This is a very real problem. If there is more electric vehicles in the future, there are various accidents (collision, soaking), how to make effective monitoring and detection? My personal thoughts are through a dedicated circuit block, probably have such an ideal:
1) With multiple power input, you can enter the external hanging into 12V configuration possibilities when 12V battery work and battery are not working.
Remarks: This is a functional design of the depletion of 48V batteries.
2) The working current is sufficiently small, and it is possible to maintain a relatively suitable working interval, a perceptual device for dangerous warning and high power sensitive threshold by low power low threshold.
3) Can form a low-power ASIC, then modular access into the BMS into part of it
The content of "Fast Thermal Runaway Detection for Lithium-Ion Cells in Large Scale Traction Batteries" is still a lot of interesting content, and I think it can be the direction of us to make the device test.
A set of sensors are selected here
Sensor S1, monomer voltage collection signal in multiplexing modules
The sensor S2 is a gas sensor made of tin ozide (SnO2), which is a gas discharged in the battery during thermal out of control of methane (CH4), propane (C3H8) or carbon monoxide (CO).
The sensor S3 is a smoke detector, which is based on the original infrared LED, which is through the photovoltaic smoke detector, considering the smoke and other gases generated during the thermal out-of control process, considering the threshold change of the sensor.
The sensor S4 is smart here, and the idea is designed with a PCB to design two pads, and evaluate the environmental changes in this in accordance with surface cleanliness. The output is characterized by changes in impedance.
Sensor S5: The temperature of the air and the exhaust system is measured using a higher precision K-type (NiCr-Ni) thermocouple.
Sensor S6: Measuring the absolute pressure in the pressure sensor in the range of 20 kPa ≤ psens ≤ 304kpa, this principle is that almost all enterprises can detect the pressure of the battery system during the cell system.
Sensor S7: Thin film dielectric force sensor, range is 0 n≤fsens ≤ 445 N, configured within the module, and is configured to measure the expansion force between the cells in the thermal out-of control and adjacent cells.
The process of configuring the experiment: The test condition is a battery core, 100% SOC, and 60 ° ambient temperature, and I will update the following SOCs and different types of configurations later, for different tests of the entire thermal out-of-control cell Summary of data. Here is the reasonable test according to the actual module configuration.
Test construction:
Experimental data results:
Sample 1
Sample 2
Sample 3
Test effect, here is three basic items
A) detection speed: how fast it detects that heat loss
B) Signal definition: the sharpness of the sensor signal, considering the problem of signal-to-noise ratio in the actual environment
C) Practical feasibility of sensors: How to easily deploy sensors in battery system
This is the result of the assessment:
From the reaction speed: gas sensor (S2), pressure sensor (S6) and module pressure (S7) reacts the fastest
From the signal clarity, the voltage (S1), the gas sensor (S2) is ok; the biography of S3 and S5 is a comparison of differentialization.
Integration: S1, S4 and S6 are more feasible
Remarks: Yesterday's article is similar, the drop in the long-scale time scale of the voltage is relatively reliable signal, and the two pressure sensors of the whole package are indeed the direction of the current work.
Small knot: I spent a lot of time to see the gas sensor. In fact, the gas sensor has a lot of life problems in this application, and it is easy to flood from other similar leaks and glue volatilizers, now the core To consider a set of descendant frequency to build a separate MCU core to build this system, how much time you need to maintain ^ _^, in this field's sensor optimization configuration and algorithm development, it is very artistic to do , Read full text, original title: detection and monitoring of battery thermal out-of control
Article Source: [Micro Signal: QCDZSJ, WeChat Public Number: Automotive Electronic Design] Welcome to add attention! Please indicate the source of the article.
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