Converter Admittance Modeling for Transient Simulation
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Solution Overview
Problem
Traditional digital electromagnetic transient simulation methods are inefficient for simulating power electronic switches in modern power systems, particularly in systems with high-frequency characteristics and complex control strategies, leading to low simulation precision and long computation times.
Innovation Solution
A converter parameterized constant admittance modeling method based on cross initialization, which models power electronic converters using a parametric historical current source constant admittance model and performs cross initialization correction during state switching to optimize simulation precision and step size, thereby improving simulation speed and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional digital electromagnetic transient simulation methods are used for power electronic switches, then simulation coverage can be maintained, but simulation efficiency is extremely low and computation time is long
Solution Approach 1:
The patent transforms the dynamic switching behavior of power electronic devices into parameterized constant admittance models. By changing the representation from time-domain switching waveforms to frequency-domain parameterized admittance matrices, the simulation achieves both accuracy and efficiency. The parameterized models capture high-frequency characteristics while enabling faster computation through algebraic equations rather than differential equations.
Solution Approach 2:
The patent replaces the traditional mechanical/time-domain switching simulation approach with an electrical/frequency-domain admittance-based approach. Instead of simulating the physical switching process of power electronic devices in the time domain, the invention uses equivalent admittance models in the frequency domain, substituting a computationally intensive mechanical process with a more efficient electrical equivalent.
2Measurement precision
If traditional simulation methods are used, then model generality is maintained, but simulation precision is insufficient for high-frequency characteristics
Solution Approach 1:
The patent introduces parameterized admittance models that explicitly capture high-frequency characteristics through frequency-dependent parameters. By representing power electronic devices with admittance matrices that vary with frequency parameters, the model achieves high simulation precision for high-frequency transient analysis while maintaining computational efficiency through parameterized formulations.
Solution Approach 2:
The patent creates dynamic equivalent models where the admittance parameters change with operating conditions and frequency. The parameterized constant admittance models adapt to different switching states and operating points, providing dynamically accurate representation of power electronic devices without requiring full-time-domain switching simulation.
3Measurement precision
If converter models are optimized for electromagnetic transient simulation, then simulation precision is improved, but model complexity increases
Solution Approach 1:
The patent uses parameterized admittance models that consolidate complex converter behavior into manageable parameter sets. By transforming complex switching dynamics into parameterized equivalent circuits with frequency-dependent admittance matrices, the model achieves high precision while keeping the mathematical structure systematic and manageable through standard circuit theory formulations.
Data Source
AI summary
A converter parameterized constant admittance modeling method based on a cross initialization including the following steps: (1) performing parameterized modeling on a converter, wherein switches are modeled using a parametric historical current source constant admittance model and other components are modeled using a traditional electromagnetic transient simulation integral model in the converter; (2) detecting whether state switching occurs, performing cross initialization correction when occurring; (3) determining model parameters, and establishing an equivalent admittance matrix and an injection current source of a whole grid, to obtain an electromagnetic transient simulation equivalent model; (4) solving a network tide according to a basic solving equation I=YU to obtain an electromagnetic transient model simulation result of the converter at current time; and (5) calculating an equivalent admittance matrix and an injection current source at next time through a current network state quantity, and returning to step (2) until a simulation terminates.