# KAIROS: Operating the grid of the future

**Introduction**

KAIROS is a high-fidelity unit commitment and economic dispatch model designed to capture the technical and economic behavior of modern power systems. It integrates granular operational constraints of generating units, multiple formulations of AC power flow, and cloud-based computational architecture to support reliability assessments and system operation studies. The tool is suited for analyzing systems with a mix of thermal, renewable, and storage technologies, under both market and reliability-driven contexts.

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**1. Unit Commitment and Thermal Generator Modeling**

KAIROS supports a comprehensive set of technical constraints for thermal generation, enabling accurate modeling of dispatchability and operational flexibility. Key features include:

* **Non-convex Heat Rate Modeling:** Supports segmented fuel efficiency curves with up to 10 operating points per unit.
* **Temperature-Dependent Start-up Trajectories:** Differentiates fuel and cost requirements based on hot, warm, or cold start conditions.
* **Ramp Rate Constraints:** Models both positive and negative ramping, configurable by absolute rates or percentages.
* **Minimum Online/Offline Durations:** Ensures compliance with technical minimum run and down times for each unit.
* **Start-up Fuel and Emissions Tracking:** Includes fuel and cost penalties for startup sequences by temperature category.

These constraints enable:

* Accurate determination of unit availability and flexibility
* Realistic marginal cost estimation, considering part-load efficiency and startup penalties
* Enhanced reliability analysis in systems with high renewable variability

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**2. Power Flow Modeling Framework**

KAIROS supports multiple formulations for AC load flow modeling to accommodate different network topologies and accuracy requirements:

* **Linearized AC Power Flows (P & Q):** Applied in transmission systems where voltage deviations are small and linear approximations are sufficient.
* **Second Order Conic Programming (SOCP):** Used for radial distribution networks, offering accurate voltage and flow profiles within a convex optimization framework.
* **SOCP with Cyclic Constraints:** Extends SOCP to model meshed distribution networks by including loop equations and cyclic constraints to improve accuracy.

This hybrid approach allows users to:

* Accurately model nodal voltages and reactive power flows
* Analyze voltage constraints and line thermal limits across network types
* Derive locational prices reflecting real and reactive marginal costs

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**3. Cloud-Based Execution and System Integration**

KAIROS is deployed on a cloud-based platform with built-in support for secure system integration and parallel execution:

* **Parallel Execution Architecture:** Enables simulation of multiple scenarios or time segments in parallel to reduce execution time.
* **API Access and JSON Data Exchange:** Facilitates integration with external forecasting, market bidding, or grid analysis tools.
* **Security Measures:** Implements IP filtering, AES-256 encryption, and anonymization protocols to manage sensitive data.

This architecture supports use cases such as:

* Intraday unit commitment re-optimization
* Probabilistic resource adequacy studies
* Market sensitivity and policy scenario analysis

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**4. Market and Dispatch Capabilities**

In addition to operational feasibility, KAIROS supports market-based features relevant to system operators and market participants:

* **Security-Constrained Unit Commitment (SCUC):** Respects transmission limits and contingency constraints (e.g., N-1) while minimizing total system cost.
* **Demand Response and Load Flexibility:** Supports demand-side resources with user-defined shifting capabilities and participation costs.
* **Storage Co-Optimization:** Models battery and pumped storage with efficiency losses, power limits, and energy capacity constraints.

These capabilities allow detailed analysis of:

* Bidding strategy outcomes under different price scenarios
* Reserve and flexibility procurement
* Impact of demand response on peak loads and costs

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**5. Output and Result Interpretation**

KAIROS outputs are available in structured CSV formats, suitable for post-processing or direct use in dashboards and reporting tools. Key outputs include:

* Unit generation, on/off status, startup classification (cold, warm, hot)
* Fuel consumption and startup energy costs
* Line flows, nodal voltages, congestion costs
* System marginal costs, unserved energy, and reserve usage
* State-of-charge and cycling of storage assets

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**Conclusion**

KAIROS provides a technically robust framework for analyzing unit commitment and economic dispatch in systems with complex operational and network requirements. By incorporating advanced thermal unit modeling and flexible AC power flow representations—including SOCP for both radial and meshed networks—it allows users to conduct detailed and accurate operational studies. Cloud-based deployment and strong system integration capabilities make KAIROS suitable for both planning and real-time operational support.