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Optimal Self-Tuning PID Controller Based on Low Power Consumption for a Server Fan Cooling System.

Lee C, Chen R - Sensors (Basel) (2015)

Bottom Line: Because the thermal model of the cooling system is nonlinear and complex, a server mockup system simulating a 1U rack server was constructed and a fan power model was created using a third-order nonlinear curve fit to determine the cooling power consumption by the fan speed control.PIDNN with a time domain criterion is used to tune all online and optimized PID gains.The proposed controller was validated through experiments of step response when the server operated from the low to high power state.

View Article: PubMed Central - PubMed

Affiliation: Department of Power Mechanical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan. d9533820@oz.nthu.edu.tw.

ABSTRACT
Recently, saving the cooling power in servers by controlling the fan speed has attracted considerable attention because of the increasing demand for high-density servers. This paper presents an optimal self-tuning proportional-integral-derivative (PID) controller, combining a PID neural network (PIDNN) with fan-power-based optimization in the transient-state temperature response in the time domain, for a server fan cooling system. Because the thermal model of the cooling system is nonlinear and complex, a server mockup system simulating a 1U rack server was constructed and a fan power model was created using a third-order nonlinear curve fit to determine the cooling power consumption by the fan speed control. PIDNN with a time domain criterion is used to tune all online and optimized PID gains. The proposed controller was validated through experiments of step response when the server operated from the low to high power state. The results show that up to 14% of a server's fan cooling power can be saved if the fan control permits a slight temperature response overshoot in the electronic components, which may provide a time-saving strategy for tuning the PID controller to control the server fan speed during low fan power consumption.

No MeSH data available.


Related in: MedlinePlus

Control results of PID controllers without an overshoot. (a) The temperature responses of the electronic components by the PID controllers; (b) The control efforts of the fans by the PID controllers.
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sensors-15-11685-f010: Control results of PID controllers without an overshoot. (a) The temperature responses of the electronic components by the PID controllers; (b) The control efforts of the fans by the PID controllers.

Mentions: Figure 9 shows the result of the fan speed control by the proposed PID controller for the study’s constructed server. To compare the fan power efficiency, the PID controller results without the temperature response overshoot is shown in Figure 10. In our system, it needs time to response the rising temperature, read by the sensors, while the thermal loading is applied to electronic components. Therefore, the time delayed is seen as shown in Figure 9 and Figure 10. The results of the proposed method indicate that each control effort of the fan consumes less power during the transient time of 800 s. Table 2 and Table 3 show the corresponding PID gains and fan power consumption. It appears that fan power efficiency is more dependent on the transient-state temperature response of the electronic components. In this study, up to 14% of fan power was saved at the time interval of 800 s by the proposed power-based optimization self-tuning PID controller while the 1U rack server operates from the idle to peak power state.


Optimal Self-Tuning PID Controller Based on Low Power Consumption for a Server Fan Cooling System.

Lee C, Chen R - Sensors (Basel) (2015)

Control results of PID controllers without an overshoot. (a) The temperature responses of the electronic components by the PID controllers; (b) The control efforts of the fans by the PID controllers.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4481903&req=5

sensors-15-11685-f010: Control results of PID controllers without an overshoot. (a) The temperature responses of the electronic components by the PID controllers; (b) The control efforts of the fans by the PID controllers.
Mentions: Figure 9 shows the result of the fan speed control by the proposed PID controller for the study’s constructed server. To compare the fan power efficiency, the PID controller results without the temperature response overshoot is shown in Figure 10. In our system, it needs time to response the rising temperature, read by the sensors, while the thermal loading is applied to electronic components. Therefore, the time delayed is seen as shown in Figure 9 and Figure 10. The results of the proposed method indicate that each control effort of the fan consumes less power during the transient time of 800 s. Table 2 and Table 3 show the corresponding PID gains and fan power consumption. It appears that fan power efficiency is more dependent on the transient-state temperature response of the electronic components. In this study, up to 14% of fan power was saved at the time interval of 800 s by the proposed power-based optimization self-tuning PID controller while the 1U rack server operates from the idle to peak power state.

Bottom Line: Because the thermal model of the cooling system is nonlinear and complex, a server mockup system simulating a 1U rack server was constructed and a fan power model was created using a third-order nonlinear curve fit to determine the cooling power consumption by the fan speed control.PIDNN with a time domain criterion is used to tune all online and optimized PID gains.The proposed controller was validated through experiments of step response when the server operated from the low to high power state.

View Article: PubMed Central - PubMed

Affiliation: Department of Power Mechanical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan. d9533820@oz.nthu.edu.tw.

ABSTRACT
Recently, saving the cooling power in servers by controlling the fan speed has attracted considerable attention because of the increasing demand for high-density servers. This paper presents an optimal self-tuning proportional-integral-derivative (PID) controller, combining a PID neural network (PIDNN) with fan-power-based optimization in the transient-state temperature response in the time domain, for a server fan cooling system. Because the thermal model of the cooling system is nonlinear and complex, a server mockup system simulating a 1U rack server was constructed and a fan power model was created using a third-order nonlinear curve fit to determine the cooling power consumption by the fan speed control. PIDNN with a time domain criterion is used to tune all online and optimized PID gains. The proposed controller was validated through experiments of step response when the server operated from the low to high power state. The results show that up to 14% of a server's fan cooling power can be saved if the fan control permits a slight temperature response overshoot in the electronic components, which may provide a time-saving strategy for tuning the PID controller to control the server fan speed during low fan power consumption.

No MeSH data available.


Related in: MedlinePlus