Low electromagnetic noise water-cooled load and application, electromagnetic compatibility test method for charging pile

Abstract

This invention belongs to the field of electromagnetic compatibility (EMC) testing technology, specifically relating to low electromagnetic noise water-cooled loads and their applications, and EMC testing methods for charging piles. The low EMC water-cooled load includes a metal outer casing, inside which a water-cooled load chamber is installed. The water-cooled load chamber comprises a water-cooling housing and a load body. The water-cooling housing has an inlet and an outlet. A charging gun interface adapter, an air switch, and a mechanical gear switch are installed on the side panel of the metal outer casing. The low EMC water-cooled load is applied to EMC testing of AC charging piles for new energy electric vehicles, providing a load for the sample while maintaining a low EMC level. This invention separates the low EMC water-cooled load from the water chiller. During testing, the active water chiller can be placed outside the test site, while the load body is placed inside the test site. A non-electrical connection is established via a waveguide, thereby cutting off the electromagnetic noise coupling path of the active component and achieving complete isolation of the active component.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic compatibility testing technology, and particularly to low electromagnetic noise water-cooled loads and their applications, and electromagnetic compatibility testing methods for charging piles. Background Technology

[0002] With the rapid popularization of new energy electric vehicles, most large commercial parking lots and residential parking spaces are equipped with AC charging piles for these vehicles. These AC charging piles are similar to small substations, and their large-scale installation inevitably leads to serious electromagnetic noise pollution, even affecting the normal function of other electronic and electrical products. For example, they can cause abnormal images in parking lot video surveillance systems or positioning errors in electronic navigation systems. If they interfere with parking lot smoke alarm systems or life support devices for patients, the consequences could be disastrous. Furthermore, these AC charging piles also serve as electricity billing settlement devices, making their electromagnetic interference resistance crucial. Therefore, electromagnetic compatibility testing is a critical step in the research and development and production of AC charging piles for new energy electric vehicles. The test results directly affect the charging pile's electromagnetic interference resistance performance in actual use and its impact on other equipment.

[0003] Electromagnetic compatibility (EMC) testing is a crucial method for evaluating the EMC performance of AC charging piles for new energy electric vehicles. During testing, AC charging piles for electric vehicles require a simulated load (simulating a vehicle or battery) to absorb their output power in order to simulate normal operation. A typical simulated load may contain switching power supplies, control modules, display screens, and cooling modules, all of which are sources of electromagnetic noise. If the simulated load exhibits significant electromagnetic noise, this unwanted noise will be picked up by the receiving antenna through spatial radiation. The resulting measurement is a mixture of noise from the charging pile under test and the simulated load, affecting the final measurement result. If a purely resistive load is used as the simulated load, it cannot be directly connected to the charging pile under test due to the lack of a communication protocol, making it difficult to simulate the charging pile's loaded operation. Furthermore, the air-cooled cooling modules of resistive loads typically exhibit significant broadband electromagnetic emissions. The connection determination module between the load and the charging gun, as well as the external handshake protocol circuit, all require corresponding adapter circuits, which also contribute to electromagnetic noise emissions.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to address the technical challenge of suppressing electromagnetic noise generated by the load itself during electromagnetic compatibility (EMC) testing of electric vehicle charging piles, while ensuring adequate heat dissipation and smooth connection of the charging pile interface. To this end, this invention provides a low-EMC water-cooled load and its application in EMC testing of AC charging piles for new energy electric vehicles, along with an EMC testing method for charging piles. The low-EMC water-cooled load utilizes water-cooled resistors and can be remotely connected to an external water chiller to solve the load's heat dissipation problem. It integrates three sets of charging gun interface adapters to ensure normal connection and load identification of the charging pile during testing. A mechanical gear switch controls the gear position and on / off state of the low-EMC water-cooled load. The overall metal casing of the low-EMC water-cooled load uses a metal shielding structure to isolate unnecessary electromagnetic radiation from the connection lines between the charging pile and the load, ensuring the standardization of the testing process and the accuracy of the test results.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A low electromagnetic noise water-cooled load includes a metal outer casing, inside which a water-cooled load box is installed. The water-cooled load box includes a water-cooled housing and a load body disposed inside the water-cooled housing. The water-cooled housing is equipped with an inlet and an outlet. A charging gun interface adapter, an air switch, and a mechanical gear switch are installed on the side plate of the metal outer casing. The charging gun interface adapter is electrically connected to the air switch, the air switch is electrically connected to the mechanical gear switch, and the mechanical gear switch is electrically connected to the load body.

[0008] The following is a further technical solution for defining the low electromagnetic noise water-cooled load in this invention: an emergency switch is installed on the side plate of the metal outer casing, and the emergency switch is located between the charging gun interface adapter and the air switch.

[0009] The following is a further technical solution for defining the low electromagnetic noise water-cooled load in this invention: a thermometer module and a thermometer switch are installed on the side plate of the metal outer casing. The thermometer module is used to detect and display the temperature inside the metal outer casing, and the thermometer switch is electrically connected to the thermometer module.

[0010] The following is a further technical solution for defining the low electromagnetic noise water-cooled load in this invention: ventilation plates are installed on the front, top, and bottom of the metal outer casing.

[0011] The following is a technical solution for further defining the low electromagnetic noise water-cooled load in this invention: universal wheels are installed at the four bottom corners of the metal outer casing.

[0012] Low electromagnetic noise water-cooled loads were applied to the electromagnetic compatibility testing of AC charging piles for new energy electric vehicles to provide load for the samples while maintaining low electromagnetic noise levels.

[0013] The electromagnetic compatibility (EMC) testing method for charging piles employs a low-electromagnetic-noise water-cooled load to conduct EMC tests on AC charging piles, including: Place the low electromagnetic noise water-cooled load inside the anechoic chamber; The inlet and outlet of the low electromagnetic noise water-cooled load are connected to the water chiller remotely through water-cooled pipes through the anechoic chamber, and the water chiller is located outside the anechoic chamber. The charging pile under test is directly connected to the charging gun interface adapter with a low electromagnetic noise water-cooled load, and the charging pile under test is located inside the anechoic chamber. The test receiver, located outside the anechoic chamber, receives the electromagnetic signals from the charging pile under test via a receiving antenna, which is located inside the anechoic chamber. The test receiver is connected to the test computer, which then performs data processing and analysis.

[0014] The following is a further technical solution for the method of the present invention: a waveguide is installed on the side wall of the anechoic chamber, and a water cooling pipe runs through the waveguide.

[0015] Compared with the prior art, the present invention has the following technical effects: This invention features a separate design for the low electromagnetic noise water-cooled load and the water chiller. During testing, the active (electromagnetically noisy) water chiller can be placed outside the test site, while the main load is placed inside. A non-electrical connection is established via a waveguide, thus cutting off the electromagnetic noise coupling path of the active component and achieving complete isolation. This low electromagnetic noise water-cooled load provides stable load consumption for AC charging piles of new energy electric vehicles during electromagnetic compatibility testing, effectively simulating real-world operating conditions and minimizing unexpected electromagnetic noise from the load itself. This effectively solves the problem of background noise from the load during EMC testing of charging piles and improves the accuracy of test results.

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the connection relationship of the low electromagnetic noise water-cooled load for electromagnetic compatibility testing of the charging pile under test in this invention. Figure 2 This is a three-dimensional structural schematic diagram of the low electromagnetic noise water-cooled load in this invention; Figure 3 This is a front view schematic diagram of the low electromagnetic noise water-cooled load in this invention; Figure 4 This is a side view of the structure on one side of the low electromagnetic noise water-cooled load in this invention. Figure 5 This is a side view of the structure on the other side of the low electromagnetic noise water-cooled load in this invention. Figure 6 This is a bottom view of the low electromagnetic noise water-cooled load structure in this invention. Figure 7 This is a top view schematic diagram of the low electromagnetic noise water-cooled load in this invention.

[0019] Attached reference numerals: 1. Water-cooled load cell; 2. Charging gun interface adapter; 3. Air switch; 4. Mechanical gear switch; 5. Emergency switch; 6. Thermometer module; 7. Thermometer switch; 8. Ventilation plate; 9. Water inlet; 10. Water outlet; 11. Casters. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0021] like Figure 1-7 As shown, this embodiment provides a low electromagnetic noise water-cooled load, which mainly consists of a metal outer casing, a water-cooled load module (including a water-cooled load box 1 composed of a water-cooled box and a load body), a mechanical control module (including three sets of air switches 3, three sets of mechanical gear switches 4, an emergency switch 5 and a thermometer switch 7), and a charging base (i.e., three sets of charging gun interface adapters 2).

[0022] Ventilation panels 8 are installed at the front, top, and bottom of the metal outer casing. The ventilation panels 8 are made of perforated metal sheet and are used for air exchange and circulation between the inside and outside of the metal outer casing. The ventilation panels 8 are fixed to the metal outer casing with metal screws. All connections of the metal outer casing must be fully welded.

[0023] The water-cooled load cell 1 is installed inside the metal outer casing. The water-cooled load cell 1 includes a water-cooled housing and a load body housed within the housing. The load body is a 35kW AC load with a resistance tolerance of less than ±10% and a resistive heat generation of less than 25000kcal / h. The load body is a sealed structure made of stainless steel. The cooler providing cooling water circulation to the load body is separate from the load body. The load body is located inside the anechoic chamber, while the water-cooled cooler is located outside. The cooler and the load body are connected by a metal pipe of customizable length, providing remote cooling circulation.

[0024] The water-cooled enclosure is equipped with an inlet 9 and an outlet 10, both with an inner diameter of 25mm. The piping for both inlet 9 and outlet 10 is made of stainless steel. In use, inlet 9 is connected to the outlet 10 of an external chiller via a pre-defined length of water-cooled piping. Outlet 10 is connected to the inlet 9 of an external chiller via a pre-defined length of water-cooled piping.

[0025] The side panels of the metal casing are equipped with three sets of charging gun interface adapters 2, three sets of air switches 3, and three sets of mechanical gear switches 4.

[0026] The charging gun interface adapter 2 is used to connect to the charging pile under test and is used to match different types of AC charging piles for new energy electric vehicles. This avoids electromagnetic leakage caused by damaging the overall shielding structure of the cable during electromagnetic compatibility testing. The charging gun interface adapter 2 is a national standard / European standard / American standard charging gun socket. The three sets of charging gun interface adapters 2 are electrically connected to three sets of air switches 3 respectively.

[0027] The three sets of air circuit breakers 3 are 800V / 63A circuit breakers, each electrically connected to one of the three sets of mechanical position switches 4, for overload safety protection during equipment operation. The mechanical position switches 4 are electrically connected to the load body.

[0028] The mechanical position switch 4 uses a purely mechanical structure to avoid additional electromagnetic noise. It can adjust the load capacity of the load body, with each set of positions having 7 levels: 1A; 2A; 2A; 5A; 10A; 20A; 20A. The three sets of mechanical position switches 4 are connected to the load body corresponding to the load capacity, providing different combinations of load capacity when testing electric vehicle charging piles.

[0029] A thermometer module 6 and a thermometer switch 7 are installed on the side panel of the metal casing. The thermometer module 6 is a battery-powered thermometer used to detect and display the temperature inside the metal casing. The thermometer switch 7 is electrically connected to the thermometer module 6 and can be turned off when not in use. The thermometer switch 7 is a mechanical switch used to turn the power to the thermometer module 6 on or off.

[0030] An emergency switch 5 is installed on the side panel of the metal casing. Emergency switch 5 is a mushroom-shaped emergency reset stop button, located between the charging gun interface adapter 2 and the air switch 3. Emergency switch 5 is used for one-button disconnection in emergencies and subsequent reset.

[0031] The bottom four corners of the metal outer casing are equipped with casters 11 for easy movement of the low electromagnetic noise water-cooled load.

[0032] Low electromagnetic noise water-cooled loads were applied to the electromagnetic compatibility testing of AC charging piles for new energy electric vehicles to provide load for the samples while maintaining low electromagnetic noise levels.

[0033] The electromagnetic compatibility (EMC) testing method for charging piles employs a low-electromagnetic-noise water-cooled load to conduct EMC tests on AC charging piles, including: like Figure 1 As shown, a low electromagnetic noise water-cooled load is placed inside an anechoic chamber. The inlet 9 and outlet 10 of the low electromagnetic noise water-cooled load are remotely connected to the water chiller through the anechoic chamber via water-cooled pipes. The water chiller is located outside the anechoic chamber. Waveguides are installed on the side wall of the anechoic chamber, through which the water-cooled pipes pass.

[0034] The charging pile under test is directly connected to the charging gun interface adapter 2 with a low electromagnetic noise water-cooled load, and the charging pile under test is located inside the anechoic chamber.

[0035] The test receiver, located outside the anechoic chamber, receives the electromagnetic signals from the charging pile under test via a receiving antenna, which is located inside the anechoic chamber.

[0036] The test receiver is connected to the test computer, which then performs data processing and analysis.

[0037] Therefore, the low electromagnetic noise water-cooled load provided in this embodiment is a split-type water-cooled load (the water chiller is a split-type remote connection), which has lower requirements for the test site and does not require consideration of load channel and filtering issues. Since the main body of the load is inside the test site (anechoic chamber), the charging pile under test can be directly connected to the charging gun interface adapter 2 on the simulated load (i.e., the low electromagnetic noise water-cooled load), ensuring the continuity of the shielding of the simulated load interface. At the same time, there is no electrical connection between the charging pile under test and the outside of the anechoic chamber, so it is not affected by external electromagnetic noise, minimizing unexpected electromagnetic noise. The electric field radiation emission noise of the entire enclosure during operation is at least 6dB lower than the most severe limit of radiated interference in the national standard GB / T 18487.2-2017 and the magnetic field radiation interference of keyless entry systems in Appendix D. The low electromagnetic noise water-cooled load can meet the typical load switching of 20%, 50%, and 80% of the load capacity of conventional 16A and 32A electric vehicle AC charging piles, and the load value error of different levels is better than ±10%. The system can achieve high power, low electromagnetic noise, switchable speed, external cooling, and plug-and-play charging pile connection. It solves the problem of external electromagnetic noise affecting charging piles in electromagnetic compatibility testing under good heat dissipation, improves the accuracy of test results, and greatly enhances testing efficiency and laboratory testing service capabilities.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any person skilled in the art can make many possible variations and modifications to the technical solution of the present invention, or modify it into equivalent embodiments, without departing from the scope of the present invention's technical solution. Therefore, all equivalent changes made based on the shape, structure, and principle of the present invention without departing from the scope of the present invention's technical solution should be covered within the protection scope of the present invention.

Claims

1. A low electromagnetic noise water-cooled load, characterized in that, The device includes a metal outer casing, inside which a water-cooled load cell (1) is installed. The water-cooled load cell (1) includes a water-cooled housing and a load body disposed inside the water-cooled housing. The water-cooled housing is equipped with a water inlet (9) and a water outlet (10). The side panel of the metal outer casing is equipped with a charging gun interface adapter (2), an air switch (3), and a mechanical gear switch (4). The charging gun interface adapter (2) is electrically connected to the air switch (3), the air switch (3) is electrically connected to the mechanical gear switch (4), and the mechanical gear switch (4) is electrically connected to the load body.

2. The low electromagnetic noise water-cooled load as described in claim 1, characterized in that, An emergency switch (5) is installed on the side panel of the metal outer casing. The emergency switch (5) is located between the charging gun interface adapter (2) and the air switch (3).

3. The low electromagnetic noise water-cooled load as described in claim 1, characterized in that, The side panel of the metal outer casing is equipped with a thermometer module (6) and a thermometer switch (7). The thermometer module (6) is used to detect and display the temperature inside the metal outer casing, and the thermometer switch (7) is electrically connected to the thermometer module (6).

4. The low electromagnetic noise water-cooled load as described in claim 1, characterized in that, Ventilation panels (8) are installed at the front, top, and bottom of the metal outer casing.

5. The low electromagnetic noise water-cooled load as described in claim 1, characterized in that, The metal outer casing is equipped with casters (11) at the four bottom corners.

6. The low electromagnetic noise water-cooled load described in any one of claims 1-5 is applied to the electromagnetic compatibility test of AC charging piles for new energy electric vehicles to provide a load for the sample and maintain a low electromagnetic noise level.

7. A method for testing the electromagnetic compatibility of charging piles, wherein the low electromagnetic noise water-cooled load described in any one of claims 1-5 is used to conduct electromagnetic compatibility testing on the AC charging pile, characterized in that... include: Place the low electromagnetic noise water-cooled load inside the anechoic chamber; The inlet (9) and outlet (10) of the low electromagnetic noise water-cooled load are connected to the water chiller remotely through the anechoic chamber via water-cooled pipes. The water chiller is located outside the anechoic chamber. The charging pile under test is directly connected to the charging gun interface adapter (2) with low electromagnetic noise water-cooled load, and the charging pile under test is located inside the anechoic chamber. The test receiver, located outside the anechoic chamber, receives the electromagnetic signals from the charging pile under test via a receiving antenna, which is located inside the anechoic chamber. The test receiver is connected to the test computer, which then performs data processing and analysis.

8. The electromagnetic compatibility testing method for charging piles as described in claim 7, characterized in that, Waveguides are installed on the side walls of the anechoic chamber, and water cooling pipes run through the waveguides.

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