Hybrid AC/DC Grid Control via Non-Linear Security-Constrained Power Flow
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Solution Overview
Problem
Hybrid AC/DC grids face challenges in balancing power distribution and managing power flows due to interference between AC and DC grids, leading to unbalanced power distribution and potential overloads, especially during component outages, which existing technologies struggle to address effectively.
Innovation Solution
A network system with a hybrid AC/DC-grid controlled by a full non-linear security-constrained optimal power flow model, utilizing converters to connect AC and DC grids and a network control component that applies an N-k security criterion to manage power flows, voltages, and reactive power, ensuring stability and security through preventive and corrective measures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a hybrid AC/DC grid is implemented to exploit benefits of both grid types, then power transmission efficiency and flexibility are improved, but interference between AC and DC grids causes unbalanced power distribution and unwanted loads
Solution Approach 1:
The patent introduces a network control component as an intermediary system that mediates between AC and DC grids. This controller applies a full non-linear security-constrained optimal power flow model to calculate optimal power distribution, preventing interference and unbalanced loads by actively managing power flows between the two grid types.
Solution Approach 2:
The system dynamically changes operational parameters (power flows, voltages, reactive power) through the optimal power flow model. By continuously adjusting these parameters based on real-time conditions and security constraints, the system maintains balanced power distribution while exploiting the efficiency benefits of both AC and DC transmission.
2Device complexity
If existing control technologies are used in hybrid AC/DC grids, then system complexity is reduced, but they struggle to address power distribution balance and overload prevention effectively
Solution Approach 1:
The network control component performs preliminary calculations using the full non-linear security-constrained optimal power flow model to determine optimal power distribution before actual power flow occurs. This preventive approach ensures that power distribution balance and overload prevention are addressed proactively, maintaining reliability without requiring overly complex real-time control mechanisms.
3Reliability
If security constraints are applied to maintain stable operation, then system reliability is improved, but control precision requirements increase due to non-linear relationships
Solution Approach 1:
The optimal power flow model incorporates security constraints that provide feedback on system state (power flows, voltages, reactive power). This feedback mechanism allows the controller to maintain system reliability by continuously monitoring and adjusting operations within safe limits, managing the non-linear relationships through iterative calculation rather than requiring extreme control precision.
Data Source
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AI summary
A network system is provided, comprising a hybrid AC/DC-grid. The hybrid AC/DC-grid in turn comprises an AC grid, a DC grid, and at least one converter configured to connect the AC grid with the DC grid. The network system further comprises a network control component, configured to control the hybrid AC/DC-grid by applying a full non-linear security-constrained optimal power flow model.