Grid-Forming Converter Control Under Grid Disturbance Limits
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Solution Overview
Problem
The increasing use of renewable energy sources in power grids, such as wind turbines and photovoltaic systems, provides less inertia and support for grid stability due to their varying power output and lack of inherent energy storage, posing challenges in grid frequency control and potentially leading to system damage or inefficiency.
Innovation Solution
A method and control system for power generation systems that operate in a grid forming mode, limiting, enforcing, or blocking the stabilizing component of electrical power exchange to prevent harmful system responses during disturbances, thereby maintaining efficient operation and reducing hardware overrating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the grid forming operated renewable energy source is designed to deliver the worst case disturbance power by using suitably rated hardware components, then the system can provide both the power and energy requested by the power grid in the worst case, but this results in an overrating of the system components on hardware level and an increased hardware effort
Solution Approach 1:
The patent applies dynamics by making the grid forming control parameterization adaptive rather than static. The control parameters are dynamically adjusted based on the actual operating conditions and disturbance characteristics, allowing the system to optimize its response in real-time. This resolves the contradiction by enabling the system to handle worst-case disturbances when necessary while avoiding component overrating during normal operation, thus maintaining reliability without increasing hardware complexity.
Solution Approach 2:
The patent changes the control parameters of the grid forming converter dynamically based on the disturbance type and severity. By adjusting parameters such as power reference, current limits, and control gains according to actual grid conditions, the system can deliver required disturbance power without being permanently oversized. This parameter adaptation resolves the contradiction between reliability during disturbances and hardware complexity by avoiding fixed overrating.
2Reliability
If the converter system is pushed beyond its respective capability to deliver disturbance power, then the stabilizing contribution to the power grid is maximized, but the converter or the generator system may be damaged or may disconnect during the disturbance
Solution Approach 1:
The patent implements beforehand cushioning by pre-configuring the grid forming control with adaptive parameterization that anticipates disturbance scenarios. The control system is designed to adjust parameters in advance or during the onset of disturbances to enable the converter to deliver required power without exceeding its safe operating limits. This prevents system damage while maintaining grid stabilizing contribution by cushioning against the harmful effects of pushing the converter beyond its capability.
Solution Approach 2:
The patent employs feedback mechanisms where the grid forming control continuously monitors the converter's operating state and adjusts control parameters based on actual performance and disturbance characteristics. This feedback loop ensures that the converter delivers maximum stabilizing contribution without exceeding its capability, preventing damage or disconnection by real-time adaptation of control settings.
3Productivity
If the grid forming control parameterization is optimized for a specific operating point, then the system efficiency is improved, but the system cannot adapt to varying disturbance characteristics and operating conditions
Solution Approach 1:
The patent makes the grid forming control parameterization dynamic rather than static. The control parameters are continuously adapted based on the actual operating point and disturbance characteristics, allowing the system to maintain optimal efficiency across varying conditions while adapting to different disturbance scenarios. This dynamic adaptation resolves the contradiction between efficiency optimization and adaptability.
Solution Approach 2:
The patent creates a universal grid forming control parameterization that can handle multiple operating conditions and disturbance types through adaptive mechanisms. The control system is designed to function effectively across a wide range of scenarios by adjusting parameters in real-time, providing multi-functionality that resolves the contradiction between optimizing for a specific operating point and adapting to varying conditions.
Data Source
AI summary
A method of controlling a power generation system is provided. The power generation system may be electrically coupled to a power grid and may include a power generation unit generating electrical power and a converter system coupled to the power grid. The converter system may convert at least electrical power that is exchanged between the power generation unit and the power grid. The method may include operating the converter system in a grid forming operation mode in which the converter system may control the exchange of electrical power with the power grid to support a grid voltage and/or a grid frequency. During a disturbance of the power grid, the exchanged electrical power may comprise a stabilizing component that may provide the support.