Voltage Detection Device Current Consumption Equalization
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Solution Overview
Problem
The existing voltage detection devices for batteries connected in series face issues with unequal consumption current among voltage detection units, leading to variations in unit cell voltage, which reduces the effective use of battery capacity and necessitates equalizing discharge.
Innovation Solution
The proposed voltage detection device includes current consumption elements connected in parallel to the blocks, equalizing the current consumption among voltage detection units, ensuring consistent communication and operation across all units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the daisy chain schema is used for communication between voltage detection units, then the scalability and ease of communication are improved, but the consumption current varies among voltage detection units due to individual differences and communication load distribution
Solution Approach 1:
The patent applies parameter changes by adjusting the resistance values of current consumption elements in different voltage detection units. Specifically, the resistance value is set to be smaller in voltage detection units that communicate with multiple other units compared to those that communicate with fewer units. This parameter adjustment equalizes the consumption current across all voltage detection units, preventing variations that would otherwise occur due to the daisy chain communication schema.
2Ease of operation
If voltage detection units communicate with multiple other units in the daisy chain, then the communication coverage is improved, but the consumption current of those units increases
Solution Approach 1:
The patent applies local quality by making each voltage detection unit have different resistance values tailored to its specific communication role in the daisy chain. Voltage detection units that serve as communication intermediaries (communicating with multiple units) are equipped with smaller resistance values, while units with fewer communication responsibilities have larger resistance values. This localized differentiation ensures that each unit's consumption current is equalized according to its specific operational requirements.
3Reliability
If equalizing discharge is performed frequently to correct unit cell voltage variations, then the battery reliability is improved, but the loss of time and productivity are worsened
Solution Approach 1:
The patent applies preliminary action by equalizing the consumption current of voltage detection units before voltage variations occur. By pre-balancing the current consumption through appropriately selected resistance values, the system prevents the voltage variations that would otherwise necessitate frequent equalizing discharge operations. This proactive approach maintains battery reliability while avoiding the time loss associated with corrective equalizing discharge.
Data Source
AI summary
It is provided that pull-down resistors (R1 to Rn-1) which are respectively connected in parallel to blocks (CB1 to CBn−1) except for a block (CBn) that corresponds to a battery monitoring IC (2n) connected to a main microcomputer (3) via an insulation I/F (4) so as to be capable of communication, thereby equalizing current consumed in battery monitoring ICs (21 to 2n).