Synchronous Machine Transient Modeling With Error-Controlled Norton Iteration

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Solution Overview

Problem

Conventional electromagnetic transient simulation software using dq0 models for rotating motors experiences accumulated errors and inaccuracy with large step sizes due to the predictor-corrector method.

Innovation Solution

A method and system for modeling electromagnetic transients of high-efficiency synchronous motors, involving linear extrapolation to predict rotor angular velocity and current components, followed by coordinate transformation and iterative error control to refine rotor angles and currents, utilizing Norton equivalent circuits and mechanical system equations to enhance accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If dq0 model with predictor-corrector method is used for electromagnetic transient simulation, then simulation efficiency is improved, but simulation accuracy deteriorates due to accumulated error with large step size

Engineering Contradiction:

Improvesimulation efficiencyVSAvoidsimulation accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent transforms the simulation parameters by converting the dq0 reference frame equations into abc reference frame equations. This parameter transformation allows the model to operate in a different mathematical space where accumulated errors are reduced, thereby maintaining both simulation efficiency and accuracy even with larger step sizes

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the traditional predictor-corrector numerical integration method with a direct algebraic solution approach in the abc reference frame. This substitution eliminates the iterative prediction-correction process that causes accumulated errors, achieving both high efficiency and accuracy simultaneously

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Loss of time

If large step size is used in simulation, then calculation efficiency is improved, but simulation accuracy deteriorates due to accumulated error

Engineering Contradiction:

Improvecalculation timeVSAvoidsimulation accuracy

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

By changing the reference frame from dq0 to abc, the patent enables the use of larger time steps without accuracy degradation. The abc reference frame formulation inherently reduces numerical accumulation errors, allowing efficient simulation with coarse time discretization

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250373183A1Electromagnetic transient modeling method and system for high-efficiency synchronous machine, and device

Publication Date: 2025.12.04 ELECTRIC POWER RES INST CHINA SOUTHERN POWER GRID CO LTD

AI summary

An electromagnetic transient modeling method and system for a high-efficiency synchronous machine, and, a device. The method comprises: predicting, of a synchronous machine, a first rotor angular velocity, a first rotor angle, and a first current q component of and a first current d component of an armature current, establishing a first Norton circuit for simulating the synchronous machine, and solving at the same time a second Norton circuit after equivalent transformation and a network conductance matrix so as to obtain a three-phase voltage of a synchronous machine port; according to the three-phase voltage, obtaining a second current q component, a second current d component, a second rotor angular velocity and a second rotor angle; and by means of error-controlled iterative solving, determining an electromagnetic transient simulation calculation result of the synchronous machine.