Future Scenario Stress Test

In contrast to the Scaling Stress Test, the Future Scenario Stress Test tool allows to add additional load/generation to the grid and disperse them stochastically.

Methodology

The random stochastic dispersion is known as a Monte Carlo Simulation. The variation ensures, that neither a lucky or unlucky placement of the devices affects the result in an unrealistically positive or negative way.

Starting at the base case of 0 additional devices, the number of new devices is increased in steps of 10% until the defined number is reached. This allows for an assessment of what amout of additional devices will start causing problems in the grid. At each step 100 random distributions of the additional devices are simulated. In total, 1100 power flow calculations are performed.

Holistic vs. Isolated

There are two modes in which the computation can be carried out:

• Holistic: The selected Scenario is applied to all grids. Furthermore, all grids in the project will be calculated together by connecting them by virtue of the Mapping.
• Isolated: The selected Scenario is applied to a single grid. Interactions between grids are not evaluated.

Thus, to account for reciprocal effects between the various voltage levels of a grid, the Holistic mode can be used.

INFO

As the calculation in holistic mode can be very time consuming for large grids, there is an option in the Project Settings to start the calculation for selected scenarios after automatically scheduled Grid Data Updates. This way, Adaptricity can compute new results every night, based on the latest grid models.

Grid

To start a Future Scenario Stress Test in Holistic mode, the Grid dropdown can be left empty.

If a grid is selected from the Grid dropdown, a computation for only that grid is started (Isolated mode).

Grid Upgrades, Connection Request and Scenarios

Grid Upgrades and Connection Requests are applied to the grid by default depending on their status. They are part of the grid model for the duration of the simulation. The selected Grid Upgrades and Connection Requests are visualized in the grid.

To change the default selection, just select or deselect the desired add-ons from the list.

Scenarios and Load Situations are never applied by default. They need to be specifically selected.

INFO

Grid upgrades, connection requests and scenarios defined here are applied first and then the Scenario is simulated with these add-ons.

Scenario

Scenarios to be simulated can be chosen from the dropdow list.

It is only possible to simulate one scenario at a time

Depending on the complexity of the scenario, the simulation may take longer to finish. The runtime depends on:

• The amount of devices that are added to the grid
• The size of the grid
• The additional power per device added to the grid
• Convergence of the power flow

Start the simulation by clicking .

Operational Limits

The operational limits for the coloring of the results can be defined by clicking on at the top of the page.

Results

INFO

Note that results are saved, so they don't need to be recomputed every time the Future Scenario Stress Test page is opened. The results are computed in the background, so the user can leave the page and return to it at a later time.

WARNING

Some distributions might lead to non-convergence of the power flow.

The following warning will be displayed: ...% of the calculations didn't converge.

Result Scope

With no grid selected, the result displayed is the analysis for the entire grid area, i.e., all the grids contained in the project.

When a specific grid is selected, the or result can be inspected.

When the Holistic result type is selected, the result shown will be a part of the simulation that has been done considering all grids, but restricted to the one selected grid.

In contrast, the Isolated result type will show a result without the reciprocal effects of the neighboring and overlaying grids.

Blood Stream Chart

The Blood Stream Chart, available for each of the violation categories (Bus Over/Undervoltage, Line, Transformer and Fuse Overload, and Grid Losses), are the main result of the stochastic dispersion of additional devices.

The x-axis shows the number of additional devices added to the grid.

The y-axis shows the number of violations (whith respect to the operational limits) in the grid as a probability distribution.

The shades of red visualise the probability density. The darker the red, the more probable the outcome. For example, the range 40% to 60% shows the number of violations that can occur, if the worst and the best 40% of cases are discarded. The black line represents the median of the number of violations over all distributions.

Violation Distribution

Below the Blood Stream Chart, the distribution of violations and warnings with respect to the currently selected number of additonal devices (shown as a vertical line in the blood stream chart) are shown as color-coded bars.

The first bar shows the global distribution over all grid elements. Below, the bars for the elements with the worst violation are shown. Clicking on the ID of the element focuses onto that element in the grid viewer and reveals the detailed distribution as a function of the additional devices added to the grid in the inspector page on the right.

Example:

In the screenshot above, line l_294 shows a maximum line overload of 242.94% (the maximum over all distributions and number of additional devices). At 20% of additional devices, the probability of the line being overloaded is 21%. The probability of a warning is 39% and the probability that the line will be loaded within the limits is 40%. The overall distribution reveals that with an increase in the number of additional devices, the line will be overloaded in more cases and the absolute value of the line loading will also increase.

Grid Viewer

The state of the grid elements is visualized in the grid viewer, showing the worst-case outcome across all Monte Carlo simulation runs. If a bus has a violation in at least one of the simulation samples, it is highlighted red in the grid viewer.