CN104454616A - Method for accurately regulating and controlling rotating speed of fan - Google Patents

Abstract

The invention provides a method for precisely controlling the fan speed, which relates to the field of system heat dissipation. The invention simultaneously calculates the difference between the actual temperature read by multiple sensors and the set temperature, and compares these temperature differences. Mathematical calculations determine the fan PWM that can meet the heat dissipation requirements of all monitored hot spots at the same time, and finally pass this PWM to the fan through the motherboard to realize real-time monitoring and fast feedback regulation of the fan speed.

Description

A Method of Accurately Regulating Fan Speed

technical field

The invention relates to system heat dissipation technology, in particular to a method for precisely regulating the rotating speed of a fan. the

Background technique

In recent years, the rapid development of Internet and cloud computing technology has affected and changed people's lives in all aspects, and these developments are inseparable from the support of hardware technology, that is, the support of server-based data centers. The data center computer room is a large-scale occasion where high-density, high-performance servers are intensively used. When it comes to data centers, words such as "temperature", "green", and "power consumption" are often used, because the stable operation of the data center affects the heat dissipation of the server. And the environmental requirements are particularly high. A good server heat dissipation design can ensure the stable operation of the equipment, prolong the life cycle of the equipment, reduce the failure rate, reduce the power consumption of the computer room, and save operation and maintenance costs.

In addition, under the development trend of electronic products getting smaller and smaller, but their performance is getting stronger and stronger, heat dissipation has become an extremely important issue in system design. If the heat dissipation is not handled properly, the operating speed of the system will be slowed down and the life of components will be reduced. Shorten, but also limit the size of the product. The server is famous for its high density and high performance. In order to achieve greater processing capacity and faster computing speed, it is often necessary to integrate and interconnect multiple subsystems to achieve performance that is far beyond the reach of a single server. Such a high-density, high-performance design is usually accompanied by high power consumption and high heat generation, so it is a very serious challenge to the system's heat dissipation reliability and noise control. There are several sources of server noise: system fans, power supply fans, and hard disk motors, with system fans being the main noise source. In order to control fan noise, the common practice in the industry is to adjust the fan speed according to different system loads. When the system load is relatively low, the fan speed can be appropriately reduced. Only when the system internal heat-generating components are relatively high under high load can the fan speed be increased. meet its cooling needs. However, the previous fan control strategy was set based on the temperature of the processor. However, during the actual server operation, in addition to the processor, other heat-generating components in the system or certain chips on the motherboard may also have heat dissipation risks. Even more serious than the heat dissipation problem of the processor, adjusting the fan speed only based on the temperature of the processor cannot accurately reflect the reliability of the system operation, nor can it obtain an accurate fan control strategy, and ultimately cannot control the fan noise well or reduce the fan speed. power consumption. the

Contents of the invention

In view of the above problems, the present invention proposes a method for precisely regulating the fan speed, which can effectively control the system noise, reduce the vibration amplitude and frequency on the basis of ensuring the reliability of system heat dissipation, and better protect the long-term operation of each component in the system at a stable temperature It can also reduce the power consumption caused by heat dissipation, realize energy saving and consumption reduction, and effectively guarantee the life and performance of CPU, memory, hard disk and other components.

The present invention is used in high-end integrated applications of large servers. The present invention proposes a method for precisely controlling the fan speed of the server. A pair of temperature sensors (Sensors) are arranged in the motherboard and the system to monitor the temperature of suspicious heating components in the system. The device sets an appropriate operating point temperature (Sensor Set point), and automatically calculates the difference between these sensor readings (Sensor Reading) and the set point (ΔT= Reading-Set point) through the controller, based on these differences based on a certain The algorithm performs weighted calculations to determine the PWM that needs to be output to the fan, so as to realize real-time monitoring, fast response and regulation of the fan speed.

The layout of the temperature sensor is based on the pre-specified sensor layout rules to determine several major areas. At the same time, it needs to be adjusted according to the layout characteristics of the server and the risk points evaluated by the previous heat dissipation simulation. The suspicious hot spots on the main board and other boards in the system are arranged. A plurality of sensors, the plurality of sensors can monitor and read a plurality of temperature values.

The sensor transmits the currently read temperature value to the controller, and the controller will compare it with the preset target value. If there is a deviation, then calculate the deviation to obtain the required PWM value and output it to the fan. Work according to the given PWM to reduce the sensor deviation; then enter the next cycle, the sensor reads the current value of the sensor again, and so on, until the fan's working speed can make the sensor deviation equal to or close to zero. In each cycle, the controller will compare these PWM values, pass the maximum value of these multiple PWMs to the fan, and identify and mark the sensor corresponding to this PWM as the master sensor. During this process, the controller continuously calculates, compares, and adjusts the PWM output value. The main sensor of each cycle may be different, but the ultimate goal is to make the real-time values of all sensors tend to the set value, so that all heat The components and the suspicious heating pad can all run stably at a suitable temperature, and the system fan keeps a certain speed and tends to be stable, reducing its vibration amplitude and frequency, so that the entire server system remains in a relatively stable state. Compared with the traditional way of regulating the fan speed only based on the temperature of the processor, this control method has the following advantages:

1) It can keep all sensors at a certain temperature;

2) As long as the temperature deviates from the set point, the fan PWM can be increased or decreased accordingly to increase or decrease the fan speed;

3) Save the energy consumption of the fan;

4) It is easier to get a more precise and accurate fan control curve and reduce fan noise.

This invention can greatly improve the timeliness and accuracy of fan regulation, comprehensively monitor the heat dissipation risk points and the temperature of heating components in the system, improve the reliability of the system, effectively control the power consumption and noise of the system, and prolong the service life of components.

Description of drawings

Figure 1. The logical schematic diagram of the traditional method of regulating the fan speed of the server system.

Fig. 2 is a diagram of a server system fan control scheme based on traditional fan control methods.

Fig. 3 is a logical schematic diagram of the method for precisely regulating the fan speed in the present invention.

Fig. 4 is a diagram of a fan control scheme of a server system based on the method of precisely controlling the fan speed.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail in conjunction with the accompanying drawings, and the process of realizing this method for effectively regulating the fan speed of the server system will be described with specific examples, and compared with conventional Compared with the fan control methods, how the control method proposed in the present invention can efficiently monitor the fan speed, reduce fan noise and power consumption, better protect the various components in the system can work at a stable temperature for a long time, and effectively ensure that the CPU, memory, hard disk life and performance of components.

As shown in Figure 1, the conventional fan control method only regulates the system fan according to the temperature of the CPU. The controller reads the temperature Tj or the temperature difference ΔTj of the CPU from the inside of the CPU. Corresponding to the system fan speed, each ΔTj has a fan PWM value corresponding to it, and this PWM is transmitted to the fan through the controller to realize the control and adjustment of the system fan speed.

As shown in Figure 2, it is a server system fan control scheme based on the traditional fan control method. From the curve relationship between CPU temperature and fan PWM, it can be seen that this linear adjustment method is relatively extensive, and only the CPU temperature cannot It reflects the heat dissipation of the entire server system. The fact that the CPU has no heat dissipation risk does not mean that other components or heat spots in the system have no potential heat dissipation problems; in addition, in order to ensure heat dissipation safety, this control scheme often leaves a certain margin for the fan speed , which is slightly higher than the actual required speed, which is not very good to control the speed within a reasonable range, and the jump between the speed and temperature is relatively large, and the noise and vibration cannot be well controlled.

As shown in Figure 3, as described in the Summary of the Invention, i Sensors are arranged in the system to monitor the temperature of each heating component and suspicious hot spots. Sensor 1 Reading, Sensor 2 Reading...Sensor i Reading, every few seconds For these temperature values, the sensor will transmit the currently read temperature value to the controller, and the controller will compare it with the preset target value Sensor 1 Setpoint, Sensor 2 Setpoint...Sensor i Setpoint, if there is a deviation error, then calculate this deviation error, get the required PWM1, PWM2... PWMi value output to the fan, the fan works according to the given PWM to reduce the sensor deviation; then enter the next cycle, the sensor reads the sensor current value, and so on, until the fan speed can make the sensor deviation equal to or close to zero. In each cycle, the controller will compare these PWM values, pass the maximum value of the i PWMs to the fan, and identify and mark the sensor corresponding to this PWM as the master sensor. During this process, the controller continuously calculates, compares, and adjusts the PWM output value. The main control sensor may be different in each cycle, but the ultimate goal is to make the real-time values of all sensors tend to the set value. In order to make all the Sensor values tend to the set value in the end, it is necessary to set a reasonable and appropriate predetermined value for each Sensor. This setting process needs to combine the actual heat dissipation of the server system and each component monitored by the Sensor or The specifications of the hot spots need to be tested and adjusted repeatedly to get a more reasonable value.

As shown in Figure 4, applying the high-efficiency control method proposed by the present invention in combination with the server system fan control scheme set by the PID controller, the air inlet of the system, CPU, memory, chip, ambient temperature in the area where the chip is located, CPU VR, The memory VR, the ambient temperature of the area where the CPU VR is located, and other heating components of the system, as well as suspicious hot spots/areas, are equipped with Sensors to monitor their temperatures. Setpoint and P/I/D values are preset for these Sensors through a series of heat dissipation tests. These settings can be Form a file that can be recognized by the coordinated BMC or BOIS and import it, and use the PID controller to control the fan speed according to these set values and combined with the real-time temperature Sensor I Reading read by the Sensor.

Claims (5)

1. A method for precisely regulating the fan speed, characterized in that several temperature sensors are arranged in the main board and the system to monitor the temperature of suspicious heating components in the system, and the operating point temperature is set for these components, and the sensor reads The received temperature is transmitted to the controller, and the controller will automatically calculate the difference between the sensor set point and the sensor reading, and determine how to adjust the PWM output to the fan according to these differences, and pass this PWM signal to fan. 2. The method according to claim 1, characterized in that the arrangement of the temperature sensors is based on the predetermined sensor arrangement rules to determine the area, and at the same time needs to be adjusted according to the layout characteristics of the server and the risk points evaluated by the previous heat dissipation simulation, Several sensors are arranged on suspicious hot spots on the main board and other boards in the system, and these sensors can monitor and read several temperature values. 3. The method according to claim 2, wherein the sensor transmits the currently read temperature value to the controller, and the controller will compare it with a preset target value, and if there is a deviation, then the This deviation is calculated, and the required PWM value is output to the fan, and the fan works according to the given PWM to reduce the sensor deviation; then enters the next cycle, the sensor reads the current value of the sensor again, and so on, until the fan works at a speed It is possible to make the sensor bias equal to or close to zero. 4. The method according to claim 3, characterized in that, in each cycle, the controller will compare these PWM values, deliver the maximum value among the several PWMs to the fan, and transfer the corresponding PWM value to the fan. The sensor identifies and marks the master sensor. 5. The method according to claim 4, characterized in that, during this process, the controller continuously calculates, compares and adjusts the PWM output value, and the main control sensor of each cycle is different, finally all the sensors' real-time The value eventually tends to the set value.