APF redundant fan seamless switching and life balance control method and system

Abstract

The application discloses a kind of APF redundancy fan seamless switching and life balance control method and system, it is applied to the APF cabinet being configured with first and second fan, comprising: normal working condition, control two fans time-sharing alternation operation, working fan is operated at the speed of adapting current cabinet temperature rise, standby fan is operated at non-zero low-power standby speed;Real-time record accumulative running time and calculate time difference, when time difference exceeds first threshold value, alternation period is dynamically adjusted according to time difference size to reduce time difference;Detect working fan state, if fault, then immediately the speed of standby fan is promoted to target speed before failure, after reaching, cut off the power supply of failure fan;After switching, obtain cabinet temperature rise, if reach or exceed safety threshold preset proportion, then control fan after switching to operate at the compensation speed greater than target speed. Compared with prior art, the application realizes dynamic life balance and seamless switching, ensures that heat dissipation is not interrupted, life balance and energy saving.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation control technology for active power filters, and in particular to a method and system for seamless switching and lifespan balancing control of redundant APF fans. Background Technology

[0002] Active power filters (APFs) are core devices for harmonic mitigation and reactive power compensation in power systems. During long-term high-load operation in industrial settings, their internal power modules, reactors, capacitors, and other components generate significant heat. The cooling fan, as a critical heat dissipation component, directly determines the stable operation of the entire APF unit. Fan failure can lead to excessive temperature rise within the APF cabinet, accelerating the aging of power devices, triggering system protection shutdowns, and even causing equipment burnout, disrupting industrial production continuity.

[0003] To improve the reliability of the cooling system, some existing APFs use a dual-fan redundant configuration, but this has the following shortcomings: (1) Redundant fans mostly adopt a fixed working mode of "one in use and one in standby". The standby fan is idle for a long time, while the working fan runs under high load continuously, resulting in a huge difference in the lifespan of the two fans. Although the standby fan is not running, it is prone to problems such as bearing jamming and coil aging due to long-term idleness. When it is really necessary to switch, it may not be able to start normally and lose the meaning of redundancy protection. (2) When the working fan fails, the existing switching control has a significant delay. During the switching process, the fan speed drops and the heat dissipation capacity drops sharply. The cabinet temperature rises rapidly in a short time, which may still trigger the APF to reduce load or stop, making it impossible to achieve seamless switching in zero seconds. (3) After switching, the backup fan is simply started without dynamically adjusting the fan speed according to the current cabinet temperature rise and APF load. This results in the heat dissipation capacity not matching the actual heat dissipation demand. Either the heat dissipation is insufficient and accelerates the aging of the equipment, or the heat dissipation is excessive and increases energy consumption and shortens the life of the fan. (4) The lack of an active balance control strategy for the lifespan of the two fans makes it impossible to avoid excessive wear and tear on a single fan, resulting in frequent fan replacements in the redundant system, increasing maintenance costs, and failing to fully utilize the redundancy value of the two fans.

[0004] A search revealed Chinese Patent Publication No. CN111946653A, which discloses a fan management method, system, and server. This solution monitors the performance of each individual rotor fan in a dual-rotor fan system in real time. When one of the individual rotor fans fails, a preset compensation strategy is used to operate the remaining single rotor fans to compensate for the failure and restore the dual-rotor fan to normal performance. However, this compensation strategy uses a fixed-ratio superposition, which may result in insufficient compensation under high-temperature conditions and ineffective energy consumption under low-temperature conditions. Furthermore, the compensation strategy is implemented by directly increasing the duty cycle, lacking a smooth speed-up transition mechanism. In addition, this solution addresses rotor failure within a single dual-rotor fan but does not address the rotation operation and lifespan balancing management among multiple independent redundant fans. Long-term operation may lead to excessive differences in the lifespan of the fans.

[0005] Therefore, how to achieve reliable and rapid fault switching of redundant fans and balanced lifespan management of dual fans in an APF redundant fan system while ensuring uninterrupted heat dissipation is a technical problem that needs to be solved. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art by providing a method and system for seamless switching and life balancing control of APF redundant fans.

[0007] The objective of this invention can be achieved through the following technical solutions: According to a first aspect of the present invention, a method for seamless switching and lifespan balancing control of redundant APF fans is provided, applied to an APF cabinet equipped with a first fan and a second fan, characterized in that it includes: Under normal operating conditions, the first fan and the second fan are controlled to operate alternately in a time-sharing manner; wherein, the currently operating fan operates at a target speed determined according to the real-time temperature rise of the cabinet, and the standby fan continues to operate at a non-zero standby speed lower than the target speed. The cumulative running time of the first fan and the second fan is recorded and updated in real time, and the cumulative running time difference between them is calculated. When the cumulative running time difference exceeds a preset first time difference threshold, the dynamic balancing mode is entered, and the duration of the next alternating running cycle is dynamically adjusted according to the magnitude of the cumulative running time difference in order to reduce the cumulative running time difference. The system monitors the operating status of the current working fan in real time. When it is determined that the current working fan has failed, the speed of the backup fan is increased to the target speed before the failure of the current working fan. After the backup fan reaches the target speed, the power supply to the failed fan is cut off. The real-time temperature rise inside the APF cabinet is obtained. If the real-time temperature rise reaches or exceeds a preset ratio of the safe temperature rise threshold, the fan that has been switched on is controlled to run at a compensation speed greater than the target speed.

[0008] As a preferred technical solution, the specific method for dynamically adjusting the duration of the next alternating operation cycle is as follows: When the cumulative running time difference exceeds a preset first time difference threshold, the duration of the next alternating running cycle is negatively correlated with the cumulative running time difference.

[0009] As a preferred technical solution, the specific calculation method for the next alternating operating cycle is as follows: Set the reference alternation period The current cumulative running time difference is Δ t The preset maximum allowable time difference is ,and Then the next alternating operation cycle ,and Not less than the preset minimum alternation period .

[0010] As a preferred technical solution, in the dynamic balancing mode, when the cumulative running time difference is reduced to below the preset second time difference threshold, the dynamic balancing mode is automatically exited and the operation is restored to the benchmark alternation cycle.

[0011] As a preferred technical solution, the real-time detection of the current operating status of the fan specifically includes: Real-time acquisition of the current operating fan speed, operating current, and vibration amplitude; The current operating fan is deemed to have malfunctioned if any of the following conditions are met and the duration exceeds a preset time: The absolute value of the deviation between the actual speed and the target speed is greater than or equal to the speed deviation threshold; The absolute value of the deviation between the actual operating current and the rated current is greater than or equal to the current deviation threshold. The vibration amplitude is greater than or equal to the vibration threshold.

[0012] As a preferred technical solution, the compensation speed is the target speed multiplied by a preset compensation coefficient; when the real-time temperature rises to below the safe temperature rise threshold, the fan that was operating after the control switch exits the overspeed compensation and resumes operation at the target speed.

[0013] As a preferred technical solution, the method further includes: When a faulty fan is detected and replaced with a new one, the initial parameters of the new fan are automatically collected and it is set as the backup fan. The cumulative running time of the new fan is initialized, while the cumulative running time of the original normal fan remains unchanged. The alternation cycle is dynamically adjusted based on the current cumulative running time difference to reduce the cumulative running time difference between the new fan and the original normal fan.

[0014] According to a second aspect of the present invention, a system is provided for implementing the APF redundant fan seamless switching and lifetime balancing control method, comprising: Redundant fan modules, including a first fan and a second fan of the same specifications, are installed in the heat dissipation duct of the APF cabinet; The sensing and detection module includes a speed sensor, a current sensor, and a vibration sensor installed on the two fans, as well as a temperature sensor installed inside the cabinet. The control module is electrically connected to the sensing and detection module and the redundant fan module, and is used to control the alternating operation, life balancing, seamless fault switching and dynamic speed adjustment of the fans. The drive module receives instructions from the control module to drive the two fans to start, stop, and adjust their speed. The alarm and maintenance module is used to issue alarms when a fan fails and push operating data and fault data to the maintenance backend.

[0015] As a preferred technical solution, the control module integrates a cumulative running time recording unit and a time difference comparison unit, which are used to monitor and dynamically adjust the alternation cycle in real time.

[0016] As a preferred technical solution, the alarm and maintenance module is also used to push a lifespan difference alarm reminder to the maintenance backend when the cumulative running time difference exceeds a preset alarm threshold.

[0017] Compared with the prior art, the present invention has the following advantages: 1. This invention records the cumulative running time of redundant fans in real time and calculates the time difference. When the time difference exceeds a threshold, the alternation cycle is dynamically adjusted according to the size of the time difference, which actively reduces the life difference between the two fans and achieves balanced life management of the two fans. At the same time, when the working fan fails, the backup fan is immediately accelerated to the target speed. After the speed is synchronized, the power supply to the failed fan is cut off, achieving seamless switching without interruption of heat dissipation.

[0018] 2. This invention sets the backup fan to a non-zero low-power standby speed. Compared with the traditional completely static standby mode, it can effectively avoid aging problems such as bearing grease solidification and motor starting difficulties caused by long-term fan idleness. At the same time, it can effectively reduce energy consumption compared with full-speed standby, taking into account both fan reliability and energy saving.

[0019] 3. This invention automatically initializes the cumulative running time of the new fan after the fan is replaced and keeps the original fan time unchanged. By shortening the alternation cycle, the time difference is gradually balanced. The new fan can be quickly integrated into the life balance management system without manual intervention, which improves the maintainability and intelligence level of the system.

[0020] 4. This invention performs comprehensive fault detection on both the working fan and the standby fan using multiple parameters such as speed, current, and vibration, and sets differentiated fault response strategies for the two. When the working fan fails, it switches immediately, while when the standby fan fails, it issues an alarm without switching, thereby improving the accuracy of fault detection and the continuity of system operation.

[0021] 5. After the switch is completed, the present invention determines whether to activate overspeed compensation based on the real-time temperature rise of the cabinet. The fan speed is increased to the compensation value only when the temperature rise reaches a certain percentage of the safety threshold. Otherwise, the target speed is maintained, thus achieving a dynamic balance between heat dissipation demand and fan life protection. Attached Figure Description

[0022] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a system architecture diagram of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0024] Example 1: like Figure 1 As shown, this invention provides a method for seamless switching and lifespan balancing control of redundant APF fans, applied to an APF cabinet equipped with a first fan and a second fan of identical specifications. The method includes: Step S1: Start the APF system, initialize the redundant fan system, collect the initial status parameters of the two fans, and confirm that they are normal; set the core control parameters, including the reference alternation cycle, cumulative running time difference threshold, fault judgment threshold, safe temperature rise threshold, dynamic speed-up compensation coefficient range, etc.

[0025] Step S2: Under normal operating conditions, control the two fans to run alternately in a time-sharing manner, and randomly select the working fan and the standby fan; the working fan runs at a speed that adapts to the temperature rise, and the standby fan runs at a low-power standby speed; record the cumulative running time in real time and calculate the time difference; when the time difference exceeds the preset threshold, enter the dynamic balancing mode, and dynamically adjust the duration of the next alternating running cycle according to the size of the time difference to actively reduce the time difference.

[0026] Step S3: Real-time collection of the speed, current, and vibration parameters of the currently operating fan and comparison with the fault threshold to achieve fault detection; at the same time, the same detection is performed on the standby fan, and an alarm is issued and the strategy is adjusted when the standby fan fails.

[0027] Step S4: After detecting a working fan failure, immediately increase the speed of the standby fan to the target speed before the failure. After the speed is synchronized, cut off the power supply to the faulty fan to achieve seamless switching. After switching, obtain the real-time temperature rise of the cabinet. If the temperature rise reaches or exceeds the preset ratio of the safe temperature rise threshold, control the current working fan to run at a compensation speed greater than the target speed until the temperature rises below the safe threshold.

[0028] Step S5: After detecting the connection of a new fan, the initial parameters are automatically collected, the cumulative running time of the new fan is initialized, the cumulative running time of the original fan remains unchanged, and the time difference is gradually balanced by temporarily shortening the alternation cycle to restore normal alternation operation.

[0029] The following provides a detailed description of each step of the present invention.

[0030] Step S1: System initialization and parameter setting.

[0031] After the APF unit is powered on and started, the initial operating parameters of the two fans are obtained. Specifically, the real-time speed of the fans is read through the speed sensor, the operating current of the fans is read through the current sensor, and the vibration amplitude of the fans is read through the vibration sensor. These parameters are compared with the preset normal range. After confirming that there are no abnormalities in the two fans, the normal control process is entered.

[0032] Parameter settings include: Reference alternation period Under normal operating conditions, the basic time for the two fans to work alternately is set to 24 hours by default in this embodiment. It can be adaptively adjusted according to the actual load conditions of the APF. For example, when the APF is in a light load state for a long time, the base period can be appropriately extended to reduce the switching frequency; when the APF is in a heavy load or the load fluctuates frequently, the base period can be appropriately shortened to improve the system responsiveness. Cumulative running time difference thresholds: These include a first time difference threshold, used to trigger dynamic balancing mode; a second time difference threshold, used to exit dynamic balancing mode; and an alarm threshold. These thresholds are used to quantify the difference in the cumulative running time of the two fans and serve as the basis for initiating dynamic cycle adjustment. In this embodiment, the first time difference threshold is set to 2 hours, the second time difference threshold is set to 0.5 hours, and the alarm threshold is set to 12 hours. These thresholds can be calibrated according to the fan specifications and APF operating conditions.

[0033] Fault determination thresholds include speed deviation threshold Δn, current deviation threshold ΔI, vibration threshold Δa, and duration determination conditions. These parameters are used to accurately identify abnormal fan conditions and avoid misjudgment due to instantaneous fluctuations.

[0034] Safe temperature rise threshold The maximum allowable temperature rise inside the APF cabinet is determined by the heat tolerance of the power devices inside the APF, and in this embodiment it is set to 45°C.

[0035] Dynamic lift compensation coefficient range: =1.1, =1.3, this coefficient is used to determine the overspeed compensation range of the standby fan after a fault switch. The engineering experience range of 1.1 to 1.3 can achieve a balance between heat dissipation compensation and fan reliability.

[0036] Step S2: Dynamic life balance control.

[0037] Under normal operating conditions of the APF and without fan failure, this invention employs a time-sharing alternating operation mode to achieve balanced lifespan of the two fans. Specifically, in the initial stage, one fan is randomly selected as the current working fan, and the other as a backup fan. The working fan operates at a speed adapted to the current temperature rise of the rack, while the backup fan does not completely stop but continues to operate at a non-zero low-power standby speed (e.g., 30%~40% of the rated speed). The reason for using a non-zero low-power standby speed is that a fan that is completely stationary for a long time is prone to problems such as solidification of bearing lubricating grease, bearing jamming, and coil aging. When a switch is actually needed, it may not be able to start normally, thus losing the meaning of redundancy protection. By keeping the backup fan running at a low speed, wear and energy consumption can be effectively reduced, while maintaining the good condition of the bearings and motor, ensuring that it can be quickly put into operation at any time.

[0038] Based on this, the present invention records and updates the cumulative operating time of the first and second fans in real time, calculates the cumulative operating time difference Δt between them, and sets a first time difference threshold and a maximum allowable time difference. When the cumulative running time difference does not exceed the first time difference threshold, the baseline alternation cycle is followed. Perform isochronous alternation: The current working fan has been running continuously for a certain period of time. Then, the speed of the backup fan is increased to match that of the current working fan. After the speeds of the two fans are synchronized, the original working fan is switched to a low-power standby state, and the original backup fan is switched to the working fan, completing one alternation. By repeating the above process, the cumulative running time of the two fans remains basically the same.

[0039] When the cumulative running time difference exceeds a preset first time difference threshold, the system automatically enters a dynamic balancing mode. In this mode, the duration of the next alternating running cycle is dynamically adjusted based on the magnitude of the cumulative running time difference to reduce the cumulative running time difference. Preferably, the dynamic adjustment method is to calculate the next alternating running cycle according to a linear proportional formula. At the same time, a minimum alternation period is set. To prevent excessively frequent switching, when Δt is larger, The smaller the difference, the shorter the alternation cycle, thus giving fans with less cumulative running time more frequent working opportunities. In addition, when the cumulative running time difference exceeds the preset second time difference threshold (which is greater than the first time difference threshold), asymmetrical working time allocation can be adopted within a single alternation cycle, allowing fans with less cumulative running time to work for a longer period of time, further accelerating the balancing speed. When the cumulative running time difference shrinks to below the preset second time difference threshold, the dynamic balancing mode is automatically exited, and the system returns to the baseline alternation cycle.

[0040] Step S3: Fan failure detection and prediction.

[0041] This invention employs a multi-parameter comprehensive judgment method to improve the accuracy and timeliness of fault detection. For the currently operating fan, the system collects parameters in real time from three dimensions: its rotational speed, operating current, and vibration amplitude. A fault is determined to have occurred in the currently operating fan when any of the following conditions are met and the duration exceeds a preset time: (1) The absolute value of the deviation between the actual speed and the target speed is greater than or equal to the speed deviation threshold Δn. The speed deviation directly reflects whether the fan can output the required air volume according to the command. The target speed is calculated in real time by the APF control module based on the cabinet temperature rise. When the speed deviation continues to exceed the standard, it indicates that there may be an abnormality in the fan motor, drive circuit or impeller.

[0042] (2) The absolute value of the deviation between the actual working current and the rated current is greater than or equal to the current deviation threshold ΔI. Abnormal working current usually reflects faults such as short circuit, open circuit or mechanical jamming of the motor winding. For example, the current will increase significantly when the fan is stalled, while the current will be close to zero when the wire is disconnected.

[0043] (3) Vibration amplitude ≥ vibration threshold Δa. Abnormal vibration amplitude reflects mechanical faults such as fan impeller imbalance and bearing wear. Vibration sensor can be implemented by acceleration sensor or displacement sensor.

[0044] Using a three-parameter comprehensive judgment can effectively avoid misjudgment. For example, when the APF cabinet temperature rises and causes changes in airflow resistance, the fan speed may decrease slightly but the current is normal. In this case, it should not be judged as a fan failure. Only when multiple parameters are abnormal at the same time or in sequence should the failure be confirmed.

[0045] For the backup fan, the same real-time data collection and fault diagnosis are performed. However, since the backup fan is in a low-power standby state, its speed, current, and vibration amplitude are all lower. Therefore, the fault diagnosis threshold can be adjusted appropriately, for example, by scaling it down. When a backup fan is detected to be faulty, since the current working fan is still running normally, the system does not perform a switching operation. Instead, it immediately issues an alarm signal to prompt maintenance personnel to replace the backup fan in a timely manner and adjust the operating strategy: shorten the inspection cycle of the current working fan and increase the monitoring frequency of its operating parameters. This role-based fault detection and response strategy ensures that faulty standby fans can be detected in a timely manner and avoids unnecessary switching operations.

[0046] Step S4: Seamless switching and dynamic acceleration compensation under fault conditions.

[0047] When a fault is detected in the currently operating fan, the present invention immediately triggers a fault switching process to ensure uninterrupted heat dissipation.

[0048] Upon detecting a fault, the control module sends a command to the drive module to rapidly increase the speed of the standby fan to the target speed before the failure of the currently operating fan. Since the standby fan has been in a low-power standby state, current has already flowed through its motor windings, and the rotor is already rotating at a low speed. Therefore, the time to increase from the standby speed to the target speed is much less than the time required to start from a standby position. In this embodiment, the speed-up process is controlled within 100ms, which is much less than the thermal time constant required for the temperature rise inside the APF cabinet to reach the safe upper limit. After the standby fan speed is synchronized to the target speed, the power supply to the faulty fan is immediately cut off. This switching sequence of first synchronizing the speed and then cutting off the faulty fan ensures that the airflow in the duct does not become interrupted or suddenly drops during the switching process, achieving seamless switching.

[0049] After the switchover is complete, the current temperature rise inside the APF cabinet is acquired in real time via temperature sensors. ,Will With safe temperature rise threshold Comparison: like ≥ ×α, where α is a preset proportional coefficient, for example, 80%, indicating that the current temperature rise is close to the safe limit, and relying solely on the backup fan to operate at the original target speed may not be effective in suppressing the temperature rise from continuing to increase. Therefore, the fan that is switched on is controlled to operate at a compensating speed. ,in k This is the compensation coefficient, with a value between 1.1 and 1.3. The specific value of the compensation coefficient can be determined based on... and The difference, temperature rise rate, and current fan health status are dynamically determined, for example, when near Furthermore, when the temperature rise rate is high, a larger value should be selected. k Value; when the temperature rise is relatively gradual, take the smaller value. k value.

[0050] like < ×α indicates that the current temperature rise is within a safe range. The backup fan can meet the heat dissipation requirements by running at the original target speed. At this time, there is no need to activate overspeed compensation to save energy and reduce fan noise and wear.

[0051] During overspeed compensation operation, the system continuously monitors the rack temperature rise, and as the temperature rise gradually decreases... Below, for example, below 0.9× When the fan speed is gradually restored to the target speed, the compensation mode is exited. This strategy of compensating on demand and exiting in a timely manner avoids excessive wear and tear on the fan's lifespan caused by prolonged overspeed operation.

[0052] After the switch is completed, the system immediately issues an audible and visual alarm signal. At the same time, it pushes the fault information, including the faulty fan's identifier, fault type, fault time, and cumulative running time, to the operation and maintenance backend through the operation and maintenance backend communication unit, so that operation and maintenance personnel can promptly grasp the fault situation and make maintenance arrangements.

[0053] Step S5: Reset and equalization calibration after fan replacement.

[0054] When maintenance personnel replace the faulty fan with a new one, the system automatically detects the new fan's connection and then performs the following operations: Collect the initial status parameters of the new fan, including speed, current, and vibration amplitude, confirm that the new fan is in normal condition, and set the new fan as the standby fan.

[0055] The cumulative running time records are processed as follows: The cumulative running time of the new fan is initialized while maintaining the cumulative running time of the existing normal fan. Since there is a significant difference in cumulative running time between the new and old fans, immediately resuming the normal baseline alternation cycle would result in a persistent time difference that cannot be effectively balanced. To address this, the alternation cycle is shortened to a certain percentage of the baseline cycle, for example, from 24 hours to 12 hours. This allows the new fan more operating opportunities to quickly catch up with the old fan's cumulative running time. During this catch-up process, the system monitors the difference in cumulative running time between the two fans in real time. Once the difference narrows to a preset reasonable range, the system gradually restores the system to the baseline alternation cycle. This reset and calibration method ensures that the system can automatically and quickly incorporate the new fan into lifespan balancing management after fan replacement, preventing long-term lifespan imbalances caused by fan replacement.

[0056] The method of this invention records the cumulative running time of redundant fans in real time and calculates the time difference. When the time difference exceeds a threshold, it dynamically adjusts the alternation cycle to shorten the negative correlation of the time difference. At the same time, it realizes seamless switching when the working fan fails and dynamic speed-up compensation based on the temperature rise threshold. After replacing the fan, it automatically resets and calibrates, thereby actively balancing the lifespan of the two fans, ensuring uninterrupted heat dissipation and improving system reliability.

[0057] The method of the present invention will be further illustrated below with specific examples.

[0058] Example scenario: A low-voltage APF device is used in conjunction with a frequency converter in an industrial workshop. The APF cabinet uses two identical DC24V 120×120×38mm cooling fans (fan A and fan B), with a rated speed n=3000rpm and a rated current I=0.3A.

[0059] System initialization: After the APF starts, the control module initializes the two fans, collecting the initial speed, operating current, and vibration amplitude of fan A and fan B to confirm that both fans are functioning normally; setting control parameters: reference alternation cycle. =24 hours, the first time difference threshold is 2 hours, and the maximum allowable time difference. =12 hours, minimum alternation period =4 hours, speed deviation threshold Δn=200rpm, current deviation threshold ΔI=0.05A, vibration threshold Δa=1.0g, cabinet safe temperature rise threshold =45℃, dynamic acceleration compensation coefficient k=1.2, compensation start ratio is 80%.

[0060] Time-sharing and dynamic lifespan balancing: Initially, fan A is set as the working fan, running at 2800 rpm, and fan B is the standby fan, operating at 1000 rpm in low-power standby mode. The system records the cumulative running time of both fans in real time. After a period of operation, due to an unexpected event, the cumulative running time of fan B is 3 hours less than that of fan A. At this point, the cumulative running time difference Δt = 3 hours, exceeding the first time difference threshold of 2 hours. The system automatically enters dynamic balancing mode, according to the formula... =24×(1-3 / 12)=18 hours, adjust the next alternating operation cycle to 18 hours; thereafter, fan B will get a working opportunity after the 18-hour cycle ends. As the time difference gradually narrows, the alternating cycle gradually returns to 24 hours. When the time difference narrows to below the second time difference threshold, the system exits the dynamic equilibrium mode.

[0061] Fault detection: During operation, after fan B (the currently operating fan) has been running for 3 months, its speed is detected to drop to 2500 rpm, which is 300 rpm ≥ Δn = 200 rpm from the target speed of 2800 rpm, and the deviation lasts for 5 seconds. The control module determines that fan B has failed.

[0062] Seamless switching and speed-up compensation: Upon determining that fan B is faulty, the control module immediately instructs fan A (the backup fan) to increase its speed from 1000 rpm to 2800 rpm within 80 ms, while simultaneously cutting off power to fan B, achieving seamless switching. After the switch, the internal temperature rise of the data acquisition cabinet is 43℃, which has reached 95% > 80% of the safe temperature rise threshold of 45℃. The control module then controls fan A to increase its speed to 2800 × 1.2 = 3360 rpm for dynamic speed-up compensation. Simultaneously, the audible and visual alarm unit issues an alarm, and the maintenance backend receives the fan B fault information.

[0063] Reset and calibration: After the maintenance personnel replaced the faulty fan B, the system detected the new fan's connection, collected its initial parameters (speed 3000rpm, current 0.3A, vibration 0.4g), and set it as the standby fan. At this time, the cumulative running time of fan A was 2160 hours, while the cumulative running time of the new fan B was 0 hours, resulting in a large time difference. The system automatically shortened the alternation cycle to 12 hours, allowing the new fan B to get a working opportunity more quickly. After about 7 days of dynamic adjustment, the cumulative running time difference between the two fans was reduced to less than 2 hours, and the system restored the 24-hour baseline alternation cycle.

[0064] After running for a total of one year, the difference in cumulative running time between the two fans was only 18 hours, demonstrating a clear effect of balanced lifespan. There was no interruption in heat dissipation during the fault switching process, the temperature rise of the cabinet did not exceed the safety threshold, and the APF did not experience load reduction or shutdown, thus reducing maintenance costs.

[0065] Example 2: This invention also provides an APF redundant fan seamless switching and life balancing control system for implementing the method in Embodiment 1, such as... Figure 2 As shown, the system includes: Redundant fan module 1: The redundant fan module includes a first fan and a second fan of the same specifications. Both fans are adapted to the heat dissipation airflow of the APF cabinet and are installed at the air inlet and air outlet of the cabinet. The selection of the two fans must ensure that each fan can provide sufficient heat dissipation airflow at its rated speed to meet the heat dissipation requirements of the APF under rated operating conditions, so as to ensure that if one fan fails, the other can independently take over the heat dissipation task.

[0066] Perception and detection module 2: The sensing and detection module includes multiple sensors: Speed ​​sensor: Installed on both fans respectively, used to collect the fan speed signal in real time. The speed sensor can be a Hall element or a photoelectric encoder, which calculates the speed by detecting the rotation pulse signal of the fan impeller.

[0067] Current sensor: Connected in series in the power supply circuit of the two fans, it is used to collect the operating current of the fans. The current sensor can be a sampling resistor plus differential amplifier circuit or a Hall current sensor.

[0068] Vibration sensors: These are installed on the housings or mounting brackets of the two fans respectively, and are used to collect the vibration amplitude during fan operation. The vibration sensors can be accelerometers.

[0069] Temperature sensor: Installed near key heat-generating components inside the APF cabinet or at the air outlet of the air duct, it is used to collect the temperature rise inside the cabinet. The temperature sensor can be an NTC thermistor or a digital temperature chip.

[0070] The output signals from all sensors are sent to the control module after undergoing necessary signal conditioning.

[0071] Control Module 3: The control module uses the APF's main control MCU or DSP, which is electrically connected to the sensing and detection module and the redundant fan module. The control module controls the first and second fans to run alternately in a time-sharing manner based on the data collected by the sensing and detection module. It updates the cumulative running time of the two fans in real time and calculates the cumulative running time difference. When the cumulative running time difference exceeds the preset first time difference threshold, it dynamically adjusts the alternation cycle according to the magnitude of the cumulative running time difference. When a working fan failure is detected, it controls the backup fan to increase its speed and cuts off the power supply to the faulty fan. After switching, it controls the fans to perform overspeed compensation based on the rack temperature rise.

[0072] The control module integrates the following: Cumulative running time recording unit: Used to store the cumulative running time of the two fans, and updated after each alternation or replacement.

[0073] Time difference comparison unit: used to calculate the cumulative running time difference in real time and compare it with preset thresholds (first time difference threshold, second time difference threshold, alarm threshold, maximum allowable time difference, etc.) and output the comparison result.

[0074] Cycle calculation unit: Calculates the duration of the next alternating operation cycle based on the time difference comparison results.

[0075] Fault diagnosis unit: Receives speed, current, and vibration signals, compares them with fault diagnosis thresholds, and comprehensively judges the fault status of the working fan and the standby fan.

[0076] Switching control unit: When a working fan failure is detected, it generates a backup fan speed-up command and a faulty fan power-off command, coordinating the timing to ensure seamless switching.

[0077] Compensation control unit: After the switch is completed, it determines whether to activate overspeed compensation and the value of the compensation coefficient based on the ratio between the cabinet temperature rise and the safe temperature rise threshold.

[0078] Driver Module 4: The drive module is electrically connected to the control module and the redundant fan module. It receives control commands from the control module and drives the two fans to start, stop, and adjust their speed. The drive module includes: Fan drive circuit: It can use an H-bridge or half-bridge circuit composed of MOSFETs to control the effective value of the fan motor voltage through pulse width modulation (PWM) signal, thereby adjusting the speed.

[0079] Power switching circuit: Used to cut off the power supply to the faulty fan in case of a fault. It can be a solid-state relay switch connected in series in the fan power supply circuit, and its on and off is controlled by the switching control unit of the control module.

[0080] Speed ​​synchronization detection circuit: used to monitor the proximity of the actual speed to the target speed during the standby fan speed-up process, and outputs a synchronization completion signal when the speed error enters the allowable range.

[0081] Alarm and Maintenance Module 5: The alarm and maintenance module includes an audible and visual alarm unit and a maintenance backend communication unit. The audible and visual alarm unit emits audible and visual alarm signals when a fan malfunctions, alerting on-site maintenance personnel. The maintenance backend communication unit connects to a centralized maintenance backend via RS485, CAN, or Ethernet interfaces. It pushes fault information, including the faulty fan identifier, fault type, fault time, and cumulative running time, as well as fan operating data, including cumulative running time, temperature, and speed, to the maintenance backend. The maintenance backend can store, analyze, and display the data, and generate a maintenance work order when the cumulative running time difference exceeds an alarm threshold, enabling preventative maintenance management. Furthermore, the alarm and maintenance module also includes a local human-machine interface for on-site querying of fan operating status and configuring control parameters.

[0082] The system of this invention includes a redundant fan module, a sensing and detection module, a control module, a drive module, and an alarm and maintenance module. The control module performs dynamic periodic adjustment, rapid fault switching, and compensation control based on the sensing data, realizing proactive balanced management of the lifespan of the two fans, seamless switching during faults, and automatic reset calibration after replacement, thereby improving the operational reliability and maintenance convenience of the APF redundant fan system.

[0083] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for seamless switching and lifespan balancing control of redundant APF fans, applied to an APF cabinet equipped with a first fan and a second fan, characterized in that, include: Under normal operating conditions, the first fan and the second fan are controlled to operate alternately in a time-sharing manner; wherein, the currently operating fan operates at a target speed determined according to the real-time temperature rise of the cabinet, and the standby fan continues to operate at a non-zero standby speed lower than the target speed. The cumulative running time of the first fan and the second fan is recorded and updated in real time, and the cumulative running time difference between them is calculated. When the cumulative running time difference exceeds a preset first time difference threshold, the dynamic balancing mode is entered, and the duration of the next alternating running cycle is dynamically adjusted according to the magnitude of the cumulative running time difference in order to reduce the cumulative running time difference. The system monitors the operating status of the current working fan in real time. When it is determined that the current working fan has failed, the speed of the backup fan is increased to the target speed before the failure of the current working fan. After the backup fan reaches the target speed, the power supply to the failed fan is cut off. The real-time temperature rise inside the APF cabinet is obtained. If the real-time temperature rise reaches or exceeds a preset ratio of the safe temperature rise threshold, the fan that has been switched on is controlled to run at a compensation speed greater than the target speed.

2. The method for seamless switching and lifespan balancing control of APF redundant fans according to claim 1, characterized in that, The specific method for dynamically adjusting the duration of the next alternating operation cycle is as follows: When the cumulative running time difference exceeds a preset first time difference threshold, the duration of the next alternating running cycle is negatively correlated with the cumulative running time difference.

3. The method for seamless switching and lifespan balancing control of APF redundant fans according to claim 2, characterized in that, The specific calculation method for the next alternating operating cycle is as follows: Set the reference alternation period The current cumulative running time difference is Δ t The preset maximum allowable time difference is ,and Then the next alternating operation cycle ,and Not less than the preset minimum alternation period .

4. The method for seamless switching and lifespan balancing control of APF redundant fans according to claim 1, characterized in that, In dynamic balancing mode, when the cumulative running time difference is reduced to below the preset second time difference threshold, the dynamic balancing mode is automatically exited and the system returns to the baseline alternation cycle.

5. The method for seamless switching and lifespan balancing control of APF redundant fans according to claim 1, characterized in that, The real-time detection of the current operating status of the fan specifically includes: Real-time acquisition of the current operating fan speed, operating current, and vibration amplitude; The current operating fan is deemed to have malfunctioned if any of the following conditions are met and the duration exceeds a preset time: The absolute value of the deviation between the actual speed and the target speed is greater than or equal to the speed deviation threshold; The absolute value of the deviation between the actual operating current and the rated current is greater than or equal to the current deviation threshold. The vibration amplitude is greater than or equal to the vibration threshold.

6. The method for seamless switching and lifespan balancing control of APF redundant fans according to claim 1, characterized in that, The compensation speed is the target speed multiplied by a preset compensation coefficient; when the real-time temperature rises to below the safe temperature rise threshold, the fan that was operating after the control switch exits the overspeed compensation and resumes operation at the target speed.

7. The method for seamless switching and lifespan balancing control of APF redundant fans according to claim 1, characterized in that, The method further includes: When a faulty fan is detected and replaced with a new one, the initial parameters of the new fan are automatically collected and it is set as the backup fan. The cumulative running time of the new fan is initialized, while the cumulative running time of the original normal fan remains unchanged. The alternation cycle is dynamically adjusted based on the current cumulative running time difference to reduce the cumulative running time difference between the new fan and the original normal fan.

8. A system for implementing the APF redundant fan seamless switching and lifetime balancing control method as described in any one of claims 1-7, characterized in that, include: Redundant fan modules, including a first fan and a second fan of the same specifications, are installed in the heat dissipation duct of the APF cabinet; The sensing and detection module includes a speed sensor, a current sensor, and a vibration sensor installed on the two fans, as well as a temperature sensor installed inside the cabinet. The control module is electrically connected to the sensing and detection module and the redundant fan module, and is used to control the alternating operation, life balancing, seamless fault switching and dynamic speed adjustment of the fans. The drive module receives instructions from the control module to drive the two fans to start, stop, and adjust their speed. The alarm and maintenance module is used to issue alarms when a fan fails and push operating data and fault data to the maintenance backend.

9. The system according to claim 8, characterized in that, The control module integrates a cumulative running time recording unit and a time difference comparison unit, which are used to monitor and dynamically adjust the alternation cycle in real time.

10. The system according to claim 8, characterized in that, The alarm and maintenance module is also used to push a lifespan difference alarm reminder to the maintenance backend when the cumulative running time difference exceeds a preset alarm threshold.

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