A high pressure sampling system and method

Abstract

The invention discloses a high-voltage sampling system and method. The system includes a first voltage sampling circuit, which is used for isolating and stepping down the voltage signal of the voltage to be measured, and then performing signal conditioning on the voltage signal after the voltage stepping down, and outputting the first Sampling signal; a second voltage sampling circuit, used for voltage division and signal conditioning of the voltage signal of the voltage to be measured, and outputting a second sampling signal, or for directly performing isolated sampling on the voltage signal of the voltage to be measured , and output the second sampling signal; the MCU is used to determine the output voltage of the voltage to be measured according to the first sampling signal and the second sampling signal. The present invention samples the voltage of the voltage to be measured through two sampling methods of different physical principles, which ensures real-time sampling and avoids common cause failure. Therefore, the present invention has strong reliability and meets the requirements of ISO26262 functional safety. Redundant security requirements. The invention can be widely used in the technical field of voltage detection.

Description

technical field [0001] The invention relates to the technical field of voltage detection, in particular to a high-voltage sampling system and method. Background technique [0002] In the new energy vehicle motor controller or battery management system, etc., it is necessary to sample the voltage of the power battery as a parameter input for software control. Generally, non-isolated sampling is used in medium and low-speed electric vehicles (referring to electric vehicles with a battery voltage not greater than 72V), that is, directly through a voltage divider circuit to reduce the battery voltage to the voltage range that the A / D conversion unit of the MCU can withstand, and then The MCU calculates the voltage of the battery through a software algorithm. However, in the power battery system of new energy electric vehicles, the general voltage is relatively high (generally not less than 144V). In this case, for safety reasons, the battery voltage sampling circuit will be des...

AI Technical Summary

Problems solved by technology

First of all, the first scheme of using the same circuit for backup redundancy does reduce the failure rate of the circuit at some point, but it cannot solve the circuit failure caused by the same problem, which is the so-called common cause failure.

The second solution is to transmit the high-voltage battery voltage signal to the system through an external signal, and there are uncertain factors such as passivity, communication delay or communication abnormality, which cannot meet the real-time performance of the system control. At the same time, the second solution cannot Avoiding Common Cause Failure Problems

[0004] In summary, the prior art has the problem of poor reliability

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