Cyber Synchronous Machine Controller for Grid Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The integration of non-synchronous distributed energy resources and power electronic converters into power systems poses challenges for frequency stability, as most loads do not participate in frequency control, and existing converters are incompatible with voltage-source dominated systems.
Innovation Solution
A cyber synchronous machine (CSM) controller is introduced, which integrates computational algorithms to replicate the synchronization mechanism of physical synchronous machines, featuring a torque-frequency channel, a quorte-flux channel, an engendering block, and virtual impedance to regulate real and reactive power, enabling self-synchronization without grid frequency measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If power electronic converters are integrated into the electrical grid for distributed generation, then the number of active players participating in frequency control increases, but system stability deteriorates due to non-synchronous and incompatible characteristics
Solution Approach 1:
The patent creates a virtual copy of synchronous machine behavior through computational algorithms. The cyber synchronous machine replicates the synchronization mechanism and control characteristics of physical synchronous machines using software-based models, allowing power electronic converters to exhibit synchronous machine-like behavior without requiring actual synchronous machines
Solution Approach 2:
The patent replaces mechanical synchronous machines with cyber-based control systems. Instead of relying on physical rotating machinery to provide frequency stability, the system uses computational algorithms running on power electronic converters to replicate synchronization functions, substituting mechanical systems with electronic/software-based solutions
2Ease of operation
If converters are controlled to behave as current sources, then controllability improves, but compatibility with voltage-source dominated power systems deteriorates
Solution Approach 1:
The patent implements dynamic control characteristics that allow converters to adapt their behavior. The cyber synchronous machine uses dynamic synchronization mechanisms that enable converters to automatically adjust their operating mode between current-source and voltage-source characteristics based on system conditions, providing both controllability and compatibility
Solution Approach 2:
The patent changes the control parameters and operating characteristics of power electronic converters. By modifying control algorithms to implement synchronous machine-like behavior, the system transforms converter parameters dynamically to achieve compatibility with voltage-source dominated grids while maintaining controllability
Data Source
AI summary
This invention discloses a controller and method for a cyber synchronous machine (CSM, in short, cybersync machine), namely, a power electronic converter that is seamlessly equipped with computational algorithms (i.e., the controller) to represent the intrinsic and fundamental principles of physical synchronous machines. The CSM can be operated in the grid-connected mode or the islanded mode to take part in the regulation of the frequency and the voltage. The controller also includes auxiliary blocks to achieve self-synchronization without measuring or estimating the grid frequency and the regulation of real power and reactive power to the given reference values without static errors. The control signal for the power electronic converter can be the output voltage generated by the engendering block or the sum of the output voltage and the virtual current. A unique feature of the disclosed CSM is that, if the system it is connected to is passive, then the whole system is passive and, hence, is guaranteed to be stable.