Cooling fan system capable of adaptively predicting faults and control method thereof

Abstract

The invention discloses a cooling fan system capable of adaptively predicting faults and a control method thereof. The cooling fan system comprises a plurality of fan circuits which are used for driving a plurality of corresponding fan devices according to a plurality of corresponding pulse width modulation signals; and the management controller is respectively used for controlling and adjusting the plurality of fan circuits in the test and operation processes, so as to detect the fault prediction state of the plurality of fan circuits. In a test program, according to a rotating speed return signal returned by each of the plurality of fan circuits, a current rotating speed vector for controlling the plurality of fan circuits is fed back to a target rotating speed vector, and a system coefficient table is established according to a preset electrical parameter vector corresponding to the target rotating speed vector. In the operation program, an operation rotating speed vector is determined according to environmental conditions, a plurality of corresponding pulse width modulation signals are transmitted to a plurality of fan circuits, and then fault prediction states of the plurality of fan circuits are detected according to a system coefficient table.

Description

Technical Field

[0001] This invention relates to a cooling fan system, and more particularly to a cooling fan system capable of adaptively predicting faults. The invention also relates to a control method for controlling the cooling fan system. Background Technology

[0002] Cooling fan systems are widely used in servers, data centers, and high-performance electronic devices. Their primary function is to maintain the equipment within a suitable temperature range. These systems typically include a control unit, such as a Baseboard Management Controller (BMC), which adjusts the fan speed based on the device's temperature or environmental conditions to meet cooling requirements. The control unit controls the fan speed via pulse-width modulation (PWM) signals and receives feedback signals from the fans to monitor their operating status. Some systems also incorporate sensors to detect the fan's electrical parameters (such as drive current or voltage) to further assess the fan's health.

[0003] However, the drawback of existing cooling fan systems is that most of them can only issue an alarm after a noticeable fan failure occurs, and cannot predict failures in advance. Furthermore, the testing procedures for existing technologies are also a significant challenge, requiring manual testing of fan speed and electrical parameters one by one. For large-scale testing, this is too time-consuming and resource-intensive, and may even be impractical in real-world applications.

[0004] Compared to the prior art, this invention provides an adaptive fault prediction cooling fan system, offering an innovative solution to the aforementioned problems. Through a system coefficient table established by a test program, the baseboard management controller can dynamically monitor the current operating status of the fans during daily operation and detect the fault prediction status of multiple fan circuits based on electrical parameter thresholds, thereby predicting faults in multiple fan circuits. Furthermore, the built-in adaptive test program of this invention can automatically test and establish a system coefficient table for multiple fan circuits, greatly simplifying the complexity of the testing process and enabling high efficiency even with a wide testing range.

[0005] Through the above innovative design, this invention effectively overcomes the shortcomings of traditional cooling fan systems, significantly improves the system's efficiency, reliability, and maintainability, and provides a more stable and reliable heat dissipation solution for high-performance electronic devices. Summary of the Invention

[0006] In one viewpoint, the present invention provides an adaptively predictive cooling fan system, comprising: a plurality of fan circuits, including a plurality of corresponding fan devices, for driving the corresponding plurality of fan devices according to a plurality of corresponding pulse width modulation signals; and a management controller, for controlling and adjusting the plurality of fan circuits in a test procedure and an operation process, thereby detecting a fault prediction state of the plurality of fan circuits; wherein in the test procedure, the management controller, based on a speed feedback signal returned by each of the plurality of fan circuits, feeds back a current speed vector of the plurality of fan circuits to a target speed vector, and establishes a system coefficient table based on a preset electrical parameter vector returned by the plurality of fan circuits corresponding to the target speed vector, wherein the system coefficient table includes the target speed vector and the corresponding preset electrical parameter vector or a corresponding electrical parameter threshold vector; In this operating procedure, the management controller determines an operating speed vector based on an environmental condition and feeds back the current speed vector of the multiple fan circuits to the operating speed vector. Then, based on the system coefficient table, it detects the fault prediction state of the multiple fan circuits, wherein the fault prediction state corresponds to a current electrical parameter vector of the multiple fan circuits exceeding the electrical parameter threshold vector.

[0007] In a preferred embodiment, the target rotational speed vector is determined based on a rotational speed range vector, which includes a plurality of the target rotational speed vectors.

[0008] In a preferred embodiment, the rotational speed range vector is preset by the system or determined by the user.

[0009] In a preferred embodiment, the system coefficient table includes a subsystem coefficient table for each of the plurality of fan circuits; wherein in the subsystem coefficient table corresponding to one of the plurality of fan circuits, the target speed vector includes a plurality of target speeds of one of the fan circuits and a fixed target speed of the other of the plurality of fan circuits, and the preset electrical parameter vector includes a plurality of preset electrical parameters of one of the fan circuits; the subsystem coefficient table of one of the fan circuits is established based on the plurality of target speeds of one of the fan circuits, the fixed target speed of the other of the plurality of fan circuits, and the corresponding plurality of preset electrical parameters.

[0010] In a preferred embodiment, the system coefficient table includes a subsystem coefficient table for each of the plurality of fan circuits; wherein in the subsystem coefficient table corresponding to each of the plurality of fan circuits, the target speed vector includes a plurality of target speeds for all the plurality of fan circuits, and the preset electrical parameter vector includes a plurality of preset electrical parameters for all the plurality of fan circuits; the subsystem coefficient table for each of the plurality of fan circuits is established based on the plurality of target speeds for all the plurality of fan circuits and the corresponding plurality of preset electrical parameters.

[0011] In a preferred embodiment, the management controller communicates with the plurality of fan circuits via a serial bus communication method, thereby controlling and adjusting the plurality of fan circuits and detecting the fault prediction status of the plurality of fan circuits.

[0012] In a preferred embodiment, the adaptively predictive cooling fan system further includes: a plurality of bus control circuits correspondingly coupled to the plurality of fan circuits, for communicating with a management controller via a serial data line (SDA) and a serial clock line (SCL), thereby controlling and adjusting the plurality of fan circuits and detecting the fault prediction state of the plurality of fan circuits.

[0013] In a preferred embodiment, the system coefficient table established by the test procedure is stored in the management controller, the plurality of fan circuits, or the plurality of bus control circuits.

[0014] In a preferred embodiment, the management controller includes: a plurality of first multitasking pins for transmitting a plurality of pulse width modulation signals to the corresponding plurality of fan circuits in a drive mode; and for transmitting a plurality of clock signals to the corresponding plurality of fan circuits in a communication mode; and a plurality of second multitasking pins for receiving a current speed vector returned by the corresponding plurality of fan circuits in the drive mode, so as to control the current speed vector based on the target speed vector; and for receiving the preset electrical parameter vector or the current electrical parameter vector returned by the corresponding plurality of fan circuits in the communication mode, so as to detect the fault prediction state of the plurality of fan circuits.

[0015] In a preferred embodiment, during the operation procedure, the management controller also reads or calculates the electrical parameter threshold vector corresponding to the operating speed vector according to the system coefficient table, thereby detecting the fault prediction state of the plurality of fan circuits.

[0016] In a preferred embodiment, the environmental conditions include a system temperature, a system load, or an airflow resistance of the cooling fan system.

[0017] In a preferred embodiment, the current electrical parameter vector includes a drive current, a drive voltage, or a duty cycle of each of the plurality of fan circuits.

[0018] In a preferred embodiment, a current speed vector of the plurality of fan circuits is positively correlated with the current electrical parameter vector.

[0019] In a preferred embodiment, the system coefficient table established by the test procedure is stored in the management controller or the plurality of fan circuits.

[0020] In another viewpoint, the present invention provides a control method for controlling a cooling fan system, wherein the cooling fan system includes a plurality of fan circuits and a management controller, the plurality of fan circuits driving corresponding fan devices according to corresponding plurality of pulse width modulation signals, and the management controller detecting a fault prediction state of the plurality of fan circuits; the control method includes: in a test procedure, based on a speed feedback signal returned by each of the plurality of fan circuits, feeding back a current speed vector of the plurality of fan circuits to a target speed vector, and establishing a system coefficient table based on a preset electrical parameter vector returned by the plurality of fan circuits corresponding to the target speed vector. The system coefficient table includes the target speed vector and the corresponding preset electrical parameter vector or a corresponding electrical parameter threshold vector; and in an operation procedure, an operating speed vector is determined according to an environmental condition, and the current speed vector of the plurality of fan circuits is fed back to the operating speed vector. Then, according to the system coefficient table, the fault prediction state of the plurality of fan circuits is detected, wherein the fault prediction state corresponds to a current electrical parameter vector of the plurality of fan circuits exceeding the electrical parameter threshold vector.

[0021] The following detailed description through specific embodiments will make it easier to understand the purpose, technical content, features and effects achieved by the present invention. Attached Figure Description

[0022] Figure 1 A schematic diagram showing an embodiment of the cooling fan system of the present invention is shown.

[0023] Figure 2A and Figure 2B The characteristic curves of drive current, duty cycle and speed are displayed respectively.

[0024] Figure 3 This diagram shows another embodiment of the fan circuit of the cooling fan system of the present invention.

[0025] Figure 4 A schematic diagram showing another embodiment of the cooling fan system of the present invention is shown.

[0026] Figure 5 This diagram shows another embodiment of the cooling fan system of the present invention.

[0027] Figure 6 This diagram shows a test procedure flowchart for an embodiment of the cooling fan system of the present invention.

[0028] Figures 7A to 7C This shows the speed range vectors of three embodiments of the cooling fan system of the present invention.

[0029] Figure 8 This diagram shows an operating procedure flowchart of an embodiment of the cooling fan system of the present invention.

[0030] Figure 9 An embodiment of the system coefficient table of the cooling fan system of the present invention is shown.

[0031] Explanation of symbols in the diagram

[0032] 30: Fan control circuit

[0033] 40: Fan assembly

[0034] 100: Baseboard Management Controller

[0035] 200: Temperature sensing circuit

[0036] 301, 302, 303, 30N: Fan circuits

[0037] 401, 402, 403, 40N: Bus control circuits

[0038] 1001, 1003, 1004: Cooling fan system

[0039] CLK1, CLK2, CLK3, CLKN: Clock signals

[0040] N: a positive integer greater than 1

[0041] PFG1, PFG2, PFG3, PFGN: Signal return pins

[0042] PPW1, PPW2, PPW3, PPWN: Pulse Width Modulation Pins

[0043] PSN1, PSN2, PSN3, PSNN: Sensing pins

[0044] S100~S111: Steps

[0045] S200~S209: Steps

[0046] SCS1, SCS2, SCS3, SCSN: Sensing signals

[0047] SFG1, SFG2, SFG3, SFGN: Speed ​​feedback signals

[0048] SPW1, SPW2, SPW3, SPWN: Pulse Width Modulation Signals

[0049] SSN1, SSN2, SSN3, SSNN: Sensing signals

[0050] X: Rotational speed

[0051] Y1, Y2, Y3: Rotational speed

[0052] Z1~Z12: Rotation speed Detailed Implementation

[0053] The accompanying drawings in this invention are schematic and are primarily intended to illustrate the coupling relationships between circuits and the relationships between signal waveforms. The circuits, signal waveforms, and frequencies are not drawn to scale. For clarity, many practical details will be described in the following description, but this is not intended to limit the scope of the patent application.

[0054] Figure 1 This diagram shows an embodiment of the cooling fan system of the present invention. In one embodiment, Figure 1 The cooling fan system 1001 includes a management controller, a temperature sensing circuit 200, and multiple fan circuits (e.g., fan circuits 301, 302, 303, and 30N, where N is a positive integer greater than 1). In one specific embodiment, the cooling fan system 1001 is, for example, a server cooling fan system, and the management controller is configured as a Baseboard Management Controller (BMC) 100.

[0055] In one embodiment, the board management controller 100 is used to control and adjust the operation of multiple fan circuits and is coupled to the corresponding multiple fan circuits through the following pins: (1) transmitting pulse width modulation signals (e.g., SPW1, SPW2, SPW3 and SPWN) through pulse width modulation pins (e.g., PPW1, PPW2, PPW3 and PPWN); (2) receiving speed feedback signals (e.g., SFG1, SFG2, SFG3 and SFGN) through signal feedback pins (e.g., PFG1, PFG2, PFG3 and PFGN); (3) receiving sensing signals (e.g., SSN1, SSN2, SSN3 and SSNN) through sensing pins (e.g., PSN1, PSN2, PSN3 and PSNN).

[0056] In one embodiment, the temperature sensing circuit 200 can detect the internal ambient temperature of the server and transmit this information to the baseboard management controller 100, providing a reference for controlling fan operation. In one embodiment, multiple fan circuits (301-30N) receive pulse width modulation signals (SPW1-SPWN) transmitted by the baseboard management controller 100 and transmit speed feedback signals (SFG1-SFGN). On the other hand, multiple fan circuits transmit sensing signals (SSN1-SSNN) to the baseboard management controller 100. In one embodiment, the speed feedback signals (SFG1-SFGN) indicate the current speed vector of the multiple fan circuits; that is, the baseboard management controller 100 can obtain the current speed of the multiple fan circuits based on the speed feedback signals (SFG1-SFGN). In one embodiment, the sensing signals indicate the electrical characteristics of the multiple fan circuits, such as current values, voltage values, or duty cycles, thereby enabling subsequent analysis and fault prediction.

[0057] In one embodiment, the cooling fan system 1001 establishes and uses a system coefficient table to detect the fault prediction status of multiple fan circuits through a "test procedure" and an "operation procedure".

[0058] In one embodiment, during the test procedure, the baseboard management controller 100 transmits pulse width modulation signals (SPW1~SPWN) to the corresponding multiple fan circuits (301~30N) via pulse width modulation pins (e.g., PPW1~PPWN) according to a target speed vector, so as to drive or adjust the speed of the multiple fan circuits. In one embodiment, the baseboard management controller 100 adjusts the pulse width modulation signals (SPW1~SPWN) according to the target speed vector and the current speed vector indicated by the speed feedback signals (SFG1~SFGN), thereby feedback controlling the current speed vector to the target speed vector.

[0059] In one embodiment, through the above-described feedback control, when the speed feedback signals (SFG1~SFGN) returned by multiple fan circuits are consistent with the target speed vector and the speed has stabilized, the board management controller 100 obtains and records the current electrical parameters (e.g., current or voltage) based on the sensing signals (SSN1~SSNN) to serve as the preset electrical parameter vector corresponding to the target speed vector. In one embodiment, a system coefficient table is established based on one or more sets of target speed vectors and corresponding preset electrical parameter vectors, or an electrical parameter threshold vector generated by further calculation based on the preset electrical parameter vectors. Specific embodiments will be described in detail below.

[0060] It should be noted that the testing procedure is typically performed at system initialization or under specific conditions to establish or update the system coefficient table; the operating procedure, on the other hand, detects the status of multiple fan circuits based on the system coefficient table and performs fault prediction during actual system operation. It should also be noted that the "fault prediction" in this invention refers to any electrical parameter in the current electrical parameter vector corresponding to multiple fan circuits exceeding the corresponding electrical parameter threshold in the electrical parameter threshold vector. The range of the electrical parameter threshold can be set slightly smaller than the range of electrical parameters that the fan circuit may actually fail, thus predicting potential failures before they occur, allowing for early maintenance, repair, or replacement.

[0061] In one embodiment, after the test procedure is completed, the system enters the operation procedure. In one embodiment, during the operation procedure, the board management controller 100 determines an operating speed vector based on environmental conditions (e.g., temperature returned by the temperature sensing circuit 200, system load, or airflow resistance). Then, the board management controller 100 adjusts the pulse width modulation signals (SPW1-SPWN) based on the difference between the operating speed vector and the current speed vector indicated by the speed feedback signals (SFG1~SFGN), thereby feeding back control of the current speed vector to the operating speed vector. In one embodiment, when the current speed vectors of multiple fan circuits reach and stabilize at the operating speed vector, the board management controller 100 obtains the corresponding current electrical parameter vector (e.g., current current or voltage) based on the sensing signals (SSN1~SSNN), and obtains (or calculates) the electrical parameter threshold vector corresponding to the operating speed vector based on the system coefficient table. In one embodiment, if the current electrical parameters of at least one of the multiple fan circuits exceed (are higher or lower than) the corresponding threshold range, the baseboard management controller 100 determines that the fan circuit may be in a fault prediction state and generates a fault prediction notification to remind maintenance personnel to repair or replace it.

[0062] For example, in one specific embodiment, according to the system coefficient table, when the fan circuit 303 rotates at 3000 RPM, its preset electrical parameters indicate a normal drive current of approximately 2.5A, and the corresponding electrical parameter threshold range is 2.3A to 2.8A. When the baseboard management controller 100 actually reads that the current value of the fan circuit 303 is lower than 2.3A or higher than 2.8A, it indicates a fault prediction state of the fan circuit 303, thus determining that the fan circuit 303 is abnormal. In one embodiment, the baseboard management controller 100 generates a fault prediction notification based on the fault prediction state of the fan circuit 303 and reports it to maintenance personnel so that maintenance, repair, or replacement can be arranged as soon as possible to ensure that the system maintains normal operation.

[0063] It is worth noting that after the above-mentioned repairs or replacements, the system coefficient table can be quickly updated through the aforementioned testing procedures.

[0064] In summary, the cooling fan system of the present invention can establish or update the system coefficient table through a test program, and then dynamically detect and predict fault states in the operation program. When the current electrical parameters of at least one of the multiple fan circuits exceed the electrical parameter threshold, the board management controller 100 can generate a notification and perform maintenance in real time, thereby improving the stability and reliability of the electronic equipment operation.

[0065] Figure 2A and Figure 2B The characteristic curves for drive current, duty cycle, and rotational speed are displayed respectively. It should be noted that in some embodiments, the aforementioned electrical parameters related to rotational speed may be, for example, drive current or voltage values, and the electrical parameter thresholds may be, for example, drive current thresholds or voltage thresholds. Figure 2A As shown, the drive current threshold includes a high current threshold and a low current threshold. Furthermore, electrical parameters related to rotational speed, such as the duty cycle of a pulse-width modulation signal, can have thresholds such as duty cycle thresholds. Figure 2B As shown, the duty cycle threshold includes a high duty cycle threshold and a low duty cycle threshold. Generally speaking, as... Figure 2A and Figure 2B As shown, the fan speed is positively correlated with the drive current, drive voltage, or duty cycle of the pulse width modulation signal.

[0066] Figure 3 This diagram shows another embodiment of the fan circuitry of the cooling fan system of the present invention. In one embodiment, Figure 1 The fan circuits 301-30N in the configuration each include a fan control circuit and a fan device. For example, in one specific embodiment, such as... Figure 3As shown, the fan circuit 301 includes a fan control circuit 30 and a fan device 40. The fan control circuit 30 is used to generate a drive power supply according to the pulse width modulation signal SPW1 transmitted by the board management controller 100 to drive the operation of the fan device, and is used to sense the fan speed and send back a speed feedback signal SFG1 and a sensing signal SSN1.

[0067] Specifically, in one embodiment, during the test procedure, the fan control circuit 30 drives the fan device 40 according to the received pulse width modulation signal SPW1, and sends back a speed feedback signal SFG1 to the substrate management controller 100 based on the current speed of the fan device 40. This allows the substrate management controller 100 to control the current speed of the fan device 40 to the target speed based on the target speed corresponding to the fan circuit 301 and the speed feedback signal SFG1. On the other hand, once the current speed of the fan device 40 has been adjusted to the target speed and stabilized, the fan control circuit 30 senses preset electrical parameters such as the drive current and voltage of the fan device 40 corresponding to the target speed, and sends back a sensing signal SSN1 related to these preset electrical parameters to the substrate management controller 100. This allows the substrate management controller 100 to establish a system coefficient table based on the target speed vector and the corresponding preset electrical parameter vector or the corresponding electrical parameter threshold vector.

[0068] In one embodiment, during operation, the substrate management controller 100 transmits a pulse width modulation signal SPW1 to the fan control circuit 30 according to the operating speed corresponding to the fan circuit 301 to drive the fan device 40, and controls the current speed of the fan device 40 to the operating speed according to the speed feedback signal SFG1. Once the current speed of the fan device 40 has been adjusted to the operating speed and stabilized, the substrate management controller 100 obtains the corresponding current electrical parameters according to the sensing signal SSN1 returned by the fan control circuit 30, and compares the current electrical parameters with the electrical parameter threshold obtained according to the system coefficient table to detect the fault prediction state of the fan circuit 301. Details not mentioned above can be found in [the following text is missing from the original extract]. Figure 1 This can be inferred from the explanation.

[0069] Figure 4 A schematic diagram showing another embodiment of the cooling fan system of the present invention is shown. Figure 4 The cooling fan system 1003 is similar to Figure 1 The cooling fan system 1001 differs in that, in one embodiment, the baseboard management controller 100 in the cooling fan system 1003 is coupled to multiple fan circuits (e.g., 301, 302, 303, and 30N) only through corresponding pulse width modulation pins (e.g., PPW1, PPW2, PPW3, and PPWN) and signal return pins (e.g., PFG1, PFG2, PFG3, and PFGN), and the cooling fan system 1003 omits the signal return pins. Figure 1Additional sensing pins are included in the design. In this embodiment, the pulse width modulation pin and the signal feedback pin are multi-tasking pins with multi-functional characteristics, capable of performing different functions in different modes (drive mode and communication mode), thereby further simplifying hardware configuration and enhancing the overall flexibility of the system.

[0070] In one embodiment, in the driving mode, the board management controller 100 transmits pulse width modulation signals (SPW1~SPWN) to the corresponding multiple fan circuits (301~30N) via pulse width modulation pins (PPW1~PPWN) to drive or adjust the speed of the multiple fan devices. On the other hand, the multiple fan circuits transmit speed feedback signals (SFG1~SFGN) back to the board management controller 100 via signal feedback pins (PFG1~PFGN), so that the board management controller 100 dynamically adjusts the duty cycle or frequency of the pulse width modulation signal according to the speed feedback signal to control the current speed vector of the multiple fan circuits to the target speed vector (test procedure) or the operating speed vector (operation procedure). For example, when the board management controller 100 wants to set the speed of fan circuit 301 to 2000 RPM, by continuously adjusting the pulse width modulation signal SPW1 and reading the speed feedback signal SFG1 in real time, under stable feedback, the fan circuit 301 can eventually be maintained at a stable speed of approximately 2000 RPM.

[0071] When it is necessary to detect or read the electrical parameter vectors (e.g., drive current, drive voltage, duty cycle, etc.) of multiple fan circuits for fault prediction, the board management controller 100 can switch to communication mode. In one embodiment, in communication mode, the pulse width modulation pins (PPW1~PPWN) and signal return pins (PFG1~PFGN) can be used for sequential communication. For example, the pulse width modulation pins (PPW1~PPWN) are used to transmit corresponding clock signals (e.g., CLK1, CLK2, CLK3, and CLKN) to multiple fan circuits (301~30N); while the signal return pins (PFG1~PFGN) are used to receive sensing signals (e.g., SCS1, SCS2, SCS3, and SCSN) returned by multiple fan circuits (301~30N). In one embodiment, the sensing signals (SCS1~SCSN) can be digital signals used to indicate a preset electrical parameter vector corresponding to a target speed vector (e.g., when establishing a system coefficient table in a test procedure), or to indicate the current electrical parameter vector in an operating procedure. Other operational details not mentioned above can be obtained from [the relevant authority / organization]. Figure 1 This can be inferred from the description of subsequent embodiments.

[0072] Figure 5 This diagram illustrates yet another embodiment of the cooling fan system of the present invention. In one embodiment, as shown... Figure 5As shown, the cooling fan system 1004 includes multiple bus control circuits (e.g., bus control circuits 401, 402, 403 and 40N), which are coupled to multiple fan circuits (e.g., fan circuits 301, 302, 303 and 30N) respectively, and are connected and communicate with the board management controller 100 through a sequential bus communication method, such as I2C (Inter-Integrated Circuit).

[0073] In this embodiment, multiple bus control circuits serve as bridging devices between the board management controller 100 and multiple fan circuits. In one embodiment, the board management controller 100 transmits a target speed vector or operating speed vector to the multiple bus control circuits (401~40N) via a serial data line (SDA) and a serial clock line (SCL). In one embodiment, in drive mode, the multiple bus control circuits (401~40N) generate pulse width modulation signals (e.g., SPW1~SPWN) based on the target speed vector or operating speed vector transmitted by the board management controller 100 to drive the multiple fan circuits (301~30N). In one embodiment, each of the plurality of bus control circuits (401~40N) further adjusts the corresponding pulse width modulation signal (SPW1~SPWN) according to the difference between the target speed vector and the current speed vector returned by the corresponding fan circuit (e.g., indicated by the speed return signals SFG1~SFGN), thereby adjusting the current speed vector of the plurality of fan circuits (301~30N) to the target speed vector.

[0074] In one embodiment, in the communication mode, the speed feedback signals SFG1~SFGN are used to indicate the preset electrical parameter vectors corresponding to the multiple fan circuits (301~30N) under the target speed vector, or to indicate the current electrical parameter vectors corresponding to the multiple fan circuits (301~30N) under the operating speed vector. In the aforementioned test and operation procedures, the preset electrical parameter vectors, electrical parameter threshold vectors, or current electrical parameter vectors required by the baseboard management controller 100 are transmitted through multiple bus control circuits (401~40N) via serial data line SDA and serial clock line SCL. Other operational details not mentioned above can be obtained from... Figure 1 This can be inferred from the description of subsequent embodiments.

[0075] Figure 6 This diagram shows a test procedure flowchart for an embodiment of the cooling fan system of the present invention. In one embodiment, during the test procedure, the aforementioned... Figure 1 , Figure 4 , Figure 5The baseboard management controller 100 can adaptively control and adjust the speed vectors of multiple fan circuits (e.g., fan circuits 301 to 30N) according to a speed range vector, and receive electrical parameter vectors returned by the multiple fan circuits. Thus, the baseboard management controller 100 can establish a system coefficient table corresponding to each fan circuit, serving as the basis for subsequent system detection of fault prediction states of the multiple fan circuits.

[0076] Please also refer to Figure 4 and Figure 6 The following description, in a specific embodiment, Figure 4 The test procedure flow is as follows: In step S100, the cooling fan system starts the test procedure. The baseboard management controller 100 initializes the operating state of multiple fan circuits and sets the pulse width modulation pins (PPW1~PPWN) and signal feedback pins (PFG1 to PFGN) to drive mode to drive and adjust the speed of multiple fan circuits. In step S101, the baseboard management controller 100 sets the pulse width modulation signal corresponding to multiple fan circuits according to a target speed vector. For example, when the target speed vector is set to (1000 RPM, 8000 RPM, 8000 RPM, 8000 RPM), the target speed corresponding to fan circuit 301 is 1000 RPM, and the target speeds corresponding to fan circuits 302~302N are all 8000 RPM.

[0077] Next, in step S102, the substrate management controller 100 controls multiple fan circuits to operate to the target speed vector based on the target speed vector and the current speed vector corresponding to the speed feedback signal, and waits for the speed of the multiple fan circuits to stabilize in step S103. For example, when the current speed of fan circuit 301 is adjusted to 1000 RPM, the substrate management controller 100 will confirm whether the current speed is stable, for example, within the range of ±50 RPM, based on the speed feedback signal SFG1.

[0078] Once the current speeds of the multiple fan circuits stabilize, the process proceeds to step S104. The baseboard management controller 100 switches the pulse width modulation pin and signal feedback pin to communication mode to receive the preset electrical parameter vectors indicated by the sensing signals (SCS1~SCSN). In step S105, the multiple fan circuits transmit the preset electrical parameter vectors (from the sensing signals SCS1~SCSN) corresponding to the target speed vectors via the signal feedback pins. For example, under the target speed vectors (1000 RPM, 8000 RPM, 8000 RPM, 8000 RPM), the corresponding drive current vectors for the multiple fan circuits are (0.8A, 1.5A, 1.5A, 1.5A), which serve as a reference for normal operation. In step S106, the baseboard management controller 100 calculates an electrical parameter threshold vector based on the returned preset electrical parameter vector. For example, if the normal operating current of the fan circuit 301 at a speed of 1000 RPM is 0.8A, then the current threshold for determining a fault or a fault risk can be set to 0.7A to 0.9A. The relationship between the current threshold and the normal operating current can be, for example, that they have an offset value from each other, or that they have a proportional relationship.

[0079] Step S107 stores the target speed vector, preset electrical parameter vector, and electrical parameter threshold vector (i.e., the system coefficient table) into the memory for use as a basis for subsequent monitoring and fault prediction status detection in the operation mode. Specifically, the vector data can be stored in the memory of the board management controller 100, multiple fan circuits, or multiple bus control circuits. After data storage is completed, in step S108, the board management controller 100 determines whether the set speed range vector has been tested successfully. For example, if the plan is to test the speed range vectors of each of multiple fan circuits at 1000 RPM, 4000 RPM, and 8000 RPM, but only the target speed vector test of fan circuit 301 at 8000 RPM has been completed, it is determined that the test is incomplete, and the process proceeds to step S109. In step S109, the system switches the pulse width modulation pin and signal feedback pin back to drive mode, preparing for the next round of testing. In step S110, the baseboard management controller 100 sets the next target speed vector based on the speed range vector, for example, the target speed vector of fan circuit 302 at 1000 RPM. Then, it returns to step S101 and sets the pulse width modulation signals corresponding to multiple fan circuits based on the target speed vector. This test is repeated until all speed range vectors have been tested. Then, the system enters step S111 and ends the test mode. At this time, the system coefficient tables for multiple fan circuits have been established, and the system can enter the normal operating procedure.

[0080] It should be noted that in some embodiments, step S106 can be omitted. That is, step S107 simply stores the system coefficient table established based on the target speed vector and the preset electrical parameter vector into the memory of the baseboard management controller 100, multiple fan circuits, or multiple bus control circuits. In subsequent operation procedures, the preset electrical parameter vector of the system coefficient table is used to calculate the electrical parameter threshold vector corresponding to the current speed vector, for example, by offset or ratio, thereby detecting the fault prediction status of multiple fan circuits.

[0081] It should be noted that the "vector" in this invention includes multiple data points, each corresponding to a fan circuit. For example, the target speed vector for fan circuits 301 to 30N might be (1000 RPM, 8000 RPM, 8000 RPM, 8000 RPM), where each value sequentially corresponds to the target speed of fan circuits 301, 302, 303, and 30N. Simultaneously, when multiple fan circuits are stably operating at this target speed vector, the returned preset electrical parameter vector can be a drive current vector (0.8A, 1.5A, 1.5A, 1.5A), where each value sequentially represents the drive current of multiple fan circuits 301, 302, 303, and 30N at the target speed.

[0082] It should also be noted that the aforementioned speed range vector may be quite extensive. In some embodiments, the speed range vector includes multiple target speed vectors. For example, if one of a number of fan circuits has a speed range of 1,000 RPM to 10,000 RPM, and the interval between each adjustment is 1,000 RPM, then the number of speed combinations that the system needs to test will increase exponentially.

[0083] Figures 7A to 7C This invention displays three embodiments of the cooling fan system's speed range vectors. The establishment of these vectors can be simple or complex. For example, if the plan is to test the speed range vectors of each of multiple fan circuits at 1000 RPM, 4000 RPM, and 8000 RPM, when establishing the subsystem coefficient table for fan circuit 301, the target speed vectors of the other fan circuits can be stationary (0 RPM) or fixed at a specific speed (e.g., ...). Figure 7A The target speed vector (X) of the fan circuit, or other fan circuits, can also vary with the target speed of the fan circuit 301, for example... Figure 7B As shown, when the rotational speeds of fan circuit 301 are 1000 RPM, 4000 RPM, and 8000 RPM, the rotational speeds of the other fan circuits 302-30N are Y1, Y2, and Y3, respectively. In other embodiments, the rotational speed range vectors of the multiple fan circuits (301-30N) can also vary simultaneously within the same range, for example... Figure 7CAs shown, in target speed vector 1, the speed of multiple fan circuits (301~30N) is Z1. Then, in target speed vector 2, the speed of multiple fan circuits (301~30N) changes to Z2, and so on up to target speed vector 12. Figures 7A to 7C X, Y1~Y3 and Z1~Z12 in the figure are arbitrary rotational speed values.

[0084] It should be noted that the above Figures 7A to 7C The vector range given is merely an example, and the scope of this invention is not limited thereto. It should also be noted that manually testing the aforementioned speed range vector using existing techniques would be excessively resource-intensive and impractical in real-world applications. Therefore, this invention employs the adaptive control mechanism of the baseboard management controller 100, which effectively reduces testing complexity and significantly improves testing efficiency.

[0085] In one embodiment, the system coefficient table is, for example, a lookup table of the target speed vector and the drive current vector, or a lookup table of the target speed vector and the drive current threshold vector. Figure 9 An embodiment showing the system coefficient table of the cooling fan system of the present invention. For example... Figure 9 As shown in the system coefficient table, the variable vector is the target speed vector, while the reference vector is the drive current threshold vector. Specifically, when the target speed vector of fan circuit 301~30N is (1000 RPM, 8000 RPM, 8000 RPM, 8000 RPM), its corresponding drive current threshold vector is (0.7A~0.9A, 1.4A~1.6A, 1.4A~1.6A, 1.4A~1.6A). When the target speed vector is (4000 RPM, 8000 RPM, 8000 RPM, 8000 RPM) and (8000 RPM, 8000 RPM, 8000 RPM, 8000 RPM), their corresponding drive current threshold vectors are (1.1~1.3A, 1.4A~1.6A, 1.4A~1.6A, 1.4A~1.6A), respectively. And (1.4A~1.6A, 1.4A~1.6A, 1.4A~1.6A, 1.4A~1.6A).

[0086] Figure 8 This diagram shows an operating procedure flowchart of an embodiment of the cooling fan system of the present invention. In one specific embodiment, when the server's cooling fan is initially installed and all fans are operating normally, the system will first perform... Figure 6 The test program was completed, and the corresponding system coefficient table was established. After the test program was completed, [the following was done / ... Figure 8 In the normal operating procedure shown, the baseboard management controller can detect the fault prediction status of multiple fan circuits based on the system coefficient table. Please also refer to... Figure 4 and Figure 8 The following description, in a specific embodiment, Figure 4 The operating procedure flow.

[0087] In step S200, the operation procedure begins, and the substrate management controller 100 sets the pulse width modulation pins (PPW1~PPWN) and signal feedback pins (PFG1~PFGN) to drive mode to ensure that multiple fan circuits can receive speed control and feedback their speed status.

[0088] In step S201, the baseboard management controller 100 determines an operating speed vector based on the current environmental conditions. Environmental conditions may include the server's internal temperature, the processor's operating load, the system's cooling requirements, and airflow resistance. For example, in one specific embodiment, if the server's internal temperature is 45°C and the processor's operating load is 50%, the operating speed vector can be set to (2000 RPM, 4000 RPM, 4000 RPM, 4000 RPM) to maintain adequate cooling. If the internal temperature rises to 60°C and the processor load increases to 80%, the operating speed vector can be adjusted to (6000 RPM, 8000 RPM, 8000 RPM, 8000 RPM).

[0089] In step S202, the baseboard management controller 100 reads or calculates an electrical parameter threshold vector corresponding to the operating speed vector from its own memory, the memory of multiple fan circuits, or the memory of multiple bus control circuits. For example, if the operating speed vector is (2000 RPM, 4000 RPM, 4000 RPM, 4000 RPM), its corresponding electrical parameter threshold vector (e.g., drive current threshold vector) can be (0.9A~1.1A, 1.3A~1.5A, 1.3A~1.5A, 1.3A~1.5A).

[0090] It should be noted that the operating speed vector may not directly correspond to the system coefficient table (e.g., drive current threshold table) established by the test program. For example, if the operating speed vector is (3000 RPM, 5000 RPM, 5000 RPM, 5000 RPM), but the system coefficient table established by the test program only includes speed data at 1000 RPM, 4000 RPM, and 8000 RPM, then the electrical parameter threshold corresponding to the current speed needs to be derived by calculation. In one embodiment, interpolation can be used to calculate the electrical parameter threshold vector of the operating speed vector. For example, if the test data of fan circuit 301 shows that the current threshold range is 0.7A to 0.9A at 1000 RPM and 1.1A to 1.3A at 4000 RPM, then the fault threshold range at 3000 RPM can be calculated, for example, by linear interpolation.

[0091] Low current threshold: 0.7A + (1.1A - 0.7A) × (3 - 1) / (4 - 1) = 1.03A

[0092] High current threshold: 0.9A + (1.3A - 0.9A) × (3 - 1) / (4 - 1) = 1.23A

[0093] Similarly, the electrical parameter thresholds for several other fan circuits can be calculated using this method to ensure that the system can still be monitored based on reasonable estimations even in the absence of direct data. Furthermore, the introduction of this calculation method ensures greater system flexibility, enabling it to dynamically respond to different operating scenarios and provide accurate fault detection capabilities even if the test program does not cover all possible speed range vectors.

[0094] Next, in step S203, the substrate management controller 100 provides feedback control to operate multiple fan circuits to the operating speed vector. For example, fan circuit 301 is adjusted to 2000 RPM, and other fan circuits 302~30N are adjusted to 4000 RPM, until multiple fan circuits operate at the target speed vector.

[0095] In step S204, the system waits for multiple fan circuits to stabilize at the target speed vector and detects whether the speed fluctuation is within the allowable range, such as ±50 RPM, through the signal feedback pin. Once the speeds of the multiple fan circuits stabilize, the system proceeds to the next step.

[0096] In step S205, the substrate management controller 100 switches the pulse width modulation pin and signal feedback pin to communication mode to receive the current electrical parameter vectors of multiple fan circuits corresponding to the operating speed vector. In step S206, the multiple fan circuits feedback their current electrical parameter vectors, such as the drive current vector (1.0A, 1.4A, 1.4A, 1.4A).

[0097] In step S207, the baseboard management controller 100 determines whether the current electrical parameter vector falls within the range of the electrical parameter threshold vector. For example, if the returned current electrical parameter vector is (1.0A, 1.6A, 1.4A, 1.4A), and the electrical parameter threshold (e.g., drive current threshold) of the fan circuit 302 is 1.3A to 1.5A, then the current electrical parameter of the fan circuit 302 exceeds the electrical parameter threshold. The system determines that the current electrical parameter vector exceeds the electrical parameter threshold vector, thereby determining that multiple fan circuits have a fault prediction state (i.e., a fault has occurred, or there is a possibility that a fault will occur in the short term).

[0098] If the result of step S207 is yes, meaning that multiple fan circuits have a fault prediction state, then proceed to step S209, where the baseboard management controller 100 transmits a fault prediction notification to remind the system administrator or maintenance personnel to perform maintenance, repair, or replacement. If the result of step S207 is no, meaning that the current electrical parameter vectors of multiple fan circuits are within the range of electrical parameter threshold vectors, then proceed to step S208.

[0099] In step S208, the baseboard management controller 100 switches the pulse width modulation pin and the signal feedback pin back to the drive mode, then returns to step S201, determines the next operating speed vector based on the current environmental conditions, and then repeats the operations below step S202 to continuously detect whether multiple fan circuits have a fault prediction state, thereby ensuring system stability.

[0100] The present invention has been described above with reference to preferred embodiments. However, the above description is only intended to facilitate understanding of the invention by those skilled in the art and is not intended to limit the scope of the invention. The described embodiments are not limited to individual application and can also be used in combination. For example, two or more embodiments can be used in combination, and a portion of a configuration in one embodiment can be used to replace a corresponding configuration in another embodiment. Furthermore, within the same spirit of the invention, those skilled in the art can conceive of various equivalent changes and combinations. For example, the phrase "processing or calculating based on a signal or generating an output result" in the present invention is not limited to the signal itself, but also includes, when necessary, performing voltage-to-current conversion, current-to-voltage conversion, and / or proportional conversion on the signal, and then processing or calculating based on the converted signal to generate an output result. Therefore, within the same spirit of the invention, those skilled in the art can conceive of various equivalent changes and combinations, and there are many ways to combine them, which will not be listed here. Therefore, the scope of the present invention should cover the above and all other equivalent changes.

Claims

1. A heat dissipation fan system capable of self-adaptive failure prediction, comprising: a plurality of fan circuits including a corresponding plurality of fan devices for driving the corresponding plurality of fan devices according to a corresponding plurality of pulse width modulation signals; a plurality of fan circuits, each of which is capable of driving a corresponding fan to rotate at a corresponding target speed, and each of which is capable of returning a corresponding speed feedback signal to a management controller, and each of which is capable of returning a corresponding preset electrical parameter vector to the management controller, wherein the corresponding preset electrical parameter vector corresponds to the corresponding target speed; and a management controller, which is used to control and adjust the plurality of fan circuits in a test procedure and an operation procedure, thereby detecting a failure prediction state of the plurality of fan circuits; wherein in the test procedure, the management controller feeds back a current speed vector of the plurality of fan circuits to a target speed vector according to the speed feedback signal returned by each of the plurality of fan circuits, and establishes a system coefficient table according to the preset electrical parameter vector returned by the plurality of fan circuits corresponding to the target speed vector, wherein the system coefficient table comprises the target speed vector and the corresponding preset electrical parameter vector or a corresponding electrical parameter threshold vector; 2. The self-adaptable failure predictable heat dissipation fan system of claim 1, wherein, wherein in the operation procedure, the management controller determines an operation speed vector according to an environmental condition, and feeds back the current speed vector of the plurality of fan circuits to the operation speed vector, and then detects the failure prediction state of the plurality of fan circuits according to the system coefficient table, wherein the failure prediction state corresponds to a current electrical parameter vector of the plurality of fan circuits exceeding the electrical parameter threshold vector.

3. The self-adaptable failure predictable heat dissipation fan system of claim 2, wherein, The target speed vector is determined according to a speed range vector, and the speed range vector comprises a plurality of target speed vectors.

4. The self-adaptable failure predictable heat dissipation fan system of claim 2, wherein, The speed range vector is determined according to system preset or according to user. The system coefficient table comprises a subsystem coefficient table of each of the plurality of fan circuits; wherein in the subsystem coefficient table corresponding to one of the plurality of fan circuits, the target speed vector comprises a plurality of target speeds of the one of the plurality of fan circuits and a fixed target speed of the others of the plurality of fan circuits, and the preset electrical parameter vector comprises a plurality of preset electrical parameters of the one of the plurality of fan circuits; 5. The self-adaptable failure predictable heat dissipation fan system of claim 2, wherein, The subsystem coefficient table of the one of the plurality of fan circuits is established according to the plurality of target speeds of the one of the plurality of fan circuits, the fixed target speed of the others of the plurality of fan circuits, and the plurality of preset electrical parameters corresponding thereto. The system coefficient table comprises a subsystem coefficient table of each of the plurality of fan circuits; wherein in the subsystem coefficient table corresponding to each of the plurality of fan circuits, the target speed vector comprises a plurality of target speeds of all the plurality of fan circuits, and the preset electrical parameter vector comprises a plurality of preset electrical parameters of all the plurality of fan circuits; 6. The self-adaptable failure predictable heat dissipation fan system of claim 2, wherein, The subsystem coefficient table of each of the plurality of fan circuits is established according to the plurality of target speeds of all the plurality of fan circuits and the plurality of preset electrical parameters corresponding thereto.

7. The self-adaptable failure predictable heat dissipation fan system of claim 6, wherein, The management controller communicates with the plurality of fan circuits through a serial bus communication mode, thereby controlling and adjusting the plurality of fan circuits, and detecting the failure prediction state of the plurality of fan circuits. Further comprising:

8. The self-adaptable failure predictable heat dissipation fan system of claim 7, wherein, a plurality of bus control circuits, which are correspondingly coupled to the plurality of fan circuits, are used to communicate with the management controller through a serial data line and a serial clock line, thereby controlling and adjusting the plurality of fan circuits, and detecting the failure prediction state of the plurality of fan circuits.

9. The self-adaptable failure predictable heat dissipation fan system of claim 1, wherein, The system coefficient table established in the test procedure is stored in the management controller, the plurality of fan circuits, or the plurality of bus control circuits. The management controller comprises: a plurality of first multi-task pins for transmitting the plurality of pulse width modulation signals to the plurality of fan circuits in a driving mode, and for transmitting a plurality of clock signals to the plurality of fan circuits in a communication mode; and a plurality of second multi-task pins for receiving a current speed vector returned by the plurality of fan circuits in the driving mode to feedback control the current speed vector to the target speed vector, and for receiving the preset electrical parameter vector or the current electrical parameter vector returned by the plurality of fan circuits in the communication mode to detect the failure prediction state of the plurality of fan circuits.

10. The self-adaptable failure predictable heat dissipation fan system of claim 1, wherein, In the operation procedure, the management controller further reads or calculates the electrical parameter threshold vector corresponding to the operation speed vector according to the system coefficient table, thereby detecting the failure prediction state of the plurality of fan circuits.

11. The self-adaptable failure predictable heat dissipation fan system of claim 1, wherein, The environmental condition includes a system temperature, a system load or an airflow resistance of the heat dissipation fan system.

12. The self-adaptable failure predictable heat dissipation fan system as claimed in claim 1, wherein, The current electrical parameter vector includes a driving current, a driving voltage or a duty cycle of each of the plurality of fan circuits.

13. The self-adaptable failure predictable heat dissipation fan system as claimed in claim 1, wherein, The current speed vector of the plurality of fan circuits is positively correlated to the current electrical parameter vector.

14. The self-adaptable failure predictable heat dissipation fan system as claimed in claim 1, wherein, The system coefficient table established in the test procedure is stored in the management controller or the plurality of fan circuits.

15. A control method for controlling a heat dissipation fan system, wherein the heat dissipation fan system includes a plurality of fan circuits for driving a plurality of fan devices according to a plurality of corresponding pulse width modulation signals, and a management controller for detecting a failure prediction state of the plurality of fan circuits; the control method comprises: In a test procedure, a current speed vector of the plurality of fan circuits is feedback controlled to a target speed vector according to a speed return signal returned by each of the plurality of fan circuits, and a system coefficient table is established according to a preset electrical parameter vector corresponding to the target speed vector returned by the plurality of fan circuits, wherein the system coefficient table includes the target speed vector and a corresponding preset electrical parameter vector or a corresponding electrical parameter threshold vector; and In an operation procedure, an operation speed vector is determined according to an environmental condition, the current speed vector of the plurality of fan circuits is feedback controlled to the operation speed vector, and the failure prediction state of the plurality of fan circuits is detected according to the system coefficient table, wherein the failure prediction state corresponds to a current electrical parameter vector of the plurality of fan circuits exceeding the electrical parameter threshold vector.

16. The control method of claim 15, wherein, The test procedure further includes determining the target speed vector according to a speed range vector; wherein the speed range vector includes a plurality of target speed vectors.

17. The control method of claim 16, wherein, The test procedure further includes determining the speed range vector according to system preset or according to user.

18. The control method of claim 16, wherein, The system coefficient table includes a subsystem coefficient table of each of the plurality of fan circuits; The target speed vector includes target speeds of the one of the plurality of fan circuits and a fixed target speed of the other of the plurality of fan circuits, and the preset electrical parameter vector includes preset electrical parameters of the one of the plurality of fan circuits. The test procedure further includes establishing the subsystem coefficient table of the one of the plurality of fan circuits according to the target speeds of the one of the plurality of fan circuits, the fixed target speed of the other of the plurality of fan circuits, and the corresponding preset electrical parameters.

19. The control method of claim 16, wherein, The system coefficient table includes a subsystem coefficient table of each of the plurality of fan circuits. The target speed vector includes target speeds of all of the plurality of fan circuits, and the preset electrical parameter vector includes preset electrical parameters of all of the plurality of fan circuits. The test procedure further includes establishing the subsystem coefficient table of each of the plurality of fan circuits according to the target speeds of all of the plurality of fan circuits and the corresponding preset electrical parameters.

20. The control method of claim 16, wherein, The test procedure or the operation procedure further includes controlling the management controller and the plurality of fan circuits to communicate by a serial bus communication mode, thereby controlling and adjusting the plurality of fan circuits and detecting the failure prediction state of the plurality of fan circuits.

21. The control method of claim 20, wherein, The test procedure or the operation procedure includes controlling the management controller and the plurality of fan circuits to communicate by a serial data line and a serial clock line, thereby controlling and adjusting the plurality of fan circuits and detecting the failure prediction state of the plurality of fan circuits.

22. The control method of claim 15, wherein, The test procedure or the operation procedure further includes: In a driving mode, transmitting the plurality of pulse width modulation signals to the corresponding plurality of fan circuits and receiving a current speed vector returned by the corresponding plurality of fan circuits to feedback control the current speed vector according to the target speed vector; and In a communication mode, transmitting a plurality of clock signals to the corresponding plurality of fan circuits and receiving the preset electrical parameter vector or the current electrical parameter vector returned by the corresponding plurality of fan circuits to detect the failure prediction state of the plurality of fan circuits.

23. The control method of claim 15, wherein, The operation procedure further includes: According to the system coefficient table, reading or calculating the electrical parameter threshold vector corresponding to the operation speed vector, thereby detecting the failure prediction state of the plurality of fan circuits.

24. The control method of claim 15, wherein, The environmental condition includes a system temperature, a system load, or an airflow resistance of the heat dissipation fan system.

25. The control method of claim 15, wherein, The current electrical parameter vector includes a driving current, a driving voltage, or a duty cycle of each of the plurality of fan circuits.

26. The control method of claim 15, wherein, A current speed vector of the plurality of fan circuits is positively correlated with the current electrical parameter vector.

27. The control method of claim 15, wherein, The test procedure further includes storing the system coefficient table in the management controller or the plurality of fan circuits.

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