CN202929177U - Lithium battery pack distributed detection apparatus with vibration and humiture detection functions - Google Patents

Abstract

The utility model discloses a lithium battery group distributed detection device with vibration and temperature and humidity detection, which includes several detection units, and each detection unit uses 16 lithium battery cells connected in series to measure, and each detection unit includes: Relay gating array, decoder gating unit, precision reference voltage source circuit, signal conditioning unit, DIP switch, microprocessor MCU, vibration sensor module and temperature and humidity sensor module. The micro-controller MCU of the utility model performs cyclic detection on the battery monomer through the relay gating array, the decoder gating unit, the precision reference voltage source circuit, and the signal conditioning unit, and the sensor module and the temperature and humidity sensor module pass the collected information through The I ² C bus and I/O port are respectively sent to the microcontroller MCU, and the detection unit sends the collected lithium battery single-chip voltage information, vibration level information, temperature and humidity information to the main control unit of the lithium battery pack through the CAN bus. The utility model is simple and clear, has high reliability, and can realize high-precision detection of the single-chip voltage signal of the lithium battery, the vibration signal of the battery pack, and the temperature and humidity signals.

Description

Lithium battery pack distributed detection device with vibration and temperature and humidity detection

technical field

The utility model belongs to a distributed detection method for a lithium battery pack, in particular to a distributed detection device for a lithium battery pack with vibration and temperature and humidity detection.

Background technique

Due to its high energy density, long life, low self-discharge rate, and no pollution, lithium batteries have rapidly become a hot spot in the research and development of modern hybrid vehicles. The battery voltage requirements of hybrid power are mostly between 300 and 400V, and some electric vehicles will make the total battery voltage reach more than 500 volts due to the power demand. Generally, the full charge of a single-chip lithium battery is above 3.32V. To achieve a power source of hundreds of volts, more than one hundred lithium batteries need to be connected in series. Due to various internal or external reasons during the operation of the lithium battery system, the lithium battery may be damaged. Abnormal operation of a single chip will affect the performance and safety of the entire lithium battery system. In order to ensure the normal operation of the lithium battery and evaluate its performance, the operating parameters should be monitored in real time. In the process of applying to the hybrid power system, many common factors will affect the work of the lithium battery, such as the vibration of the lithium battery in the car body caused by rough roads, crashes, rollovers, etc., may affect the performance of the battery system; the lithium battery pack is working During the process, a certain temperature gradient will be formed in the battery box due to heat generation. When the temperature is too high, the performance of the battery will be severely degraded, and the battery will even be burned; the presence of moisture in the lithium battery can not only lead to the decomposition of lithium salt in the lithium battery electrolyte And it has a certain corrosion and damage effect on the positive and negative electrode materials and current collectors, and it also leads to a decrease in battery cycle performance and safety performance. Excessive water molecules will also cause battery capacity attenuation. Therefore, the detection of vibration conditions and temperature and humidity information is also a very important part of the detection of lithium batteries.

A distributed detection method for lithium battery packs with vibration and temperature and humidity detection As a new detection method for lithium battery packs, not only the extremely important detection of vibration and temperature and humidity is added to the traditional detection method, but also the detection of voltage Improvements have been made. In the traditional detection method, multiple battery cells are used as a group to form a battery module, and the voltage of the module is measured. Generally, the voltage of the module is about 20 volts (taking five battery cells as an example), and the voltage is relatively high. High, generally needs to be isolated to output to the next level, this method not only cannot know the performance of each single battery (only the performance of the battery module), but also makes the detection unit more complicated.

Contents of the invention

The purpose of the utility model is to provide a simple, reliable, and highly expandable distributed detection device for lithium battery packs with vibration and temperature and humidity detection, so as to overcome the shortcomings of the prior art.

In order to achieve the above object, the technical solution adopted by the utility model is:

A distributed detection device for lithium battery packs with vibration and temperature and humidity detection, including several detection units, each detection unit is measured by a plurality of lithium battery cells connected in series, and each detection unit is for each lithium battery cell Detect, it is characterized in that: described each detection unit comprises: relay gating array, decoder gating unit, signal conditioning unit, dial switch, microprocessor MCU and self-powered power supply module, described relay gating The array is connected to the microprocessor MCU through the decoder gating unit, and the microprocessor MCU is also connected to the signal conditioning unit and the dial switch respectively, and the microprocessor MCU is connected to the main control unit of the lithium battery pack through the CAN bus , the input end of the self-powered power supply module is connected to the lithium battery pack, and the output end thereof supplies power to the entire device.

It also includes a vibration sensor module and a temperature and humidity sensor module, the input terminals of the vibration sensor module and the temperature and humidity sensor module are respectively connected to the lithium battery pack, and the output terminals of the vibration sensor module and the temperature and humidity sensor module are respectively connected to the microprocessor device MCU is connected.

The signal conditioning unit is connected with the microprocessor MCU through a precision reference voltage source circuit.

The number of lithium battery cells connected in series is 16, and m/16 detection units are used when detecting a lithium battery pack in which m single cells are connected in series.

The input end of the decoder is connected with the I/O port of the microprocessor MCU.

The relay array is composed of 16 relays, each lithium battery cell corresponds to a relay, and each relay contains two single relays, and the two single relays are respectively connected to the positive and negative poles of the lithium battery cell.

The signal conditioning unit includes a voltage follower composed of precision rail-to-rail operational amplifiers, a voltage inverter, a differential proportional amplifier circuit, precision resistors R1-R6, capacitors C1-C2 and voltage regulator tubes, wherein the input of the single-chip voltage signal The terminal is connected with the same-phase terminal of the differential proportional amplifier circuit, the precision reference voltage source is connected with the inverting terminal of the differential proportional amplifier circuit through a voltage inverter, and the output terminal of the signal conditioning unit is provided with a capacitor and a regulator tube. Limiting output protection circuit.

Compared with many modern battery detection systems, the utility model introduces the detection of vibration signals and temperature and humidity signals, which enhances the reliability of the battery system application. In order to achieve the purpose, the acceleration sensor MMA7455L of freescale company is used to collect the vibration signal at first. MMA7455L provides I ² C and SPI digital interface, which enables the microcontroller MCU to connect with the peripheral modules through the main control synchronous serial port. After the micro-control MCU of the detection unit obtains the vibration signal through the I ² C bus, it judges and grades the vibration signal (divided into severe vibration and slight vibration). Secondly, for the collection of temperature and humidity, AM2303 of Aosong Company is used. This is a digital integrated temperature and humidity sensor with high precision and does not require an A/D converter. Send message.

In addition, compared with the traditional detection system, this detection method adopts a self-power supply mode, and does not need a switching power supply to supply power to the detection board. The detection unit uses 24V power supply, and eight lithium batteries are connected in series as the power supply. Then use the power supply module to convert the 24V voltage into various levels of voltage required.

Since there are many detection boards, and each detection board is connected to the CAN network in a similar parallel manner to send the collected information to the main control unit of the lithium battery pack, the main control unit of the lithium battery pack will receive information from each detection board through the CAN network. information collected by the board. In order to enable the main control unit of the lithium battery to distinguish which detection board the information collected on the CAN network comes from, a 5-digit DIP switch is added to each detection board, and each detection board is numbered through the DIP switch. This number is used as The identifier of the detection board during CAN communication. The dialing codes of the dialing switch are sequentially from 00001 to 11111 to mark the 31 fast detection board. When the lithium battery main control unit communicates with CAN, it first judges the CAN network identifier of the sending end (detection board) to clarify which detection board the received signal comes from.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the utility model.

Fig. 2 is a schematic structural diagram of the self-powered power supply module of the detection unit of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail.

As shown in Figure 1, the detection system can be divided into two parts first: the lithium battery detection unit and the lithium battery main control unit. These two parts are connected through the CAN network. For the lithium battery main control unit.

The self-powered mode is adopted in the detection unit, as shown in Figure 2, eight lithium batteries are connected in series as a power supply, and the single-chip voltage of the phosphate lithium battery is about 3.3V during normal operation, and the range of voltage variation during charging and discharging is The voltage is 3.0V~3.4V, and the voltage of eight lithium batteries connected in series is 24~27.2V, which can be regarded as a power supply of about 24V, and then the power module is used to convert the 24V power supply to the required voltage level. The required voltage levels are plus or minus 12V and +5V, so the 24V to plus or minus 12V power module A2412S-1W and the 24V to +5V power module B2405-2W are used. Considering that the optically isolated power supply in the CAN interface circuit needs to be separated, two 24V to +5V power supply modules are used.

The utility model adopts a distributed detection method, with 16 lithium battery cells as a detection unit for measurement, and the i-th detection unit is for lithium battery cells C _(16t+1) ~ C _(16t+16) (where t =i-1) for detection, each detection unit has exactly the same structure, mainly including: relay gating array, decoder gating unit, precision reference voltage source circuit, signal conditioning unit, DIP switch, microprocessor MCU and Vibration sensor module and temperature and humidity sensor module. The only difference is that the ID numbers of each detection unit are different. The dial switches on the detection unit are 00001, 00010, 00011, 00100... to set IDs for detection units 1 to N respectively (N is generally less than 31). By judging the ID number, the lithium battery main control unit can judge which detection unit the data received on the CAN network comes from.

The single lithium battery in each detection unit of the utility model is connected to the output end (K1, K2...K32) of the corresponding relay gating array, and the input end of the relay gating array is connected to the output end of the decoder. connect. The input terminal of the decoder is controlled by the I/O port of the microcontroller MCU. When the input terminals A0, A1, A2, and A3 of the decoder perform 16 state switching from 0000 to 1111, the output terminal Y0～ The output of Y15 in turn is low-level driving corresponding switches K (2i-1) and K2i (i=1, 2...32) in the corresponding relay Ji (i=1, 2...16) are closed, so that the gated lithium The negative electrode of the single battery is grounded and the positive electrode is connected to the input terminal of the signal conditioning unit. Only one output of the decoder is low at any time, which ensures that only a single battery is detected online at any time. The voltage signal of the single-chip battery detected online is sent to the input terminal Vin of the signal conditioning unit for voltage conditioning. A 4.096V reference voltage source is introduced in the signal conditioning unit to raise the potential of the input signal in order to measure the negative voltage caused by the fault. value. The output terminal Vout of the signal conditioning unit is directly connected to the internal A/D module of the microcontroller MCU. The relay is AQW214EHAZ, and each AQW214EHAZ contains two single relays, which respectively control the positive and negative poles of lithium battery cells. Since each detection unit detects 16 battery cells, the selected decoder uses 4 —16-wire decoder 74HC154, the resistors in the signal conditioning unit are precision resistors to ensure the accuracy of the inverter and the proportional differential circuit. Considering that the input voltage of the signal conditioning power supply may exceed 5V, the selected operation The amplifier is a precision operational amplifier chip MAX479 with a power supply voltage greater than 5V. It contains 4 operational amplifiers, which just meet the needs of 4 operational amplifiers in the signal conditioning circuit. The limiter output protection circuit in the signal conditioning unit uses a 5.1V voltage regulator. The tube is enough, because the output of the signal conditioning unit will not exceed 5V. The voltage reference used in the internal A/D module is +4.096V, provided by the precise +4.096V voltage source X60008ES8-41.

The vibration sensor module in the utility model adopts the acceleration sensor MMA7455L of the freescale company to collect vibration signals, and the MMA7455L provides I ² C and SPI digital interfaces, which enables the microcontroller MCU to be connected to the peripheral modules through the main control synchronous serial port. The temperature and humidity sensor module adopts the AM2303 of Aosong Company. This is a digital integrated temperature and humidity sensor with high precision and does not require an A/D converter. It only needs to transmit information to the microcontroller MCU through a simple I/O port. .

The detection unit of the utility model sends the collected voltage signal, vibration signal, temperature and humidity signal to the main control unit of the lithium battery pack through the CAN network, and a CAN interface circuit is required before the CAN connection between the detection unit and the main control unit. Circuit includes opto-isolation and CAN transceiver. The optical isolation used in the CAN interface circuit is a high-speed optical isolation 6N137, and the CAN transceiver uses PCA82C250, which is used in the high-speed field of automobiles. This is the most widely used CAN transceiver at present, and supports the ISO-11898 standard. It can be seen from Figure 1 that the microcontroller MCU needs rich I/O ports, with internal A/D converter, I ² C bus, and CAN bus, so the microcontroller MCU in the detection unit uses PIC18F258 from MICROCHIP Company.

The utility model has been described above in conjunction with the best embodiments, but the utility model is not limited to the above-disclosed embodiments, but should cover various modifications and equivalent combinations based on the essence of the utility model.

Claims (7)

1. lithium battery distribution type pick-up unit with vibration and humiture detection, comprise several detecting units, each detecting unit is measured with the lithium battery monomer of a plurality of series connection, each detecting unit detects each lithium battery monomer, it is characterized in that: described each detecting unit comprises: relay gating array, the code translator gating unit, the signal condition unit, toggle switch, Micro-processor MCV and self powered supply module, described relay gating array is connected with Micro-processor MCV by the code translator gating unit, described Micro-processor MCV also joins with signal condition unit and toggle switch respectively, Micro-processor MCV is connected with lithium battery bag main control unit by the CAN bus, described self powered supply module input connects the lithium battery bag, its output terminal is given whole device power supply.

2. the lithium battery distribution type pick-up unit that band as claimed in claim 1 vibrates and humiture detects, it is characterized in that: go back involving vibrations sensor assembly and Temperature Humidity Sensor module, the input end of described vibration transducer module and Temperature Humidity Sensor module is connected with the lithium battery bag respectively, and the output terminal of described vibration transducer module and Temperature Humidity Sensor module is connected with described Micro-processor MCV respectively.

3. the lithium battery distribution type pick-up unit of band as claimed in claim 1 vibration and humiture detection is characterized in that: described signal condition unit is connected with Micro-processor MCV by the accurate reference voltage circuit.

4. the lithium battery distribution type pick-up unit that band as claimed in claim 1 vibrates and humiture detects, it is characterized in that: the lithium battery monomer of described series connection is 16, when detecting the lithium battery bag of m sheet monocell series connection, adopts m/16 detecting unit.

5. the lithium battery distribution type pick-up unit that band as claimed in claim 1 vibrates and humiture detects, it is characterized in that: the input end of described code translator gating unit is connected with the I/O mouth of Micro-processor MCV.

6. the lithium battery distribution type pick-up unit that band as described in claim 1 or 4 vibrates and humiture detects, it is characterized in that: described relay array is comprised of 16 relays, the corresponding relay of each lithium battery monomer, contain two single relays in each relay, two single relays are connected with the both positive and negative polarity of lithium battery monomer respectively.

7. the lithium battery distribution type pick-up unit that band as claimed in claim 1 vibrates and humiture detects, it is characterized in that: described signal condition unit comprises the voltage follower that accurate rail-to-rail amplifier consists of, voltage inverter, difference ratio amplifying circuit, precision resistance R1～R6, capacitor C 1～C2 and stabilivolt, wherein the input end of monolithic voltage signal is connected with the in-phase end of difference ratio amplifying circuit, described accurate reference voltage is connected with the end of oppisite phase of difference ratio amplifying circuit through voltage inverter, the output terminal of signal condition unit is provided with the amplitude limit output protection circuit of electric capacity and stabilivolt composition.

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