Induction Motor Parameter Estimation Using Voltage Pulse Stabilization
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Solution Overview
Problem
Existing motor control systems for induction motors lack comprehensive parameter estimation, which is essential for effective speed control, torque-based control, and overall motor operation, as they do not provide information about all motor parameters.
Innovation Solution
A parameter estimation system that applies voltage pulses through two phase paths of an induction motor for a stabilization period, measures stator voltage and current, and calculates fluxes to estimate the coupling factor, total resistance, stator resistance, and leakage inductance, using these measurements to determine the required motor parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage pulses are applied through two phase paths for a stabilization period to estimate coupling factor, then parameter estimation accuracy is improved, but measurement time and system complexity increase
Solution Approach 1:
The system applies voltage pulses through two phase paths during a stabilization period before actual measurement to ensure the motor reaches a stable state. This preliminary action ensures accurate parameter estimation by eliminating transient effects, allowing the system to measure coupling factor, total resistance, stator resistance, and leakage inductance with high precision.
Solution Approach 2:
The measurement process uses periodic voltage pulse applications at specific frequencies (e.g., 50Hz, 400Hz, 1kHz) to excite the motor in different operating conditions. By applying pulses periodically at multiple frequencies during the stabilization period, the system captures comprehensive parameter information while managing measurement time through structured periodic excitation.
2Reliability
If comprehensive parameter estimation is implemented for all motor parameters, then control performance is improved, but device complexity increases
Solution Approach 1:
The parameter estimation system is designed to estimate multiple motor parameters (coupling factor, total resistance, stator resistance, leakage inductance) using a unified measurement approach. By making the system multi-functional, it can provide comprehensive parameter information for various control applications (sensorless control, temperature monitoring, health assessment) without requiring separate measurement systems for each parameter, thus managing complexity while improving reliability.
Solution Approach 2:
The system uses the motor's own electrical characteristics and existing phase paths to perform self-diagnosis and parameter estimation. By utilizing the motor's inherent properties and built-in sensors, the system achieves comprehensive parameter estimation without requiring external test equipment or additional complex measurement infrastructure, maintaining simplicity while enhancing control performance.
3Measurement precision
If multiple measurements are taken during stabilization period, then parameter accuracy is improved, but loss of information increases due to transient effects
Solution Approach 1:
The system performs preliminary measurements during the stabilization period to capture transient effects and use them to calculate accurate parameter values. By measuring during the transition phase rather than waiting for steady state, the system extracts valuable information about resistance, inductance, and coupling factors that would otherwise be lost, converting transient information into useful parameter data.
Solution Approach 2:
The measurement system continuously monitors voltage and current during the stabilization period and uses feedback from these measurements to adjust and refine parameter estimates. By implementing feedback mechanisms, the system can distinguish between transient effects and actual parameter values, using the transient information constructively to improve measurement accuracy rather than treating it as noise to be eliminated.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables comprehensive parameter estimation for induction motors, facilitating improved sensorless control, temperature monitoring, and health status assessment, with accurate estimation of parameters like total resistance, leakage inductance, and coupling factor, enhancing motor control and operation efficiency.
Implementation Method 1
applying voltage pulses through two phase paths of the motor for a plurality of electrical cycles over a stabilization period
Implementation Method 2
measuring stator voltage and stator current in response to the applied voltage pulses for each of the plurality of electrical cycles
Data Source
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AI summary
A method of estimating stator resistance of an induction motor is provided. The method includes applying voltage pulses through two phase paths of the motor for a plurality of electrical cycles to inject current in the motor, wherein the voltage pulses are applied until rotor flux of the motor is substantially stabilized and measuring stator voltage and stator current in response to the applied voltage pulses for each of the plurality of electrical cycles. The method also includes calculating the stator resistance based upon the measured stator voltages and the stator currents.