On-line monitoring control method of electric car power cell high voltage loop resistor and apparatus thereof

Abstract

The invention relates to an on-line monitoring control method of an electric car power cell high voltage loop resistor and an apparatus thereof. The method comprises the following steps: (1) wire connection; (2) measurement and calculation of voltage of each electrical core and total voltage of a power cell system; (3) on-line monitoring of an electric car power cell system high voltage loop coupling assembly resistor; (4) abnormity control of a power cell system high voltage loop coupling assembly. In the invention, a mode of carrying out double wire system wiring on the power cell system is employed, influence of connection board voltage drop on electrical core voltage is eliminated, and measured data is more accurate. In the condition of not increasing any complex circuit elements, through calculation and derivation, on-line monitoring and abnormity control of the power cell system high voltage loop coupling assembly resistor are realized. Cost is saved, internal space of the power cell system is saved, the method is convenient and fast, and accuracy is high.

Description

technical field [0001] The invention relates to an on-line monitoring and control method and device for the resistance of a high-voltage circuit of an electric vehicle power battery, and belongs to the technical field of electric vehicles. Background technique [0002] As environmental pollution and energy scarcity have brought more and more impact on the earth's ecology and human life, adjusting the structure of the automobile industry and developing new energy vehicles to replace traditional fuel vehicles have become an inevitable trend in the development of today's society. With the development of lithium-ion battery technology, electric vehicles have become the mainstream direction for governments to develop and produce new energy vehicles. my country's Twelfth Five-Year Plan clearly proposes to vigorously develop electric vehicles to realize the transformation and sustainable development of the automobile industry. [0003] The power battery system is the heart of an e...

AI Technical Summary

Problems solved by technology

For battery segmentation, the total positive pole, total negative pole and each segment point of the battery pack are connected to the excitation unit through the excitation signal line, each single battery is connected to the detection unit, and the signal generator in the excitation unit is divided into two parts with the constant current source. Inject a certain frequency, constant current rectangular wave or sine wave signal into the battery in the section, use the detection unit to test the voltage response of each single battery to the excitation signal, calculate the internal resistance of the battery, and analyze the deterioration state of the battery, This method requires the installation of excitation units, detection units and complex circuits, which will occupy the internal space of the power battery system, affect the layout of the power battery system, and increase the cost of the power battery system

Chinese patent CN101943743A uses a high-voltage photorelay as the front end to switch the input, directly measure the internal resistance voltage of each battery in the battery pack and the resistance voltage of the connection bar, and cooperate with the analog-to-digital conversion circuit with double high speed to realize high-precision sampling and measurement connection Strip resistance and battery internal resistance, and the processing of collected data also adopts distributed control and data processing unit hardware architecture to realize multi-task real-time processing function, but it is necessary to install high-voltage photorelays to switch the sampled data, which increases the complexity of control and improves manufacturing cost

[0008] The power battery system on the above-mentioned electric vehicle does not directly judge whether the internal resistance of the battery cell and the connection resistance inside the power battery system are normal, but only judges whether the voltage of the battery cell and the total voltage of the power battery system are normal. It is difficult for personnel to understand; secondly, the wiring method of the test voltage of the power battery system is single-wire, and the measured voltage covers the voltage on the connecting strip, making the measured voltage value inaccurate, and the problem is that it is impossible to distinguish the problem of the battery cell It is still a problem of battery connection; moreover, the existing wiring method does not include the voltage difference caused by the shunt, positive relay and negative relay when measuring the total voltage of the power battery system, so the obtained power battery system voltage is inaccurate

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