Capacitor Connection Testing Circuit for High-Voltage Fault Detection
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Solution Overview
Problem
Existing systems lack the ability to effectively test whether a capacitor is open or faulty, particularly in high voltage applications such as battery charging systems for electric vehicles, and fail to address disconnection issues due to environmental factors like heat, cold, humidity, and impact.
Innovation Solution
A testing circuit is implemented with an AC-DC converter, DC-DC converter, noise filter, testing voltage source, discharge network, voltage detection circuit, and controllers to control switches, allowing for the determination of capacitor connectivity and functionality by disconnecting and reconnecting the capacitor to these components during testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a capacitor is used in a high voltage circuit without testing capability, then the system can operate continuously, but the capacitor may fail due to environmental factors causing open circuits and reducing system performance
Solution Approach 1:
The testing circuit is merged with the main circuit board, integrating testing functionality into the existing system structure. The testing circuit shares the same physical platform and control resources as the main circuit, reducing overall system complexity while maintaining testing capability.
Solution Approach 2:
The controller serves multiple functions: it controls the main circuit operation, manages the testing sequence, and processes test results. The switching network performs both circuit connection and testing isolation functions. This multi-functionality reduces the need for dedicated testing components.
2Measurement precision
If the capacitor is continuously connected to the main circuit, then the system maintains full functionality, but the capacitor cannot be tested for faults or disconnection
Solution Approach 1:
The capacitor testing is performed periodically through switching operations. The controller periodically activates the testing sequence, which temporarily isolates the capacitor from the main circuit, performs voltage application and measurement, then restores the capacitor to its operational state. This periodic testing ensures fault detection while minimizing interruption to system productivity.
Solution Approach 2:
The testing circuit prepares test voltage and measurement resources in advance before actual testing begins. The controller pre-configures the switching network and ensures testing components are ready, allowing rapid transition between operational and testing modes with minimal system interruption.
3Measurement precision
If the capacitor is isolated for testing, then fault detection is enabled, but the main circuit operation is interrupted
Solution Approach 1:
The testing sequence is designed to execute rapidly through predefined switching states. The controller manages fast switching transitions between testing phases (voltage application, measurement, and restoration), minimizing the time the capacitor is isolated from the main circuit while ensuring complete testing functionality.
4Measurement precision
If a simple testing method is used, then the testing circuit is easy to implement, but it cannot accurately determine capacitor connectivity and functionality
Solution Approach 1:
The switching network acts as an intermediary between the capacitor and both the main circuit and testing circuit. It provides controlled isolation and connection, enabling the testing voltage source and measurement circuit to interface with the capacitor without directly interfering with main circuit operation. This intermediary structure enables precise measurement while maintaining system integrity.
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
The system efficiently determines if a capacitor is connected to the noise filter by measuring voltage thresholds, ensuring proper operation and preventing open circuits, thus maintaining system performance.
Implementation Method 1
a discharge network configured to dissipate power from the capacitor
Implementation Method 2
a voltage detection circuit configured to measure a voltage of the capacitor, as a measured voltage
Data Source
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AI summary
Disclosed techniques relate to a system for testing a capacitor (606). In an example, a testing circuit (600) includes a testing voltage source (626) configured to output a testing voltage to the capacitor; a discharge network (630) configured to dissipate power from the capacitor; a voltage detection circuit (632) configured to measure a voltage of the capacitor; a first switch (611) configured to connect the capacitor to a main circuit; a second switch (612) configured to connect the capacitor to the discharge network; a third switch (613) configured to connect the capacitor to the testing voltage source; and a fourth switch (614) configured to connect the capacitor to the voltage detection circuit; and one or more controllers. The controllers are configured to control an operation of the switches to test the capacitor using the testing voltage source, the discharge network, and the voltage detection circuit, and to determine, from the test, whether the capacitor is connected.