Battery High Voltage Sampling Circuit Ground Interference
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Solution Overview
Problem
Existing battery high voltage sampling circuits face accuracy issues due to interference from isolation units, which are used to prevent high voltage ground signals from affecting sampling units, leading to decreased accuracy of sampled signals.
Innovation Solution
A battery high voltage sampling circuit is designed with positive and negative relays connected to a common low voltage ground, eliminating the need for additional isolation units by using a reference voltage terminal for both sampling units, thereby simplifying the circuit and improving signal accuracy. This configuration includes resistor networks and voltage pull-up units to adjust and enhance sampled signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If an isolation unit is added to isolate high voltage ground signal from sampling unit, then high voltage ground interference is reduced, but new interference signals are introduced and circuit complexity increases
Solution Approach 1:
The patent removes the isolation unit from the circuit configuration. By extracting this component that was causing new interference signals, the sampling accuracy is improved while still maintaining proper ground reference connections for accurate measurement.
Solution Approach 2:
The patent connects both the high voltage sampling circuit and low voltage sampling circuit to a common low voltage ground. This merging of ground references eliminates the need for isolation units while providing a stable reference for accurate voltage sampling across different voltage domains.
2Reliability
If an isolation unit is added to prevent high voltage ground signal interference, then isolation is improved, but circuit structure becomes more complex
Solution Approach 1:
The patent extracts and removes the isolation unit from the circuit. This simplifies the overall circuit structure by eliminating unnecessary components while maintaining reliable ground signal references through the common low voltage ground connection.
Solution Approach 2:
The common low voltage ground serves multiple functions simultaneously: it provides a reference for low voltage sampling, a reference for high voltage sampling, and a stable ground connection for the processor. This multi-functionality eliminates the need for separate isolation circuits.
Data Source
AI summary
The present disclosure provides a battery high voltage sampling circuit and a battery management system. The battery high voltage sampling circuit includes a positive relay, a negative relay, a first positive sampling unit, a first negative sampling unit and a reference voltage terminal, wherein: a first terminal of the positive relay is connected to a positive electrode of a power battery pack to be detected, a first terminal of the negative relay is connected to a negative electrode of the power battery pack to be detected, and both of the first positive sampling unit and the first negative sampling unit are connected to the reference voltage terminal.