Power Supply Device Cutoff Abnormality Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power supply devices with semiconductor switching elements connected in series face challenges in accurately sensing cutoff abnormalities, leading to potential overvoltage issues due to erroneous voltage detection methods.
Innovation Solution
A power supply device with a switch circuit and a control device that uses terminal-to-terminal voltages of semiconductor switching elements to accurately sense cutoff abnormalities by producing cutoff commands and determining the state of each switching element during power conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If terminal-to-terminal voltage of semiconductor switching element is used for sensing cutoff abnormality, then cutoff abnormality detection is enabled, but erroneous sensing occurs when input and output voltages are equal
Solution Approach 1:
The patent introduces an intermediary measurement approach by detecting the voltage between the input node and output node of the switch circuit, and comparing it with the sum of individual semiconductor switching element voltages. This intermediary comparison mechanism resolves the erroneous detection problem that occurs when input and output voltages are equal, as it measures the voltage distribution across each switching element rather than relying solely on terminal-to-terminal voltage.
Solution Approach 2:
The patent segments the voltage measurement into individual contributions from each semiconductor switching element. By measuring and summing the voltages across each switching element separately, and comparing this sum with the overall input-output voltage difference, the system can accurately detect cutoff abnormalities without erroneous sensing, even when input and output voltages are equal.
2Stability of the object's composition
If bidirectional converter supplies AC power synchronized with AC power supply, then power supply stability is maintained during abnormalities, but voltage difference between input and output terminals becomes zero
Solution Approach 1:
The patent uses an intermediary measurement strategy by comparing the sum of individual switching element voltages with the overall input-output voltage. This allows accurate detection of cutoff abnormalities even when the bidirectional converter maintains equal input and output voltages for stability, as the intermediary comparison reveals discrepancies in individual element voltage distribution.
Solution Approach 2:
The patent shifts the measurement dimension from terminal-to-terminal voltage to individual switching element voltage distribution. By measuring voltages across each switching element separately and comparing the sum with the overall voltage, the system gains another dimension of measurement that remains effective even when traditional terminal voltage difference becomes zero.
Data Source
AI summary
A switch circuit includes n switching elements (n≥2) connected in series between an input node and an output node. A control device is configured to convert DC power in a power storage device into AC power synchronized with AC power supplied from an AC power supply during a normal state and supply the AC power to the output node, by controlling a power converter, when an abnormality of at least one of the AC power supply and the switch circuit is sensed in a state where the control device outputs conduction commands for the n switching elements. The control device is further configured to produce cutoff commands for cutting off the n switching elements during execution of power conversion in the power converter, and sense a cutoff abnormality of the switch circuit based on terminal-to-terminal voltages of the n switching elements during production of the cutoff commands.