Multi-objective inversion-based control of building integrated energy systems

Student thesis: Doctoral Thesis

Abstract

Buildings are a key target for energy efficiency measures and the integration of renewable technologies. However, a high penetration of intermittent renewable energy in the electrical grid and in the buildings themselves will result in a reduction of the grid’s ability to absorb excess generation freely.One method for improving the efficiency of buildings and addressing the intermittent availability of renewables is to make them more energy autonomous i.e. creating and consuming the majority of their own energy. The needs of a building cannot usually be met by a single energy resource alone, but requires the adoption and coordinated operation of a multitude of energy sources such as combined heat and power (chp) units, thermal energy storage (tes), electrical energy storage (ees) and photovoltaics (pv). Making these systems work together presents a control challenge for their efficient use, especially since they can have a simultaneous effect on both the thermal and electrical energy networks.This research addresses the design of a robust multi-input multi-output (mimo) controller applicable to any configuration of the aforementioned systems, with the control goal of minimising the electrical grid utilisation of a building while fulfilling the thermal demands of the building. The controller employs the inverse dynamics of the building, mechanical/servicing systems, and energy storage with a robust control methodology. This inverse dynamics provides the controller with knowledge of the complex cause and effect relationships between the system, the controlled inputs, and the external disturbances, while an outer-loop control ensures robust, stable control in the presence of modelling deficiencies/uncertainty and unknown disturbances.The physical limitations of the systems are also accounted for via variable structure control whereby the control strategy employed switches depending on the current utilisation and availability of the energy supplies.Results indicate that the control strategy is effective in minimising the electrical grid use and maximising the utilisation of the available energy when compared to conventional system operation.
Date of Award1 May 2014
LanguageEnglish
Awarding Institution
  • University Of Strathclyde
SponsorsEPSRC (Engineering and Physical Sciences Research Council) & BRE Trust
SupervisorNicolas Kelly (Supervisor)

Cite this