Performance models - Johnson Controls - LIT-12013036 - OpenBlue Central Utility Plant - OBEM Central Utility Plant Optimization - v2024.Q2

OpenBlue Plant Optimizer Administration and User Guide

Product name
OBEM Central Utility Plant Optimization
Document type
Administration Guide
User Guide
Document number
Revision date

The Plant Optimizer uses as-run measured data collected from the plant automation system to update the equipment performance models and subplant performance models. It also predicts utility resource use for electric power, natural gas, steam, and water as a function of different operating conditions such as load and ambient conditions. If equipment degrades and performance changes substantially over time, the Plant Optimizer software adapts and continues to operate the plant based on current equipment efficiencies.

This adaptation process is semi-automated. The system alerts the Johnson Controls CUP technical support team whenever the model kernel identifies significant change in system performance. Technical support reviews new performance models before they implement changes in the Plant Optimizer. This process is expected to become fully automated in future releases.

Note: You can set the ValidDataStartDate in Solver Parameters to set the start date, from which high-quality data is used, to update the performance models.

CUP optimization decisions are based on performance models for each piece of equipment in the plant that predict how much utilities are consumed under different conditions. Use the Performance Model tab to view the goodness of fit for these models and update them based on the most recent measured operating data.

About this task:

To view a model curve for equipment goodness of fit, complete the following steps:
  1. In the Administration interface, from the menu at the top of the page, select Commissioning.
  2. In the Performance Models tab, in the Entity Type field, enter an entity type.
  3. From the table of entities, select the appropriate entity. A model curve displaying goodness of fit and graphs appears.
  4. In the Actions column, click on the View icon to view the goodness of fit graph.
  5. Click Apply to apply all new coefficients.
For Chiller equipment types, two types of models are available: Goodness of Fit and Before/After Model Adaptation Comparisons.
  • Goodness of Fit displays the existing graph of Fitted Power versus Measured Power, and also shows the scatter chart of Power versus Residuals. When the Plant Optimizer runs the model adaptation, it uses past measured data and compares it to see if the Plant Optimizer's performance model for the equipment can be improved to be more accurate for current operating conditions. The existing model and new model display in parallel, which makes it easy to compare the models.
  • Before/After Model Adaptation Comparisons compares plots of the performance models. Two plots display, Power Predictions which shows Power versus Production (Capacity) and Efficiency Predictions which shows Efficiency versus Production (Capacity). On the left side of the screen you can select the check boxes for which plot lines you want to see on the chart: Leaving Chilled Water Temperature options, Leaving Condenser Water Temperature options, and Model Types of Existing model and New model.
Note: Before/After Model Adaptation Comparisons is applicable only for the Chiller equipment types. For the rest of the equipment types the performance model only plots Goodness of Fit data for the existing model or the new model.
Note: The Model Adaptation Horizon default value has been updated to 8760 hours (365 days).