Shoot-Through Detector Circuit for UPS Reliability
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Solution Overview
Problem
Conventional UPS systems face challenges in detecting and mitigating shoot-through conditions without increasing cost, complexity, and physical footprint, as existing solutions like advanced gate drivers are costly and complex.
Innovation Solution
A shoot-through detector circuit is implemented that measures capacitor voltage, delays the measurement, and compares it to a subsequent measurement to detect shoot-through conditions, then controls switching devices to prevent discharge, using a comparator and logic circuit to generate a signal for mitigating the condition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If advanced gate drivers are used to detect and mitigate shoot-through conditions, then reliability is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the shoot-through detection function from the complex advanced gate driver and implements it as a separate, simpler detector circuit. This detector circuit uses basic components like voltage dividers, comparators, and logic gates to monitor capacitor voltages independently, thereby maintaining reliability while reducing the complexity burden on the gate driver itself.
Solution Approach 2:
The patent introduces an intermediary detector circuit that mediates between the power converter components and the control system. This intermediary uses simple voltage sampling and comparison mechanisms to detect shoot-through conditions, translating complex electrical state monitoring into basic voltage threshold comparisons that are computationally inexpensive and hardware-simple.
2Reliability
If advanced gate drivers are used to detect shoot-through conditions, then reliability is improved, but cost increases
Solution Approach 1:
The patent employs inexpensive, readily available electronic components in the detector circuit, such as standard voltage dividers, basic comparators, and simple logic gates. These components are mass-produced and low-cost, replacing the need for expensive advanced gate drivers while maintaining adequate detection reliability for the application.
Solution Approach 2:
By separating the detection function from the expensive gate driver, the patent allows the gate driver to remain a standard, cost-effective component. The extracted detection functionality is implemented using budget-friendly circuitry, thereby reducing the overall bill of materials cost while preserving the critical shoot-through protection capability.
3Reliability
If voltage measurement and comparison circuits are added to detect shoot-through, then reliability is improved, but device complexity increases
Solution Approach 1:
The detector circuit is segmented into distinct functional blocks: voltage sampling network, delay circuit, comparison logic, and output generation. Each segment performs a single, well-defined function using minimal components. This modular segmentation makes the overall circuit easier to design, implement, and verify, reducing the perceived complexity despite adding detection functionality.
Solution Approach 2:
The patent incorporates a delay circuit that preliminarily processes the voltage measurement before comparison. This delay circuit prepares the voltage signal in advance, holding it for a predetermined time to ensure stable comparison results. By performing this preliminary action, the main comparison logic remains simple and straightforward, avoiding the need for complex real-time processing.
Data Source
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AI summary
According to one aspect, an uninterruptible power supply system is provided including an input configured to receive input power, an interface configured to be coupled to a backup power supply and to receive backup power from the backup power supply, an output configured to provide output power derived from at least one of the input power and the backup power to a load, a power converter coupled to the input, a capacitor, and a shoot-through detector coupled to the capacitor. The shoot-through detector is configured to obtain a first voltage value indicative of a first voltage across the capacitor, obtain a second voltage value indicative of a second voltage across the capacitor, compare the first voltage value to the second voltage value, determine, based on the comparison, that the capacitor is experiencing a shoot-through condition, and provide an output signal indicative of the shoot-through condition.