| Product(s): | WaterSight |
| Version(s): | 10.00. |
| Area: | Documentation |
Overview
This feature is particularly useful when using hydraulic models of distribution systems in WaterSight that do not cover the transmission line.
Hydraulic models of distribution systems commonly have reservoirs elements representing DMA's inflow node (such as storage tanks). In that case, model's scope doesn´t cover the transmission line of the network that feeds the DMA, and usually a virtual reservoir is placed as starting point.
Whenever this happens, and instead of assuming a fixed hydraulic grade for the reservoir for the all period of the simulation run (corresponding for example to simulate the tank always full or always with an average level), WaterSight can forecast the real level of the tank and from that calculate a pattern that can be applied to any reservoir model element in order to simulate the correct pressure levels at the boundary condition, for all the period of the run (not only as initial conditions).
Please note that the real-world upstream element may not be a tank, it may just be a pipe that connects a complicated upstream network that is not part of the model. So the real-world sensor might be a level, or it might be a pressure, or it might even already be an HGL. For all those cases, this feature can be applied, following the steps mentioned below.
In order to be able to enable or disable HGL adjustment for each reservoir, it is required that the hydraulic model contains at least one reservoir as model element with an associated hydraulic grade signal. The hydraulic grade signal needs to be created/added both on the WaterGEMS file and also uploaded in WaterSight, through sensor administration. Please see below for the detailed steps:
Steps
- At least one Reservoir element needs to exist in the model. If the model contains tank elements at the boundary conditions (whenever the network ustream the tank is not represented in the model, preventing the WaterGEMS model to successfully run in EPS mode), please make sure to convert them to a Reservoir element. The "virtual" reservoirs should represent real tanks or other input sources such as delivery in a transmission main (usually when the upstream conditions/network is not available).
- Define correct elevation of the reservoir model element in WaterGEMS (consider the tanks base elevation or valve’s network centroid elevation).
- A hydraulic grade signal must be added in the WaterGEMS file. If needed, please create a derived signal for example converting tank level to hydraulic grade. Please make sure to save/update the model file with the new added signals inside the folder "Models" inside the OFOSC/pusher tool.
- Create a SCADA element in WaterGEMS and assign it to the reservoirs, being the mapping field Hydraulic Grade (the signal just created). In case the real world sensor is already an HGL, no need to create a derived signal.
5. Add in WaterSight (through the sensors administration page) the hydraulic grade signals that already exists in the WaterGEMS file. Please note that the signal SCADA tag configured in the model must match the one configured in the sensor administration page of WaterSight.
6. Import the WaterGEMS model into WaterSight, through the numerical model settings page.
7. In the numerical modeling configuration page, please select HGL adjustment field. Then assign the desired HGL signal(s) (which is referred to the reservoir(s) model element for which we want to calculate the HGL pattern and use it as boundary conditions for the model runs).
WaterSight will automatically compute a HGL pattern for each reservoir based on sensor data, and will automatically assigned it to each selected reservoir defined by the user in the numerical model settings page. For the reservoirs with no pattern assigned (those not selected by the user), the hydraulic grade value and patterns used will be those defined in the WaterGEMS file. The HGL pattern is automatically calculated by the software following the below methodology:
- Last month of historical data (HGL signal, which can be a derived signal) is used to calculate a pattern for each reservoir (dimensional values);
- Each HGL pattern, including one week forecast, is calculated using a machine learning algorithm, together with advanced data analytics methods. Bad data, including outliers and spikes are removed from the analysis and a different pattern for week days and weekends is also computed;
- Each HGL pattern with dimensional values is transformed into a pattern multiplier (or dimensionless pattern) and applied to each reservoir selected by the user in the numerical model administration page;
The HGL dimensionless pattern covers all simulation window period defined by the user in the Numerical model settings (hindcast + forecast). The HGL dimensionless pattern also differentiates between weekday, Saturday and Sunday. For example if the simulation window covers a Friday and a Saturday, the pattern multiplier for Friday and Saturday will be quite different.
Another important aspect to mention is that HGL patterns are continuously and automatically being updated in real time (whenever new data arrives into WaterSight) using always last month of historical data. This means that the pattern for today is slightly different than the pattern of the previous day and will be slightly different from tomorrow pattern.
Analyzing patterns
The user can analyze each HGL dimensional pattern automatically calculated by WaterSight and that is being used as boundary conditions for the model runs by acceding to the sensor details graph (under Network Monitoring page), see image below. Once in the sensor detail graph (for hydraulic grade), the user should change the interval to "15 min" and the interval dropdown option to "Last month" and change what is displayed by clicking on the visibility button located on the top right of the graph.
Figure 1 - Hydraulic grade pattern displayed in the sensor details page.
In the example shown above:
- the model hydraulic grade values were overridden by the calculated hydraulic grade pattern for all hindcast period;
- the hydraulic grade pattern (dimensional) used in the model simulations pages (current simulation and operational response) is displayed with a grey line in the sensor details (for the hydraulic grade sensor);
- the user can also compare simultaneously the model result, the hydraulic grade pattern (dimensional) and the real sensor data (raw or re-sampled).
Besides this, it is also possible to export and further analyze the dimensionless pattern generated by WaterSight. Please go to Realtime Simulation page > Previous Simulations and download the latest simulation.
Then open the sqlite file in WaterGEMS, go to Components > Patterns. Patterns automatically generated by WaterSight are automatically exported and can be analyzed in WaterGEMS.
For more information about WaterSight, please go to OpenFlows WaterSight TechNotes and FAQ's.
See also
Numerical Model administration
WaterSight TechNotes and FAQ's