Induction Machine Rotor Angle Determination Without Sensors
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Solution Overview
Problem
Conventional methods for determining the rotor angle of an induction machine without sensors often result in undesired voltage and current fluctuations due to the need to interrupt the modulation unit for measuring voltage pulses, which complicates the control process and requires additional components.
Innovation Solution
A control device and method that integrates the generation of measuring voltage pulses into the modulation unit's typical operating sequence, synchronizing these pulses with control voltage pulses to minimize interruptions and eliminate the need for separate signal processors and sensors, allowing for precise rotor angle determination without additional modifications to the control operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage pulses are supplied to the phase lines for measuring the system response of the induction machine, then the rotor angle can be determined without sensors, but undesired voltage and current fluctuations occur at the input connectors
Solution Approach 1:
The patent combines the measurement function with the control function by integrating the angle determining device into the modulation unit. The measuring voltage pulses are generated and synchronized within the existing control architecture, merging two previously separate functions (measurement and control) into a single integrated system, thereby eliminating the need for separate measurement operations that cause fluctuations
Solution Approach 2:
The modulation unit is designed to perform multiple functions: it generates both control voltage pulses for normal operation and measuring voltage pulses for rotor angle determination. This multi-functionality allows the same hardware component to serve dual purposes, eliminating the need for separate measurement equipment and reducing overall system complexity
2Measurement precision
If the modulation unit is interrupted to supply measuring voltage pulses, then rotor position can be measured, but the control operation is disrupted and additional components are required
Solution Approach 1:
The patent merges the measurement function with the control function by integrating the angle determining device into the modulation unit. The measuring voltage pulses are generated and synchronized within the existing control architecture, eliminating the need for separate measurement operations and reducing device complexity
Solution Approach 2:
The modulation unit is designed to perform multiple functions: it generates both control voltage pulses for normal operation and measuring voltage pulses for rotor angle determination. This multi-functionality eliminates the need for additional separate components and simplifies the overall control process
3Object-generated harmful factors
If measuring voltage pulses are synchronized with control voltage pulses, then voltage and current fluctuations are minimized, but the integration complexity increases
Solution Approach 1:
The patent combines the measurement function with the control function by integrating the angle determining device into the modulation unit. The measuring voltage pulses are generated and synchronized within the existing control architecture, merging two previously separate functions into a single integrated system, thereby managing integration complexity while minimizing fluctuations
Data Source
AI summary
A control device for an induction machine includes an angle determining device designed to determine a rotor angle of the induction machine without requiring use of sensors. The angle determining device generates measuring voltage pulses which can be selectively used to replace control voltage pulses used to control the induction machine. Machine currents generated by the measuring voltage pulses can be used to determine a rotor angle without interrupting the control voltage pulses and/or operation of the induction machine.