Novel anti-electromagnetic interference method

Abstract

The invention discloses a novel electromagnetic interference prevention method, and relates to the technical field of electromagnetic interference prevention, and the method comprises the steps: changing the installation direction of an inverter, changing the direction of a magnetic field penetrating through the inverter, and rotating the direction of a main panel of the inverter. The interference of an external magnetic field on internal devices of the equipment is reduced; a shielding case is manufactured and optimized; an electric energy quality analysis instrument is adopted to measure the quality of electric energy on the alternating-current side and the direct-current side of the inverter, data comparison is analyzed, components on the two sides are optimized and controlled through improved software, and tests are carried out through the different test methods, so that the problem of magnetic field interference of a project is solved; according to the invention, the device stability is improved, the device is enabled to operate stably and reliably, the power generation efficiency is increased, the anti-electromagnetic interference data and the corresponding analysis result are managed, visualized and stored by constructing the anti-electromagnetic interference system, the anti-electromagnetic interference management is realized through Internet cloud management and control, and the intelligent level of the anti-electromagnetic interference management is improved.

Description

Technical Field

[0001] The invention relates to the technical field of electromagnetic interference prevention, and in particular to a novel electromagnetic interference prevention method. Background Art

[0002] The rooftop distributed photovoltaic power generation project of Yixin Aluminum Factory is located in Heqing Yixin Aluminum Factory, 500 meters east of Xiyi Town, Heqing, Yunnan Province, with an altitude of about 2306m. It is arranged through the roofs of 9 factory buildings and building roofs of Huaneng Heqing Yixin Aluminum Factory, 6 open spaces and a slope for photovoltaic arrangement, and adopts domestic Yingli monocrystalline single-sided 540Wp monocrystalline silicon solar cell modules. 48,916 540w photovoltaic modules are installed in the factory, and the brackets are aluminum alloy fixed brackets. 103 Huawei SUN2000-196KTL-H0 inverters are used; 7 booster box transformers are built in matching, with capacities of 1600kVA (1 unit), 2250kVA (1 unit), 3000kVA (1 unit), 3150kVA (2 units), and 3500kVA (2 units), with a total installed capacity of 20MW, which will be put into operation at full capacity in January 2022.

[0003] The project uses Huawei SUN2000-196KTL-H0 inverters, 34 of which are installed on the roofs of the aluminum electrolysis workshops in electrolysis areas 1 to 8. The electrolysis workshop uses a 940V*500KA DC bus for electrolysis work. The measured electromagnetic field strength on site is 39V / m. The inverters in the electrolysis workshop frequently start and stop, affecting the power generation efficiency of the photovoltaic plant.

[0004] After analysis and research, it is mainly due to the electromagnetic interference generated in the electrolysis workshop, which affects the normal operation of the inverter load and shortens its service life. In order to improve the operating reliability of the inverter and reduce the power generation loss caused by frequent start and stop, it is planned to carry out the following technical research. The challenges are: the strong magnetic environment is a special environment. The strong magnetic field will have a strong impact on the operation, sampling, and service life of power electronic equipment. To eliminate the impact of the magnetic field, the on-site rectification plan is required to be high, and there are currently no successful typical cases at home and abroad for reference.

[0005] Therefore, the present invention needs to design a new type of anti-electromagnetic interference method to solve the above-mentioned problems. Summary of the invention

[0006] The purpose of the present invention is to provide a new type of electromagnetic interference protection method in order to solve the above problems, thereby solving the problems mentioned in the background technology.

[0007] In order to solve the above problems, the present invention provides a technical solution:

[0008] A novel electromagnetic interference prevention method, the electromagnetic interference prevention method comprising:

[0009] S1. By changing the installation direction of the inverter, changing the direction of the magnetic field passing through the inverter, rotating the direction of the inverter main panel, and switching the direction of the magnetic field interference, the interference is reduced;

[0010] S2. Use soft magnetic patches to stick to the outside of the inverter to form an attraction with the on-site magnetic field, reducing the interference of the external magnetic field on the internal devices of the equipment;

[0011] S3, making and optimizing the shielding cover;

[0012] S4. Use power quality analyzer to measure the power quality on both sides of the inverter, analyze the data and compare them, and optimize the control of the components on both sides by improving the software;

[0013] S5. Use the above different test methods to conduct experiments to solve the magnetic field interference problem of the project, improve the stability of the equipment, make the equipment run stably and reliably, and increase the power generation efficiency;

[0014] After five rounds of optimization, most of the inverters on site were able to connect to the grid and generate electricity normally. The problem of some equipment not being able to operate was solved by replacing equipment and moving the inverter installation location, and the problem loop was closed.

[0015] As a preferred technical solution, after switching the direction of magnetic field interference in step S1, it is tested that the alarm frequency of the current inverter installation direction is the lowest; changing the inverter installation method from vertical installation to horizontal installation will aggravate the fault.

[0016] As a preferred technical solution, step S3 includes the following specific steps:

[0017] S301. Use special silicon steel sheet materials and place them at the bottom and top of the inverter to test the vertical magnetic field shielding effect;

[0018] S302, making a shielding cover from silicon steel sheets to fully cover the inverter, and using Permalloy materials to perform a shielding test on the magnetic field to shield the interference problem caused by the magnetic environment to the equipment;

[0019] S303. Optimize the shielding cover by punching holes and fixing with wire or welding to eliminate gaps at the connection of silicon steel sheets to ensure the sealing of the shielding cover;

[0020] Special silicon steel sheet materials were placed at the bottom and top of the inverter to test the vertical magnetic field shielding effect, which reduced the alarm frequency. The silicon steel sheets were made into shielding covers to fully cover the inverter, and Permalloy materials were used to perform magnetic field shielding tests, which reduced the alarm frequency, but the fault was not completely resolved.

[0021] As a preferred technical solution, step S4 includes the following specific steps:

[0022] S401: In response to the frequent DC component alarm phenomenon on site, R&D tried to optimize the DC component control solution through software and perform software upgrades on the faulty inverter;

[0023] S402, observe the operating status of the inverter after the upgrade and analyze the operating data;

[0024] S403, targeted version optimization was made. After the upgrade, the alarms of most inverters disappeared, but alarms still existed in some inverters. R&D further optimized according to the actual situation and optimized the control of the components on both sides by improving the software.

[0025] As a preferred technical solution, when performing the test in step S5, unified power equipment control processing needs to be performed through a controller, and the controller includes a handheld mobile device, a PC terminal and a display screen.

[0026] As a preferred technical solution, the environment for installing the inverter needs to be screened before step S1, and an environment with low magnetic field strength is selected for equipment installation. Since the DC component threshold is very low, the DC component measurement circuit is a high-precision circuit, and the machine also has a magnetic field protection design inside. However, for magnetic field strengths that exceed standard requirements, slight differences in sampling will occur, resulting in DC component alarms.

[0027] As a preferred technical solution, before step S1, the anti-electromagnetic interference system is constructed, and the anti-electromagnetic interference system includes an anti-electromagnetic interference terminal, a monitoring module for implementing each method, and a test detection module. The output end of the monitoring module for implementing each method is communicatively connected to the input end of the test detection module, and the output end of the test detection module is communicatively connected to the input end of the anti-electromagnetic interference terminal.

[0028] As a preferred technical solution, the anti-electromagnetic interference terminal is used for unified management of power equipment installed in various locations, for visualization of data that needs to be queried and managed, and for cutting off the anti-electromagnetic interference system with one click, thereby solving risks and dangerous problems caused by unexpected situations.

[0029] As a preferred technical solution, the monitoring modules for implementing each method are used to monitor the equipment implemented in each step in real time, and record the real-time changes of electromagnetic data in each step.

[0030] As a preferred technical solution, the test detection module is used to record the electromagnetic change data before and after the installation of each step, and at the same time verify whether the solution is identical by changing the installation area.

[0031] The beneficial effects of the present invention are as follows: the present invention changes the installation orientation of the inverter, changes the direction in which the magnetic field passes through the inverter, rotates the orientation of the inverter main panel, switches the direction of magnetic field interference, and uses soft magnet magnetic patches to be attached to the outside of the inverter to form attraction with the on-site magnetic field, thereby reducing the interference of the external magnetic field on the internal devices of the equipment, and makes and optimizes the shielding cover. The power quality of the AC and DC sides of the inverter is measured by using a power quality analyzer, and the data is analyzed and compared. The components on both sides are optimized and controlled by improving the software, and the above different test methods are used to conduct experiments to solve the project magnetic field interference problem, improve the equipment stability, make the equipment run stably and reliably, and increase the power generation efficiency. By constructing an anti-electromagnetic interference system, the anti-electromagnetic interference data and the corresponding analysis results are managed, visualized and stored, which is helpful to realize anti-electromagnetic interference management through Internet cloud management and control, and improve the intelligence level of anti-electromagnetic interference management. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] For ease of explanation, the present invention is described in detail with reference to the following specific implementations and the accompanying drawings.

[0033] Figure 1 It is an overall flow chart of a novel anti-electromagnetic interference method of the present invention;

[0034] Figure 2 It is a schematic diagram of magnetic field environment monitoring of a novel anti-electromagnetic interference method of the present invention;

[0035] Figure 3 It is a schematic diagram of a novel electromagnetic interference prevention method of the present invention, which uses a power quality analyzer to measure the power quality of the power grid side;

[0036] Figure 4 It is a schematic diagram of changing the inverter installation mode of a novel anti-electromagnetic interference method of the present invention;

[0037] Figure 5 It is a schematic diagram of an optimized shielding cover of a novel anti-electromagnetic interference method of the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0039] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

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

[0041] It should be understood that although the terms first, second, third, etc. may be used to describe in the embodiments of the present application, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, without departing from the scope of the embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first.

[0042] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0043] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0044] It should be particularly noted that any symbols and / or numbers in the specification that are not marked in the accompanying drawings are not drawing marks.

[0045] The optional embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0046] like Figure 1-Figure 5 As shown, this specific implementation adopts the following technical solutions:

[0047] A novel electromagnetic interference prevention method, the electromagnetic interference prevention method comprising:

[0048] S1. By changing the installation direction of the inverter, changing the direction of the magnetic field passing through the inverter, rotating the direction of the inverter main panel, switching the direction of magnetic field interference, the interference is reduced. After switching the direction of magnetic field interference, after testing, the inverter installation direction has the lowest alarm frequency; changing the inverter installation method from vertical installation to horizontal installation, the fault is aggravated;

[0049] S2. Use soft magnetic patches to stick to the outside of the inverter to form an attraction with the on-site magnetic field, reducing the interference of the external magnetic field on the internal devices of the equipment;

[0050] S3, making and optimizing the shielding cover;

[0051] S4. Use power quality analyzer to measure the power quality on both sides of the inverter, analyze the data and compare them, and optimize the control of the components on both sides by improving the software;

[0052] S5. Use the above different test methods to conduct experiments to solve the magnetic field interference problem of the project, improve the stability of the equipment, make the equipment run stably and reliably, and increase the power generation efficiency;

[0053] After five rounds of optimization, most of the inverters on site were able to connect to the grid and generate electricity normally. The problem of some equipment not being able to operate was solved by replacing equipment and moving the inverter installation location, and the problem loop was closed.

[0054] In this solution, step S3 includes the following specific steps:

[0055] S301. Use special silicon steel sheet materials and place them at the bottom and top of the inverter to test the vertical magnetic field shielding effect;

[0056] S302, making a shielding cover from silicon steel sheets to fully cover the inverter, and using Permalloy materials to perform a shielding test on the magnetic field to shield the interference problem caused by the magnetic environment to the equipment;

[0057] S303. Optimize the shielding cover by punching holes and fixing with wire or welding to eliminate gaps at the connection of silicon steel sheets to ensure the sealing of the shielding cover;

[0058] Special silicon steel sheet materials were placed at the bottom and top of the inverter to test the vertical magnetic field shielding effect, which reduced the alarm frequency. The silicon steel sheets were made into shielding covers to fully cover the inverter, and Permalloy materials were used to perform magnetic field shielding tests, which reduced the alarm frequency, but the fault was not completely resolved.

[0059] In this solution, step S4 includes the following specific steps:

[0060] S401: In response to the frequent DC component alarm phenomenon on site, R&D tried to optimize the DC component control solution through software and perform software upgrades on the faulty inverter;

[0061] S402, observe the operating status of the inverter after the upgrade and analyze the operating data;

[0062] S403, targeted version optimization was made. After the upgrade, the alarms of most inverters disappeared, but alarms still existed in some inverters. R&D further optimized according to the actual situation and optimized the control of the components on both sides by improving the software.

[0063] As a preferred technical solution, when performing the test in step S5, unified power equipment control processing needs to be performed through a controller, and the controller includes a handheld mobile device, a PC terminal and a display screen.

[0064] As a preferred technical solution, the environment for installing the inverter needs to be screened before step S1, and an environment with low magnetic field strength is selected for equipment installation. Since the DC component threshold is very low, the DC component measurement circuit is a high-precision circuit, and the machine also has a magnetic field protection design inside. However, for magnetic field strengths that exceed standard requirements, slight differences in sampling will occur, resulting in DC component alarms.

[0065] In the present scheme, before step S1, the anti-electromagnetic interference system is constructed, and the anti-electromagnetic interference system includes an anti-electromagnetic interference terminal, a monitoring module for implementing each method, and a test detection module. The output end of the monitoring module for implementing each method is communicatively connected to the input end of the test detection module, and the output end of the test detection module is communicatively connected to the input end of the anti-electromagnetic interference terminal; the anti-electromagnetic interference terminal is used for unified management of power equipment installed in various places, for visualization of data that needs to be queried and managed, and for one-click cutting off of the anti-electromagnetic interference system to solve the dangers caused by risks and unexpected situations; the monitoring module for implementing each method is used for real-time monitoring of the equipment implemented in each step, and recording the real-time changes of electromagnetic data in each step; the test detection module is used for recording the electromagnetic change data before and after the installation of each step, and at the same time, checking whether this scheme is identical by changing the installation area.

[0066] Example

[0067] A total of 99 Huawei SUN2000-196KTL-H0 inverters were installed and used on site, of which 34 were installed on the roofs of the aluminum electrolytic workshops in electrolytic zones 1 to 8;

[0068] The inverters installed on the ground and on the roofs of non-electrolytic aluminum workshops are running stably and generating electricity normally; the inverters installed on the roofs of electrolytic aluminum workshops can be connected to the grid and generate electricity normally, but they frequently give alarms: the DC component of the output current is too large, and it starts and stops frequently. Some equipment does not work. After the boards of the non-working equipment are returned to the laboratory for testing, they are found to have no problems and can be used normally. It is determined that the abnormal operation of the equipment is caused by the on-site magnetic field interference;

[0069] The electrolysis workshop uses 940V*500KA DC busbar for electrolysis work. The measured electromagnetic field strength on site is 39V / m. After entering the aluminum electrolysis workshop, the mobile phone cannot work normally due to the interference of the magnetic field. Figure 2 Show:

[0070] The electromagnetic field strength test equipment was used to measure the electromagnetic field strength of the inverter operating environment. The test results showed that the magnetic field strength of the equipment operating environment has far exceeded the equipment operating environment standard. The measured on-site electric field strength is 39V / m, and the standard calibrated electromagnetic field strength should not exceed 10V / m;

[0071] The power quality on the grid side was measured using a power quality analyzer. According to the test data, there were short-term high harmonics on the AC side, and the total harmonic distortion of the BC phase reached 27.3%;

[0072] The inverter circuit boards of Area 2 No. 8 and No. 9 that could not be started due to shutdown were sent back to the laboratory for analysis. Under the normal laboratory environment, the circuit boards resumed normal operation. After applying a magnetic field to the circuit boards in the laboratory to simulate the high magnetic field environment on site, the inverters began to alarm: the DC component of the output current was too large, and the inverters started and stopped frequently.

[0073] Field data collection:

[0074] (1) Measure the DC component of the AC output line under different working conditions;

[0075] ①Measure the DC component of the A / B / C three-phase AC cable to see if the sum is zero, to ensure that the measuring instrument is not disturbed and the measured data is accurate and reliable;

[0076] ②Measure the DC component value of the AC cable when the inverter is shut down;

[0077] ③ Test the changes in the DC component value of the inverter from startup to grid connection, and record the inverter power and cable DC component value;

[0078] ④ Limit the power of the inverter according to the gradient (down to 1%) and measure the DC component of the AC cable at different powers;

[0079] ⑤Measure the DC component value of the AC output cable of the inverter without alarm and compare it with the faulty inverter.

[0080] (2) Measure the DC component of the output line under different string connection conditions;

[0081] ① Enable reactive power at night, connect only one PV closest to the inverter, and test the DC component of the inverter output;

[0082] ② Enable reactive power at night, connect only one PV farthest from the inverter, and test the DC component of the inverter output;

[0083] ③ Enable reactive power at night, connect only the nearest 1 / 3 strings, and test the DC component of the inverter output;

[0084] ④ Enable reactive power at night, connect only the farthest 1 / 3 strings, and test the DC component of the inverter output;

[0085] (3) Limit the inverter power according to the gradient and check at what percentage the inverter stops alarming;

[0086] (4) Collect the logs of the faulty inverter and the normal inverter with the same DC capacity access and compare the power generation;

[0087] (5) The DC component in the inverter AC output cable was measured. When the inverter was turned off, a DC component of 8.4 A was sensed in the AC cable. This shows that the DC component in the AC cable was not generated by the inverter operation.

[0088] In summary, it can be determined that the strong magnetic field interference on site caused a large DC component in the inverter's AC output cable, causing the inverter to operate abnormally.

[0089] After three months of R&D investment and joint verification by on-site engineers, the on-site equipment has been able to operate normally and continuously by adding hardware and software optimization and shifting the inverter position, and the problem of magnetic field affecting inverter operation has been solved.

[0090] In a strong magnetic environment, cables, power generation equipment, and transformers will be affected to varying degrees by magnetic field interference. Electromagnetic induction occurs in the input and output cables, resulting in DC induced current in the AC cables, triggering the DC component protection of the inverter. At the same time, the magnetic field will also affect the sampling data of the equipment sampling components, resulting in sampling anomalies. For grid-connected inverters, strictly speaking, it is required to only inject AC current into the grid, but in fact, the grid-connected current often contains a DC component. Excessive DC injection will have adverse effects on grid equipment, such as causing transformer or mutual inductor saturation, substation grounding grid corrosion and other problems. Therefore, the inverter needs to monitor the DC component of the grid-connected current in real time to ensure that it is within a certain range. When the DC component exceeds this range, the alarm protection will be triggered.

[0091] The application environment of photovoltaic inverters is a typical industrial environment. According to the classification and requirements of the national standard GB / T17626.8, the inverter is required to operate stably in the following environment.

[0092] Stable continuous magnetic field strength ≤30A / m (0.0378mT / 0.378G),

[0093] 1s~3s short-term magnetic field strength ≤300A / m (0.378mT / 3.78G)

[0094] (1A / m is equivalent to the magnetic field strength of 1.26uT in free space - refer to national standard GB / T17626.8).

[0095] Specifically: In actual applications, there are multiple monitoring units for implementing each method, which are respectively used in conjunction with the anti-electromagnetic interference terminal and the test detection unit. The multiple monitoring units for implementing each method are respectively located in different geographical locations. The present invention changes the installation orientation of the inverter, changes the direction of the magnetic field passing through the inverter, rotates the orientation of the inverter main panel, switches the direction of magnetic field interference, and uses soft magnet magnetic patches to stick on the outside of the inverter to form attraction with the on-site magnetic field, thereby reducing the interference of the external magnetic field on the internal devices of the equipment, making and optimizing the shielding cover, and using a power quality analyzer to measure the power quality on both sides of the inverter, analyzing the data for comparison, and optimizing the control of the components on both sides by improving the software. The above different test methods are used to conduct experiments to solve the project magnetic field interference problem, improve the equipment stability, make the equipment run stably and reliably, and increase the power generation efficiency. By constructing an anti-electromagnetic interference system, the anti-electromagnetic interference data and the corresponding analysis results are managed, visualized and stored, which is helpful to realize anti-electromagnetic interference management through Internet cloud management and control, and improve the intelligence level of anti-electromagnetic interference management.

[0096] Those of ordinary skill in the art will appreciate that the modules and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0097] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices, equipment and modules can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0098] In the several embodiments provided in the present application, it should be understood that the disclosed devices, systems and methods can be implemented in other ways. For example, the system embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or modules can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or equipment, which can be electrical, mechanical or other forms.

[0099] The modules used as the anti-electromagnetic interference terminal and the monitoring and test detection methods may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0100] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0101] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program instructions, such as a USB flash drive, a mobile hard disk, a read-only storage server, a random access storage server, a magnetic disk or an optical disk.

[0102] In addition, it should be noted that the combination of the various technical features in this case is not limited to the combination described in the claims of this case or the combination described in the specific embodiments. All technical features described in this case can be freely combined or combined in any way unless there is a contradiction between them.

[0103] It should be noted that the above examples are only specific embodiments of the present invention, and the present invention is obviously not limited to the above examples, and there are many similar variations. All variations directly derived or associated from the contents disclosed by the technicians in this field should fall within the protection scope of the present invention.

[0104] The above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A novel method for preventing electromagnetic interference, characterized in that: The anti-electromagnetic interference method comprises: S1. By changing the installation direction of the inverter, the direction of the magnetic field passing through the inverter is changed, and the direction of the inverter main panel is rotated to switch the direction of the magnetic field interference; S2. Use soft magnetic patches to stick to the outside of the inverter to form an attraction with the on-site magnetic field, reducing the interference of the external magnetic field on the internal devices of the equipment; S3, making and optimizing the shielding cover; S4. Use power quality analyzer to measure the power quality on both sides of the inverter, analyze the data and compare them, and optimize the control of the components on both sides by improving the software; S5. Conduct experiments using the different test methods mentioned above.

2. The novel electromagnetic interference protection method according to claim 1 is characterized in that: After switching the direction of magnetic field interference in step S1, the original inverter installation mode needs to be changed from vertical installation to horizontal installation.

3. The novel electromagnetic interference prevention method according to claim 1 is characterized in that: The step S3 includes the following specific steps: S301. Use special silicon steel sheet materials and place them at the bottom and top of the inverter to test the vertical magnetic field shielding effect; S302, making a shielding cover from silicon steel sheets to fully cover the inverter, and performing a shielding test on the magnetic field with Permalloy materials; S303. Optimize the shielding cover and eliminate the gaps at the connection of the silicon steel sheets by punching holes and fixing them with iron wire or welding.

4. The novel electromagnetic interference prevention method according to claim 3 is characterized in that: The step S4 includes the following specific steps: S401: In response to the frequent DC component alarm phenomenon on site, R&D tried to optimize the DC component control solution through software and perform software upgrades on the faulty inverter; S402, observe the operating status of the inverter after the upgrade and analyze the operating data; S403, targeted version optimization was made. After the upgrade, the alarms of most inverters disappeared, but alarms still existed in some inverters. R&D further optimized according to the actual situation and optimized the control of the components on both sides by improving the software.

5. The novel electromagnetic interference prevention method according to claim 1 is characterized in that: When the test is performed in step S5, unified power equipment control processing needs to be performed through a controller, and the controller includes a handheld mobile device, a PC terminal and a display screen.

6. The novel electromagnetic interference protection method according to claim 5 is characterized in that: Before step S1, the environment for installing the inverter needs to be screened, and an environment with low magnetic field strength is selected for equipment installation. Since the DC component threshold is very low, the DC component measurement circuit is a high-precision circuit, and the machine also has a magnetic field protection design inside. However, for magnetic field strengths that exceed standard requirements, slight differences in sampling will occur, resulting in DC component alarms.

7. The novel electromagnetic interference prevention method according to claim 1 is characterized in that: Before step S1, the anti-electromagnetic interference system is constructed, and the anti-electromagnetic interference system includes an anti-electromagnetic interference terminal, a monitoring module for implementing each method, and a test detection module. The output end of the monitoring module for implementing each method is communicatively connected to the input end of the test detection module, and the output end of the test detection module is communicatively connected to the input end of the anti-electromagnetic interference terminal.

8. The novel electromagnetic interference protection method according to claim 7 is characterized in that: The anti-electromagnetic interference terminal is used for unified management of power equipment installed in various places, for visualization of data that needs to be queried and managed, and for cutting off the anti-electromagnetic interference system with one click, thereby solving the danger problems caused by risks and unexpected situations.

9. The novel electromagnetic interference protection method according to claim 7 is characterized in that: The monitoring modules for implementing each method are used to monitor the equipment implemented in each step in real time, and record the real-time changes of electromagnetic data in each step.

10. The novel electromagnetic interference prevention method according to claim 7 is characterized in that: The test detection module is used to record the electromagnetic change data before and after the installation of each step, and at the same time verify whether the scheme is identical by changing the installation area.

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