HYBUILD Control System: functional requirements specification

A new HYBUILD public report led by our partner Engineering has been released on the Deliverables page of our website.

Executive Summary

This report introduces the main steps and requirements for performing an optimised control of the HYBUILD system energy flows in residential buildings by considering internal and external requests. The process involves the definition of the systems operations and layouts, along with user scenarios and use cases in order to define high-level functionalities of the Building Energy Management System (BEMS).

This report is part of the work which addresses the development of the BEMS in accordance to the monitoring strategy and system defined in earlier activities. Relying on a strict cooperation between the simulation tools and the optimiser, the models take advantage from earlier project outputs in which the software TRNSYS is used for simulating the behaviour of the building thermal flows.

The dissertation begins from the general layout of the HYBUILD Mediterranean and Continental configurations, which is then adapted to the three demo-sites (see our Pilots page). Piping and Instrumentation Diagram (P&ID) and descriptions of sensors and components are provided in order to understand the differences in each specific case.

A thorough work has been done for defining the system operational modes. In this document, for each of them, the specific status of pumps, valves and equipment has been identified in order to schedule all the possible configurations of the Mediterranean and Continental solutions.

The other part of the report is dedicated to the software analysis. It was performed for defining the specifications of the BEMS, also considering its integration with Distribution Service Operators (DSOs) and energy retailer entities, in order to participate to Demand Response (DR) programmes. For this purpose, a methodological approach composed by three main steps has been adopted:

  • Usage scenario description;
  • Use case definition;
  • Requirements elicitation.

The first step is the usage scenarios description; a scenario is a narrative description of a realistic situation which takes place in each demo site. Thanks to this approach, the potential users can well-understand the BEMS functionalities and return feedbacks on the tools features. From the proposed and validated scenarios, pieces of system behaviour can be extracted. These elements are the use cases and represent the second step of the used methodology. By means of the use cases, a step-wise representation of the energy processes performed by the BEMS is given. In the end, functional and non-functional software requirements have been listed taking into account the actions addressed by each step of the use case modelling. While the functional requirements determine the behaviour expected by the software components for reaching the objectives detailed in the use cases, the non- functional requirements define the performance attributes of the system.

Figure: Early BEMS software architecture

In conclusion, three main pillars can be extracted from the present report. The first is the higher detailed P&IDs, better defined in terms of components, sensors and valves and related to both Mediterranean and Continental solutions. Afterwards, the definition of conditions and constraints related to the operational modes is noteworthy since they determine the activation of the different parts of the system for satisfying the four identified categories of operational modes: heating modes, cooling modes, domestic hot water (DHW) modes, and charging modes. The third pillar is the definition of the BEMS functional requirements, which represent the arrival point of a shared view of the software behaviour and will drive the BEMS implementation activities. Below, some of these identified requirements are listed together with a brief description.

  • Building Energy Management System optimiser – BEMS OPT. The module will be able to perform the requested optimisation process, re-working the requests in case of unexpected events and processing operational modes in case of missing connectivity.
  • Building Energy Management System energy manager/user dashboard – BEMS EMD/EUD. The modules provide all the graphical interface functionalities to the energy manager and the energy users, respectively. These dashboards are able to get the inputs and show to the energy manager/user the results of the optimisation process.
  • Building Energy Management System reporting module – BEMS REP. This module calculates the energy consumptions and other energy and economical related data in a chosen time period.
  • Building Energy Management System monitoring module – BEMS MON. This module retrieves energy, temperature and all the relevant data from the building and notifies potential operational discrepancies.

Read the full report

Download the full report here