Storage battery monitoring device

Abstract

The invention provides a storage battery monitoring device which comprises an intelligent monitoring platform, a storage battery monitoring device collection unit, a storage battery monomer monitoring module and a storage battery monomer monitoring module, and the storage battery monomer monitoring module is controlled by a master control MCU and collects the voltage, internal resistance and pole temperature of a monomer battery in a floating charge state. Real-time monitoring of the internal resistance, the voltage and the pole temperature of the single battery running in the floating charge state for a long time is achieved, the monitoring result can be displayed on the intelligent monitoring platform, a historical data curve can be displayed, the health state of the storage battery can be detected in real time, installation is convenient, and communication is stable. The invention further provides a double-loop serial port communication mode, field installation of the storage battery monomer module and the storage battery monitoring device collection unit is facilitated, and the communication speed and stability are improved on the premise that wiring is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and in particular to a battery monitoring device. Background Art

[0002] The statements in this section merely provide background technical information related to the present application and do not necessarily constitute prior art.

[0003] Batteries are widely used in many industries, whether in AC or DC power supply, communication power supply, UPS power supply, EPS power supply, etc. Batteries play an extremely important role in the system as a backup power supply. Once the city power is interrupted, the battery discharges to supply power to the load, ensuring the normal power consumption of the load within a certain period of time.

[0004] Therefore, it is necessary to have requirements for battery stability and reliability. Different types and models of batteries have different factors affecting their stability due to their different functional principles, materials, and manufacturing processes. If batteries are grouped together for use, each battery has slight differences due to factors such as manufacturing process and position in the group. Over time, the life loss of each single cell in the battery group will also be different. This will cause fluctuations in the discharge voltage, current, and discharge time of the battery group, thus affecting the stability of the power supply.

[0005] With the development of battery technology, battery monitoring devices have gradually become a research hotspot, but the current mainstream research tends to monitor the charging and discharging of battery packs. In substations, most batteries work in a floating charge state, and there is a lack of single-cell monitoring of batteries in the floating charge state. Summary of the invention

[0006] In order to solve or partially solve the problems in the background technology, the present application proposes a battery monitoring device.

[0007] The present application provides a battery monitoring device, comprising: an intelligent monitoring platform, a battery monitoring device collection unit, and a battery single-cell monitoring module;

[0008] Each single cell in the battery pack is equipped with a battery cell monitoring module, which is controlled by the main control MCU and collects the voltage, internal resistance and pole temperature of the single cell in the floating charge state. The specific collection method is as follows:

[0009] The DC voltage sampling circuit is designed using the internal ADC of the main control MCU to map the voltage sampling range of the single cell battery to the voltage sampling range of the corresponding ADC;

[0010] The internal resistance of a single cell is measured by the AC signal injection method;

[0011] Two temperature sensors are used to detect the temperature of the two poles of the single battery respectively, and the temperature sensors and the main control MCU are connected by signal line multiplexing;

[0012] Each battery monitoring device collection unit is connected to multiple battery cell monitoring modules, collects sample values, and uploads them to the intelligent monitoring platform via the TCP protocol.

[0013] Preferably, the specific method of the battery cell monitoring module using the DC voltage sampling circuit to collect the voltage of the single cell is as follows:

[0014] S101: Input voltage V in Connect the voltage divider resistors R01 and R02 in series and then ground them. Draw out the voltage signal V between the voltage divider resistors. out , V out =V in *(R02 / (R02+R01)), guaranteed V out The amplitude is within the range of the ADC inside the MCU;

[0015] S102: voltage signal V out After quantization, the voltage follower is input to the ADC interface of the MCU.

[0016] Preferably, the specific method of the battery cell monitoring module measuring the internal resistance of the single cell by the AC signal injection method is as follows:

[0017] Step S201: The main control MCU generates an SPWM waveform, which is filtered by a full-bridge circuit and LC to obtain a sinusoidal voltage. The sinusoidal voltage generates an AC constant current signal through a Howland circuit and is injected into a single battery, thereby generating a response voltage on the positive and negative poles of the battery;

[0018] Step S202: simultaneously setting a current transformer and a voltage transformer to synchronously sample the injected excitation AC current signal and the response voltage, and obtaining the internal resistance of the battery after FFT calculation.

[0019] Preferably, in step S202, the sampling frequency of the current transformer and the voltage transformer is greater than or equal to 3 times the frequency of the injected AC signal;

[0020] The current sampling is transmitted to the ADC inside the MCU through the differential circuit;

[0021] The response voltage sampling circuit shares the DC voltage sampling circuit of the single battery.

[0022] Preferably, the battery monitoring device collection unit collects information of the battery cell monitoring module through a two-way loop hand-in-hand communication method, and its connection and networking method is as follows:

[0023] S401: The battery cell monitoring module is designed with two independent 485 serial ports A and B. The battery monitoring device aggregation unit is also designed with two independent 485 serial ports A and B. The connection method is that the B port of the battery monitoring device aggregation unit is connected to the A port of the first battery cell monitoring module, the B port of the first battery cell monitoring module is connected to the A port of the second battery cell monitoring module, until the B port of the last battery cell monitoring module is connected to the A port of the battery monitoring device aggregation unit;

[0024] S402: In the initial stage of the networking process, the battery single monitoring modules are in a non-networked state. The battery monitoring device aggregation unit sends a networking command to the first battery single monitoring module through port B. After receiving the command, since the first battery single monitoring module is in a non-networked state, it sends its own ID to the battery monitoring device aggregation unit through port A.

[0025] After receiving the ID of the first battery cell monitoring module, the battery monitoring device collection unit sends a networking command to the first battery cell monitoring module through port B. At this time, since the first battery cell monitoring module has been networked, the command is transmitted from port B of the first battery cell monitoring module to port A of the second one. The second one is in the unnetworked stage at this time. After receiving the command, it transmits its own ID to port B of the first one through port A. The first one then transmits the ID of the second one to the battery monitoring device collection unit through port A. The battery monitoring device collection unit sends a networking command again to network the third one.

[0026] When the last battery cell monitoring module is networked, the battery monitoring device aggregation unit sends a networking command again. Since all battery cell monitoring modules in the system have been networked, the networking command is transmitted and returned by the last one through port B to port A of the battery monitoring device aggregation unit, proving that the networking is completed.

[0027] Preferably, the specific method for the battery monitoring device collection unit to collect battery cell monitoring module information is as follows:

[0028] S411: The battery monitoring device aggregation unit sends a super read command from both 485 ports A and B at the same time;

[0029] S412: After the command sent through port B is received by the first battery cell monitoring module through port A, the reading data plus its own ID is sent to the second port A through port B. The second module adds the reading data plus its own ID to the data of the first module, and then transmits it to the third port A through port B, and replies to the first port B through port A, and the information is transmitted backward in sequence;

[0030] S413: Assume that the number of battery cell monitoring modules is N. After the command sent through port A is received by the last battery cell monitoring module through port B, the reading data is added with its own ID and sent to port B of the N-1th battery cell monitoring module through port A. The N-1th battery cell monitoring module adds its own ID to the reading data of the Nth battery cell monitoring module and replies to port A of the Nth battery cell monitoring module through port B. The information is then transmitted to port B of the N-2th battery cell monitoring module through port A. The information is transmitted forward in sequence.

[0031] S413: The two paths of data will eventually converge at a certain monitoring module in the middle, and the converged data will be transmitted to the aggregation unit along the shortest path.

[0032] Preferably, if any battery cell monitoring module fails and data cannot be transmitted, the previous one will not be able to receive the response of this device. After a preset time, the data will be reflected backward in the direction of the information transmission. At this time, the battery monitoring device aggregation unit will receive data on both 485 ports and automatically determine the ID of the faulty battery cell monitoring module based on the ID number of the received data.

[0033] Preferably, the intelligent monitoring platform supports access to multiple battery monitoring device aggregation units via TCP / IP;

[0034] The intelligent monitoring platform sends a command to the battery monitoring device collection unit, the command includes the battery single monitoring module networking, re-networking, and monitoring information reporting frequency. The battery monitoring device collection unit transcribes the data of the battery single monitoring module through the configured information and reports it to the intelligent monitoring platform;

[0035] The intelligent monitoring platform supports setting the internal resistance, voltage, and pole temperature alarm thresholds of single battery cells. When the operating data of a single battery cell exceeds this threshold, an early warning message will be issued.

[0036] The intelligent monitoring platform can save the sampling data of single batteries in the database and display the historical data in the form of curves.

[0037] Compared with the prior art, the beneficial effects of this application are:

[0038] (1) This application uses micro-signal processing and high-precision measurement technology to transform a "dumb device" battery into a visual smart device, and realizes real-time monitoring of the internal resistance, voltage, and pole temperature of a single cell battery that operates in a floating charge state for a long time. The monitoring results will be displayed on the intelligent monitoring platform, and the historical data curve can be displayed. The health status of the battery can be detected in real time. It is easy to install and has stable communication, which has high practical significance.

[0039] (2) The present application provides a dual-circuit serial communication method, which facilitates the on-site installation of the battery cell module and the battery monitoring device collection unit, and improves the communication speed and stability while reducing wiring. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0041] Figure 1 This is the MCU circuit schematic used in this application.

[0042] Figure 2 The AC SPVM circuit schematic diagram of this application is shown below.

[0043] Figure 3 HowLand current source circuit schematic diagram for this application,

[0044] Figure 4 This is the voltage synchronous sampling circuit schematic diagram of this application,

[0045] Figure 5 This is the schematic diagram of the current synchronous sampling circuit of this application,

[0046] Figure 6 This is the circuit schematic diagram of the RS485-A port of this application.

[0047] Figure 7 This is the circuit schematic diagram of the RS485-B port of this application.

[0048] Figure 8 This is the temperature measurement circuit schematic diagram of this application.

[0049] Fig. 9 This is a schematic diagram of the system composition of this application. DETAILED DESCRIPTION

[0050] The present application is further described below in conjunction with the accompanying drawings and embodiments.

[0051] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0052] In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present disclosure, and do not specifically refer to any part or element in the present disclosure and should not be understood as limitations on the present disclosure.

[0053] Example 1

[0054] like Figures 1 to 9 As shown, the present application provides a battery monitoring device, including: an intelligent monitoring platform, a battery monitoring device collection unit, and a battery single-cell monitoring module;

[0055] Each single cell in the battery pack is equipped with a battery cell monitoring module, which is controlled by the main control MCU and collects the voltage, internal resistance and pole temperature of the single cell in the floating charge state. The specific collection method is as follows:

[0056] The DC voltage sampling circuit is designed using the internal ADC of the main control MCU to map the voltage sampling range of the single cell battery to the voltage sampling range of the corresponding ADC;

[0057] The internal resistance of a single cell is measured by the AC signal injection method;

[0058] Two temperature sensors are used to detect the temperature of the two poles of the single battery respectively, and the temperature sensors and the main control MCU are connected by signal line multiplexing;

[0059] Each battery monitoring device collection unit is connected to multiple battery cell monitoring modules, collects sample values, and uploads them to the intelligent monitoring platform via the TCP protocol.

[0060] Specifically, Figure 1 As shown in FIG. 1 , the schematic diagram of the main control MCU circuit used in this application is shown in FIG. Figure 4 As shown in the figure, the DC voltage sampling circuit used in this application has a sampling range of 0-3.3V for the internal ADC of the main control MCU, and a sampling range of 0-20V for the battery cell monitoring module. The following steps are adopted to map all 0-20V input voltages into the sampling voltage range of 0-3.3V and provide safety protection:

[0061] Step 1: Input voltage is connected in series with 170kΩ resistor and 30kΩ resistor to ground, thus realizing voltage division. Voltage signal is derived from the middle of 170kΩ resistor and 30kΩ resistor. The calculation formula of voltage signal is V out =V in*(3 / 20), when the input voltage is 1V, the voltage signal is 0.15V, when the input voltage is 2V, the voltage signal is 0.3V, when the input signal is 3V, the voltage signal is 0.45......, when the input voltage is 20V, the voltage signal is 3V, the voltage signal is within the ADC range of the MCU, and meets the design standard;

[0062] Step 2, after the voltage is quantized, it is input to the ADC interface of the MCU through the voltage follower. The voltage follower is designed using the LM741 integrated operational amplifier. The sampling circuit is connected to the V+ of the LM741, and the V- of the LM741 is directly connected to the Vout. At this time, the gain multiple of the amplifier circuit is 1, and the phase is the same, which has the function of voltage following. Because the V+ of the LM741 is in a high configuration, the isolation of the sampling circuit and the measurement circuit is achieved, ensuring the safety of the battery cell monitoring module.

[0063] Specifically, the internal resistance acquisition method of the battery cell monitoring module uses the AC signal injection method. The internal resistance acquisition line is divided into a positive pole and a negative pole, which are respectively connected to the positive pole and the negative pole of the battery. When measuring the internal resistance of the battery, the AC injection method is used to input an AC signal of a certain frequency, and the signal is I=I max Sinωt, the voltage response generated at both ends of the battery is U=U max sin(ωt+θ), the internal resistance of the battery is

[0064] The injected AC signal is passed through the SPWM wave generated by the MCU, and the full-bridge circuit and LC filter circuit output a sinusoidal voltage. The sinusoidal voltage generates an AC constant current source through the How l and circuit and is injected into the battery, thereby generating a corresponding voltage on the positive and negative poles of the battery. After being collected by the voltage transformer, the ADC chip converts the analog signal into a digital signal, and the MCU calculates the voltage signal that is the same as the injected current signal through the FFT (Fast Fourier Transform) algorithm, thereby calculating the internal resistance of the battery. The specific method is as follows:

[0065] Step 1: Perform Fourier expansion on SPWM to obtain

[0066]

[0067] Where U is the DC power supply signal; u is the circuit output signal; M is the modulation signal, ω1 is the angular frequency of the modulation wave, ω s is the sampling angular frequency of the carrier;

[0068] It can be seen that after the SPWM signal passes through the filter, a sinusoidal signal of a certain frequency can be obtained. The signal frequency injected in this scheme is designed to be 1kHz. The SPWM signal is generated by the MCU timer peripheral. The signal passes through the full-bridge rectifier circuit to output an AC SPWM with polarity. Figure 2 Among them, M1 and M4 form a group, M2 and M3 form a group, M1 and M2 receive SPWM signals, M3 and M4 control the conduction state of the circuit, in the first half cycle of SPWM, M2 and M3 are turned off, M4 is turned on, M1 receives SPWM input from the front stage, and the rear stage outputs SPWM with positive polarity, in the second half cycle of SPWM, M1 and M4 are turned off, M3 is turned on, M2 receives SPWM input from the front stage, and the rear stage outputs SPWM with negative polarity;

[0069] The polarity-adjusted SPWM is input to the LC filter circuit to filter out high-frequency harmonics, leaving a 1KHz characteristic signal, which is then input to the Howl and current source circuit. Figure 3 It is the schematic diagram of the Howl and circuit, which outputs a current signal with an effective value of 1mA and a frequency of 1kHz, and the characteristic current injection line is injected into the battery;

[0070] Step 2: synchronously sample the injected AC current signal and the generated voltage, the response voltage generated by the injected signal and the single battery voltage sampling share a voltage, and the injected current signal and the response voltage signal are sampled simultaneously;

[0071] According to the Quenest sampling law, the sampling frequency should be greater than twice the highest frequency of the spectrum. Since the injected signal frequency is 1kHz, the sampling frequency is designed to be 3.2kHz. The sampling signal is calculated by 64-point FFT, where frequency point 1 is the DC component, frequency point 2 is the 50Hz signal, frequency point 3 is the 100Hz signal, and frequency point 22 is the 1000Hz signal. The real and imaginary parts of the 1000Hz signal are selected to calculate the amplitude and angle of the voltage signal.

[0072] The current is sampled using CT (TYCT-D051 5A: 2.5mA), and sent to the ADC through a differential circuit. The ADC uses the internal ADC of the MCU. According to the Quenest sampling theorem, the sampling frequency should be greater than twice the highest frequency of the spectrum. Because the injected signal frequency is 1kHz, the sampling frequency is designed to be 3.2kHz. The sampling signal is calculated by 64-point FFT, where frequency point 1 is the DC component, frequency point 2 is a 50Hz signal, frequency point 3 is a 100Hz signal, and frequency point 22 is a 1000Hz signal. The real and imaginary parts of the 1000Hz signal are selected to calculate the amplitude and angle of the current signal.

[0073] The amplitude and phase of the two signals can be calculated by the real and imaginary parts of the voltage and current complex signals, and the internal resistance of the battery can be calculated by substituting them into the real and imaginary parts. Figure 5 This is the schematic diagram of synchronous sampling of injected AC signal.

[0074] Specifically, the temperature detection method of the single battery pole is realized by collecting the temperature on the two poles of the single battery through the battery single monitoring module. The model of the temperature sampling module is the DS18B20 round hole temperature sensor, and the two DS18b20 multiplexed signal lines. The battery single monitoring module supports automatic device identification. If the identification fails, the abnormal indicator light will flash.

[0075] The specific method for detecting the pole temperature is as follows:

[0076] Step 1. Fasten the DS18b20 temperature sensor to the positive and negative poles of the battery with bolts. DS18b20 has three wires, namely VCC, GND and DQ (digital signal input and output). Because DS18B20 supports multiple devices to multiplex signal lines, VCC, GND and DQ of two devices are connected in parallel. VCC and GND are used as power supplies to DS18b20. DQ is connected to MCU as a digital data input and output terminal to realize the temperature reading function. Figure 8 This is the DS18b20 wiring schematic;

[0077] Step 2, DS18b20 is a single bus protocol. Because the DQ buses of two DS18b20 are multiplexed, before reading the temperature, the 64-bit device addresses of the two DS18b20 must be determined. First, send the F0H command to the bus to search the address, and then read the device address from low to high. Reading a bit is divided into three steps. The first step is to read the value of the bit, the second step is to read the inverse code of the bit, and the third step is to write 0 or 1, which respectively represents shielding the device whose bit is 0 or 1, and shielding other devices. After 64 operations are completed in sequence, the address of a device is determined;

[0078] In the reading process, the address bits of multiple devices have an AND relationship. If the value and the inverse code of the bit are 0 and 1 respectively, it means that the value of the bit is 0. If they are 1 and 0, it means that the value of the bit is 1. If they are both 0, it means that there are devices with two values ​​of 0 and 1 in this bit, that is, a branch appears. There are two devices connected to the battery cell monitoring module, which means that there will be only one branch in the process of searching the address. If a branch appears after the first search, and the device of another branch can be read after the second search, it means that the search is completed. If no branch appears in the first search, it means that only one device is successfully connected, and the abnormal indicator light of the battery cell monitoring module will flash;

[0079] Step 3. The battery cell monitoring module reads the temperature of the pole. First, pull down the DQ bus for 480us to reset the device, send 55H plus the address of one of the DS18b20 to select one of the DS18b20, send a conversion command, send a temperature read command, read the temperature again, repeat this operation, send 55H plus the address of another DS18b20 to select another DS18b20, send a conversion command, send a temperature read command, and read another temperature. The temperatures of the two poles are read.

[0080] Example 2

[0081] like Fig. 9 As shown, based on Example 1, the present application also discloses an automatic networking method for battery cell monitoring modules, a two-way loop hand-in-hand communication method for a battery monitoring device aggregation unit to receive information from a battery cell monitoring device, and the specific method is as follows:

[0082] Step 1: Install the battery cell monitoring module on each battery cell in order. At this stage, there is no need to record the ID number of the battery cell monitoring module. The battery cell monitoring module is designed with two 485 serial ports, A and B, which are independent of each other. Figure 6 RS485 A port and Figure 7 RS485 B port, the battery monitoring device collection unit is also designed with two 485 serial ports A and B, the two serial ports are independent of each other, the circuit principle is referenced Figure 6 , Figure 7 ;

[0083] The connection method is that the B port of the battery monitoring device collection unit is connected to the A port of the first battery cell monitoring module, the B port of the first battery cell monitoring module is connected to the A port of the second battery cell monitoring module, the B port of the second battery cell monitoring module is connected to the A port of the third battery cell monitoring module, until the B port of the last one is connected to the A port of the battery monitoring device collection unit.

[0084] Step 2, during the networking process, in the initial stage, the battery cell monitoring modules are all in a non-networked state. The battery monitoring device collection unit sends a networking command to the first battery cell monitoring module through port B. After the first battery cell monitoring module receives the command, since the first unit is in a non-networked state, the platform sends its own ID to the battery monitoring device collection unit through port A. After the battery monitoring device collection unit receives the ID of the first battery cell monitoring module, it sends a networking command to the first battery cell monitoring module through port B. At this time, since the first battery cell monitoring module has been networked, the message is transmitted to the second unit's port A through port B of the first battery cell monitoring module. The second unit is in a non-networked stage at this time. After receiving the command, it transmits its own ID to the first unit's port B through port A. The first unit then transmits the second unit's ID to the battery monitoring device collection unit through port A. The battery monitoring device collection unit sends a networking command again to network the third unit.

[0085] When the last battery cell monitoring module is networked, the battery monitoring device aggregation unit sends a network command again. Since all battery cell monitoring modules in the system have been networked, the network command is transmitted and returned to the A port of the battery monitoring device aggregation unit through the B port at the last unit, proving that the network is complete. If the command cannot be returned, it proves that the intermediate link has a fault, and the fault point needs to be obtained according to the number of networked units for troubleshooting.

[0086] Step 3, when the battery monitoring device collection unit reads data from the battery single-cell monitoring module group, the collection unit simultaneously sends a super read command from the two 485 ports A and B. After the command sent through the B port is received by the first monitoring module through the A port, the reading data is added with its own ID and the information is sent to the A port of the second through the B port. The second module merges the reading data with its own ID into the data of the first module, and then passes it to the A port of the third module through the B port, and replies to the B port of the first module through the A port, and the information is transmitted backward in sequence; after the command sent through the A port is received by the last (Nth) monitoring module through the B port, the reading data is added with its own ID and the information is sent to the B port of the N-1th module through the A port. The N-1th module merges the reading data with its own ID into the data of the Nth module, and replies to the A port of the Nth module through the B port, and then passes it to the B port of the N-2th module through the A port, and the information is transmitted forward in sequence; the two paths of data will eventually converge at a certain monitoring module in the middle, and the merged data will be transmitted to the collection unit along the shortest path.

[0087] For example, if there are 10 battery cell monitoring modules in total, and the data is collected at the 7th module, then the data will be sent to the battery monitoring device collection unit along the shortest chain, in the order of 7->8->9->10->battery monitoring device collection unit.

[0088] If a fault occurs in one of the monitoring modules and data cannot be transmitted, the previous one that failed will not be able to receive the response of this device. After a certain period of time, the data will be reflected backward in the direction of the information transmission. At this time, the device aggregation unit will receive data on both 485 ports. This proves that one of the middle ports is disconnected, and it will automatically judge based on the ID number of the received data.

[0089] In the case where the system includes only one or two battery cell monitoring modules, the information is directly read through the battery monitoring device collection unit.

[0090] The battery monitoring device collection unit transmits data to the intelligent monitoring platform through TCP / IP protocol and displays it graphically, including the internal resistance, floating charge voltage, and temperature of the single battery. Fig. 9 This is the structure diagram of the intelligent monitoring platform.

[0091] The intelligent monitoring platform is deployed on a computer, which supports access to multiple battery monitoring device aggregation units via TCP / IP.

[0092] The intelligent monitoring platform sends commands to the battery monitoring device aggregation unit, which include battery monitoring device networking, re-networking, and monitoring information reporting frequency. The battery monitoring device aggregation unit transcribes the data of the single battery monitoring module through the configured information and reports it to the intelligent monitoring platform.

[0093] The intelligent monitoring platform supports setting alarm thresholds for the internal resistance, voltage, and pole temperature of single-cell batteries. When the operating data of a single-cell battery is monitored to exceed this threshold, an early warning will be issued to alert the operation and maintenance personnel.

[0094] The intelligent monitoring platform can save the sampling data of single batteries in the database and display the historical data in the form of curves, helping operation and maintenance personnel to infer the trend of the health status of single batteries so as to take countermeasures.

[0095] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0096] Although the above describes the specific implementation methods of the present application in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present application. Technical personnel in the relevant field should understand that on the basis of the technical solution of the present application, various modifications or deformations that can be made by technical personnel in this field without creative work are still within the scope of protection of the present application.

Claims

1. A battery monitoring device, characterized in that: include: Intelligent monitoring platform, battery monitoring device collection unit, battery single-cell monitoring module; Each single cell in the battery pack is equipped with a battery cell monitoring module, which is controlled by the main control MCU and collects the voltage, internal resistance and pole temperature of the single cell in the floating charge state. The specific collection method is as follows: The DC voltage sampling circuit is designed using the internal ADC of the main control MCU to map the voltage sampling range of the single cell battery to the voltage sampling range of the corresponding ADC; The internal resistance of a single cell is measured by the AC signal injection method; Two temperature sensors are used to detect the temperatures of the two poles of the single battery respectively, and the temperature sensors and the main control MCU are connected by signal line multiplexing; Each battery monitoring device collection unit is connected to multiple battery cell monitoring modules, collects sample values, and uploads them to the intelligent monitoring platform via the TCP protocol.

2. A battery monitoring device according to claim 1, characterized in that: The specific method of the battery cell monitoring module using the DC voltage sampling circuit to collect the voltage of the single cell is as follows: S101: Input voltage V in Connect the voltage divider resistors R01 and R02 in series and then ground them. Draw out the voltage signal V between the voltage divider resistors. out , V out =V in *(R02 / (R02+R01)), guaranteed V out The amplitude is within the range of the ADC inside the MCU; S102: voltage signal V out After quantization, the voltage follower is input to the ADC interface of the MCU.

3. A battery monitoring device according to claim 2, characterized in that: The specific method of measuring the internal resistance of a single cell by the battery cell monitoring module through the AC signal injection method is as follows: Step S201: The main control MCU generates an SPWM waveform, which is filtered by a full-bridge circuit and LC to obtain a sinusoidal voltage. The sinusoidal voltage generates an AC constant current signal through a Howland circuit and is injected into a single battery, thereby generating a response voltage on the positive and negative poles of the battery; Step S202: simultaneously setting a current transformer and a voltage transformer to synchronously sample the injected excitation AC current signal and the response voltage, and obtaining the internal resistance of the battery after FFT calculation.

4. A battery monitoring device according to claim 3, characterized in that: In step S202, the sampling frequency of the current transformer and the voltage transformer is greater than or equal to 3 times the frequency of the injected AC signal; The current sampling is transmitted to the ADC inside the MCU through the differential circuit; The response voltage sampling circuit shares the DC voltage sampling circuit of the single battery.

5. A battery monitoring device according to claim 1, characterized in that: The battery monitoring device collection unit collects information from the battery single-cell monitoring module through a two-way loop hand-in-hand communication method, and its connection and networking method is as follows: S401: The battery cell monitoring module is designed with two independent 485 serial ports A and B. The battery monitoring device aggregation unit is also designed with two independent 485 serial ports A and B. The connection method is that the B port of the battery monitoring device aggregation unit is connected to the A port of the first battery cell monitoring module, the B port of the first battery cell monitoring module is connected to the A port of the second battery cell monitoring module, until the B port of the last battery cell monitoring module is connected to the A port of the battery monitoring device aggregation unit; S402: In the initial stage of the networking process, the battery single monitoring modules are in a non-networked state. The battery monitoring device aggregation unit sends a networking command to the first battery single monitoring module through port B. After receiving the command, since the first battery single monitoring module is in a non-networked state, it sends its own ID to the battery monitoring device aggregation unit through port A. After receiving the ID of the first battery cell monitoring module, the battery monitoring device collection unit sends a networking command to the first battery cell monitoring module through port B. At this time, since the first battery cell monitoring module has been networked, the command is transmitted from port B of the first battery cell monitoring module to port A of the second one. The second one is in the unnetworked stage at this time. After receiving the command, it transmits its own ID to port B of the first one through port A. The first one then transmits the ID of the second one to the battery monitoring device collection unit through port A. The battery monitoring device collection unit sends a networking command again to network the third one. When the last battery cell monitoring module is networked, the battery monitoring device aggregation unit sends a networking command again. Since all battery cell monitoring modules in the system have been networked, the networking command is transmitted and returned by the last one through port B to port A of the battery monitoring device aggregation unit, proving that the networking is completed.

6. A battery monitoring device according to claim 5, characterized in that: The specific method for the battery monitoring device collection unit to collect battery single monitoring module information is as follows: S411: The battery monitoring device aggregation unit sends a super read command from both 485 ports A and B at the same time; S412: After the command sent through port B is received by the first battery cell monitoring module through port A, the reading data plus its own ID is sent to the second port A through port B. The second module adds the reading data plus its own ID to the data of the first module, and then transmits it to the third port A through port B, and replies to the first port B through port A, and the information is transmitted backward in sequence; S413: Assume that the number of battery cell monitoring modules is N. After the command sent through port A is received by the last battery cell monitoring module through port B, the reading data is added with its own ID and sent to port B of the N-1th battery cell monitoring module through port A. The N-1th battery cell monitoring module adds its own ID to the reading data of the Nth battery cell monitoring module and replies to port A of the Nth battery cell monitoring module through port B. The information is then transmitted to port B of the N-2th battery cell monitoring module through port A. The information is transmitted forward in sequence. S413: The two paths of data will eventually converge at a certain monitoring module in the middle, and the converged data will be transmitted to the aggregation unit along the shortest path.

7. A battery monitoring device according to claim 6, characterized in that: If any battery cell monitoring module fails and data cannot be transmitted, the previous one will not be able to receive the response of this device. After a preset time, the data will be reflected back in the direction of the information transmission. At this time, the battery monitoring device aggregation unit will receive data from both 485 ports and automatically determine the ID of the faulty battery cell monitoring module based on the ID number of the received data.

8. A battery monitoring device according to claim 6, characterized in that: The intelligent monitoring platform supports access to multiple battery monitoring device aggregation units via TCP / IP; The intelligent monitoring platform sends a command to the battery monitoring device collection unit, which includes the networking, re-networking, and monitoring information reporting frequency of the battery single-cell monitoring module. The battery monitoring device collection unit transcribes the data of the single-cell battery monitoring module through the configured information and reports it to the intelligent monitoring platform; The intelligent monitoring platform supports setting the internal resistance, voltage, and pole temperature alarm thresholds of single battery cells. When the operating data of a single battery cell exceeds this threshold, an early warning message will be issued. The intelligent monitoring platform can save the sampling data of single batteries in the database and display the historical data in the form of curves.

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