Master's Thesis Björn Michael Pauly

 

Petri-net-based control of building energy compound systems

The aim of this thesis is the development and proving of a Petri-net-based control for building energy
compound systems. Additionally, Petri nets are proved for the implementation of a mode-based
control. Therefore different real energy compound systems aremodelled and controlled using Petri
nets.
Initially, the theory of Petri nets is presented and methods for their analysis are introduced. The
basis for the description of controls are statecharts, which are used according to VDI 3814 sheet 6.
To generate Petri net-based controls, methods for the conversion of statecharts to Petri nets and
backwards are presented.
After that, the mode-based consideration for requirements and controls of buildings are introduced.
To quantify the requirements, room-modes are presented. For the satisfaction of the requirements
a three-parted structure of controls is shown.
As first usage Petri nets are inserted in an existing control-model of a battery storage device. After
that the influence of the Petri-net-elements is discussed. It is shown that the usage of Petri nets
in the existing model is possible. As an example for the implementation of mode-based control a
control for the energy compound system of an appartement is elaborated and implemented. Based
on the description of these control a system-based and a mode-based approach for the Petri net
building process are demonstrated. It is shown that the previously introduced analysis methods of
Petri nets are useful to verify the control in the build-up-process. Additionally, it is presented that
Petri nets are suitable for the implementation of mode-based controls. After that, the functionality
of system-based and mode-based Petri nets is demonstrated.
In the last partmethods for the reduction of Petri nets and the building process of hierarchical Petri
nets in reference to the builded Petri nets are shown. Finally, it is demonstrated that the transformation
of both constructed Petri nets in a statechart is possible.