Motor Voltage Reconstruction via ADC Oversampling for Plausibility Checks
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Solution Overview
Problem
Existing methods for verifying motor voltage plausibility in three-phase motors are inefficient, requiring additional hardware or increased computational power, and do not effectively check the entire signal chain for motor voltage verification.
Innovation Solution
A method using ADC oversampling and averaging to reconstruct motor voltages, reducing hardware and computational requirements by measuring two phases and reconstructing the third phase, allowing for plausibility checks in the alpha-beta reference frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional hardware or increased computational power is used to verify motor voltage plausibility, then measurement precision and reliability are improved, but device complexity and cost increase
Solution Approach 1:
The patent creates a virtual copy of the motor voltage signal through software-based reconstruction in the alpha-beta reference frame. Instead of using additional physical hardware to measure and verify all three phase voltages, the system reconstructs the third phase voltage from measurements of the other two phases, transforming the verification problem into a computational copying task that maintains accuracy without adding hardware complexity
Solution Approach 2:
The patent replaces the need for additional physical measurement hardware with a software-based signal processing system. By using coordinate transformation and mathematical reconstruction in the alpha-beta reference frame, the system substitutes computational methods for hardware-based voltage measurement and verification, reducing device complexity while maintaining measurement precision
2Measurement precision
If all three motor phase voltages are directly measured, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts only the essential voltage information needed for plausibility verification by measuring just two of the three phase voltages. The third phase voltage is then reconstructed through mathematical transformation rather than direct measurement, extracting the necessary verification data with minimal sensor requirements while maintaining sufficient measurement precision for safety applications
Solution Approach 2:
The patent makes the measured voltage signals serve multiple functions: they are used both for motor control and for plausibility verification of the voltage signal chain. By processing the two measured phases through coordinate transformation to reconstruct all three phases in the alpha-beta frame, the system achieves comprehensive voltage verification using measurements from only two phases, reducing sensor requirements while maintaining verification accuracy
Data Source
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AI summary
A method for motor voltage reconstruction by Analog to Digital Converter (ADC) oversampling and averaging includes measuring a first phase voltage with an ADC, the first phase voltage proportional to a first duty cycle of a first Pulse Width Modulation (PWM) signal. A second phase voltage is measured with the ADC, the second phase voltage proportional to a second duty cycle of a second PWM signal, wherein the first PWM signal and the second PWM signal control consecutive phases of a three-phase motor. A third duty cycle of a third PWM signal of the three-phase motor is reconstructing from the first phase voltage and the second phase voltage.