Multi-phase Motor Drive Sensor Calibration via Current Loop Comparison
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for systems and methods to cross-check the outputs of sensors and estimate system parameters in power converters and vehicle electronic systems to ensure accuracy and integrity, particularly in power electronic converters and motor drives, which is critical for proper operation and fault detection amidst potential energy shortages.
Innovation Solution
The method involves using current sensors in multi-phase motor drives to create specific current loops, compare current magnitudes, and determine differences across phase windings, allowing for the estimation of circuit parameters and sensor accuracy, including inductance and capacitance, through various switch configurations and equations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sensor outputs are used directly for control without cross-checking, then the control system operates simply and quickly, but the reliability and accuracy of sensor measurements cannot be guaranteed
Solution Approach 1:
The patent implements feedback by using multiple sensors to continuously monitor the same physical quantity and comparing their outputs. The control system receives feedback signals from multiple current sensors and voltage sensors, cross-checks their consistency, and uses this feedback to detect sensor failures or drift, thereby improving measurement reliability without requiring complex external verification systems
Solution Approach 2:
The system performs self-diagnosis by using its own operational data to verify sensor accuracy. During normal operation, the control system uses the relationship between measured current, voltage, and power to automatically detect inconsistencies in sensor readings, enabling the system to self-verify sensor reliability without external intervention or additional complex diagnostic equipment
2Measurement precision
If multiple sensors are installed to monitor the same parameter for cross-checking, then measurement reliability improves, but the device complexity and cost increase
Solution Approach 1:
The patent makes existing sensors serve multiple functions: they not only provide control signals but also serve as diagnostic elements for cross-checking. The current sensors and voltage sensors already installed in the power converter are utilized for both normal operation and reliability verification, eliminating the need for dedicated diagnostic sensors and reducing overall system complexity
Solution Approach 2:
The control system acts as an intermediary that processes and cross-checks sensor outputs. Rather than adding complex hardware verification systems, the patent uses the control unit to mediate between multiple sensors, comparing their outputs and detecting inconsistencies through software algorithms, thereby achieving high measurement precision with minimal additional hardware
3Reliability
If sensor outputs are monitored continuously for fault detection, then system reliability improves, but the processing time and computational load increase
Solution Approach 1:
The patent implements periodic cross-checking of sensor outputs at predetermined intervals during normal operation, rather than continuous monitoring. The control system periodically compares sensor readings against expected relationships (e.g., power balance equations), which reduces computational load and processing time while still maintaining effective fault detection capability
Solution Approach 2:
The system performs preliminary verification of sensor consistency during normal operation before actual failures occur. By continuously cross-checking sensor outputs against physical relationships in the power converter, the system detects drift or incipient failures early, enabling preventive maintenance before catastrophic failures happen, thus reducing overall system downtime
Data Source
AI summary
In a multi-phase motor drive that includes a bus capacitor, a multi-phase motor, a multi-phase inverter, multiple switches each having an on-state and an off-state, and multiple current sensors each being in series with respective phase winding, a method for checking the accuracy of circuit parameters of the motor drive, including using the switches to produce a first loop that includes the capacitor bank, a first phase winding, a first current sensor, a second phase winding, and a second current sensor, using the current sensors to determine a magnitude of current in the first and second phase windings, comparing a magnitude of current indicated by the first current sensor and the second current sensor, and determining a magnitude of a difference between the current in the first and second phase windings.