Building energy and control system modeling and simulation using Modelica

Abstract

To design and operate energy efficient buildings, it is important to properly account for the dynamic system performance over a wide range of time scales and operating conditions. At the time scale of hours to days, the system dynamics determine how much energy can be stored passively or actively to exploit natural sources for heating and cooling. At the time scale of minutes or even seconds, the system dynamics determine whether equipment is cycling, which can negatively impact its energy performance and may cause premature equipment failure. To design control algorithms that exploit such behavior in order to increase system-level efficient, simulation models need to reflect the change in efficient at various steady-state and dynamic operating conditions[1]. As buildings become increasingly integrated to reduce energy and peak power and to increase occupant comfort and productivity, new challenges are posed to building simulation programs to support decision making during product development, building design, commissioning and operation [2]. These applications require the integration of multiple domains (air-flow, thermodynamics, controls, indoor environmental quality, and electrical grid) and multiple disciplines (HVAC/energy consultant, architect, controls engineer, electrical engineer).Using building simulation programs for such applications leads to new requirements for modeling and simulation tools. A lot of building simulation programs has been developed for the past decades, such as Energy Plus, ESP-r, SPARK, IDAICE or TRNSYS which are written using an imperative language (FORTRAN, C or C++).However, today's building simulation programs were primarily designed as tools for energy analysis and use of these

On the assessment and control optimisation of demand response programs in residential buildings

“…The library contains several standard integration elements that can be used to develop sophisticated algorithms and control designs. The separation between the control elements and the equation systems allows for the possibility to restart the integrator, as in the case of model predictive controllers, or to connect the system to other developing environments such as MATLAB \Simulink for control design [83]. In comparison to TRNSYS or other building simulation software, Modelica has numerous libraries available and it has a faster solver, while the main disadvantage is represented by its modular nature [82].…”