Motor Control Device Current Balancing for Communication Reliability
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Solution Overview
Problem
Conventional motor control devices face issues with power supply current imbalances between systems due to differences in battery voltages and wiring resistances, leading to potential communication abnormalities between microcomputers with independent ground potentials.
Innovation Solution
The motor control device employs a power supply current balancing process, where microcomputers in each system monitor and adjust current command values or voltage command values to ensure the power supply current difference between systems remains within a target limit, thereby reducing the likelihood of inter-computer communication abnormalities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If power supply currents are not balanced between systems, then system independence is maintained, but communication abnormalities arise due to ground potential differences
Solution Approach 1:
The control device monitors power supply currents from both batteries and uses feedback control to adjust current distribution. When an imbalance is detected, the system actively regulates the power supply to reduce the current difference, thereby minimizing ground potential differences and preventing communication abnormalities.
Solution Approach 2:
The power supply current parameter is dynamically adjusted through feedback control. By changing the current distribution parameter in response to detected imbalances, the system maintains communication reliability while preserving the benefits of independent power supplies.
Data Source
AI summary
A motor control device includes a plurality of systems capable of controlling current supply to a motor. Each microcomputer of first and second systems is configured to communicate information of the own system and the other system by inter-computer communication and has an independent ground potential. A power supply current flowing between a power supply and a power converter is assumed to be positive and negative in a power running state and a regeneration state. Each microcomputer monitors the power supply current of each system by the inter-computer communication, and executes a power supply current balancing process of limiting a current command value or a voltage command value of at least one of the two systems thereby to decrease a power supply current difference between the two systems when the power supply current difference between the two systems exceeds a target value.