Development of a New Model of Single-Speed Air Conditioners at Part-Load Conditions for Hourly Simulations

2005 ◽  
Vol 127 (2) ◽  
pp. 294-301 ◽  
Author(s):  
Thierry Alex Mara ◽  
Eric Fock ◽  
Franc¸ois Garde ◽  
Frank Lucas
Keyword(s):  
Sensitivity Analysis ◽  
System Performance ◽  
Hvac Systems ◽  
Time Step ◽  
Air Conditioners ◽  
New Model ◽  
Part Load ◽  
Step Model ◽  
Short Time ◽  
Load Conditions

This paper deals with a new model of HVAC systems for hourly simulations. The former is derived from a short time step model that is priory described. The hourly model is appraised by comparing its predictions to those of the short time step simulations. Finally, a sensitivity analysis is carried out to understand the cause of the discrepancies between the two models when it occurs. The analysis also allows to identify the factors that mainly affect the system performance.

scholarly journals An Adaptive Model Predictive Voltage Control for LC-Filtered Voltage Source Inverters

2021 ◽  
Vol 11 (2) ◽  
pp. 704
Author(s):  
Hosein Gholami-Khesht ◽  
Pooya Davari ◽  
Frede Blaabjerg
Keyword(s):  
Control System ◽  
System Performance ◽  
State Space Model ◽  
Adaptive Observer ◽  
Voltage Source ◽  
Adaptive Model ◽  
Space Model ◽  
System Uncertainties ◽  
Augmented State ◽  
Load Conditions

The three-phase inductor and capacitor filter (LC)-filtered voltage source inverter (VSI) is subjected to uncertain and time-variant parameters and disturbances, e.g., due to aging, thermal effects, and load changes. These uncertainties and disturbances have a considerable impact on the performance of a VSI’s control system. It can degrade system performance or even cause system instability. Therefore, considering the effects of all system uncertainties and disturbances in the control system design is necessary. In this respect and to tackle this issue, this paper proposes an adaptive model predictive control (MPC), which consists of three main parts: an MPC, an augmented state-space model, and an adaptive observer. The augmented state-space model considers all system uncertainties and disturbances and lumps them into two disturbance inputs. The proposed adaptive observer determines the lumped disturbance functions, enabling the control system to keep the nominal system performance under different load conditions and parameters uncertainty. Moreover, it provides load-current-sensorless operation of MPC, which reduces the size and cost, and simultaneously improves the system reliability. Finally, MPC selects the proper converter voltage vector that minimizes the tracking errors based on the augmented model and outputs of the adaptive observer. Simulations and experiments on a 5 kW VSI examine the performance of the proposed adaptive MPC under different load conditions and parameter uncertainties and compare them with the conventional MPC.

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