Grid-Forming Inverter Stability Control for Renewable Power Grids
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Solution Overview
Problem
The transition of power systems from synchronous generators to inverters poses challenges in maintaining dynamic stability, as existing power system stabilizers designed for synchronous generators are not fully applicable to inverter-based systems.
Innovation Solution
A method and system for dynamic stability control of renewable energy power systems, involving the creation of a non-linear system for grid-forming inverters, construction of an external subsystem based on Lie derivatives, and implementation of sliding mode control to generate a dynamic stability control unit that modifies the voltage instruction value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional power system stabilizer designed for synchronous generators is used, then the dynamic stability of synchronous generator-dominated power systems is improved, but it cannot be fully applicable to inverter-based renewable energy power systems due to huge differences in operation characteristics
Solution Approach 1:
The patent transforms the traditional power system stabilizer from being designed for synchronous generators to being adapted for inverter-based systems by changing the underlying mathematical model parameters. Specifically, it replaces the synchronous generator model with an inverter model and modifies the control parameters accordingly, allowing the stabilizer to maintain effectiveness across different system types while improving adaptability.
Solution Approach 2:
The patent creates a universal power system stabilizer that can function effectively in both synchronous generator-dominated systems and inverter-based renewable energy systems. By developing a unified control framework that accommodates different system characteristics, the stabilizer achieves multi-functionality and can be applied across diverse power system configurations without requiring complete redesign.
2Productivity
If the penetration of renewable energy is increased to reduce fossil energy consumption and carbon emission, then the proportion of renewable energy in primary energy supply is improved, but the dynamic stability control becomes more challenging as synchronous generators are eliminated
Solution Approach 1:
The patent addresses the challenge of maintaining dynamic stability in inverter-based systems by substituting the traditional mechanical system stabilizer (designed for synchronous generators) with an electronically-controlled inverter-based stabilizer. This substitution enables the system to maintain or improve stability while accommodating higher renewable energy penetration, as the electronic control can respond more quickly and adaptively to system variations.
Data Source
AI summary
A dynamic stability control method for power systems with renewable energy, in which a non-linear system of a grid-forming inverter corresponding to a renewable energy power system is created. An external subsystem corresponding to the grid-forming inverter is constructed based on a Lie derivative. According to the external subsystem, a linear sliding surface corresponding to the external subsystem is constructed, and a dynamic stability control unit corresponding to the external subsystem is generated based on sliding mode control. A first instruction data corresponding to the dynamic stability control unit is generated to control dynamic stability of the renewable energy power system in real time. The voltage instruction value of the grid-forming inverter is modified to improve the dynamic stability of the renewable energy power system. A system for implementing such method is also provided.