Electromagnetic Interference Measurement Method and Device for In-situ Protection Device of Smart Substation

Abstract

The present invention relates to a method and device for measuring electromagnetic interference of an in-situ protection device in a smart substation, belonging to the technical field of electromagnetic interference measurement. It includes a voltage probe assembly, a current probe assembly, a magnetic field probe assembly, and a processing assembly. The voltage probe assembly is used to collect the high-voltage side voltage signal and the voltage signal of the cabinet chassis to the ground. The current probe assembly is used to collect the high-voltage side current signal and the grounding current signal of the cabinet chassis. The magnetic field probe assembly is used to collect the in-box magnetic field signal and the out-of-box magnetic field signal. The processing assembly is used to calculate the electromagnetic interference intensity of the in-situ protection device according to the high-voltage side voltage signal, the voltage signal of the cabinet chassis to the ground, the high-voltage side current signal, the grounding current signal of the cabinet chassis, the in-box magnetic field signal, and the out-of-box magnetic field signal, so as to be able to measure the electromagnetic interference intensity of the in-situ protection device and facilitate the study of the influence degree of different electromagnetic interferences on the in-situ protection device.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic interference measurement, and particularly to a method and device for measuring electromagnetic interference of a non-contact in-situ protection device in a smart substation. Background Art

[0002] With the popularization and application of unattended substations in the power system, the requirements for relay protection devices are getting higher and higher. In response to the problems existing in the current secondary system, the State Grid has proposed in-situ protection, which can effectively improve the quick-acting performance and reliability of relay protection devices. Traditional relay protection devices are installed in special cabinets in protection rooms, while in-situ protection devices are directly installed near primary equipment using brackets. The different working environments make in-situ protection devices face more severe electromagnetic interference. The electromagnetic interference sources in smart substations include external interference and internal interference: External interference includes radiation interference sources such as high-voltage switch operations, lightning, short-circuit faults, corona discharges, cables and equipment with high voltage and large current radiating electromagnetic waves to the surrounding, high-frequency carriers, walkie-talkies, etc., as well as electromagnetic interference, electrostatic discharge, etc. generated by nearby radio stations, communications, etc.; Internal interference is determined by the structure, component layout, and production process of the automation system, mainly including different signal inductions caused by stray inductance and capacitance, wave reflections caused by long-line transmission, parasitic oscillations, and interference caused by spike signals. The characteristics of external interference and internal interference are different. Distinguishing external interference and internal interference, analyzing the influence degree of different electromagnetic interferences on in-situ protection devices, and proposing corresponding improvement measures are beneficial to improving the reliability of in-situ protection devices, reducing the misoperation of in-situ protection devices, and are of great significance for ensuring the operation of smart grids.

[0003] Based on this, there is an urgent need for a method and device for measuring electromagnetic interference of a non-contact in-situ protection device in a smart substation. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for measuring electromagnetic interference of an in-situ protection device in a smart substation, which can measure the electromagnetic interference intensity of the in-situ protection device and facilitate studying the influence degree of different electromagnetic interferences on the in-situ protection device.

[0005] To achieve the above purpose, the present invention provides the following solution:

[0006] An electromagnetic interference measurement device for an in-situ protection device in a smart substation, the electromagnetic interference measurement device includes: a voltage probe assembly, a current probe assembly, a magnetic field probe assembly, and a processing assembly;

[0007] The voltage probe assembly is connected to the high-voltage terminal of the in-situ protection device; the voltage probe assembly is used to collect the high-voltage side voltage signal and the chassis-to-ground voltage signal of the in-situ protection device;

[0008] The current probe assembly is connected to the high-voltage cable and the chassis grounding cable of the in-situ protection device; the current probe assembly is used to collect the high-voltage side current signal and the chassis grounding current signal of the in-situ protection device;

[0009] The magnetic field probe assembly is installed on the in-situ protection device; the magnetic field probe assembly is used to collect the in-box magnetic field signal and the out-of-box magnetic field signal of the in-situ protection device; the in-box magnetic field signal is the magnetic field signal inside the housing of the in-situ protection device; the out-of-box magnetic field signal is the magnetic field signal outside the housing of the in-situ protection device;

[0010] The processing component is communicatively connected to the voltage probe assembly, the current probe assembly, and the magnetic field probe assembly respectively; the processing component is used to calculate the electromagnetic interference intensity of the in-situ protection device according to the collected signals; the collected signals include the high-voltage side voltage signal, the chassis-to-ground voltage signal, the high-voltage side current signal, the chassis grounding current signal, the in-box magnetic field signal, and the out-of-box magnetic field signal.

[0011] In some embodiments, the voltage probe assembly includes a first voltage probe and a second voltage probe; the first voltage probe is used to collect the high-voltage side voltage signal; the second voltage probe is used to collect the chassis-to-ground voltage signal; the current probe assembly includes a first current probe and a second current probe; the first current probe is installed on the outer layer of the high-voltage cable, and the first current probe is used to collect the high-voltage side current signal; the second current probe is installed on the outer layer of the chassis grounding cable, and the second current probe is used to collect the chassis grounding current signal; the magnetic field probe assembly includes a first magnetic field probe and a second magnetic field probe; the first magnetic field probe is used to collect the in-box magnetic field signal; the second magnetic field probe is used to collect the out-of-box magnetic field signal.

[0012] In some embodiments, the first current probe, the second current probe, the first magnetic field probe, and the second magnetic field probe are all TMR sensors.

[0013] In some embodiments, the processing component includes an electromagnetic interference acquisition card and a processor; the voltage probe assembly, the current probe assembly, and the magnetic field probe assembly are all communicatively connected to the electromagnetic interference acquisition card; the electromagnetic interference acquisition card is configured to acquire the acquisition signals; the electromagnetic interference acquisition card is communicatively connected to the processor; the processor is configured to calculate the electromagnetic interference intensity of the in-situ protection device according to the acquisition signals.

[0014] In some embodiments, the electromagnetic interference measurement device further includes a fully enclosed shielding housing; the voltage probe assembly, the current probe assembly, the magnetic field probe assembly, and the processor are located outside the fully enclosed shielding housing; the electromagnetic interference acquisition card is located inside the fully enclosed shielding housing.

[0015] In some embodiments, the voltage probe assembly, the current probe assembly, and the magnetic field probe assembly are all communicatively connected to the electromagnetic interference acquisition card through shielded cables; the electromagnetic interference acquisition card is communicatively connected to the processor through an optical fiber.

[0016] In some embodiments, the electromagnetic interference acquisition card includes a signal conditioning unit and an AD converter connected in sequence; the signal conditioning unit is configured to amplify the acquisition signals to obtain amplified acquisition signals; the AD converter is configured to perform AD conversion on the amplified acquisition signals to obtain digitized acquisition signals.

[0017] In some embodiments, the electromagnetic interference measurement device further includes a first optoelectronic converter located between the AD converter and the optical fiber and a second optoelectronic converter located between the optical fiber and the processor; the first optoelectronic converter is configured to perform optoelectronic conversion on the digitized acquisition signals to obtain optical signals; the second optoelectronic converter is configured to perform optoelectronic conversion on the optical signals to obtain the digitized acquisition signals.

[0018] In some embodiments, each path of the acquisition signals, the signal conditioning unit, the AD converter, the first optoelectronic converter, and the second optoelectronic converter are arranged in one-to-one correspondence.

[0019] An electromagnetic interference measurement method for an in-situ protection device of an intelligent substation, which works by using the above-mentioned electromagnetic interference measurement device, the electromagnetic interference measurement method includes:

[0020] Receiving the high-voltage side voltage signal and the chassis-to-ground voltage signal of the in-situ protection device acquired by the voltage probe assembly;

[0021] Receiving the high-voltage side current signal and the chassis grounding current signal of the in-situ protection device acquired by the current probe assembly;

[0022] Receive the in-box magnetic field signal and out-box magnetic field signal of the in-situ protection device collected by the magnetic field probe assembly; the in-box magnetic field signal is the magnetic field signal inside the housing of the in-situ protection device; the out-box magnetic field signal is the magnetic field signal outside the housing of the in-situ protection device.

[0023] Calculate the electromagnetic interference intensity of the in-situ protection device based on the collected signals; the collected signals include the high-voltage side voltage signal, the chassis-to-ground voltage signal, the high-voltage side current signal, the chassis grounding current signal, the in-box magnetic field signal, and the out-box magnetic field signal.

[0024] According to the specific embodiments provided by the present invention, the following technical effects are disclosed by the present invention:

[0025] The present invention is used to provide a method and device for measuring electromagnetic interference of an in-situ protection device in an intelligent substation, including a voltage probe assembly, a current probe assembly, a magnetic field probe assembly, and a processing assembly. The voltage probe assembly is connected to the high-voltage terminal of the in-situ protection device and is used to collect the high-voltage side voltage signal and the chassis-to-ground voltage signal. The current probe assembly is connected to the high-voltage cable and the chassis grounding cable of the in-situ protection device and is used to collect the high-voltage side current signal and the chassis grounding current signal. The magnetic field probe assembly is installed on the in-situ protection device and is used to collect the in-box magnetic field signal and the out-box magnetic field signal. The processing assembly is communicatively connected to the voltage probe assembly, the current probe assembly, and the magnetic field probe assembly respectively, and is used to calculate the electromagnetic interference intensity of the in-situ protection device based on the high-voltage side voltage signal, the chassis-to-ground voltage signal, the high-voltage side current signal, the chassis grounding current signal, the in-box magnetic field signal, and the out-box magnetic field signal, so as to be able to measure the electromagnetic interference intensity of the in-situ protection device and facilitate studying the influence degree of different electromagnetic interferences on the in-situ protection device. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 It is the technical roadmap of the electromagnetic interference measurement device provided in Embodiment 1 of the present invention;

[0028] Figure 2 It is the measurement schematic diagram of the high-voltage side current signal provided in Embodiment 1 of the present invention;

[0029] Figure 3It is the overall design diagram of the electromagnetic interference measurement device provided in Embodiment 1 of the present invention;

[0030] Figure 4 It is the overall design diagram of the electromagnetic interference acquisition card provided in Embodiment 1 of the present invention. Specific embodiments

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] The purpose of the present invention is to provide a method and device for measuring electromagnetic interference of an in-situ protection device in an intelligent substation, which can measure the electromagnetic interference intensity of the in-situ protection device and facilitate studying the influence degree of different electromagnetic interferences on the in-situ protection device.

[0033] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0034] Embodiment 1:

[0035] This embodiment is used to provide an electromagnetic interference measurement device for an in-situ protection device in an intelligent substation. As Figure 1 shown, the electromagnetic interference measurement device includes: a voltage probe assembly, a current probe assembly, a magnetic field probe assembly, and a processing assembly.

[0036] The voltage probe assembly is connected to the high-voltage terminal of the in-situ protection device. The voltage probe assembly is used to collect the high-voltage side voltage signal and the voltage signal of the in-situ protection device's case to ground. Specifically, the voltage probe assembly in this embodiment includes a first voltage probe and a second voltage probe. The first voltage probe is used to collect 3 high-voltage side voltage signals, and the second voltage probe is used to collect 1 voltage signal of the case to ground.

[0037] In this embodiment, the voltage probe assembly is used to measure the impact of transient electromagnetic waves generated on-site such as high-voltage switch actions and lightning. Based on the collected voltage signals, the electromagnetic interference intensity of the in-situ protection device under external interference can be calculated, which is convenient for studying the influence degree of external interference on the in-situ protection device.

[0038] The current probe assembly is connected to the high-voltage cable and the chassis grounding cable of the in-situ protection device. The current probe assembly is used to collect the high-voltage side current signal and the chassis grounding current signal of the in-situ protection device. Specifically, the current probe assembly includes a first current probe and a second current probe. The first current probe is installed on the outer layer of the high-voltage cable, and the first current probe is used to collect 3 high-voltage side current signals. The second current probe is installed on the outer layer of the chassis grounding cable, and the second current probe is used to collect 1 chassis grounding current signal.

[0039] In this embodiment, both the first current probe and the second current probe can adopt TMR sensors. The steps of non-contact measurement of current are as follows:

[0040] (1) As Figure 2 shown, it is the measurement schematic diagram of the 3 high-voltage side current signals. Three non-contact TMR sensors S11, S21, and S31 are respectively arranged outside the three high-voltage cables. The three high-voltage cables are named cable 1, cable 2, and cable 3 from left to right. According to the Biot-Savart law, the relationship between the spatial magnetic field and the current at the positions of the three TMR sensors can be expressed as:

[0041]

[0042] Among them, B 11 , B 21 , B 31 are the magnetic field intensities measured by the TMR sensors installed at cable 1, cable 2, and cable 3 respectively; μ0 is the vacuum permeability; r1 is the distance between the center of the high-voltage cable and the TMR sensor; d1 and d2 are the distances between cable 1 and cable 2 and between cable 2 and cable 3 respectively; I1, I2, and I3 are the currents of cable 1, cable 2, and cable 3 respectively.

[0043] (2) r1, d1, and d2 can be measured when the TMR sensors are deployed. Therefore, the currents I1, I2, and I3 of the three high-voltage cables can be solved by the following formula:

[0044]

[0045] (3) The 1 chassis grounding current signal of the in-situ protection device is measured by a single TMR sensor, and its current is expressed as:

[0046]

[0047] Among them, I is the chassis grounding current; L is the distance between the TMR sensor and the center of the chassis grounding cable; B1 is the measured magnetic field intensity.

[0048] The magnetic field probe assembly is installed on the in-situ protection device. The magnetic field probe assembly is used to collect the in-box magnetic field signal and the out-box magnetic field signal of the in-situ protection device. The in-box magnetic field signal is the magnetic field signal inside the housing of the in-situ protection device, and the out-box magnetic field signal is the magnetic field signal outside the housing of the in-situ protection device. Specifically, the magnetic field probe assembly includes a first magnetic field probe and a second magnetic field probe. The first magnetic field probe is installed on the inner surface of the housing of the in-situ protection device and is used to collect the three-dimensional magnetic field signals of the X-axis, Y-axis, and Z-axis inside the in-situ protection device box. The second magnetic field probe is installed on the outer surface of the housing of the in-situ protection device and is used to collect the three-dimensional magnetic field signals of the X-axis, Y-axis, and Z-axis outside the in-situ protection device box.

[0049] The processing component is communicatively connected to the voltage probe assembly, the current probe assembly, and the magnetic field probe assembly respectively. The processing component is used to calculate the electromagnetic interference intensity of the in-situ protection device according to the collected signals. The collected signals include the high-voltage side voltage signal, the chassis-to-ground voltage signal, the high-voltage side current signal, the chassis ground current signal, the in-box magnetic field signal, and the out-box magnetic field signal.

[0050] In this embodiment, the steps of calculating the electromagnetic interference intensity are as follows:

[0051] (1) The in-box magnetic field signal and the out-box magnetic field signal of the in-situ protection device are composed of two parts: the magnetic field generated by the alternating current in the cable and the space radiation magnetic field.

[0052] (2) According to the collected high-voltage side current signals (I1, I2, I3), the electromagnetic interference intensity B of the three cable currents (including external interference) in the box is calculated through the Biot-Savart law. i The calculation formula used in this process is as follows:

[0053]

[0054] Among them, is the magnetic field strength to be measured; L is the integration path; μ0 is the vacuum permeability, μ0 = 4π×10 -7 ; l1, l2, l3 are the alternating currents of the three cables in the box that generate the magnetic field, that is, the three collected high-voltage side current signals; dl1, dl2, dl3 are current elements; is the unit vector of the current element pointing to the magnetic field point to be calculated; r1, r2, r3 are the distances from the current element to the magnetic field point to be calculated.

[0055] (3) Compare the electromagnetic interference intensity (i.e., the in-box magnetic field signal) B m measured by the in-box magnetic sensor (i.e., the first magnetic field probe) with the electromagnetic interference intensity B iConduct a comparative verification. When the two numerical values are the same, it indicates that the electromagnetic interference inside the box completely originates from the alternating current of the three cables and is entirely caused by external interference. When the two numerical values are different, the electromagnetic interference intensity caused by internal interference existing inside the box is expressed as B e = B m - B i , and the electromagnetic interference intensity caused by external interference is B i .

[0056] (4) Compare and analyze the calculated results of the above electromagnetic interference intensity with the electromagnetic interference index specified for the in-situ protection device to obtain the influence degree of different electromagnetic interferences on the inside of the in-situ protection device.

[0057] (5) The magnetic field intensity measured by the magnetic sensor outside the box is the spatially distributed magnetic field, mainly the external electromagnetic radiation interference. Compare and analyze the electromagnetic interference intensity outside the box with the electromagnetic interference index specified for the in-situ protection device to obtain the influence degree of the external electromagnetic interference on the housing of the in-situ protection device.

[0058] Magnetic sensors are widely used in modern industries and electronic products. They measure physical parameters such as current, position, and direction by sensing the magnetic field intensity. Magnetic sensors with Hall elements as sensitive elements usually use a magnetic concentrating ring structure to amplify the magnetic field and improve the Hall output sensitivity. However, the device has a large volume, and at the same time, the Hall element has defects such as high power consumption and poor linearity. Although the sensitivity of the AMR element is much higher than that of the Hall element, its linear range is narrow, and the power consumption is large. At the same time, a magnetic sensor with the AMR as the sensitive element needs to set up Set / Reset coils to perform preset / reset operations on it, resulting in a complex manufacturing process. The magnetic sensor with the GMR element as the sensitive element has higher sensitivity than the magnetic sensor with the Hall element as the sensitive element, but its linear range is relatively low. With the development of technology, the third-generation TMR sensor has advantages such as higher sensitivity, a wider linear range, better temperature stability, and lower power consumption compared with Hall sensors, AMR sensors, and GMR sensors. Therefore, the electromagnetic interference measurement device designed in this embodiment is a non-contact in-situ protection device for intelligent substations based on TMR sensors, that is, the first current probe, the second current probe, the first magnetic field probe, and the second magnetic field probe are all TMR sensors.

[0059] This embodiment adopts a new type of TMR magnetic field sensor. When measuring the three-dimensional magnetic field inside and outside the in-situ protection device, the TMR sensor utilizes the tunneling magnetoresistance effect of magnetic multilayer materials to sense the magnetic field. It has the characteristics of good temperature stability, high sensitivity, low power consumption, and wide linear range. Moreover, the TMR sensor adopted is an axial magnetic sensor, and the sensor has a unique push-pull type Wheatstone full-bridge structure design. The Wheatstone full-bridge provides a differential voltage output, and the output has good temperature stability, with a range of ±80 Gs, which can ensure an accuracy of 1% within the range of 0 - 30 Gs, and the bandwidth can reach 5 MHz, meeting the technical parameters required by the project. By adopting the TMR sensor, the magnetic field measurement range is large, ranging from 0.125 Gs to 30 Gs, and the bandwidth is high, at least 5 MHz.

[0060] As Figure 3 shown, the processing component of this embodiment includes an electromagnetic interference acquisition card and a processor. The voltage probe component, current probe component, and magnetic field probe component are all communicatively connected to the electromagnetic interference acquisition card, and the electromagnetic interference acquisition card is used to acquire the acquisition signal. The electromagnetic interference acquisition card is communicatively connected to the processor, and the processor is used to calculate the electromagnetic interference intensity of the in-situ protection device based on the acquisition signal.

[0061] Preferably, the electromagnetic interference measurement device of this embodiment further includes a fully enclosed shielding housing. The voltage probe component, current probe component, magnetic field probe component, and processor are located outside the fully enclosed shielding housing, and the electromagnetic interference acquisition card is located inside the fully enclosed shielding housing. By designing the housing of the electromagnetic interference measurement device as a fully enclosed shielding housing, interference can be effectively shielded. More preferably, the voltage probe component, current probe component, and magnetic field probe component are all communicatively connected to the electromagnetic interference acquisition card through shielded cables. At this time, the acquisition signal is transmitted into the electromagnetic interference acquisition card inside the fully enclosed shielding housing through the shielded cables. The electromagnetic interference acquisition card is communicatively connected to the processor through an optical fiber. At this time, the acquisition signal is then transmitted into the processor in the form of an optical signal through the optical fiber, which can effectively shield the interference during the transmission process. The housing of the electromagnetic interference measurement device of this embodiment is a fully enclosed shielding housing, and the transmission process of the acquisition signal adopts shielded cables and optical fibers, which can effectively shield the interference and ensure the accuracy of the acquisition signal transmitted to the processor.

[0062] As Figure 4As shown in the figure, the electromagnetic interference acquisition card of this embodiment is designed according to the principle of "system + functional module". The data receiving module is responsible for collecting the primary-side conducted interference (high-voltage side voltage signal, chassis-to-ground voltage signal, high-voltage side current signal, chassis ground current signal) and radiated interference (magnetic field signal inside the box and magnetic field signal outside the box). It consists of four parts: a voltage attenuation circuit, a signal conditioning unit, an AD converter, and an FPGA controller. The FPGA controller is the data terminal and controller of the data receiving module. On the one hand, the FPGA controller realizes the acquisition of interference signals. On the other hand, the FPGA controller completes the fast detection and analysis of the acquired signals. The data cache module is controlled by the FPGA controller and the cache operation is completed by DDR2 SDRAM. The data transmission link is the interface for physical interconnection and data exchange between the electromagnetic interference acquisition card and the processor (which can be an x86 microcomputer platform), and accesses the physical memory of the x86 microcomputer through direct memory access.

[0063] Specifically, the electromagnetic interference acquisition card of this embodiment includes a signal conditioning unit and an AD converter connected in sequence. The signal conditioning unit can be a conditioning circuit, which is used to amplify the acquired signal to obtain the amplified acquired signal. The AD converter is used to perform AD conversion on the amplified acquired signal to obtain the digitized acquired signal. At this time, the acquired signal is transmitted to the signal conditioning unit through a shielded cable, amplified by the signal conditioning unit and then input to the AD converter. After the AD converter performs AD conversion on the acquired signal, the acquired signal is interacted with the processor through an optical fiber. After being analyzed and processed by the processor, the electromagnetic interference intensity is obtained.

[0064] The electromagnetic interference acquisition card of this embodiment also includes an FPGA controller and a memory. The FPGA controller is used to store the digitized acquired signal in the memory. The electromagnetic interference acquisition card can also include a voltage attenuation circuit located before the signal conditioning unit, which can realize the attenuation of the primary-side signal with high voltage and large bandwidth.

[0065] In order to be able to realize the transmission process of the acquired signal between the electromagnetic interference acquisition card and the processor through an optical fiber, the electromagnetic interference measurement device also includes a first optoelectronic converter located between the AD converter and the optical fiber and a second optoelectronic converter located between the optical fiber and the processor. The first optoelectronic converter is used to perform optoelectronic conversion on the digitized acquired signal to obtain an optical signal, and the second optoelectronic converter is used to perform optoelectronic conversion on the optical signal to obtain the digitized acquired signal.

[0066] Preferably, in this embodiment, each acquired signal, signal conditioning unit, AD converter, first optoelectronic converter, and second optoelectronic converter are set in one-to-one correspondence, so that each signal of the acquired signal can be collected separately and in parallel, and the ADC acquisition rate and acquisition accuracy of each channel are very high.

[0067] The processor in this embodiment can be a computer, on which upper-layer analysis software is configured.

[0068] Based on the structure of the electromagnetic interference measurement device for the above non-contact intelligent substation in-situ protection device, the measurement method in this embodiment is as follows:

[0069] (1) The electromagnetic interference measurement device has 4 current acquisition ports, 4 voltage acquisition ports, and 6 magnetic field acquisition ports, and acquires multiple high-frequency high-voltage signals and magnetic field signals on the primary side, that is, acquires the high-frequency high-voltage signals and magnetic field signals of the in-situ protection device.

[0070] Among them, the specific steps for the electromagnetic interference measurement device to acquire 4 current signals and 4 voltage signals include: the voltage probe assembly and the current probe assembly perform signal acquisition to obtain 8 signals; the 8 signals are transmitted to the electromagnetic interference acquisition card through a grounded shielded cable. In the electromagnetic interference acquisition card, the 8 signals are amplified by the signal conditioning unit to reach the input voltage range of the AD converter and are sent into the high-speed AD converter.

[0071] The specific steps for the electromagnetic interference measurement device to acquire 6 magnetic field signals (respectively the in-box magnetic field signal and the out-of-box magnetic field signal) include: the magnetic field probe assembly acquires the three-dimensional magnetic fields inside and outside the in-situ protection device to obtain 6 magnetic field signals; the 6 magnetic field signals are transmitted to the electromagnetic interference acquisition card through a shielded cable; in the electromagnetic interference acquisition card, the 6 magnetic field signals are amplified by the signal conditioning unit to reach the input voltage range of the AD converter and are sent into the high-speed AD converter.

[0072] (2) The digitized acquisition signals output by the high-speed AD converter are controlled by the FPGA controller in the electromagnetic interference acquisition card and stored in the memory. The digitized acquisition signals are converted from electrical signals into optical signals through the first optical-electric converter and are transmitted through the optical fiber to the second optical-electric converter.

[0073] (3) The second optical-electric converter converts the optical signals transmitted through the optical fiber into digitized acquisition signals of electrical signals, and these signals are analyzed and processed by the data analysis platform (upper-layer analysis software) to obtain the electromagnetic interference intensity. The electromagnetic interference intensity is calculated through the current, and at the same time, the electromagnetic interference intensity is measured through the TMR sensor for verification to ensure the accuracy of the electromagnetic interference intensity.

[0074] This embodiment provides an electromagnetic interference measurement device for a non-contact in-situ protection device of an intelligent substation, which is used to measure the electromagnetic interference intensity of the in-situ protection device of the intelligent substation, compare the measured electromagnetic interference intensity with the specified electromagnetic interference index of the in-situ protection device, obtain the influence degree of different electromagnetic interferences on the in-situ protection device, and be able to evaluate the service life and performance of the in-situ protection device. At the same time, the electromagnetic interference measurement device of this embodiment has strong anti-interference ability and will not be interfered by the magnetic field, ensuring high accuracy of the measurement data.

[0075] Embodiment 2:

[0076] An electromagnetic interference measurement method for an in-situ protection device of an intelligent substation, which works by using the electromagnetic interference measurement device described in Embodiment 1. The electromagnetic interference measurement method includes:

[0077] Receiving the high-voltage side voltage signal and the chassis-to-ground voltage signal of the in-situ protection device collected by the voltage probe assembly;

[0078] Receiving the high-voltage side current signal and the chassis grounding current signal of the in-situ protection device collected by the current probe assembly;

[0079] Receiving the in-box magnetic field signal and the out-of-box magnetic field signal of the in-situ protection device collected by the magnetic field probe assembly; the in-box magnetic field signal is the magnetic field signal inside the housing of the in-situ protection device; the out-of-box magnetic field signal is the magnetic field signal outside the housing of the in-situ protection device;

[0080] Calculating the electromagnetic interference intensity of the in-situ protection device according to the collected signals; the collected signals include the high-voltage side voltage signal, the chassis-to-ground voltage signal, the high-voltage side current signal, the chassis grounding current signal, the in-box magnetic field signal and the out-of-box magnetic field signal.

[0081] Specific examples are used in this article to elaborate on the principles and implementation methods of the present invention. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. An electromagnetic interference measurement device for an in-situ protection device of an intelligent substation, characterized in that, The electromagnetic interference measurement device includes: a voltage probe assembly, a current probe assembly, a magnetic field probe assembly, and a processing assembly; The voltage probe assembly is connected to the high-voltage terminal of the in-situ protection device; the voltage probe assembly is used to collect the high-voltage side voltage signal and the chassis-to-ground voltage signal of the in-situ protection device; The current probe assembly is connected to the high-voltage cable and the chassis grounding cable of the in-situ protection device; the current probe assembly is used to collect the high-voltage side current signal and the chassis grounding current signal of the in-situ protection device; The magnetic field probe assembly is installed on the in-situ protection device; the magnetic field probe assembly is used to collect the internal magnetic field signal and the external magnetic field signal of the in-situ protection device; the internal magnetic field signal is the magnetic field signal inside the housing of the in-situ protection device; the external magnetic field signal is the magnetic field signal outside the housing of the in-situ protection device; The processing assembly is communicatively connected to the voltage probe assembly, the current probe assembly, and the magnetic field probe assembly respectively; the processing assembly is used to calculate the electromagnetic interference intensity of the in-situ protection device according to the collected signals; the collected signals include the high-voltage side voltage signal, the chassis-to-ground voltage signal, the high-voltage side current signal, the chassis grounding current signal, the internal magnetic field signal, and the external magnetic field signal; The steps for calculating the electromagnetic interference intensity are as follows: The magnetic field signals inside and outside the box of the in-situ protection device consist of two parts: the magnetic field generated by the alternating current in the cable and the space radiation magnetic field. According to the collected high-voltage side current signal, the electromagnetic interference intensity B of the currents in the three cables inside the box is calculated through the Biot-Savart law i , and the calculation formula is as follows: Among them, is the magnetic field strength to be measured, are respectively the magnetic field strengths to be measured of the three cables in the box, the first cable among the three cables in the box, the second cable among the three cables in the box, and the third cable among the three cables in the box, which is the electromagnetic interference strength B i ; L is the integration path, and L1, L2, and L3 are respectively the integration paths of the three cables in the box; μ0 is the magnetic permeability of vacuum; l1, l2, and l3 are respectively the alternating currents of the three cables in the box, that is, the current signals on the high-voltage side collected; dl1, dl2, and dl3 are respectively the current elements of the three cables in the box; are respectively the unit vectors of the current elements pointing to the magnetic field point to be determined; r1, r2, and r3 are respectively the distances from the current elements to the magnetic field point to be determined; Compare the collected in-box magnetic field signal B m with the calculated electromagnetic interference intensity B i for verification. When the two are consistent, it indicates that the electromagnetic interference in the box completely comes from the alternating current of the three cables and is entirely caused by external interference. When the two are inconsistent, the electromagnetic interference intensity caused by internal interference in the box is expressed as B e = B m - B i , and the electromagnetic interference intensity caused by external interference is B i ; Compare and analyze the calculation results of the electromagnetic interference intensity with the electromagnetic interference index specified for the in-situ protection device to obtain the influence degree of different electromagnetic interferences on the inside of the in-situ protection device; The out-of-box magnetic field signal is a spatially distributed magnetic field, mainly external electromagnetic radiation interference. Compare and analyze the out-of-box magnetic field signal with the electromagnetic interference index specified for the in-situ protection device to obtain the influence degree of external electromagnetic interference on the housing of the in-situ protection device.

2. The electromagnetic interference measuring device of the in-situ protection device for an intelligent substation according to claim 1, wherein, The voltage probe assembly includes a first voltage probe and a second voltage probe; the first voltage probe is used to collect the high-voltage side voltage signal; the second voltage probe is used to collect the chassis-to-ground voltage signal; the current probe assembly includes a first current probe and a second current probe; the first current probe is installed on the outer layer of the high-voltage cable, and the first current probe is used to collect the high-voltage side current signal; the second current probe is installed on the outer layer of the chassis grounding cable, and the second current probe is used to collect the chassis grounding current signal; the magnetic field probe assembly includes a first magnetic field probe and a second magnetic field probe; the first magnetic field probe is used to collect the internal magnetic field signal; the second magnetic field probe is used to collect the external magnetic field signal.

3. The electromagnetic interference measuring device for the in-situ protection device of an intelligent substation according to claim 2, characterized in that, The first current probe, the second current probe, the first magnetic field probe, and the second magnetic field probe are all TMR sensors.

4. The electromagnetic interference measuring device for the in-situ protection device of an intelligent substation according to claim 1, characterized in that, The processing assembly includes an electromagnetic interference acquisition card and a processor; the voltage probe assembly, the current probe assembly, and the magnetic field probe assembly are all communicatively connected to the electromagnetic interference acquisition card; the electromagnetic interference acquisition card is used to collect the collected signals; the electromagnetic interference acquisition card is communicatively connected to the processor; the processor is used to calculate the electromagnetic interference intensity of the in-situ protection device according to the collected signals.

5. The electromagnetic interference measuring device of the in-situ protection device for an intelligent substation according to claim 4, characterized in that, The electromagnetic interference measurement device further includes a fully enclosed shielding housing; the voltage probe assembly, the current probe assembly, the magnetic field probe assembly, and the processor are located outside the fully enclosed shielding housing; the electromagnetic interference acquisition card is located inside the fully enclosed shielding housing.

6. The electromagnetic interference measuring device for the in-situ protection device of an intelligent substation according to claim 5, characterized in that, The voltage probe assembly, the current probe assembly, and the magnetic field probe assembly are all communicatively connected to the electromagnetic interference acquisition card through shielded cables; the electromagnetic interference acquisition card is communicatively connected to the processor through an optical fiber.

7. The electromagnetic interference measuring device of the in-situ protection device for an intelligent substation according to claim 6, characterized in that, The electromagnetic interference acquisition card includes a signal conditioning unit and an AD converter connected in sequence; the signal conditioning unit is configured to amplify the acquired signal to obtain an amplified acquired signal; the AD converter is configured to perform AD conversion on the amplified acquired signal to obtain a digitized acquired signal.

8. The electromagnetic interference measuring device of a local protection device for an intelligent substation according to claim 7, characterized in that, The electromagnetic interference measurement device further includes a first optoelectronic converter located between the AD converter and the optical fiber and a second optoelectronic converter located between the optical fiber and the processor; the first optoelectronic converter is configured to perform optoelectronic conversion on the digitized acquired signal to obtain an optical signal; the second optoelectronic converter is configured to perform optoelectronic conversion on the optical signal to obtain the digitized acquired signal.

9. The electromagnetic interference measuring device of the in-situ protection device for an intelligent substation according to claim 8, characterized in that Each path of the acquired signal, the signal conditioning unit, the AD converter, the first optoelectronic converter, and the second optoelectronic converter are provided in one-to-one correspondence.

10. A method for measuring electromagnetic interference of an in-situ protection device in a smart substation, which works by using the electromagnetic interference measuring device for an in-situ protection device in a smart substation according to any one of claims 1-9, characterized in that, The electromagnetic interference measurement method includes: Receiving the high-voltage side voltage signal acquired by the voltage probe assembly and the chassis-to-ground voltage signal of the in-situ protection device; Receiving the high-voltage side current signal acquired by the current probe assembly and the chassis grounding current signal of the in-situ protection device; Receiving the in-box magnetic field signal and the out-of-box magnetic field signal of the in-situ protection device acquired by the magnetic field probe assembly; the in-box magnetic field signal is the magnetic field signal inside the housing of the in-situ protection device; the out-of-box magnetic field signal is the magnetic field signal outside the housing of the in-situ protection device; Calculating the electromagnetic interference intensity of the in-situ protection device based on the acquired signal; the acquired signal includes the high-voltage side voltage signal, the chassis-to-ground voltage signal, the high-voltage side current signal, the chassis grounding current signal, the in-box magnetic field signal, and the out-of-box magnetic field signal.

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