Air Conditioner EMI Test Method

Abstract

The present invention relates to the field of electromagnetic interference of air conditioners, and specifically to an air conditioner EMI testing method, which improves the accuracy of EMI detection, reduces costs, and greatly reduces safety risks in testing. The air conditioner EMI testing method of the present invention comprises: pre-storing a corresponding relationship table of defined EMI test codes and air conditioner load operation modes in the air conditioner control software; then sending the EMI test code to select the corresponding air conditioner load operation mode, running the corresponding air conditioner load according to the corresponding air conditioner load operation mode, and setting corresponding operation protection conditions; finally, detecting whether the EMI value of the running air conditioner load exceeds the standard, if so, recording the EMI exceeding the standard; otherwise, recording the test passing. The present invention is suitable for air conditioner electromagnetic interference detection.

Description

Technical Field

[0001] The invention relates to the field of electromagnetic interference of air conditioners, and in particular to an EMI testing method for air conditioners. Background Art

[0002] Air conditioners will generate electromagnetic interference (EMI) during operation, which will have adverse effects on the power grid or other electrical equipment. Therefore, the national standard requires that all air conditioners must pass the EMI test.

[0003] EMI has always been a difficult problem for many technicians. To determine the cause of EMI exceeding the standard, it is usually necessary to disassemble the indoor or outdoor unit of the air conditioner, remove the stepper motor, fan motor, four-way valve, compressor and other loads one by one, and then reassemble the air conditioner and test it again to determine the main reason for the EMI exceeding the standard. This process of "disassembling → unplugging the load → assembling and restoring → testing" makes the work efficiency very low and occupies a large amount of experimental resources. Moreover, after unplugging certain components, the air conditioner may fail to work due to a fault, and the test cannot continue.

[0004] Prior art, such as patent number CN111239510A, discloses a self-service test method and test system for air conditioner EMC, which discloses a self-service test method for air conditioner EMC interference (EMI for short), which uses an external test module connected to the air conditioner indoor unit main board and the outdoor unit main board to simulate the air conditioner indoor unit signal or outdoor unit signal to assist in testing.

[0005] However, this method has the following disadvantages: 1. The external test module (i.e., test fixture) itself will generate electromagnetic interference, and the EMI of the external test module will be coupled with the EMI of the air conditioner, which will affect the accuracy of the test; 2. Both the indoor and outdoor mainboards of the air conditioner need to add additional communication interfaces to communicate with the external test module, which will increase the number of pins of the indoor and outdoor mainboard MCUs and the demand for resources such as memory, increase the layout area of ​​the PCB board, and increase the hardware cost of the interface circuit, which is not economically viable; 3. Safety issues are not considered during the test process, and safety accidents are very likely to occur during the test process. Summary of the invention

[0006] The purpose of the present invention is to provide an air conditioner EMI testing method, which improves the accuracy of EMI detection, reduces costs, and greatly reduces the safety risks in the test.

[0007] The present invention adopts the following technical scheme to achieve the above purpose, an air conditioner EMI testing method, comprising:

[0008] Step 1: Pre-store a corresponding relationship table between defined EMI test codes and air conditioning load operation modes in the air conditioning control software;

[0009] Step 2: Send the EMI test code to select the corresponding air conditioning load operation mode;

[0010] Step 3: operate the corresponding air-conditioning load according to the corresponding air-conditioning load operation mode, and set the corresponding operation protection conditions;

[0011] Step 4: Check whether the EMI value of the running air conditioner load exceeds the standard. If so, record the EMI exceeding the standard; otherwise, record the test passed.

[0012] Furthermore, in step 1, the correspondence between the EMI test code and the air conditioner load operation mode includes:

[0013] The first test code corresponds to the on / off of all loads of the indoor and outdoor units of the air conditioner;

[0014] The second test code corresponds to the on / off of all loads of the air conditioner indoor unit;

[0015] The third test code corresponds to the on / off of all loads of the air conditioner outdoor unit;

[0016] The fourth test code corresponds to the on / off of the fan motor of the air conditioner indoor unit;

[0017] The fifth test code corresponds to the on / off switching of the air conditioner indoor unit display screen;

[0018] The sixth test code corresponds to the on / off of the air conditioner outdoor unit compressor;

[0019] The seventh test code corresponds to the on / off of the air conditioner outdoor unit fan motor;

[0020] The eighth test code corresponds to the on / off of the PFC of the air conditioner outdoor unit;

[0021] The ninth test code corresponds to the opening / closing of the four-way valve of the air conditioner outdoor unit.

[0022] Furthermore, in step 2, sending the EMI test code to select the corresponding air conditioning load operation mode specifically includes:

[0023] When the EMI test code is sent for the first time, all corresponding air-conditioning loads are turned off. When the same EMI test code is sent for the second time, all corresponding air-conditioning loads are turned on.

[0024] Furthermore, when the EMI test code is sent for the first time, all corresponding air conditioning loads are turned off, and when the same EMI test code is sent for the second time, all corresponding air conditioning loads are turned on. The specific operation method includes:

[0025] When the first test code is sent for the first time, all loads of the indoor and outdoor units of the air conditioner are turned off. When the first test code is sent for the second time, all loads of the indoor and outdoor units of the air conditioner are turned on.

[0026] When the second test code is sent for the first time, all loads of the air conditioner indoor unit are turned off, and when the second test code is sent for the second time, all loads of the air conditioner indoor unit are turned on;

[0027] When the third test code is sent for the first time, all loads of the air conditioner outdoor unit are turned off, and when the third test code is sent for the second time, all loads of the air conditioner outdoor unit are turned on;

[0028] When the fourth test code is sent for the first time, the fan motors of the indoor units of the air conditioners are all turned off, and when the fourth test code is sent for the second time, the fan motors of the indoor units of the air conditioners are all turned on;

[0029] When the fifth test code is sent for the first time, all the indoor air conditioner display screens are turned off. When the fifth test code is sent for the second time, all the indoor air conditioner display screens are turned on.

[0030] When the sixth test code is sent for the first time, the compressors of the air conditioner outdoor units are all turned off, and when the sixth test code is sent for the second time, the compressors of the air conditioner outdoor units are all turned on;

[0031] When the seventh test code is sent for the first time, the fan motors of the air conditioner outdoor units are all turned off, and when the seventh test code is sent for the second time, the fan motors of the air conditioner outdoor units are all turned on;

[0032] When the eighth test code is sent for the first time, the PFC of the air conditioner outdoor unit is turned off, and when the eighth test code is sent for the second time, the PFC of the air conditioner outdoor unit is turned on;

[0033] When the ninth test code is sent for the first time, the four-way valve of the air-conditioning outdoor unit is closed, and when the ninth test code is sent for the second time, the four-way valve of the air-conditioning outdoor unit is opened.

[0034] Furthermore, in step 3, the setting of corresponding operation protection conditions specifically includes:

[0035] The maximum operating frequency of the compressor is set to be lower than the first threshold frequency, the shutdown protection current of the compressor is set to be lower than the first threshold shutdown protection current, and a safe operation time is set for the air-conditioning load operation, and the normal operation mode is automatically restored after the safe operation time is reached.

[0036] The present invention no longer adopts the method of adding hardware to the air conditioner to perform electromagnetic interference testing, but only pre-stores a corresponding relationship table of defined EMI test codes and air conditioner load operation modes in the air conditioner control software, controls the corresponding air conditioner load operation through software control, and detects whether EMI exceeds the standard, thereby avoiding additional electromagnetic interference caused by redundant hardware equipment, improving the accuracy of detection, and reducing costs; and in the process of controlling the operation of the air conditioner, corresponding operation protection conditions are also set, which greatly reduces safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0038] The air conditioner EMI testing method of the present invention has a flow chart as shown in FIG. Figure 1 As shown, including:

[0039] Step 101, pre-store a corresponding relationship table between defined EMI test codes and air conditioning load operation modes in the air conditioning control software;

[0040] Step 102: Send an EMI test code to select a corresponding air conditioning load operation mode;

[0041] Step 103: operate the corresponding air-conditioning load according to the corresponding air-conditioning load operation mode, and set the corresponding operation protection condition;

[0042] Step 104, detect whether the EMI value of the running air conditioner load exceeds the standard, if it exceeds the standard, record the EMI exceeding the standard; otherwise, record the test passed.

[0043] In step 101, the correspondence between the EMI test code and the air conditioner load operation mode includes:

[0044] The first test code corresponds to the on / off of all loads of the indoor and outdoor units of the air conditioner;

[0045] The second test code corresponds to the on / off of all loads of the air conditioner indoor unit;

[0046] The third test code corresponds to the on / off of all loads of the air conditioner outdoor unit;

[0047] The fourth test code corresponds to the on / off of the fan motor of the air conditioner indoor unit;

[0048] The fifth test code corresponds to the on / off switching of the air conditioner indoor unit display screen;

[0049] The sixth test code corresponds to the on / off of the air conditioner outdoor unit compressor;

[0050] The seventh test code corresponds to the on / off of the air conditioner outdoor unit fan motor;

[0051] The eighth test code corresponds to the on / off of the PFC of the air conditioner outdoor unit;

[0052] The ninth test code corresponds to the opening / closing of the four-way valve of the air conditioner outdoor unit.

[0053] The corresponding relationship table is as follows:

[0054] Air conditioning load operation mode EMI test code All loads of indoor and outdoor units are turned on / off 00 All loads of indoor unit on / off 01 All loads of the external unit are turned on / off 02 Indoor fan motor on / off 03 Internal display on / off 04 External compressor on / off 05 Outdoor fan motor on / off 06 External unit PFC on / off 07 External unit four-way valve on / off 08

[0055] You can also set the corresponding EMI test code and corresponding relationship table according to the order or combination of running loads.

[0056] In step 2, sending the EMI test code to select the corresponding air conditioning load operation mode specifically includes:

[0057] When the EMI test code is sent for the first time, all corresponding air-conditioning loads are turned off. When the same EMI test code is sent for the second time, all corresponding air-conditioning loads are turned on.

[0058] The specific operation methods include:

[0059] When the first test code 00 is sent for the first time, all loads of the indoor and outdoor units of the air conditioner are turned off, and the EMI test data is detected. If the EMI exceeds the standard, the electromagnetic interference mainly comes from the indoor unit mainboard. When the first test code 00 is sent for the second time, all loads of the indoor and outdoor units of the air conditioner are turned on;

[0060] When the second test code 01 is sent for the first time, all loads of the indoor unit of the air conditioner are turned off, and only the load of the outdoor unit is kept running, and the EMI test data is detected. If the EMI exceeds the standard, the electromagnetic interference mainly comes from the outdoor unit. When the second test code 01 is sent for the second time, all loads of the indoor unit of the air conditioner are turned on;

[0061] When the third test code 02 is sent for the first time, all loads of the air conditioner outdoor unit are turned off, and only the load of the indoor unit is kept running, and the EMI test data is detected. If EMI exceeds the standard, the electromagnetic interference mainly comes from the indoor unit. When the third test code 02 is sent for the second time, all loads of the air conditioner outdoor unit are turned on;

[0062] When the fourth test code 03 is sent for the first time, all the fan motors of the air conditioner indoor units are turned off, and all other loads are kept running, and the EMI test data is detected. If the EMI is no longer excessive, the interference mainly comes from the fan motor or its drive circuit; if the EMI is still excessive, the interference mainly comes from other loads of the indoor unit. When the fourth test code 03 is sent for the second time, all the fan motors of the air conditioner indoor units are turned on;

[0063] When the fifth test code 04 is sent for the first time, all the indoor air conditioner display screens are turned off. If the EMI is no longer excessive, the interference mainly comes from the display-related circuits; if the EMI is still excessive, the interference mainly comes from other loads in the indoor unit. When the fifth test code 04 is sent for the second time, all the indoor air conditioner display screens are turned on.

[0064] When the sixth test code 05 is sent for the first time, all compressors of the air conditioner outdoor units are turned off. If the EMI is no longer excessive, the main source of interference is the compressor or its drive circuit; if the EMI is still excessive, the main source of interference is other loads of the outdoor unit. When the sixth test code 05 is sent for the second time, all compressors of the air conditioner outdoor units are turned on.

[0065] When the seventh test code 06 is sent for the first time, all the fan motors of the air conditioner outdoor units are turned off. If the EMI is no longer excessive, the interference mainly comes from the outdoor fan motor or its drive circuit; if the EMI is still excessive, the interference mainly comes from other loads of the outdoor unit. When the seventh test code 06 is sent for the second time, all the fan motors of the air conditioner outdoor units are turned on.

[0066] When the eighth test code 07 is sent for the first time, the PFC (Power Factor Correction) of the air conditioner outdoor unit is turned off. If the EMI is no longer excessive, the interference mainly comes from the PFC circuit of the outdoor unit; if the EMI is still excessive, the interference mainly comes from other loads of the outdoor unit. When the eighth test code 07 is sent for the second time, the PFC of the air conditioner outdoor unit is turned on;

[0067] When the ninth test code 08 is sent for the first time, the four-way valve of the air conditioner outdoor unit is closed. If the EMI is no longer excessive, the interference mainly comes from the four-way valve related circuit; if the EMI is still excessive, the interference mainly comes from other loads of the outdoor unit. When the ninth test code 08 is sent for the second time, the four-way valve of the air conditioner outdoor unit is opened.

[0068] During specific operation, the sending button of the test code can be integrated into the air-conditioning remote controller, and the operation mode of the air-conditioning load can be controlled by the air-conditioning remote controller, which is more convenient.

[0069] In step 3, the setting of corresponding operation protection conditions specifically includes:

[0070] The maximum operating frequency of the compressor is set to be lower than the first threshold frequency, the shutdown protection current of the compressor is set to be lower than the first threshold shutdown protection current, and a safe operation time is set for the air-conditioning load operation, and the normal operation mode is automatically restored after the safe operation time is reached.

[0071] Specifically, when sending EMI test code 01 and EMI test code 03, because the indoor fan motor is not running, and the outdoor compressor and other loads are fully turned on, the indoor heat exchanger will have poor heat exchange due to lack of wind. If it is in cooling mode, the indoor heat exchanger will be overcooled and condensed; if it is in heating mode, the indoor heat exchanger will be overheated and easily oxidized, and the pressure in the pipeline will increase, leading to safety hazards such as refrigerant leakage and pipeline bursting. Therefore, it is necessary to set safe operating conditions and optimize the control:

[0072] (1) Limit the load operating capacity of the air conditioner compressor and reduce the operating capacity to prevent the system pressure from increasing rapidly. For example, change the maximum operating frequency of the compressor from 80Hz to 60Hz during cooling.

[0073] (2) Adjust the system protection parameter range and appropriately widen the system protection parameter range. For example, for a 1.5-horsepower air conditioner, when in normal cooling, the outdoor unit will shut down when the operating current reaches 5A; when the indoor unit fan load is turned off, the outdoor unit will shut down when the operating current reaches 7A. This prevents the air conditioner from shutting down quickly and not being able to observe and test the EMI data in time.

[0074] (3) Set an air conditioner safety operation time for the fan load. If the tester does not manually restore the normal operation of the load within the safety operation time, the air conditioner will automatically restore the indoor unit fan load operation when the safety operation time is reached (for example, 40 seconds).

[0075] According to the above method, other EMI test codes can be sent, other loads can be operated and shut down one by one, and the EMI test data under different load operation conditions can be observed to assist testers in determining the cause of the air conditioner's EMI exceeding the standard.

[0076] In summary, the present invention improves the accuracy of EMI detection, reduces costs, and greatly reduces safety risks in testing.

Claims

1. Air conditioner EMI test method, characterized in that: include: Step 1: Pre-store a corresponding relationship table of defined EMI test codes and air conditioning load on / off in the air conditioning control software; The correspondence between the EMI test code and the air conditioning load operation mode includes: The first test code corresponds to the on / off of all loads of the indoor and outdoor units of the air conditioner; The second test code corresponds to the on / off of all loads of the air conditioner indoor unit; The third test code corresponds to the on / off of all loads of the air conditioner outdoor unit; The fourth test code corresponds to the on / off of the fan motor of the air conditioner indoor unit; The fifth test code corresponds to the on / off switching of the air conditioner indoor unit display screen; The sixth test code corresponds to the on / off of the air conditioner outdoor unit compressor; The seventh test code corresponds to the on / off of the air conditioner outdoor unit fan motor; The eighth test code corresponds to the on / off of the PFC of the air conditioner outdoor unit; The ninth test code corresponds to the opening / closing of the four-way valve of the air conditioner outdoor unit; Step 2: Send the EMI test code to select the corresponding air conditioning load operation mode; Step 3: operate the corresponding air-conditioning load according to the corresponding air-conditioning load operation mode, and set the corresponding operation protection conditions; Step 4: Check whether the EMI value of the running air conditioner load exceeds the standard. If so, record the EMI exceeding the standard; otherwise, record the test passed.

2. The air conditioner EMI testing method according to claim 1, characterized in that: In step 2, sending the EMI test code to select the corresponding air conditioning load operation mode specifically includes: When the EMI test code is sent for the first time, all corresponding air-conditioning loads are turned off. When the same EMI test code is sent for the second time, all corresponding air-conditioning loads are turned on.

3. The air conditioner EMI testing method according to claim 2, characterized in that: The specific operation method of sending the EMI test code for the first time, then all corresponding air conditioning loads are turned off, and sending the same EMI test code for the second time, then all corresponding air conditioning loads are turned on includes: When the first test code is sent for the first time, all loads of the indoor and outdoor units of the air conditioner are turned off. When the first test code is sent for the second time, all loads of the indoor and outdoor units of the air conditioner are turned on. When the second test code is sent for the first time, all loads of the air conditioner indoor unit are turned off, and when the second test code is sent for the second time, all loads of the air conditioner indoor unit are turned on; When the third test code is sent for the first time, all loads of the air conditioner outdoor unit are turned off, and when the third test code is sent for the second time, all loads of the air conditioner outdoor unit are turned on; When the fourth test code is sent for the first time, the fan motors of the indoor units of the air conditioners are all turned off, and when the fourth test code is sent for the second time, the fan motors of the indoor units of the air conditioners are all turned on; When the fifth test code is sent for the first time, all the indoor air conditioner display screens are turned off. When the fifth test code is sent for the second time, all the indoor air conditioner display screens are turned on. When the sixth test code is sent for the first time, the compressors of the air conditioner outdoor units are all turned off, and when the sixth test code is sent for the second time, the compressors of the air conditioner outdoor units are all turned on; When the seventh test code is sent for the first time, the fan motors of the air conditioner outdoor units are all turned off, and when the seventh test code is sent for the second time, the fan motors of the air conditioner outdoor units are all turned on; When the eighth test code is sent for the first time, the PFC of the air conditioner outdoor unit is turned off, and when the eighth test code is sent for the second time, the PFC of the air conditioner outdoor unit is turned on; When the ninth test code is sent for the first time, the four-way valve of the air-conditioning outdoor unit is closed, and when the ninth test code is sent for the second time, the four-way valve of the air-conditioning outdoor unit is opened.

4. The air conditioner EMI testing method according to claim 3, characterized in that: In step 3, the setting of corresponding operation protection conditions specifically includes: The maximum operating frequency of the compressor is set to be lower than the first threshold frequency, the shutdown protection current of the compressor is set to be lower than the first threshold shutdown protection current, and a safe operation time is set for the air-conditioning load operation, and the normal operation mode is automatically restored after the safe operation time is reached.

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