angle, changing the output voltage of the full-bridge circuit, thereby controlling the output current and providing a stable current to the transmitting coil. Furthermore, a compensation capacitor is connected between the phase-shifted full-bridge circuit and the transmitting coil. The compensation capacitor and the transmitting coil can form an LC series resonant circuit to maximize the output energy of the transmitting coil. It also enables the switches in the phase-shifted full-bridge circuit to achieve zero-voltage turn-on and zero-current turn-off, improving the operating efficiency of the phase-shifted full-bridge circuit. Additionally, the compensation capacitor absorbs the back electromotive force generated when the switches in the phase-shifted full-bridge circuit are turned off, protecting the phase-shifted full-bridge circuit and the transmitting coil.

[0023] More specifically, the soft-start circuit includes a first switch k1, a second switch k2, a current-limiting resistor R, and a buffer capacitor Cdc. The first terminal of the first switch k1 is connected to the positive output terminal of the filter, the second terminal of the first switch k1 is connected to the first terminal of the current-limiting resistor R, the second terminal of the current-limiting resistor R is connected to the positive input terminal of the phase-shifted full-bridge circuit, the first terminal of the second switch k2 is connected to the positive output terminal of the filter, the second terminal of the second switch k2 is connected to the positive input terminal of the phase-shifted full-bridge circuit, the first terminal of the buffer capacitor Cdc is connected to the positive input terminal of the phase-shifted full-bridge circuit, and the second terminal of the buffer capacitor Cdc is connected to the negative output terminal of the filter and the negative input terminal of the phase-shifted full-bridge circuit, respectively. When the soft-start circuit is in use, the first switch k1 is closed first. The battery voltage charges the buffer capacitor Cdc through the EMI filter, the first switch k1, and the current-limiting resistor R. Due to the current-limiting effect of the current-limiting resistor R, the charging current is limited to a safe range to avoid surge impact. When the voltage of the buffer capacitor Cdc approaches the output voltage of the battery, the second switch k2 is closed. Since the second switch k2 is connected in parallel across the first switch k1 and the current-limiting resistor R, the current-limiting resistor R is short-circuited. At this time, the current flows directly through the second switch k2, and the circuit enters a stable working state.

[0024] It also includes a main control module connected to the excitation power supply module. The main control module comprises a first sampling circuit, a frequency detection circuit, an RMS value detection circuit, and a first digital signal processor. The first sampling circuit, frequency detection circuit, and RMS value detection circuit are all connected to the first digital signal processor. The first digital signal processor uses a TMS320F28335 chip. Combined with the first sampling circuit, frequency detection circuit, and RMS value detection circuit, it can realize the detection of the RMS value and frequency of output voltage and current, DC voltage detection, and temperature detection, thereby achieving output current control of the excitation power supply and overcurrent, overvoltage, and overtemperature protection. Simultaneously, the first digital signal processor is also connected to a microcontroller via a communication circuit. The microcontroller is connected to a digital tube driver circuit. The communication circuit uses RS845 communication, and the microcontroller uses an STM32F103 chip. The STM32F103 chip displays the RMS voltage, RMS current, frequency, and the operating status of the excitation power supply through the digital tube driver circuit.

[0025] like Figure 6As shown, the signal processing module in this invention includes an envelope detection circuit, a second sampling circuit, and a second digital signal processor. The second digital signal processor uses an STM32H743 chip. The envelope detection circuit is connected to the receiving coil, and the second digital signal processor is connected to the envelope detection circuit through the second sampling circuit. The envelope detection circuit converts the alternating voltage of the receiving coil into a voltage analog signal reflecting the amplitude. The second sampling circuit converts the voltage analog signal into a voltage digital signal (i.e., the output voltage of the receiving coil) that can be received by the second digital signal processor. The second digital signal processor determines the on / off state of the zero flux coil based on the voltage digital signal. Based on the output voltage value, the second digital signal processor specifically determines whether the zero flux coil is disconnected, and if so, the specific location of the disconnection.

[0026] The second digital signal processor (DSP) is connected to the industrial control computer (ICC) via Ethernet. The DSP uploads the voltage digital signal and the on / off status of the zero-flux coil to the ICC via Ethernet. Specifically, the DSP connects to the Ethernet PHY via a MAC address, and finally to the ICC's RJ45 port via the Ethernet PHY, thus establishing a communication link between the DSP and the ICC to achieve automated fault detection and diagnosis of the zero-flux coil.

[0027] like Figure 7 and Figure 8 As shown, the transmitting coil in this invention is wound with insulated copper Litz wire to reduce the AC resistance loss of the coil and thus reduce the heat generation of the transmitting coil. The receiving coil is a PCB coil, which is lighter, thinner and more durable.

[0028] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] 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 number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0030] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and simple improvements made on the substantive content of the present invention should be included within the protection scope of the present invention.

Claims

1. A zero flux coil on-off detection device, characterized by: The system includes an excitation power supply module, a transmitting coil, a receiving coil, and a signal processing module. The excitation power supply module is electrically connected to the transmitting coil and provides a stable current to the transmitting coil, causing it to generate a magnetic field. The transmitting coil is arranged on one side of the track and parallel to a zero-flux coil. The signal processing module is electrically connected to the receiving coil, which is arranged on the other side of the track and parallel to a zero-flux coil connected to the transmitting coil side via a hinge line. The signal processing module is used to detect the output voltage of the receiving coil when the transmitting and receiving coils move synchronously.

2. The zero flux coil continuity detection device according to claim 1, characterized in that: The excitation power supply module includes a battery, a filter, a soft-start circuit, and a phase-shifting full-bridge circuit. The output terminal of the battery is connected to the input terminal of the filter, the output terminal of the filter is connected to the input terminal of the soft-start circuit, the output terminal of the soft-start circuit is connected to the input terminal of the phase-shifting full-bridge circuit, and the output terminal of the phase-shifting full-bridge circuit is connected to the transmitting coil.

3. The zero flux coil continuity detection device according to claim 2, characterized in that: A compensation capacitor is connected between the phase-shifting full-bridge circuit and the transmitting coil.

4. The zero flux coil continuity detection device according to claim 2, characterized in that: The soft-start circuit includes a first switch, a second switch, a current-limiting resistor, and a buffer capacitor. The first terminal of the first switch is connected to the positive output terminal of the filter, and the second terminal of the first switch is connected to the first terminal of the current-limiting resistor. The second terminal of the current-limiting resistor is connected to the positive input terminal of the phase-shifted full-bridge circuit. The first terminal of the second switch is connected to the positive output terminal of the filter, and the second terminal of the second switch is connected to the positive input terminal of the phase-shifted full-bridge circuit. The first terminal of the buffer capacitor is connected to the positive input terminal of the phase-shifted full-bridge circuit, and the second terminal of the buffer capacitor is connected to both the negative output terminal of the filter and the negative input terminal of the phase-shifted full-bridge circuit.

5. A zero-flux coil continuity detection device according to claim 1 or 2, characterized in that: It also includes a main control module connected to the excitation power supply module. The main control module includes a first sampling circuit, a frequency detection circuit, an RMS detection circuit, and a first digital signal processor. The first sampling circuit, the frequency detection circuit, and the RMS detection circuit are all connected to the first digital signal processor.

6. The zero flux coil continuity detection device according to claim 4, characterized in that: The first digital signal processor is also connected to a microcontroller via a communication circuit, and the microcontroller is connected to a digital tube driver circuit.

7. The zero flux coil continuity detection device according to claim 1, characterized in that: The signal processing module includes an envelope detection circuit, a second sampling circuit, and a second digital signal processor. The envelope detection circuit is connected to the receiving coil. The second digital signal processor is connected to the envelope detection circuit through the second sampling circuit. The envelope detection circuit converts the alternating voltage of the receiving coil into a voltage analog signal reflecting the amplitude. The second sampling circuit converts the voltage analog signal into a voltage digital signal that the second digital signal processor can receive. The second digital signal processor determines the on / off state of the zero flux coil based on the voltage digital signal.

8. The zero flux coil continuity detection device according to claim 7, characterized in that: The second digital signal processor is connected to the industrial control computer via Ethernet. The second digital signal processor uploads the voltage digital signal and the on / off status of the zero flux coil to the industrial control computer via Ethernet.

9. The zero flux coil continuity detection device according to claim 1, characterized in that: The transmitting coil is wound with insulated copper Litz wire.

10. The zero flux coil continuity detection device according to claim 1, characterized in that: The receiving coil is a PCB coil.

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