A fan testing system, testing method and testing device thereof

Abstract

The application relates to a fan testing system, a testing method and a testing device thereof, four to six channel independent power supply is realized through a programmable direct current power supply module, adaptive testing of 12V / 24V voltage specification fans is supported, a single fan testing channel is integrated with a fan interface, a PWM driving circuit, a current sampling loop and an FG waveform acquisition circuit, current and rotating speed signals are synchronously collected through a high-speed converter, PWM parameters and FG pull-up modes are configured in an initialization stage, current surge and rotating speed waveforms are synchronously collected after starting, current effective value, rotating speed, waveform width ratio / height ratio are calculated in real time, and the actually measured waveform is compared with a standard waveform through a cross-correlation algorithm, limit testing is supported, fan power supply adaptability is evaluated, a testing report containing a Pass / Fail conclusion is finally generated, and a factory quality management system is connected, a single-chip microcomputer and an industrial computer are communicated through LAN, testing parameters are issued, waveforms are displayed in real time, and testing results are automatically uploaded to a user MES system, and the application has the effect of improving fan testing efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fan testing, and in particular to a fan testing system, a testing method and a testing device thereof. BACKGROUND

[0002] At present, single-channel or double-channel testing equipment is generally used in the field of fan performance testing, and the hardware architecture is fixed and the number of channels is limited. The traditional scheme adjusts the power supply voltage manually and manually switches the resistance network to match the fan feedback signal (such as the pull-up level of the FG speed signal), which results in a single test time of more than 5 minutes, and only 1-2 fans can be tested in parallel. For mass-produced products such as computer cooling fans, such a scheme cannot meet the needs of the flow line batch detection, especially when mixed-line production of multi-specification fans, frequent hardware adjustment is easy to introduce operation errors, and the test efficiency is more than 60% lower than the automation requirement. In addition, the single-channel design leads to high hardware cost, which is difficult to meet the efficiency requirements in large-scale production scenarios. SUMMARY

[0003] In order to improve the test efficiency of the fan, the present application provides a fan testing system, a testing method and a testing device thereof.

[0004] The fan testing system, the testing method and the testing device thereof provided by the present application adopt the following technical solutions:

[0005] First aspect

[0006] A fan testing system, comprising a programmable DC power supply module, a fan testing channel module, a single-chip microcomputer and an industrial computer;

[0007] The programmable DC power supply module is electrically connected to the fan through a wire, is used to output an adjustable voltage to the fan, and is connected to the single-chip microcomputer through a digital signal control line to receive a voltage adjustment instruction;

[0008] The fan testing channel module comprises a fan interface, a PWM drive circuit, a current sampling loop and an FG waveform acquisition circuit;

[0009] The fan interface comprises a power supply pin, a PWM control pin and an FG feedback pin, and is used to physically connect the fan;

[0010] The input end of the PWM drive circuit is connected to the single-chip microcomputer, and the output end is connected to the PWM control pin, which is used to amplify the PWM signal generated by the single-chip microcomputer to drive the fan;

[0011] A high-speed A / D converter is connected between the current sampling loop and the single-chip microcomputer, one end of the current sampling loop is connected to the negative electrode of the programmable DC power supply module, and the other end is grounded, and the current sampling loop is used to input a voltage signal to the high-speed A / D converter;

[0012] The FG feedback pin is connected with the single-chip microcomputer through a pull-up resistor network.

[0013] The single-chip microcomputer communicates with the industrial computer through a LAN interface, for generating a PWM signal, controlling a programmable DC power supply module, collecting current and FG signals through the high-speed A / D converter, and calculating current effective value, FG rotating speed and waveform parameters in real time.

[0014] The industrial computer is used for configuring test parameters, displaying waveform data, and uploading test results to an MES system through a TCP / IP protocol.

[0015] By adopting the above technical solution, the programmable DC power supply module is physically connected with the fan structure, compatible power supply for fans of different voltage specifications is realized, the PWM driving circuit drives the fan to rotate, the probability of occurrence of the situation that the fan is damaged due to large current impact is reduced, the FG waveform acquisition circuit can filter out high-frequency noise, and the reliability of the rotating speed signal is improved, the LAN communication architecture of the single-chip microcomputer and the industrial computer supports real-time data interaction and remote control, at the same time, the test results are uploaded to the MES system through the TCP / IP protocol, realizing automatic tracing of the test results, and the system can support multi-channel expansion and adapt to fan test requirements of different needs.

[0016] Preferably, the pull-up resistor network comprises a first resistor, a second resistor and a third resistor connected in series, one end of the first resistor away from the second resistor is connected to the programmable DC power supply module through an analog switch, and one end of the third resistor away from the second resistor is grounded.

[0017] By adopting the above technical solution, the pull-up mode of the first resistor, the second resistor and the third resistor is switched through the analog switch, the FG signal level standard of fans of different specifications is flexibly adapted, the compatibility problem caused by the traditional fixed pull-up resistor is avoided, the cost of hardware re-soldering or resistor replacement is reduced, and the universality is improved.

[0018] Preferably, the resolution of the high-speed A / D converter is ≥12 bits, and the sampling rate is ≥10 kHz, an operational amplifier is connected between the current sampling circuit and the single-chip microcomputer, the analog channel of the high-speed A / D converter is connected to the output end of the operational amplifier and the output end of the FG waveform acquisition circuit respectively, and the digital channel is connected to the single-chip microcomputer.

[0019] By adopting the above technical solution, a high-precision quantization of current / voltage signals can be realized by a resolution of 12 bits or more, and current inrush and rotating speed fluctuation at the moment of fan start can be captured by cooperating with a sampling rate of 10 kHz or more.

[0020] Preferably, the output voltage precision of the programmable DC power supply module is ±0.1%, and the ripple is ≤50mV, to receive the single-chip microcomputer instruction, support multi-channel independent power supply, and connect each channel to the fan interface through a wire.

[0021] By adopting the technical scheme, the voltage precision of ±0.1% and the ripple of ≤50mV ensure the stability of the test power supply, and avoid introducing additional errors due to power supply fluctuation.

[0022] The second aspect

[0023] A fan testing device includes a test bench and a circuit board, the test bench is provided with a fan interface panel and a state indicator lamp, and the circuit board integrates the programmable DC power supply module, the single-chip microcomputer, the high-speed A / D converter and the fan testing channel module in the first aspect, the current and the FG signal are connected to the high-speed A / D converter in parallel through an analog switch, the common end of the analog switch is connected to the analog channel of the high-speed A / D converter, and the address end of the analog switch is connected to the single-chip microcomputer.

[0024] By adopting the technical scheme, the test bench and the circuit board are integrated, the programmable power supply module, the single-chip microcomputer, the A / D converter and the fan testing channel module are modularly packaged, and the fan interface panel is combined with the analog switch to realize parallel collection and time-sharing multiplexing of 4-6 channel signals.

[0025] Preferably, the state indicator lamp is electrically connected to the single-chip microcomputer, includes a normal indicator lamp and an abnormal indicator lamp, and is used for indicating the test result of the fan.

[0026] By adopting the technical scheme, the linkage design of the state indicator lamp and the single-chip microcomputer provides intuitive test feedback, the operator can quickly locate the faulty fan through the indicator lamp, does not need to check the computer interface one by one, and reduces the risk of misoperation.

[0027] The third aspect

[0028] A fan testing method applies the fan testing system in the first aspect, and includes the following steps: S1, parameter configuration: an industrial computer sends an instruction to a single-chip microcomputer through a LAN, sets the output voltage of a programmable DC power supply module, the PWM frequency and the duty cycle of the single-chip microcomputer, and selects an FG pull-up resistor mode through an analog switch;

[0029] S2, signal collection: the single-chip microcomputer outputs a PWM signal to drive the fan to work, and a high-speed A / D converter synchronously collects a voltage signal and an FG feedback signal of a current sampling loop;

[0030] S3, data processing: the single-chip microcomputer calculates the effective value of the current, calculates the rotating speed through the FG signal period, analyzes the width / height ratio of the waveform, and the industrial computer compares the measured waveform with a preset standard waveform, and marks the abnormality.

[0031] S4, result output: the industrial computer generates a test report containing Pass / Fail conclusion, and automatically uploads the result to the MES system through TCP / IP protocol.

[0032] By adopting the above technical solutions, the whole process automation from parameter configuration, signal acquisition to data processing is realized, and the manual operation error is eliminated. For example, the industrial computer automatically issues PWM parameters through LAN to avoid manual input error; the high-speed A / D synchronous acquisition of current and speed signals ensures the consistency of data time stamp, facilitating subsequent waveform correlation analysis. The automatic generation of test report and the uploading to the MES system realize the seamless traceability of test data, which meets the requirements of ISO 9001 quality management system.

[0033] Preferably, in S2, when the fan starts, the single-chip microcomputer captures the inrush current peak value of the current sampling loop at a sampling rate of 10 kHz, and if the inrush current peak value exceeds 150% of the rated current, it is determined that the start is abnormal.

[0034] By adopting the above technical solutions, the current peak value is captured at a sampling rate of 10 kHz during the fan starting stage, which can effectively identify potential defects such as motor winding short circuit and bearing jam.

[0035] Preferably, in S3, the industrial computer calculates the similarity of the measured waveform and the standard waveform through cross-correlation algorithm, and triggers an alarm when the similarity is less than 90%, while recording the time stamp and parameter deviation value of the abnormal point.

[0036] By adopting the above technical solutions, the cross-correlation algorithm calculates the Pearson correlation coefficient of the measured waveform and the standard waveform to quantitatively evaluate the signal consistency. When the similarity is less than 90%, the system automatically marks the waveform distortion point (such as FG signal pulse loss, current ripple is too large), and records the time stamp and parameter deviation.

[0037] Preferably, it further includes a limit test link, which simulates ±10% rated voltage fluctuation through a programmable DC power supply module, with a duration of ≥2min, and collects the current ripple coefficient and speed fluctuation ratio of the fan under voltage fluctuation.

[0038] By adopting the above technical solutions, by simulating ±10% rated voltage fluctuation and testing for more than 1 minute, the adaptability of the fan under unstable power grid or aged power supply can be evaluated. This test link fills the gap of conventional no-load test, and ensures the long-term reliable operation of the fan under complex working conditions.

[0039] In summary, the present application has the following at least one beneficial technical effect:

[0040] 1. Independent power supply and precise voltage regulation are achieved through a programmable DC power supply module, combined with an analog switch switching mechanism using an FG pull-up resistor, making it compatible with fans of different voltage specifications;

[0041] 2. The high-speed A / D converter captures the details of current and speed waveforms in real time. Combined with the surge current peak detection, waveform parameter calculation and cross-correlation similarity algorithm of the microcontroller, it can accurately identify hidden defects such as abnormal fan start-up, speed fluctuation and signal distortion.

[0042] 3. Seamless integration between the industrial control computer and the MES system enables end-to-end digitalization from data acquisition and report generation to quality traceability. Test results are automatically generated into PDF reports with Pass / Fail conclusions, avoiding errors from manual recording and meeting ISO9001 traceability requirements. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the overall structure of a fan testing device according to this application.

[0044] Figure 2 This is a flowchart of a fan testing method according to this application.

[0045] Figure 3 This is an example diagram of the display interface of a fan testing system on an industrial control computer according to this application.

[0046] Figure 4 This is a schematic diagram of signal transmission between the modules of a fan testing system according to this application.

[0047] Figure 5 This is a system interface diagram of a fan testing system according to this application.

[0048] Explanation of reference numerals in the attached diagram: 1. Test bench; 2. Fan interface panel; 3. Status information, etc.; 31. Normal indicator light; 32. Abnormal indicator light; JP1. Fan interface; JP2. Programmable DC power supply module; RS2. Sampling resistor; R1. First resistor; R2. Second resistor; R3. Third resistor; R61. Current limiting resistor. Detailed Implementation

[0049] The following is in conjunction with the appendix Figures 1-5 This application will be described in further detail.

[0050] First, this application discloses a fan testing system, referring to... Figure 3 and Figure 4The system includes a programmable DC power supply module JP2, a fan test channel module, a microcontroller, and an industrial control computer. The programmable DC power supply module JP2 is electrically connected to the fan via wires, outputting an adjustable voltage to drive the fan. It connects to the microcontroller via a digital signal control line to receive voltage adjustment commands. The fan test channel module includes a fan interface JP1, a PWM drive circuit, a current sampling circuit, and an FG waveform acquisition circuit. The fan interface includes power pins, PWM control pins, and FG feedback pins for physical connection to the fan. The input of the PWM drive circuit is connected to the microcontroller, and its output is connected to the PWM control pin to amplify the PWM signal generated by the microcontroller to drive the fan. A high-speed A / D converter is connected between the fan, the current sampling circuit, and the microcontroller. One end of the current sampling circuit is connected to the negative terminal of the programmable DC power supply module, and the other end is grounded. The current sampling circuit is used to input the voltage signal into the high-speed A / D converter. The FG feedback pin is connected to the microcontroller via a pull-up resistor network. The microcontroller communicates with the industrial control computer through the LAN interface to generate PWM signals, control the programmable DC power supply module JP2, collect current and FG signals through the high-speed A / D converter, and calculate the effective value of the current, the FG speed, and waveform parameters. The industrial control computer is used to configure test parameters, display waveform data, and upload the test structure to the MES system via the TCP / IP protocol.

[0051] Specifically, the fan interface JP1 is equipped with a PWM pin, an FG pin, a FAN+ pin, and a FAN- pin for connecting to the fan. The FAN+ programmable DC power supply module JP2 is connected to the positive power supply pin FAN+ of the fan interface JP1 via a wire, providing the fan interface JP1 with a voltage compatible with the fan's voltage specifications. The programmable DC power supply module JP2 is also connected to the microcontroller via a digital signal control line to receive voltage regulation commands sent by the microcontroller (MCU processor).

[0052] It should be noted that the high-speed A / D converter includes A / D FG waveform acquisition and A / D current waveform acquisition. Since they are integrated into the same high-speed A / D converter, the following instructions will not distinguish between them.

[0053] Further, the current sampling circuit comprises a sampling resistor RS2, an operational amplifier and a high-speed A / D converter, one end of the sampling resistor RS2 is connected to the FAN-pin of the fan interface JP1, the other end is suspended, the 3-pin of the operational amplifier is connected between the FAN-pin of the fan interface JP1 and the sampling resistor RS2, the 2-pin of the operational amplifier is connected to the suspended end of the sampling resistor RS2, and the high-speed A / D converter is connected between the 1-pin of the operational amplifier and the single-chip microcomputer, thus the voltage signal between the two ends of the sampling resistor RS2 is input to the non-inverting input terminal of the operational amplifier, the inverting input terminal is suspended, and the output terminal transmits the amplified voltage signal (such as 0-5V) to the analog channel of the high-speed A / D converter, the high-speed A / D converter converts the analog voltage signal into a digital signal and transmits it to the single-chip microcomputer through the data bus.

[0054] The pull-up resistor network comprises a first resistor R1, a second resistor R2 and a third resistor R3 connected in series, one end of the first resistor R1 away from the second resistor R2 is connected to the programmable DC power module JP2 through an analog switch, and one end of the third resistor away from the second resistor is suspended and grounded. The FG-pin of the fan interface JP1 is connected between the first resistor R1 and the second resistor R2, the voltage signal of the FG-pin of the fan interface passes through the pull-up resistor network, filters out high-frequency noise, and the high-speed A / D converter is connected between the second resistor R2 and the third resistor R3, and the output is transmitted to the single-chip microcomputer after filtering out high-frequency noise, so as to realize the measurement of the signal frequency.

[0055] The pull-up resistor network has three working modes. When one end of the first resistor R1 is connected to the programmable DC power module JP2 and the other end is connected to the FG-pin of the fan interface JP1 through an analog switch, it corresponds to the "fan voltage high" mode; when one end of the second resistor R2 is connected to the 5V voltage provided by the system and the other end is connected to the FG-pin of the fan interface JP1 through an analog switch, it corresponds to the "system 5V high" mode; when one end of the third resistor R3 is suspended and the other end is connected to the FG-pin of the fan interface JP1 through an analog switch, it corresponds to the "suspended" mode. The control end of the analog switch is connected to the single-chip microcomputer, and the pull-up mode is switched through the level signal.

[0056] It should be noted that the PWM driving circuit is a conventional driving circuit, which is provided with a current-limiting resistor R61 connected to the PWM-pin of the fan interface JP1 to amplify the PWM signal into the driving current required by the fan, which will not be described in detail here.

[0057] Correspondingly, the resolution of the high-speed A / D converter is greater than or equal to 12 bits, the sampling rate is greater than or equal to 10 kHz, an operational amplifier is connected between the current sampling circuit and the single-chip microcomputer, the analog channel of the high-speed A / D converter is connected to the output end of the operational amplifier and the output end of the FG waveform acquisition circuit respectively, and the digital channel is connected to the single-chip microcomputer. The high-precision quantization of the current / voltage signal can be realized by the resolution of more than 12 bits, and the current surge and speed fluctuation at the instant of fan starting can be captured by the sampling rate of more than 10 kHz.

[0058] Meanwhile, the output voltage precision of the programmable DC power module is ±0.1%, and the ripple is less than or equal to 50 mV, so as to receive the instructions of the single-chip microcomputer, support multi-channel independent power supply, and connect each channel to the fan interface through a wire. The voltage precision of ±0.1% and the ripple of less than or equal to 50 mV ensure the stability of the test power supply, and avoid introducing additional errors due to power fluctuations.

[0059] Further, the embodiment of the application discloses a fan testing device, referring to Figure 1 , which comprises a test table 1 and a circuit board. The test table is provided with a fan interface JP1 panel 2 and a state indicator 3. The circuit board integrates a programmable DC power module JP2, a single-chip microcomputer, a high-speed A / D converter and a fan testing channel module of a fan testing system. The current and FG signals are connected in parallel to the high-speed A / D converter through an analog switch. The common end of the analog switch is connected to the analog channel of the high-speed A / D converter. The address end of the analog switch is connected to the single-chip microcomputer. The test table 1 and the circuit board are integrated. The programmable power module, the single-chip microcomputer, the A / D converter and the fan testing channel module are modularly packaged. The analog switch realizes the parallel acquisition and time division multiplexing of 4-6 channel signals in cooperation with the fan interface panel.

[0060] Correspondingly, the state indicator 3 is electrically connected to the single-chip microcomputer and comprises a normal indicator 31 and an abnormal indicator 32, which are used for indicating the test result of the fan. The linkage design of the state indicator and the single-chip microcomputer provides intuitive test feedback. The operator can quickly locate the faulty fan through the indicator without checking the computer interface one by one, thereby reducing the risk of misoperation.

[0061] In a third aspect, a fan testing method is disclosed, referring to Figures 2-5 , which is applied to the fan testing system and comprises the following steps.

[0062] S1, parameter configuration: the industrial computer sends instructions to the single-chip microcomputer through LAN, sets the output voltage of the programmable DC power module, the PWM frequency and the duty cycle of the single-chip microcomputer, and selects the FG pull-up resistor mode through the analog switch;

[0063] The industrial computer sends instructions (such as "channel 1 voltage = 12V, PWM frequency = 25kHz, duty cycle = 50%") to the single-chip microcomputer through the LAN interface, and the single-chip microcomputer transmits the instructions to the programmable DC power supply module JP2 to adjust the output voltage to the rated value of the fan,

[0064] S2, signal acquisition: the single-chip microcomputer outputs a PWM signal to drive the fan to work, and a high-speed A / D converter synchronously acquires the voltage signal of the current sampling loop and the FG feedback signal; the single-chip microcomputer sends a level signal to the analog switch according to the fan model to switch the FG pull-up resistor working mode.

[0065] The single-chip microcomputer outputs a PWM signal, which is limited by the current-limiting resistor R61 to drive the fan PWM pin. The power device works in switch mode, adjusts the voltage across the fan, and the fan start-up current is sampled through the sampling resistor RS2 to generate a voltage signal input to the A / D converter. The FG signal is filtered and input to the single-chip microcomputer to measure the square wave period.

[0066] S3, data processing: the single-chip microcomputer calculates the current effective value, calculates the speed through the FG signal period, and analyzes the waveform width / height ratio. The industrial computer compares the measured waveform with the preset standard waveform and marks the abnormality.

[0067] Current effective value: the root mean square of 100 sampling points is calculated, formula: , error <0.5%, error <0.5%.

[0068] Among them, is the i-th current instantaneous value (unit: ampere, A) collected by the high-speed A / D converter.

[0069] n: number of sampling points (such as 100 points, corresponding to a 10ms sampling duration, sampling rate 10kHz).

[0070] Speed calculation: if the fan outputs three FG pulses per revolution, and the measured period is 50ms, the formula is: , where the period is a complete waveform period of the FG signal (unit: seconds, s), which is measured by the single-chip microcomputer timer.

[0071] Pulse number: the number of FG pulses output by the fan per revolution (determined by the fan structure, such as 3 pulses / revolution), from which the speed is obtained: 60 / (0.05x3)=4000RPM.

[0072] Width / height ratio: calculate the FG waveform high level time / period to evaluate the duty cycle stability.

[0073] Industrial computer waveform analysis: receive 1000-point waveform data uploaded by the single-chip microcomputer, and perform cross-correlation operation with the standard waveform (stored in the database), formula: , similarity < 90% is marked as abnormal.

[0074] wherein, is the amplitude (such as current or FG voltage) of the measured waveform at time ;

[0075] and : the amplitude of the standard waveform at time ;

[0076] : the mean of the measured / standard waveform;

[0077] N: the number of waveform data points (such as 1000 points, corresponding to a time length of 100 ms);

[0078] : the waveform time offset.

[0079] S4, result output: the industrial computer generates a test report containing Pass / Fail conclusion, and automatically uploads the result to the MES system through TCP / IP protocol.

[0080] The industrial computer encapsulates the test result (such as current 3.2A, speed 1200RPM, Pass) into JSON format, and uploads it to the "fan test" database table of the MES system through TCP / IP protocol, and associates the fan SN code with the production line station number.

[0081] Wherein, in S2, when the fan starts, the single-chip microcomputer captures the inrush current peak value of the current sampling loop at a sampling rate of 10 kHz, and if the inrush current peak value exceeds 150% of the rated current, it is determined that the start is abnormal. The current peak value is captured at a sampling rate of 10 kHz during the fan start-up stage, which can effectively identify potential defects such as motor winding short circuit and bearing jamming, and generate a PDF report containing waveform comparison chart, parameter list and determination conclusion, supporting electronic signature and printing archive.

[0082] Correspondingly, the single-chip microcomputer triggers high-speed A / D to enter burst sampling mode (sampling rate is increased to 50 kHz) at the same time as the fan start signal (PWM duty cycle from 0%→100%), and continuously collects current data for the first 100 ms. The peak detection algorithm: real-time comparison of current sampling value and historical maximum value, record the starting current peak value (such as rated current 2A fan, threshold is set to 3A), if it exceeds, it is determined as starting abnormality, and the abnormality indicator light works.

[0083] At the same time, for step S3, the industrial computer calculates the similarity of the measured waveform and the standard waveform by the cross-correlation algorithm, and triggers an alarm when the similarity is less than 90%, and records the timestamp and parameter deviation value of the abnormal point. The cross-correlation algorithm quantitatively evaluates the signal consistency by calculating the Pearson correlation coefficient of the measured waveform and the standard waveform. When the similarity is less than 90%, the system automatically marks the waveform distortion point (such as FG signal pulse loss, current ripple too large), and records the timestamp and parameter deviation.

[0084] First, the measured waveform and the standardized waveform need to be de-meaned and normalized to eliminate DC bias and amplitude difference. The 1-second waveform is divided into 10 100ms windows, and the cross-correlation coefficient is calculated window by window. If the similarity of any window is less than 90%, it is determined to be abnormal. When a sharp drop in similarity is detected, the timestamp corresponding to the abnormal point is marked, and the current mutation value and FG frequency jump value at that time are extracted.

[0085] In addition, it also includes a limit test link. A programmable DC power module JP2 simulates ±10% rated voltage fluctuation with a duration of ≥2min. The current ripple coefficient and speed fluctuation ratio of the fan under voltage fluctuation are collected. The programmable DC power module JP2 receives single-chip microcomputer instructions, superimposes ±10% disturbance on the basis of the rated voltage (such as 12V fan test voltage circulating between 10.8V-13.2V) with a period of 100 milliseconds, and lasts for 2 minutes. The single-chip microcomputer collects current ripple (effective value) and FG period fluctuation at a sampling rate of 2kHz. Thus,

[0086] Current ripple coefficient: (standard value ≤8%);

[0087] Wherein, : The effective value of the current ripple (unit: A), that is, the amplitude of the alternating component.

[0088] : The average value of the DC component of the current (unit: A).

[0089] Rotational fluctuation rate: ;

[0090] Wherein, : The maximum / minimum speed during the test (unit: RPM).

[0091] : The average speed during the test (unit: RPM)

[0092] If the current ripple coefficient is >15% or the speed fluctuation rate is >10%, it is determined that the fan power supply suppression capability is insufficient.

[0093] The implementation principle of the fan test system, test method and test device of the embodiment of the application is as follows: a programmable DC power supply module JP is used to provide adjustable voltage for the fan and support multi-channel expansion, a PWM drive circuit in the fan test channel module receives a PWM signal generated by a single-chip microcomputer through a current limiting resistor R61 to drive the fan, a current sampling loop collects a current signal through a sampling resistor RS2 and an operational amplifier, an FG waveform acquisition circuit acquires a speed feedback signal by using a pull-up resistor network (a first resistor R1 / a second resistor R2 / a third resistor R3) in combination with an analog switch switching mode, the two types of signals are transmitted to the single-chip microcomputer through a high-speed A / D converter to calculate data such as current effective value, speed, waveform parameters and the like in real time, an industrial computer receives data through a LAN interface and performs waveform comparison, cross-correlation analysis and the like, and simultaneously uploads test results to a MES system through a TCP / IP protocol; the test method covers parameter configuration, multi-channel synchronous acquisition, start-up surge detection, limit condition simulation (such as ±10% voltage fluctuation) and automatic report generation, realizes precise test and digital management of performance indexes such as fan current, speed and stability, and improves test efficiency, compatibility and intelligent level through hardware modular design and software algorithm optimization.

[0094] The above are preferred embodiments of the application, and do not limit the protection scope of the application, so that: equivalent changes made according to the structure, shape, principle of the application should be covered within the protection scope of the application.

Claims

1. A fan testing system, characterized in that: This includes a programmable DC power supply module, a fan test channel module, a microcontroller, and an industrial control computer; The programmable DC power supply module is electrically connected to the fan via a wire to output an adjustable voltage to the fan, and is connected to the microcontroller via a digital signal control line to receive voltage regulation commands. The fan test channel module includes a fan interface, a PWM drive circuit, a current sampling loop, and an FG waveform acquisition circuit. The fan interface includes a power pin, a PWM control pin, and an FG feedback pin, which are used to physically connect the fan. The input terminal of the PWM drive circuit is connected to the microcontroller, and the output terminal is connected to the PWM control pin, which is used to amplify the PWM signal generated by the microcontroller to drive the fan. A high-speed A / D converter is connected between the current sampling circuit and the microcontroller. One end of the current sampling circuit is connected to the negative terminal of the programmable DC power supply module, and the other end is grounded. The current sampling circuit is used to input the voltage signal into the high-speed A / D converter. A pull-up resistor network is connected between the FG feedback pin and the microcontroller. The microcontroller communicates with the industrial control computer via a LAN interface to generate PWM signals, control the programmable DC power supply module, acquire current and FG signals through the high-speed A / D converter, and calculate the effective value of current, FG speed, and waveform parameters in real time. The industrial control computer is used to configure test parameters, display waveform data, and upload test results to the MES system via TCP / IP protocol. The pull-up resistor network includes a first resistor, a second resistor, and a third resistor connected in series. The end of the first resistor away from the second resistor is connected to the programmable DC power supply module via an analog switch. The end of the third resistor away from the second resistor is grounded. There are three working modes for the pull-up resistor network. When one end of the first resistor is connected to the programmable DC power supply module and the other end is connected to the FG pin of the fan interface through an analog switch, it corresponds to the fan voltage master mode. When one end of the second resistor is connected to the 5V voltage provided by the system and the other end is connected to the FG pin of the fan interface through an analog switch, it corresponds to the system 5V master mode. When one end of the third resistor is floating and the other end is connected to the FG pin of the fan interface through an analog switch, it corresponds to the floating mode. The control terminal of the analog switch is connected to the microcontroller, and the pull-up mode is switched through the level signal.

2. The fan testing system according to claim 1, characterized in that: The high-speed A / D converter has a resolution of ≥12 bits and a sampling rate of ≥10kHz. An operational amplifier is connected between the current sampling circuit and the microcontroller. The analog channels of the high-speed A / D converter are respectively connected to the output terminal of the operational amplifier and the output terminal of the FG waveform acquisition circuit, and the digital channels are connected to the microcontroller.

3. The fan testing system according to claim 1, characterized in that: The programmable DC power supply module has an output voltage accuracy of ±0.1% and a ripple of ≤50mV. It can receive instructions from the microcontroller and supports independent power supply for multiple channels. Each channel is connected to the fan interface through wires.

4. A fan testing device, characterized in that: The device includes a test bench and a circuit board. The test bench is equipped with a fan interface panel and status indicator lights. The circuit board integrates the programmable DC power supply module, microcontroller, high-speed A / D converter, and fan test channel module as described in any one of claims 1-3. Its current and FG signal are connected in parallel to the high-speed A / D converter through an analog switch. The common terminal of the analog switch is connected to the analog channel of the high-speed A / D converter, and the address terminal of the analog switch is connected to the microcontroller.

5. The testing apparatus according to claim 4, characterized in that: The status indicator lights are electrically connected to the microcontroller and include normal indicator lights and abnormal indicator lights, used to indicate the test results of the fan.

6. A fan testing method, applied to the fan testing system according to any one of claims 1-3, characterized in that, include: S1. Parameter configuration: The industrial control computer sends instructions to the microcontroller via LAN to set the output voltage of the programmable DC power supply module, the PWM frequency and duty cycle of the microcontroller, and selects the FG pull-up resistor mode through the analog switch. S2. Signal Acquisition: The microcontroller outputs a PWM signal to drive the fan, and the high-speed A / D converter synchronously acquires the voltage signal of the current sampling circuit and the FG feedback signal. S3. Data Processing: The microcontroller calculates the effective value of the current, calculates the rotational speed through the FG signal cycle, and analyzes the waveform width-to-width ratio / high-to-low ratio. The industrial control computer compares the measured waveform with the preset standard waveform and marks the abnormality. S4. Result Output: The industrial control computer generates a test report containing Pass / Fail conclusions and automatically uploads the results to the MES system via TCP / IP protocol.

7. The fan testing method according to claim 6, characterized in that, In S2, when the fan starts, the microcontroller captures the peak value of the surge current in the current sampling circuit at a sampling rate of 10kHz. If the peak value of the surge current exceeds 150% of the rated current, the start-up is determined to be abnormal.

8. The test method according to claim 6, characterized in that: In step S3, the industrial control computer calculates the similarity between the measured waveform and the standard waveform using a cross-correlation algorithm. When the similarity is less than 90%, an alarm is triggered, and the timestamps and parameter deviation values ​​of the abnormal points are recorded.

9. The test method according to claim 6, characterized in that: It also includes an extreme test, which uses a programmable DC power supply module to simulate ±10% rated voltage fluctuation for a duration of ≥2 minutes, and collects the current ripple coefficient and speed fluctuation ratio of the fan under voltage fluctuation.

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