Electrical Storage System Overvoltage Protection Failure Detection
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Solution Overview
Problem
Existing electrical storage systems fail to detect abnormalities in overvoltage protection elements, such as Zener diodes, which can lead to leakage current and voltage decreases, requiring complex circuit configurations and additional failure detection elements.
Innovation Solution
An electrical storage system with a voltage detection circuit, a protection circuit including an overvoltage protection element connected in parallel with a first resistor, and a discharge circuit with a second resistor of higher resistance value, allowing the controller to detect abnormalities by comparing voltages between electrical storage blocks, thereby identifying leakage current through faulty overvoltage protection elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an additional failure detection switching element is provided to detect Zener diode failure, then detection capability is improved, but circuit complexity increases
Solution Approach 1:
The system uses its existing voltage detection circuits and control unit to perform self-diagnosis of the Zener diodes. The control unit activates discharge circuits to intentionally discharge electrical storage blocks and compares voltage changes detected by existing voltage detection circuits. This self-service approach enables failure detection without adding external detection elements, resolving the contradiction between detection capability and circuit complexity.
Solution Approach 2:
The existing voltage detection circuits and control unit are made multi-functional by enabling them to perform both normal voltage monitoring and failure detection functions. The control unit's existing capability to control discharge circuits is extended to include diagnostic operations. This universal usage of existing components achieves failure detection capability without increasing circuit complexity.
2Device complexity
If voltage comparison method is used to detect leakage current, then additional detection elements are eliminated, but detection precision may be affected
Solution Approach 1:
The control unit performs preliminary actions by intentionally discharging selected electrical storage blocks using discharge circuits before comparing voltages. This controlled discharge creates a known test condition where leakage current effects can be isolated and detected. By preparing the system in advance with controlled discharge states, the method achieves accurate abnormality detection using only existing voltage detection circuits, maintaining precision while simplifying the overall device.
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
This configuration enables the detection of abnormal overvoltage protection elements without additional failure detection switching elements, simplifying the circuit and allowing for the identification of Zener diode failures, thus maintaining system stability and efficiency.
Implementation Method 1
a voltage detection circuit connected to each of the electrical storage blocks via corresponding voltage detection lines and configured to detect a voltage of each of the electrical storage blocks
Implementation Method 2
when any one of the Zener diodes fails and there occurs an abnormality, leakage current may flow through the any one of the Zener diodes. The voltage of the single cell connected in parallel with the failed Zener diode decreases due to the leakage current
Implementation Method 3
a discharge circuit connected in parallel with each of the overvoltage protection elements via the corresponding voltage detection lines and connected in series with the first resistor, the discharge circuit including a second resistor having a larger resistance value than the first resistor
Data Source
AI summary
An electrical storage system includes: serially connected electrical storage blocks each including at least one electrical storage element; a voltage detection circuit connected to each electrical storage block via voltage detection lines; a protection circuit including an overvoltage protection element connected in parallel with each electrical storage block via the voltage detection lines and a first resistor connected in series with the overvoltage protection element; a discharge circuit connected in parallel with each overvoltage protection element via the voltage detection lines and in series with the first resistor, the discharge circuit including a second resistor having a larger resistance value than the first resistor; and a controller detecting an abnormality in the overvoltage protection elements by, while the electrical storage elements are not connected to the load, comparing a voltage of a discharging first electrical storage block with a voltage of a non-discharging second electrical storage block.