Synchronous Reluctance Machine Saturation Mapping Without Rotor Sensors
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Solution Overview
Problem
Existing methods for determining the saturation characteristic of synchronous reluctance machines are complex, require a rotor position sensor, and involve lengthy measurement processes.
Innovation Solution
A method and apparatus that apply a voltage sequence to the stator of a synchronous reluctance machine using a pulse inverter, ensuring that torques acting on the rotor cancel each other out, allowing for the measurement of electrical currents and determination of the saturation characteristic without a rotor position sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If measurement of flux functions is performed on test stands with rotor position sensors and drive machines, then measurement precision is improved, but device complexity and measurement time increase
Solution Approach 1:
The invention extracts the essential measurement capability from the complex test stand environment and implements it directly in the drive controller. By calculating flux functions from measured voltages and currents using the relationship ψ = ∫(u - R*i)dt, the system obtains accurate saturation characteristics without requiring external test stands, rotor position sensors, or drive machines, thus resolving the contradiction between measurement precision and device complexity
Solution Approach 2:
The drive controller performs self-diagnosis by using its own measurement capabilities (voltage and current sensors) to determine the saturation characteristic of the synchronous reluctance machine. The controller autonomously calculates flux functions during normal operation or dedicated measurement sequences, eliminating the need for external measurement equipment and reducing both device complexity and measurement time
2Measurement precision
If rotor position sensors and drive machines are used for measurement, then saturation characteristic determination accuracy is improved, but measurement time is increased
Solution Approach 1:
The invention enables continuous determination of saturation characteristics during normal motor operation. By continuously measuring voltages and currents and calculating flux functions in real-time, the system maintains accurate saturation data without interrupting motor operation for separate measurement procedures, thus reducing measurement time while maintaining accuracy
Solution Approach 2:
The drive controller pre-calculates and stores flux functions and saturation characteristics during manufacturing or initial operation. These pre-determined characteristics are then available for immediate use during motor control, eliminating the need for time-consuming measurements at the point of use while maintaining high measurement precision through controlled measurement sequences
3Reliability
If complex measurement procedures with multiple components are used, then reliability of saturation characteristic determination is improved, but device complexity increases
Solution Approach 1:
The drive controller serves multiple functions: it controls the motor, measures voltages and currents, calculates flux functions, and determines saturation characteristics all within a single integrated system. This multi-functionality eliminates the need for separate measurement equipment, reducing device complexity while maintaining reliability through consistent measurement and calculation processes within the same control environment
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 a reliable, simple, and autonomous determination of the saturation characteristic, reducing measurement time and eliminating the need for a rotor position sensor, thus improving operational efficiency and robustness of synchronous reluctance machines.
Implementation Method 1
By applying the voltage sequence, stator fluxes are introduced in the stator
Implementation Method 2
torques acting on a rotor of the synchronous reluctance machine cancel each other out during the application of the voltage sequence
Data Source
AI summary
A method for determining a saturation characteristic of a synchronous reluctance machine includes applying with a pulse inverter a voltage sequence to a stator of the synchronous reluctance machine, wherein the voltage sequence introduces stator fluxes and is applied such that torques acting on a rotor of the synchronous reluctance machine cancel each other out during the application of the voltage sequence. Electrical currents resulting from the stator fluxes are measured and the saturation characteristic is determined based on the stator fluxes and the measured electrical currents.