Induction Machine Parameter Identification for Faster Vector-Control Start-Up
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Solution Overview
Problem
The determination of control parameters for electric drives using vector control is often time-consuming due to the lack, incompleteness, or incorrectness of equivalent circuit data for electric machines.
Innovation Solution
A method involving the application of a current indicator as a signal to the three-phase winding connections of an electric machine, measuring d- and q-components of stator voltage and current, and determining stator impedance as a control parameter through specific measurement steps and numerical methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional parameter determination methods are used during start-up, then control parameters can be obtained, but the process is very time-consuming
Solution Approach 1:
The patent applies preliminary action by performing parameter determination during the start-up phase before normal operation begins. The method executes measurement steps and numerical calculations in advance to establish control parameters (stator impedance, rotor resistance, magnetizing inductance) before the electric drive enters service, eliminating the need for time-consuming parameter determination during later operation or commissioning.
Solution Approach 2:
The patent employs parameter changes by varying the frequency of the current indicator signal across multiple measurement steps. By measuring at different frequencies (including standstill conditions) and using numerical methods to extract parameters from frequency response data, the system efficiently determines control parameters without requiring lengthy traditional testing procedures.
2Measurement precision
If equivalent circuit data is used for parameterization, then control parameters can be obtained, but the data is often not at all, incompletely or incorrectly available
Solution Approach 1:
The patent applies self-service by enabling the control apparatus to automatically determine its own control parameters through built-in measurement capabilities. The system uses its own power converter and measurement devices to perform impedance measurements and numerical calculations, generating accurate control parameters independently without relying on external equivalent circuit data that may be incomplete or incorrect.
Solution Approach 2:
The patent replaces the traditional mechanical/electrical testing approach with a numerical method based on frequency response analysis. Instead of using physical equivalent circuit measurements that require complete and accurate data, the system uses electrical impedance measurements combined with numerical algorithms (such as curve fitting or optimization methods) to extract control parameters, substituting computational analysis for traditional measurement techniques.
Data Source
AI summary
A method and a control apparatus for determining parameters for controlling an electric drive having an electric machine improve the start-up of the electric drive by applying a current indicator as a signal at three-phase winding connections of the electric machine, and measuring a d-component and a q-component of the stator voltage and of the stator current at the winding connections. In a first measurement step, a rotating current indicator is applied to the three-phase winding connections and the electric machine is oriented such that an exciter current in the q-axis assumes a minimum. In a second measurement step, when the rotor of the electric machine is stationary, a field winding of the electrical machine is short-circuited and a current indicator in form of a binary noise signal is applied to the winding connections. A stator impedance is then determined as a first control parameter.