| 1. |
- Lionello, Michele, et al.
(författare)
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Energy‐efficient operation of indirect adiabatic data center cooling systems via Newton‐like phasor extremum seeking control
- 2021
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Ingår i: International journal of adaptive control and signal processing (Print). - : John Wiley & Sons. - 0890-6327 .- 1099-1115. ; 35:7, s. 1298-1315
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Tidskriftsartikel (refereegranskat)abstract
- This paper considers the problem of optimizing the operation of Indirect Adiabatic Cooling (IAC) systems with application to data centers. Optimal operation is achieved when the required cooling demand is satisfied at the minimum energy cost. For this purpose, we design a supervisory control system, where the higher layer determines the optimal set‐points for the local controllers by employing an Extremum Seeking Control (ESC) scheme. In particular, we consider a Newton‐like phasor ESC, which augments the derivative estimator underlying the phasor approach to capture also the Hessian of the plant index and then it uses these estimates to steer the system along a Newton‐like direction. The effectiveness of the considered approach is tested in simulation by exploiting a Matlab‐based simulation environment including an IAC system and a computer room.
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| 2. |
- Lucchese, Riccardo, et al.
(författare)
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Newton-like phasor extremum seeking control with application to cooling data centers
- 2019
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Ingår i: IFAC-PapersOnLine. - : IFAC Papers Online. - 2405-8963.
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Konferensbidrag (refereegranskat)abstract
- We design a Newton-like phasor-based Extremum Seeking Control (ESC) aimed at multi-variable nonlinear control systems. We first augment the derivative estimator underlying the phasor approach to capture the Hessian of the plant index. Then we use these estimates to steer the system along a Newton-like direction. We assess the closed-loop stability of the proposed scheme and demonstrate its effectiveness in a data center cooling scenario.
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| 3. |
- Lucchese, Riccardo, et al.
(författare)
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On Economic Cooling of Contained Server Racks using an Indirect Adiabatic Air Handler
- 2020
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Ingår i: Thirty Sixth Annual Semiconductor Thermal Measurment, Modeling and Management Symposium. - : IEEE. ; , s. 24-31
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Konferensbidrag (refereegranskat)abstract
- We study the economic operation of a free-cooling setup in which an Indirect Adiabatic Air Handler (IAAH) recovers heat from an array of server racks placed in a contained aisle. For this setting we propose two different control policies: in the first approach, the airflow supply rate to the racks is maintained constant while only the process- side operations of the IAAH are optimized. In the second approach, also the room-side rate is updated adaptively. Building on calibrated models of the IAAH and the servers, we design experimental trials considering different outdoor temperatures and humidity conditions as well as varying computational workloads. The in silico analysis contributes actionable insights on the optimal thermal and cost operations of the system.
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