Central Plant Load Allocation Using Hierarchical Energy Optimization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Central plants face challenges in optimally allocating energy loads across subplants due to real-time pricing and resource management complexities, leading to inefficiencies in energy production and consumption.

Innovation Solution

A high-level optimizer is configured to manage energy assets by defining storage elements, adding decision variables for resource storage and discharge, and incorporating constraints on operational domains, distribution costs, and efficiency losses to optimize resource allocation across sources, subplants, and sinks, ensuring resource balance and minimizing economic costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple control strategies are implemented in a central plant, then system control capability is improved, but system complexity increases

Engineering Contradiction:
Improvesystem control capabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple control strategies (rule-based control, model predictive control, and real-time optimization) into a unified hierarchical control architecture. The optimizer receives data from all control layers and provides coordinated setpoints, merging previously separate control functions into an integrated system that improves overall control capability while managing complexity through structured organization.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The real-time optimizer serves multiple functions simultaneously: it performs economic optimization, coordinates different control strategies, adapts to changing plant conditions, and provides setpoints to various control layers. This multi-functional approach allows a single system to address multiple control needs without proportionally increasing complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If real-time data processing is implemented for dynamic optimization, then operational efficiency is improved, but computational requirements increase

Engineering Contradiction:
Improveoperational efficiencyVSAvoidcomputational requirements
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The system pre-processes sensor data and maintains updated plant models before real-time optimization is needed. By preparing data structures, validation rules, and model parameters in advance, the system reduces the computational burden during real-time execution, allowing efficient dynamic optimization without excessive computational requirements.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The optimizer processes data at different levels of detail depending on the situation. For routine operations, it uses simplified models and processed data summaries. For exceptional conditions or when high precision is needed, it performs more comprehensive calculations. This selective processing approach maintains operational efficiency while managing computational requirements.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3602716B1Central plant with high level optimizer
Publication Date: 2024.06.12 JOHNSON CONTROLS TYCO IP HLDG LLP
  • EP3602716B1 patent drawingFigure 1
  • EP3602716B1 patent drawingFigure 2
  • EP3602716B1 patent drawingFigure 3

AI summary

A central plant includes a high level optimizer configured to determine an optimal allocation of energy loads across central plant equipment. The high level optimizer identifies sources configured to supply input resources, subplants configured to convert the input resources to output resources, and sinks configured to consume the output resources. The high level optimizer generates a cost function and a resource balance constraint. The resource balance constraint requires balance between a total amount of each resource supplied by the sources and the subplants and a total amount of each resource consumed by the subplants and the sinks. The high level optimizer determines the optimal allocation of the energy loads across the central plant equipment by optimizing the cost function subject to the resource balance constraint. The high level optimizer is configured to control the central plant equipment to achieve the optimal allocation of the energy loads.