EV Converter PWM Interval Counting for Failure Detection
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Solution Overview
Problem
Conventional control systems for electric vehicle converters are prone to damaging electric components due to incorrect PWM signal outputs, which can lead to delayed failure detection and increased risk of component damage, and require sensitive current sensors that increase production costs and research time.
Innovation Solution
A control method and system that uses a counting unit to determine converter failure by analyzing the time intervals of PWM signals generated by the converter, eliminating the need for current sensors and enabling quick detection of wrong PWM signal outputs, thereby reducing component damage and operational risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a current sensor is used to detect overcurrent for determining converter failure, then failure detection can be achieved, but production cost increases and research time extends due to the need for high precision elements and noise filtering components
Solution Approach 1:
The patent extracts the failure detection function from the current sensor and relocates it to the counting unit that monitors PWM signal intervals. By taking out the detection function from the expensive current sensor system, the invention eliminates the need for high precision elements and noise filtering components while maintaining reliable failure detection capability
Solution Approach 2:
The patent introduces the PWM signal interval as an intermediary parameter for failure detection. Instead of directly monitoring current (which requires sensitive sensors), the system uses the PWM signal timing characteristics as an indirect indicator of converter health, thereby avoiding the complexity of current sensing while achieving reliable failure detection
2Measurement precision
If a current sensor operates sensitively to detect overcurrent, then failure detection accuracy improves, but false detection due to noise increases
Solution Approach 1:
The patent inverts the detection approach by not directly measuring current (which is prone to noise interference) but instead measuring the PWM signal interval. This inversion transforms the detection from a direct electrical measurement susceptible to noise into a timing measurement that is inherently more stable and less prone to false detection
Solution Approach 2:
The patent creates a copy of the failure detection function in the counting unit that operates independently from the current sensor. The counting unit monitors PWM signal intervals as a redundant detection mechanism, providing a noise-resistant alternative that prevents false detection while maintaining measurement precision
3Stability of the object's composition
If failure control is activated only after PWM signal wrong output is detected, then system stability is maintained, but electric components are stressed seriously by high voltage and high current during the delay period
Solution Approach 1:
The patent implements preliminary action by detecting PWM signal interval abnormalities before they result in severe overcurrent conditions. The counting unit monitors PWM timing characteristics and triggers failure control early in the fault development process, preventing the system from reaching the dangerous state where components are seriously stressed
Solution Approach 2:
The patent rushes through the failure detection process by using the counting unit to rapidly identify PWM signal interval deviations. This quick detection bypasses the delay inherent in conventional current-based methods, allowing failure control to be activated before harmful high voltage and high current stress can significantly damage components
Data Source
AI summary
A method for control of an electric vehicle converter is provided. The converter is adapted to drop voltage and a counting unit is adapted to count a signal generated by the converter. The method includes inputting a signal that is generated by the converter to the counting unit during operation of the converter and counting the signal. Additionally, whether a counting result of the counting unit corresponds to a predetermined interval is determined and the converter is determined to be out-of-order when the counting result does not correspond to the predetermined interval.