Converter transformer equipment grounding current monitoring method and device

Abstract

The invention provides a converter transformer equipment grounding current monitoring device which comprises a current transformer, a cross coupling type rectifier bridge, a DC-DC module, a wireless sensing module and a differential amplifier. It is ensured that appropriate and stable direct-current voltage output can be provided for the sensor module when the current is too small or too large, the problem of insufficient power or circuit damage is effectively avoided, in the aspect of a rectifying circuit, the energy conversion efficiency under the low-amplitude current condition is remarkably improved through a high-efficiency rectifying technology, and the energy conversion efficiency is improved. And the high-efficiency operation of the sensor module can be maintained even in a micro-current environment. Meanwhile, by optimizing a starting mechanism, quick response and starting of small current signals are achieved, the response time of the monitoring device is greatly shortened, and the accuracy and timeliness of fault early warning are improved.

Description

Technical Field

[0001] The present invention relates to the field of power monitoring, and more specifically, to a method and device for monitoring grounding current of a converter transformer. Background Art

[0002] Current induction power supply, also known as CT power supply or current transformer power supply, is powered by the magnetic field generated by the load current of the conductor. CT power supply is mainly used in power lines to solve the problem that the equipment cannot obtain power supply in other ways. Specifically:

[0003] 1) High-voltage power transmission and distribution: Current induction power supplies are mainly used in high-voltage power transmission and distribution areas where conventional power supply measures are lacking. In the power transmission and distribution network, the voltage is as high as 10kV-1150kV, and the working current is tens of amperes to thousands of amperes. Although there is huge power transmission, many intelligent electronic devices cannot be installed due to lack of electricity, or have to be equipped with expensive and bulky solar or wind power generation equipment.

[0004] 2) Smart grid field: With the development of smart grid, the demand for installing smart electronic devices on high-voltage primary equipment (such as overhead transmission lines, cables, ring network cabinets, converter transformers, etc.) has increased, and the application of current sensing power supplies has become more and more widespread. The current transformer is used to induce electrical energy from the high-voltage and high-current transmission line, and output it from the secondary coil of the transformer. After rectification, filtering, voltage stabilization and other links, it can supply power to the load. The existing current transformer power supply equipment often designs the corresponding uncontrolled rectifier circuit or partially controlled rectifier circuit for a constant input current. For the grounding current of the converter transformer equipment, the grounding current range of the converter transformer equipment during a fault can be from 1 ampere to 20 amperes. When the primary side grounding current is small, the energy collected by the existing current transformer is insufficient to supply the sensor to work, and when the primary side grounding current is too large, the existing current transformer circuit will be damaged due to excessive sudden current. In addition, the rectifier circuit in the existing technology has limitations in energy conversion efficiency, especially when processing low-amplitude current, its conversion efficiency is often significantly reduced, which not only affects the overall energy efficiency of the system, but also limits the stable operation of the current sensor in low-power mode. At the same time, the ability to start quickly under low current conditions is also a major technical bottleneck. Many existing systems are difficult to respond quickly and start monitoring tasks under low current environments, thus delaying the timing of fault warning. Summary of the invention

[0005] In order to solve the technical problems of unstable power supply, low energy conversion efficiency of rectifier circuit, and difficulty in rapid response and start monitoring under low current conditions in the prior art of the grounding current monitoring system of converter transformer equipment, the present invention provides a grounding current monitoring device for converter transformer equipment, the device comprising a current transformer, a cross-coupled rectifier bridge, a DC-DC module, a wireless sensor module and a differential amplifier, wherein:

[0006] The current transformer is used to collect the current in the power frequency AC circuit of the converter transformer device in the working state and convert it into a small current signal of a set ratio, and send the small current signal to the cross-coupled rectifier bridge;

[0007] The positive input terminal and the negative input terminal of the cross-coupled rectifier bridge are connected to the current transformer, so as to convert the small current signal into a DC output voltage;

[0008] The DC-DC module is used to power the wireless sensor module after voltage regulation of the DC output voltage of the cross-coupled rectifier bridge;

[0009] One end of the differential amplifier is electrically connected to the cross-coupled rectifier bridge circuit, and the other end is electrically connected to the wireless sensor module, so as to collect the current signal output by the current transformer and transmit it to the wireless sensor module;

[0010] The wireless sensing module is used to collect the current signal output by the differential sensor and upload it to the cloud server for real-time monitoring and display.

[0011] Optionally, the cross-coupled rectifier bridge includes a resistor Rcurrent-sense and several boost sub-modules, wherein the positive input end of the first boost sub-module is connected to one end of the resistor Rcurrent-sense, the other end of the resistor Rcurrent-sense is connected to the positive input end of the secondary side of the current transformer, and the negative input end of the first boost sub-module is connected to the negative input end of the secondary side of the current transformer, and the boost sub-modules are cascaded with each other in parallel at the positive input end and the negative input end.

[0012] Optionally, the cross-coupled rectifier bridge includes a resistor Rcurrent-sense, a first boost sub-module, several second boost sub-modules and a third boost sub-module, wherein the positive input end of the first boost sub-module is connected to one end of the resistor Rcurrent-sense, the other end of the resistor Rcurrent-sense is connected to the positive input end of the secondary side of the current transformer, the negative input end of the first boost sub-module is connected to the negative input end of the secondary side of the current transformer, and the several second boost sub-modules and the third boost sub-modules are cascaded with each other in parallel at the positive input end and the negative input end.

[0013] Optionally, the second boost submodule includes a capacitor C1, a capacitor C2, a transistor MP2, a transistor MP1, a resistor R FB2 , resistor R FB1 , transistor MN1, transistor MN2, capacitor C3, capacitor C4, capacitor C5 and capacitor C6, wherein the positive input terminal is connected to one end of capacitor C1, capacitor C2 and capacitor C6, and the other end of capacitor C1 is connected to the gate of transistor MP2 and resistor R FB2 One end of the resistor R FB2 The other end of capacitor C2 is connected to the source of transistor MP2, the other end of capacitor C2 is connected to the source of transistor MN1, the drain of transistor MP1 and the gate of transistor MN2, the negative input end is connected to one end of capacitor C3, capacitor C4 and capacitor C5, the other end of capacitor C3 is connected to the source of transistor MN2, the drain of transistor MP2 and the gate of transistor MN1, the other end of capacitor C4 is connected to the gate of transistor MP1 and resistor R FB1 One end of the resistor R FB1 The other end of capacitor C5 is connected to the source of transistor MP1, the drains of transistor MN1 and transistor MN2 are grounded, the other end of capacitor C5 is connected to the source of transistor MP1, the other end of capacitor C6 is connected to the source of transistor MP2, the source of transistor MP1 and the source of transistor MP2 are respectively connected to the drains of transistor MN1 and transistor MN2 of the next second boost sub-module in cascade as the input of the next second boost sub-module, the source of transistor MP1 and the source of transistor MP2 of the first sub-boost module are grounded, the third boost sub-module removes capacitor C6, and the end of capacitor C5 not connected to the source of transistor MP1 is grounded.

[0014] Optionally, the device further includes a compensation capacitor Cm, which is connected in series with a resistor Rcurrent-sense, and the other end of which is connected to the positive input end of the secondary side of the current transformer.

[0015] Optionally, the DC-DC module uses a TPS63900 chip to implement programmable input current limit and dynamic voltage regulation.

[0016] Optionally, the wireless sensing module includes an MCU and a wireless communication module, wherein the MCU is used to collect the current signal output by the differential sensor and perform quantization processing, and the wireless communication module is used to transmit the quantized current data to a cloud server using an intelligent sleep strategy.

[0017] Optionally, the positive input terminal of the differential amplifier is connected to the positive input terminal of the secondary side of the current transformer, the negative input terminal is connected to the positive input terminal of the first boost submodule, and the output terminal is connected to the wireless sensor module.

[0018] The ground current monitoring device for converter transformer equipment described in the present invention includes a current transformer, a cross-coupled rectifier bridge, a DC-DC module, a wireless sensor module and a differential amplifier. It can not only dynamically adjust the energy collection strategy according to the actual size of the current, ensuring that the sensor module can provide a suitable and stable DC voltage output when the current is too small or too large, effectively avoiding the problem of insufficient power or circuit damage, but also in terms of the rectifier circuit, through high-efficiency rectification technology, significantly improve the energy conversion efficiency under low-amplitude current conditions, ensuring that the sensor module can maintain efficient operation even in a micro-current environment. At the same time, by optimizing the startup mechanism, a rapid response and startup to a small current signal is achieved, which greatly shortens the response time of the monitoring device and improves the accuracy and timeliness of the fault warning. In short, the device integrates an efficient coupling coil design, advanced energy collection technology and an intelligent power management system to achieve efficient and stable collection and energy conversion of the ground current and other primary currents of the transformer equipment, fully ensuring the efficient operation of the sensor model in the monitoring device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0020] Figure 1 It is a structural schematic diagram of a ground current monitoring device for a converter transformer device according to a preferred embodiment of the present invention;

[0021] Figure 2 is an equivalent circuit diagram of a current transformer according to a preferred embodiment of the present invention;

[0022] Figure 3 is a structural schematic diagram of a second boost submodule according to a preferred embodiment of the present invention;

[0023] Figure 4 It is a structural schematic diagram of a differential amplifier collecting a current signal output by a current transformer according to a preferred embodiment of the present invention;

[0024] Figure 5A flowchart of an intelligent sleep strategy of a wireless sensor module according to a preferred embodiment of the present invention;

[0025] Figure 6 It is a schematic structural diagram of a ground current monitoring device for converter transformer equipment according to another preferred embodiment of the present invention. DETAILED DESCRIPTION

[0026] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0027] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0028] Figure 1 FIG. 1 is a schematic diagram of the structure of a ground current monitoring device for a converter transformer according to a preferred embodiment of the present invention. Figure 1 As shown, the ground current monitoring device 100 for converter transformer equipment in this preferred embodiment includes a current transformer 101, a cross-coupled rectifier bridge 102, a DC-DC module 103, a wireless sensor module 104 and a differential amplifier 105, wherein:

[0029] The current transformer 101 is used to collect the current in the industrial frequency AC circuit of the converter transformer device in the working state and convert it into a small current signal of a set ratio, and send the small current signal to the cross-coupled rectifier bridge.

[0030] Figure 2 FIG. 1 is an equivalent circuit diagram of a current transformer according to a preferred embodiment of the present invention. Figure 2 As shown, p (t) = I p sinωt is the primary sinusoidal AC current source, i s (t) is the secondary side inductive current source, i s (t) = I s sinωt / N / k, N is the number of coil turns, k is the coupling coefficient between the primary and secondary sides, k=I p / I s / N, Lm is the excitation inductance, R mis the core loss equivalent resistance, L σ is the leakage inductance, R wire is the coil resistance, R load is the load equivalent resistance, v core (t), v load (t) and i load (t) are the output voltage of the core, the voltage and current of the load respectively.

[0031] Since the silicon steel core used in the current transformer has a high magnetic permeability, Lσ can be ignored compared with Lm. To simplify the analysis, the core loss equivalent resistance Rm is ignored. According to the law of electromagnetic induction, v core (t) is proportional to the rate of change of the magnetic flux density of the magnetic core with time, as shown in formula (1).

[0032]

[0033] In the formula, A core is the cross-sectional area of ​​the core.

[0034] The BH curve of the core can be divided into a saturation region and an unsaturation region. When the core works in the unsaturation region, Lm is large and it can be considered that all i s (t) flows into the magnetic core. When the magnetic core enters the saturation region, the magnetic flux density amplitude approaches the magnetic flux density B sat , B changes less with time, v core (t) will decrease to 0, so it can be considered that i s (t) All flows into Lm. Generally speaking, the load can only obtain energy when the core is in a non-saturated working state. The stage when the core is in a non-saturated state is called the transfer window.

[0035] Assume that at t 0 At this moment, the core begins to exit the saturation region. The magnetic flux density of the core is -B sat , open the transfer window. All i s (t) Flow into R load . In v core Under the driving force of (t), the magnetic flux density gradually increases. 0 +t sat At this moment, the core enters the saturation region and the transfer window ends. core (t) decreases to 0, and the magnetic flux density gradually approaches B sat The next transfer window during this period is [t 0 +T / 2,t 0 +t sat +T / 2]. The average power harvested by the load over a period of time is expressed as:

[0036]

[0037] From the above analysis, we can see that the use of current transformers can achieve efficient and stable energy collection from the industrial frequency AC feedback of electrical equipment.

[0038] The positive input terminal and the negative input terminal of the cross-coupled rectifier bridge 102 are connected to the current transformer, so as to convert the small current signal into a DC output voltage.

[0039] according to Figure 1 It can be seen that the cross-coupled rectifier bridge 102 includes a resistor Rcurrent-sense, a first boost sub-module 121, a plurality of second boost sub-modules 122 and a third boost sub-module 123, wherein the positive input end of the first boost sub-module 121 is connected to one end of the resistor Rcurrent-sense, the other end of the resistor Rcurrent-sense is connected to the positive input end of the secondary side of the current transformer, the negative input end of the first boost sub-module 121 is connected to the negative input end of the secondary side of the current transformer, and the plurality of second boost sub-modules 122 and the third boost sub-modules 123 are cascaded with each other in parallel at the positive input end and the negative input end.

[0040] Figure 3 This is a schematic diagram of the structure of the second boost submodule according to a preferred embodiment of the present invention. Figure 3 As shown, the second boost submodule 122 includes a capacitor C1, a capacitor C2, a transistor MP2, a transistor MP1, and a resistor R FB2 , resistor R FB1 , transistor MN1, transistor MN2, capacitor C3, capacitor C4, capacitor C5 and capacitor C6, wherein the positive input terminal is connected to one end of capacitor C1, capacitor C2 and capacitor C6, and the other end of capacitor C1 is connected to the gate of transistor MP2 and resistor R FB2 One end of the resistor R FB2 The other end of capacitor C2 is connected to the source of transistor MP2, the other end of capacitor C2 is connected to the source of transistor MN1, the drain of transistor MP1 and the gate of transistor MN2, the negative input end is connected to one end of capacitor C3, capacitor C4 and capacitor C5, the other end of capacitor C3 is connected to the source of transistor MN2, the drain of transistor MP2 and the gate of transistor MN1, the other end of capacitor C4 is connected to the gate of transistor MP1 and resistor R FB1 One end of the resistor R FB1The other end of capacitor C5 is connected to the source of transistor MP1, the drains of transistor MN1 and transistor MN2 are grounded, the other end of capacitor C5 is connected to the source of transistor MP1, the other end of capacitor C6 is connected to the source of transistor MP2, the source of transistor MP1 and the source of transistor MP2 are respectively connected to the drains of transistor MN1 and transistor MN2 of the next second boost sub-module 122 in cascade as the input of the next second boost sub-module 122, the source of transistor MP1 and the source of transistor MP2 of the first sub-boost module 121 are grounded, the third boost sub-module 123 removes capacitor C6, and the end of capacitor C5 not connected to the source of transistor MP1 is grounded.

[0041] Compared with the traditional cross-coupled rectifier bridge, the preferred embodiment improves it by using a high feedback resistor (R FB1 , R FB2 ) applies the output DC voltage directly to the gate of the rectifier transistor (MP1, MP2) without interfering with the signal at the differential input terminal, thereby realizing self-biasing. This self-biasing mechanism can further reduce the conduction threshold of the MP1 and MP2 transistors and reduce the leakage current; and divides the output capacitor of the traditional cross-coupled rectifier bridge into two. This configuration can provide an auxiliary power supply for each stage of the boost sub-module, thereby increasing the output voltage of each boost sub-module and further improving the efficiency and rectified output voltage.

[0042] The DC-DC module 103 is used to power the wireless sensor module after voltage regulation of the DC output voltage of the cross-coupled rectifier bridge.

[0043] Preferably, the DC-DC module adopts a TPS63900 chip to implement programmable input current limit and dynamic voltage regulation.

[0044] The DC-DC module in this preferred embodiment can achieve efficient synchronous buck-boost conversion, and can provide a stable power supply while extending the life of the battery containing the DC-DC module. It combines programmable input current limit and integrated dynamic voltage regulation to optimize the power architecture, support applications that run for many years on a single battery, and save energy in wireless connection applications. It has a wide input voltage range from 1.8V to 5.5V and can be used with a variety of battery types, including primary batteries such as 3 alkaline batteries, 1 lithium manganese dioxide (Li-MnO2) or 1 lithium thionyl chloride (Li-SOCl2), and secondary batteries. The output voltage range is 1.8V to 5V and can be programmed by an external resistor, while the SEL pin allows switching between two output voltage presets to meet the voltage requirements of the application in different operating modes. The module has an extremely low quiescent current, typically 75nA, which helps to further extend battery life. Under appropriate conditions, the output current is greater than 400mA, and higher output currents can be obtained by paralleling multiple devices. In addition, the module integrates dynamic voltage regulation to provide power while keeping the system at a lower voltage required for effective operation, thereby maximizing battery life and reducing maintenance required for industrial applications. The module also features a programmable input current limit function with multiple settings to increase available battery capacity and safety. Its protection features include output short circuit and overtemperature protection to ensure safe and reliable operation of the equipment.

[0045] One end of the differential amplifier 104 is electrically connected to the cross-coupled rectifier bridge circuit, and the other end is electrically connected to the wireless sensor module 105 , so as to collect the current signal output by the current transformer 101 and transmit it to the wireless sensor module 105 .

[0046] Preferably, the positive input terminal of the differential amplifier is connected to the positive input terminal of the secondary side of the current transformer, the negative input terminal is connected to the positive input terminal of the first boost submodule, and the output terminal is connected to the wireless sensor module.

[0047] Figure 4 FIG. 1 is a schematic diagram of a structure of a differential amplifier collecting a current signal output by a current transformer according to a preferred embodiment of the present invention. Figure 4 As shown, one end of the resistor Rcurren-sense is connected to the positive input of the differential amplifier, and the other end is connected to the negative input of the differential amplifier. The output of the differential amplifier is connected to the MCU for current collection. R g is the feedback resistor, R f is the differential input resistance, then the current I flowing through the resistor Rcurren-sense CThe calculation formula is as follows:

[0048]

[0049] Through the above formula, the current signal output from the current transformer can be determined, and after being processed by the MCU of the wireless sensor module, it can be uploaded to the cloud server, thereby realizing current monitoring.

[0050] The wireless sensor module 105 is used to collect the current signal output by the differential sensor 104 and upload it to the cloud server for real-time monitoring and display.

[0051] Preferably, the wireless sensing module includes an MCU and a wireless communication module, wherein the MCU is used to collect the current signal output by the differential sensor and perform quantization processing, and the wireless communication module is used to transmit the quantized current data to a cloud server using an intelligent sleep strategy.

[0052] The wireless sensor module in this preferred embodiment can realize efficient wireless communication function. The MCU accurately collects the current signal output by the current transformer and uses its high-precision analog-to-digital converter (ADC) for quantization processing. The quantized current data is stably and reliably transmitted to the cloud server through the wireless network for real-time monitoring and display. In order to optimize energy utilization, the module adopts an intelligent sleep strategy. Figure 5 FIG. 1 is a flow chart of an intelligent sleep strategy of a wireless sensor module according to a preferred embodiment of the present invention. Figure 5 As shown, the MCU of the wireless sensor module can automatically enter a low-power sleep mode during non-data collection and transmission, significantly reducing overall energy consumption. Once the collection instruction is received or the preset collection cycle is reached, the MCU will quickly wake up, perform the current signal collection task, upload the data to the cloud through the wireless communication module, and calculate the next wake-up time based on the energy storage capacitor power and the current of the current transformer at this time, and then enter the sleep state again, thereby ensuring the real-time data while maximizing the battery life of the module.

[0053] Preferably, the device further comprises a compensation capacitor Cm, which is connected in series with a resistor Rcurrent-sense, and the other end of which is connected to the positive input end of the secondary side of the current transformer.

[0054] Figure 6 FIG. 1 is a schematic diagram of the structure of a ground current monitoring device for a converter transformer according to another preferred embodiment of the present invention. Figure 6 As shown, in order to further improve the output power of the current transformer, this preferred embodiment uses a series compensation capacitor to compensate for the equivalent inductance of the current transformer.

[0055] In summary, the converter transformer equipment grounding current monitoring device described in this preferred embodiment has the following beneficial effects:

[0056] 1. Efficient energy collection and conversion: By combining the current transformer with the improved cross-coupled rectifier bridge, it is possible to efficiently and stably collect energy from the power frequency AC circuit of the electrical equipment and convert it into DC output. The design of the improved cross-coupled rectifier bridge not only improves the rectification efficiency, but also further improves the stability and reliability of the output voltage through the parallel cascade of multiple boost submodules. This design enables the monitoring device to work continuously and stably in a complex power grid environment, providing a solid energy foundation for subsequent current monitoring and data transmission.

[0057] 2. Low power design and long life: The wireless sensor module in this preferred embodiment adopts the STM32L series single-chip microcomputer and the NB-IoT communication module, and realizes efficient operation in low power mode through the intelligent sleep strategy. During non-data collection and transmission, the single-chip microcomputer can automatically enter the low-power sleep mode, which significantly reduces the overall energy consumption. At the same time, the DC-DC module has extremely low quiescent current and efficient dynamic voltage regulation function, which further extends the battery life of the monitor. These designs enable the monitor to maintain high performance and long life in long-term, uninterrupted monitoring tasks.

[0058] 3. Due to the use of energy collection and high-efficiency management methods, the device can collect sufficient real-time current data, combined with background data processing and intelligent prediction functions, to achieve preventive intelligent monitoring of the monitoring system and enhance system stability and safety. At the same time, the improved cross-coupled rectifier bridge and DC-DC module have perfect protection features, such as output short circuit and overheating protection, to ensure the stable operation of the monitoring device under abnormal conditions. In addition, through the programmable input current limiting function, the available battery capacity and safety are also improved, further enhancing the stability and reliability of the monitoring system.

[0059] 4. Solve the problem of large workload and high risk of manual inspection of transformer core grounding current. Through the self-energy extraction of this preferred implementation method, the passive wireless core grounding current sensor can be quickly transformed, effectively improving the quality and efficiency of power equipment status monitoring and intelligent operation and maintenance.

[0060] The basic principles of the present disclosure are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present disclosure are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present disclosure. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, and are not limitations. The above details do not limit the present disclosure to the necessity of adopting the above specific details to be implemented.

[0061] Each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system embodiment, since it basically corresponds to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0062] The block diagrams of the devices, apparatuses, equipment, and systems involved in this disclosure are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including," "comprising," "having," and the like are open words, referring to "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or," and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0063] The apparatus and method of the present disclosure may be implemented in many ways. For example, the apparatus and method of the present disclosure may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above order of steps for the method is for illustration only, and the steps of the method of the present disclosure are not limited to the order specifically described above, unless otherwise specifically stated. In addition, in some embodiments, the present disclosure may also be implemented as a program recorded in a recording medium, which includes machine-readable instructions for implementing the method according to the present disclosure. Therefore, the present disclosure also covers a recording medium storing a program for executing the method according to the present disclosure.

[0064] It should also be noted that in the apparatus, equipment and method of the present disclosure, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present disclosure. The above description of the disclosed aspects is provided to enable any technician in the field to make or use the present disclosure. Various modifications to these aspects are very obvious to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown here, but to the widest scope consistent with the principles and novel features disclosed herein.

[0065] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A ground current monitoring device for converter transformer equipment, characterized in that: The device comprises a current transformer, a cross-coupled rectifier bridge, a DC-DC module, a wireless sensor module and a differential amplifier, wherein: The current transformer is used to collect the current in the power frequency AC circuit of the converter transformer device in the working state and convert it into a small current signal of a set ratio, and send the small current signal to the cross-coupled rectifier bridge; The positive input terminal and the negative input terminal of the cross-coupled rectifier bridge are connected to the current transformer, so as to convert the small current signal into a DC output voltage; The DC-DC module is used to power the wireless sensor module after voltage regulation of the DC output voltage of the cross-coupled rectifier bridge; One end of the differential amplifier is electrically connected to the cross-coupled rectifier bridge circuit, and the other end is electrically connected to the wireless sensor module, so as to collect the current signal output by the current transformer and transmit it to the wireless sensor module; The wireless sensing module is used to collect the current signal output by the differential sensor and upload it to the cloud server for real-time monitoring and display.

2. The device according to claim 1, characterized in that The cross-coupled rectifier bridge includes a resistor Rcurrent-sense, a first boost sub-module, a plurality of second boost sub-modules and a third boost sub-module, wherein the positive input end of the first boost sub-module is connected to one end of the resistor Rcurrent-sense, the other end of the resistor Rcurrent-sense is connected to the positive input end of the secondary side of the current transformer, the negative input end of the first boost sub-module is connected to the negative input end of the secondary side of the current transformer, and the plurality of second boost sub-modules and the third boost sub-modules are cascaded with each other in parallel to the positive input end and the negative input end.

3. The device according to claim 2, characterized in that The second boost submodule includes a capacitor C1, a capacitor C2, a transistor MP2, a transistor MP1, a resistor R FB2 , resistor R FB1 , transistor MN1, transistor MN2, capacitor C3, capacitor C4, capacitor C5 and capacitor C6, wherein the positive input terminal is connected to one end of capacitor C1, capacitor C2 and capacitor C6, and the other end of capacitor C1 is connected to the gate of transistor MP2 and resistor R FB2 One end of the resistor R FB2 The other end of capacitor C2 is connected to the source of transistor MP2, the other end of capacitor C2 is connected to the source of transistor MN1, the drain of transistor MP1 and the gate of transistor MN2, the negative input end is connected to one end of capacitor C3, capacitor C4 and capacitor C5, the other end of capacitor C3 is connected to the source of transistor MN2, the drain of transistor MP2 and the gate of transistor MN1, the other end of capacitor C4 is connected to the gate of transistor MP1 and resistor R FB1 One end of the resistor R FB1 The other end of capacitor C5 is connected to the source of transistor MP1, the drains of transistor MN1 and transistor MN2 are grounded, the other end of capacitor C5 is connected to the source of transistor MP1, the other end of capacitor C6 is connected to the source of transistor MP2, the source of transistor MP1 and the source of transistor MP2 are respectively connected to the drains of transistor MN1 and transistor MN2 of the next second boost sub-module in cascade as the input of the next second boost sub-module, the source of transistor MP1 and the source of transistor MP2 of the first sub-boost module are grounded, the capacitor C6 is removed from the third boost sub-module, and the end of capacitor C5 not connected to the source of transistor MP1 is grounded.

4. The device according to claim 2, characterized in that The device also includes a compensation capacitor Cm, which is connected in series with a resistor Rcurrent-sense, and the other end of which is connected to the positive input end of the secondary side of the current transformer.

5. The device according to claim 1, characterized in that The DC-DC module adopts the TPS63900 chip to realize programmable input current limit and dynamic voltage regulation.

6. The device according to claim 1, characterized in that The wireless sensing module includes an MCU and a wireless communication module, wherein the MCU is used to collect the current signal output by the differential sensor and perform quantization processing, and the wireless communication module is used to transmit the quantized current data to a cloud server using an intelligent sleep strategy.

7. The device according to claim 2, characterized in that The positive input end of the differential amplifier is connected to the positive input end of the secondary side of the current transformer, the negative input end is connected to the positive input end of the first boost submodule, and the output end is connected to the wireless sensor module.

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