Current Interruption Circuit for Relay Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical storage systems face challenges in reliably interrupting energization of electrical storage devices without relying on program processing, particularly when the controller's program changes, and in maintaining the longevity of relays used for switching states.
Innovation Solution
An electrical storage system incorporating a current interruption circuit with an alarm circuit, latch circuit, and transistor to independently control the relay's state, allowing it to switch from an on to an off state based on voltage comparisons, thereby decoupling from controller-executed control and reducing relay operation frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the controller executes program control to manage relay switching, then the control flexibility is improved, but the reliability of interrupting energization deteriorates when program changes occur
Solution Approach 1:
The control system is segmented into two independent parts: the controller for normal operation and the current interruption circuit for safety-critical functions. This segmentation allows the controller to maintain flexibility through program changes while the separate current interruption circuit ensures reliable energization interruption independent of controller software state.
Solution Approach 2:
The current interruption circuit acts as an intermediary between the alarm circuit and the relay, providing a dedicated signal path that bypasses the controller. This intermediary mechanism ensures that safety-critical relay switching can occur without relying on controller program execution, thereby maintaining reliability during program transitions.
2Measurement precision
If the controller controls the relay on-off state, then the control precision is improved, but the relay service life deteriorates due to increased operation frequency
Solution Approach 1:
The control functions are segmented such that the controller handles normal precision control while the current interruption circuit handles only emergency stopping. This segmentation reduces the overall operation frequency of the relay by separating routine control from safety-critical actions, thereby extending relay service life while maintaining control precision for normal operations.
Solution Approach 2:
The system uses periodic control from the controller for normal operations and reserves the relay for occasional emergency interruptions only when the alarm circuit detects critical conditions. This periodic versus event-driven action pattern minimizes relay wear while maintaining precise control capability when needed.
3Reliability
If the current interruption circuit operates independently, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The current interruption circuit serves as a specialized intermediary component with a single dedicated function: to interrupt energization when alarm conditions occur. This focused intermediary design improves reliability by eliminating dependency on controller software while adding minimal complexity through a dedicated but functionally simple circuit path.
Solution Approach 2:
The critical safety function of interrupting energization is extracted from the controller and placed in a separate current interruption circuit. This extraction improves reliability by isolating the safety-critical function from potential controller software issues, while the extracted circuit remains relatively simple in structure, adding only the necessary components for its specific purpose.
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 solution ensures continuous operation of the current interruption circuit, enhances versatility, and extends the service life of relays by minimizing their operational cycles, while maintaining the ability to detect and respond to overcharged or overdischarged states.
Implementation Method 1
The alarm circuit is configured to output an alarm signal indicating that any one of the electrical storage blocks is in an overcharged state or an overdischarged state by comparing an input voltage value of each electrical storage block with a threshold
Implementation Method 2
The transistor is configured to cause the relay to switch from the on state to the off state upon reception of an output signal of the latch circuit
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
An electrical storage system includes an electrical storage device (10); a relay (SMR-B, SMR-G, SMR-P) switching between on/off states; a current interruption circuit (60) interrupting energization of the electrical storage device by causing the relay to switch from the on state to the off state; and a controller (30) executing drive control over the relay The current interruption circuit includes an alarm circuit (63) outputting an alarm signal indicating overcharging/overdischarging of any one electrical storage block by comparing a voltage value of each electrical storage block with a threshold; a latch circuit (64) retaining the alarm signal; and a transistor (68) causing the relay to switch from the on state to the off state upon reception of an output signal of the latch circuit. The controller detennines an energization state of the electrical storage device by executing control for turning on the relay while control for causing the alarm circuit to output the alarai signal is being executed.