VSC Decoupling Circuit for Faster Electromagnetic Transient Simulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electromagnetic transient simulation methods for voltage source converters (VSCs) face a contradiction between accuracy and efficiency, particularly in simulating complex and diverse power electronic equipment with tight electric and magnetic coupling, leading to low simulation efficiency.
Innovation Solution
A general decoupling method and system that involves obtaining topological structures, generating equivalent circuits, determining state equations and switch state tables, splitting and decoupling capacitor and inductor elements, and constructing a decoupling model circuit using recurrence relations to improve simulation efficiency and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If detailed device-level models are used for electromagnetic transient simulation, then simulation accuracy is improved, but calculation time increases significantly
Solution Approach 1:
The patent segments the VSC model into independent modular units (basic units) that can be combined to form complete converter models. Each basic unit represents a simplified version of the converter with decoupled AC and DC sides, allowing for faster calculation while maintaining accuracy through modular composition of multiple units.
Solution Approach 2:
The patent changes the modeling parameters by introducing a decoupled equivalent circuit model where the AC and DC sides are separated. This parameter transformation allows the model to avoid solving the full coupled system, reducing calculation complexity and time while preserving essential electromagnetic transient characteristics.
2Measurement precision
If more detailed devices and components are included in the VSC model, then simulation accuracy is improved, but device complexity increases
Solution Approach 1:
The patent divides the complex VSC model into segmented basic units with standardized structures. This segmentation reduces model complexity by creating reusable modular components that can be assembled to represent different converter configurations without requiring complete redesign of the entire system model.
Solution Approach 2:
The patent creates a universal basic unit model that can represent multiple VSC configurations through parameter adjustments and modular combination. This multi-functional basic unit can simulate different converter topologies and operating conditions, reducing the need for multiple specialized models and simplifying the overall modeling process.
3Measurement precision
If coupled AC-DC side models are used, then electromagnetic transient characteristics are accurately captured, but calculation efficiency decreases
Solution Approach 1:
The patent segments the coupled AC-DC model into decoupled basic units where each unit independently models one side of the converter. This segmentation allows parallel calculation of AC and DC sides, improving calculation efficiency while maintaining transient accuracy through the modular recombination of results.
Solution Approach 2:
The patent introduces an intermediary control layer that coordinates between the decoupled AC and DC side models. This intermediary mechanism ensures that the independent basic units work together to accurately represent the coupled electromagnetic transient behavior without requiring direct coupling in the mathematical model, thus maintaining efficiency.
Data Source
AI summary
A general decoupling method and system for electromagnetic transient simulation of a VSC are provided. The method includes: determining state equations of equivalent circuits and switch state tables of different VSCs; splitting the state equations, and decoupling and delaying capacitor elements and inductor elements to determine split equations; determining a recurrence relation of a state variable group with respect to a time sequence based on each split equation; obtaining a topological structure of a to-be-simulated VSC, and determining a decoupling model circuit; determining a switch state of the to-be-simulated VSC at a current simulation moment, and constructing a final decoupling model circuit; determining an external port voltage based on the final decoupling model circuit; and updating the state variable group at the current simulation moment based on the external port voltage and the parameters of the decoupling model circuit corresponding to the switch state.