AIT Test Case - District heating production units following electrical network optimal schedule
The test case provides a set of conditions under which a test can determine whether or how well a system, component or one of its aspects is working given its expected function.
Name of test case: District heating production units following electrical network optimal schedule
Scope and Goal
What is the test objective, i.e. what is the purpose of carrying out the test? Try to formulate the objective within one of the following three categories:
- Characterization: a measure is given without specific requirements for passing the test. Examples: understanding the behaviour of a system, developing a mathematical model of a component.
- Validation: a requirement and abstract measure is provided, but the results are subject to interpretation, i.e. passing a test depends on a qualitative evaluation by an expert or user of the system. These tests seek to answer the question are we building the right system? Example: Is the mathematical model good enough?
- Verification: acceptance of a test result depends on the direct evaluation against fixed and formalized assessment criteria. These criteria can be formulated as quantitative measures with a set/range of acceptable values of these measures, i.e. quantitative tests. These tests seek to answer the question are we building the system right? Example: Testing whether a component conforms to a standard.
Verification of operational strategy of thermal-electrical coupling units and thermal storages (e.g., heat pumps and CHPs)
To which system configuration does this test apply? Pseudodorf
To which use case does this test apply? Joint Use Case 3 / AIT UC 1
Formulate one paragraph of narrative summarizing the test and its purpose:
This test verifies the capability of thermal production units and storages in a district heating network to follow an operational schedule received from the electrical network operator. The goal of this schedule is to maximize the utilization of local surplus electricity while considering electrical network restrictions. Therefore, heat pump and CHP operation aims at following electrical network demand. The test verifies that the thermal production units can follow this schedule while maintaining necessary district heating network requirements and without worsening electrical grid condition.
Identification of Test Components
What is the System Under Test, i.e. which subset of the entire system configuration needs to be simulated in order to achieve the test objective? (Note: In some cases this may be the entire system)
The thermal domain is meant to provide flexibility to the electrical domain. A schedule is enforced at the thermal production units that aim at following this schedule as closely as possible, considering district heating network requirements. Thermal storages are used to thereby increase operational flexibility of these units. Hence the SuT comprises:
- The district heating network
- The thermal production units (especially all powerto-heat and CHP appliances)
- The thermal storage units
- The electrical distribution network
What is the Object Under Investigation, i.e. which are the components of the System Under Test that are to be characterized or validated?
What is the Function Under Investigation, i.e. which of the system behaviour defined in the use case is to be characterized, validated or verified?
- Negative residual load of electrical network
- Deviations from original production schedule
- Supply line temperature limits at consumers
- Voltage levels at thermal-electrical coupling points (i.e., at CHP and HP)
- Loading of transformer and lines
Formulate the target metrics, i.e. a list of quantities in the context of the System Under Test which can be used to qualify/quantify the test result with respect to the test objective.
- Sum of negative residual load of electrical network is significantly reduced
- Deviations from original production schedule are small
- Temperature operating limits of district heating network are not violated
- Electrical network constraints (such as component loading and voltages levels) are not further violated compared to base case (i.e., no coupling)
Define quality attributes for assessing an acceptable test result. In case of a characterization test, this may be the remaining model uncertainty. For verification tests, the acceptance threshold (worst case for passing the test) is stated. For validation tests a criterion for ending the test execution is required.
Sum of negative residual loads of electrical network is reduced compared to base case (i.e., no coupling)
Minimal supply line temperature is met at each consumer
Pareto improvement for set of KPIs (e.g., time period where voltage deviations occur, maximum loading of transformer etc.) from electrical domain compared to base case