Variable CAN Filter Capacitance for Battery Management Noise Control
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Solution Overview
Problem
Existing CAN communication systems face challenges in maintaining communication quality when the number of connected controllers varies, as they require replacing capacitors with fixed capacitance to manage noise, which is inefficient and costly.
Innovation Solution
A battery management system with variable capacitors and switching units that adjust capacitance based on voltage levels, allowing dynamic noise cut-off frequency adjustment without replacing filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a capacitor with fixed capacitance is used in the CAN communication system, then the filter structure is simple, but the communication quality deteriorates when the number of controllers increases or communication frequency changes
Solution Approach 1:
The patent applies the dynamics principle by replacing the fixed capacitor with a variable capacitor whose capacitance can be dynamically adjusted based on the number of connected controllers and communication frequency requirements. The control unit monitors system conditions and adjusts the capacitor value in real-time, allowing the filter to adapt to changing system configurations while maintaining optimal noise filtering performance.
Solution Approach 2:
The patent implements parameter changes by modifying the capacitance value of the filter capacitor based on system conditions. The control unit calculates the appropriate capacitance value according to the number of controllers connected and the communication frequency, then adjusts the variable capacitor to the calculated value, ensuring optimal noise filtering across different operating conditions.
2Adaptability or versatility
If the number of controllers connected in parallel increases, then the system capacity increases, but the total capacitance increases causing communication quality to deteriorate
Solution Approach 1:
The patent applies feedback by implementing a control unit that continuously monitors the number of controllers connected to the CAN bus and adjusts the variable capacitor accordingly. The control unit receives information about system configuration, calculates the required capacitance value to maintain proper filtering, and adjusts the capacitor in real-time, creating a closed-loop system that maintains communication quality regardless of the number of connected controllers.
Solution Approach 2:
The patent changes the capacitance parameter dynamically based on the number of controllers. When more controllers are connected, the control unit increases the capacitance value to compensate for the increased total capacitance effect, thereby maintaining the appropriate cut-off frequency and communication quality across different system configurations.
3Reliability
If the capacitor is replaced to effectively remove noise when the number of controllers changes, then the communication quality improves, but the time and cost increase
Solution Approach 1:
The patent implements self-service by enabling the system to automatically adjust its own filtering characteristics without external intervention. The control unit monitors system conditions and autonomously adjusts the variable capacitor to maintain optimal noise filtering, eliminating the need for manual capacitor replacement and reducing maintenance time and costs.
Solution Approach 2:
The patent uses dynamics by replacing static fixed capacitors with dynamic variable capacitors that can change their capacitance value in real-time. This allows the system to adapt to changing configurations automatically, eliminating the need for physical component replacement and reducing maintenance requirements.
4Reliability
If the capacitor is replaced to effectively remove noise when the communication frequency changes, then the communication quality improves, but the productivity decreases
Solution Approach 1:
The patent changes the capacitance parameter dynamically in response to communication frequency changes. The control unit monitors the communication frequency and adjusts the variable capacitor value accordingly, allowing the system to maintain optimal noise filtering performance across different communication speeds without requiring physical capacitor replacement.
Solution Approach 2:
The patent implements universality by designing a single variable capacitor that can serve multiple communication frequency requirements. Instead of needing different fixed capacitors for different frequencies, the system uses one variable capacitor that can be adjusted to handle various communication speeds, simplifying the system and improving productivity.
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
Enables effective noise removal in CAN communication systems by dynamically adjusting capacitance, saving time and costs associated with capacitor replacements.
Implementation Method 1
a variable capacitor connected between a Controller Area Network (CAN) communication line and a ground, wherein a capacitance of the variable capacitor varies according to a voltage level supplied to the variable capacitor
Data Source
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AI summary
The present invention relates to a battery management system, an energy storage device, and a battery system for removing noise in Controller Area Network (CAN) communication, and the battery management system is for managing a battery pack having a plurality of battery cells connected in series, the battery management system including: a variable capacitor which is connected between a Controller Area Network (CAN) communication line and a ground and in which capacitance corresponding to a level of received voltage is accommodated; a switching unit including a plurality of resistors connected between an external power source and the ground and a plurality of switches electrically connecting each of the plurality of resistors and the variable capacitor; and a control unit for controlling the switching unit so that a voltage of the external power source is transmitted to the variable capacitor.