CN106814332A - A kind of multifunction structure lithium battery interior voltage detecting system - Google Patents

Abstract

The invention belongs to the field of aerospace technology and relates to a lithium battery internal voltage detection system with a multifunctional structure, which includes a voltage measurement management module and a plurality of grouped voltage detection modules. The voltage measurement management module is connected to the spacecraft platform; the voltage measurement management module is connected to the two ends of the multifunctional structure lithium battery through the total voltage detection line; each of the group voltage detection modules is respectively connected to each lithium battery inside the multifunctional structure lithium battery. battery pack; the voltage measurement management module controls the power-on and power-off operations of each group voltage detection module through the control line, and obtains the voltage data of the single battery from the group voltage detection module through the internal RS485 bus; the voltage measurement management module passes the external RS485 The bus outputs the total voltage data and single battery voltage data to the spacecraft platform. The invention independently measures the voltage of each lithium battery pack by grouping, has flexible configuration, good scalability, reduces the power discharge of the battery under test, and has better equalization performance.

Description

A multi-functional structure lithium battery internal voltage detection system

technical field

The invention belongs to the field of aerospace technology, and in particular relates to a detection system for the internal voltage of a lithium battery with a multifunctional structure.

Background technique

With the development of aerospace technology, high-orbit, high-value, and long-life large spacecraft have put forward a clear and urgent demand for lightweight products. Multifunctional structure technology organically integrates functions, subsystems or independent units such as data processing, thermal control, radiation protection, propulsion, power generation and storage with the spacecraft structure platform, which can realize the integrated molding of structure, function and materials, and eliminate Traditional spacecraft have a large amount of redundant weight and volume to achieve lightweight structure.

Among the numerous subsystems of the spacecraft, the power supply subsystem (the battery part is the main component of the power supply subsystem) and the structural subsystem are one of the subsystems with the largest mass and space ratio of the spacecraft. The spacecraft multifunctional structure lithium battery system adopts the multifunctional structure lithium battery technology newly researched by the National University of Defense Technology, combined with advanced structural vibration reduction technology, composite material/solid lithium ion battery preparation technology, and integrates the battery pack with the structural subsystem The fusion design achieves a high degree of integration of structure and power supply, which can effectively reduce the weight and volume of the spacecraft platform, greatly improve the payload ratio of the spacecraft, prolong the life of the spacecraft, and increase the effective space of large spacecraft.

In order to monitor the performance of the internal storage battery of the spacecraft multifunctional structure lithium battery system, it is necessary to develop a new battery internal voltage detection system to collect and store the battery voltage data of the spacecraft multifunctional structure lithium battery system during the launch phase and on-orbit operation , processing and transmission. Due to the particularity of the lithium battery itself, the detection circuit is required to have little impact on the balance of battery power, and at the same time, the battery pack voltage range of the spacecraft platform that can be collected is wide, and the detection accuracy of the battery voltage is high. Moreover, the voltage acquisition system must meet the strict requirements of electromagnetic compatibility and reliability of the rocket platform and the satellite platform.

Contents of the invention

In view of the above technical problems, the present invention proposes a multifunctional structure lithium battery internal voltage detection system. Before introducing the technical solution, the internal battery of the multifunctional structure lithium battery is divided into N lithium battery packs connected in series, and a single lithium battery The pack in turn contains M single lithium cells connected in series. Each group voltage detection module is responsible for the voltage measurement of a single lithium battery pack, and the voltage measurement management module is responsible for managing the detection process of each group voltage detection module. The specific technical scheme is as follows:

A lithium battery internal voltage detection system with a multifunctional structure includes a voltage measurement management module and a plurality of group voltage detection modules. The voltage measurement management module is connected with the spacecraft platform, and is used to obtain the power required for work and realize the measurement and control data transmission between the spacecraft platform; Both ends are used to measure the total voltage data of the lithium battery with a multifunctional structure; the voltage measurement management module is connected to each group voltage detection module through a control line, and obtains the voltage data of the single battery from the group voltage detection module through the internal RS485 bus; The voltage measurement management module outputs the total voltage data and the single battery voltage data to the spacecraft platform through the external RS485 bus; each of the group voltage detection modules is respectively connected to the corresponding lithium battery pack inside the multifunctional structure lithium battery for detection Single cell voltage of each lithium battery pack.

Further, the voltage measurement management module includes a data management circuit, a power interface circuit, a total voltage detection circuit, a control interface circuit, an external RS485 bus interface circuit and an internal RS485 bus interface circuit; the data management circuit is respectively connected to the power interface circuit, The total voltage detection circuit, the control interface circuit, the external RS485 bus interface circuit and the internal RS485 bus interface circuit are used to be responsible for the data management and control functions in the voltage measurement management module; the input end of the power interface circuit is connected to the spacecraft platform once The power supply interface is connected to the telemetry and remote control signal interface, and the output terminals are respectively connected to the total voltage detection circuit and the data management circuit; the total voltage detection circuit is connected to the total voltage output terminal of the lithium battery with a multi-functional structure; the control interface circuit is connected to the group voltage detection module, Used to transmit power-on and power-off control signals; the internal RS485 bus interface circuit is connected to the group voltage detection module for transmitting control signals and voltage data; the external RS485 bus interface circuit is connected to the spacecraft platform for transmitting control signals and voltage data.

Further, the grouping voltage detection module includes a power switch control circuit, a DC/DC circuit, a single voltage detection circuit, a data management circuit and an isolated RS485 bus interface circuit; the data management circuit is respectively connected to the DC/DC circuit, the single The body voltage detection circuit and the isolated RS485 bus interface circuit are responsible for the data management and control functions in the group voltage detection module; the two input terminals of the power switch control circuit are respectively connected to the voltage measurement management module and the lithium battery pack, and the output terminal is connected to the DC /DC circuit; the DC/DC circuit provides power for the single cell voltage detection circuit and the data management circuit respectively; the single cell voltage detection circuit is connected to the M-section single cells in the lithium battery pack for measuring the voltage of the single cells ; The isolated RS485 bus interface circuit is connected to the voltage measurement management module for obtaining the required power supply and transmitting control signals and voltage data.

Further, the isolated RS485 interface circuit adopts an optocoupler isolation design circuit.

The beneficial effects obtained by adopting the present invention: the system of the present invention independently measures the voltage signals of each lithium battery group by grouping, so that the scale of the measurement system can be flexibly configured and has good scalability; because each group voltage detection module does not need to use the traditional method of dividing The design of piezoelectric resistance network and compensation resistance network can avoid the problem of battery power imbalance caused by uneven discharge of the measurement network; whether each group voltage detection module is powered on can be controlled independently, and can be powered off when no detection is needed. Reduce the discharge of the detection circuit to the battery pack under test; by flexibly configuring the power-on and power-off states of each group voltage detection module, it can also actively realize the power balance operation among lithium battery packs.

Description of drawings

Fig. 1 is a schematic block diagram of the composition structure of the system of the present invention;

Figure 2 is a schematic block diagram of the composition of the voltage measurement management module;

Fig. 3 is a circuit diagram of the power supply interface of the voltage measurement management module;

Fig. 4 is a voltage measurement management module data management circuit diagram;

Figure 5 is a block diagram of the composition of the group voltage acquisition module;

Fig. 6 is a power switch control circuit diagram in the group voltage detection module;

Figure 7 is a diagram of the RS485 bus communication interface with optocoupler isolation in the packet voltage detection module.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

The block diagram of the internal voltage detection system of the multi-functional structure lithium battery provided by the present invention is shown in Figure 1. The system mainly includes two types of functional modules: a voltage measurement management module and multiple group voltage detection modules. The voltage measurement management module has the interface functions with the primary power supply of the spacecraft platform, telemetry and remote control, and RS485 bus, and inputs the primary power supply and control commands of the external spacecraft platform, and is connected through the control line and is responsible for controlling and managing each group voltage inside the system detection module. The voltage measurement management module polls and summarizes the single battery voltage data collected by each group voltage detection module through the internal RS485 bus, and finally outputs the voltage data to the spacecraft platform through the RS485 bus.

The voltage measurement management module inputs an external primary power supply and converts it into an internal working power supply; outputs control signals to the group voltage detection module for controlling the power switch control circuit of the latter to realize power-on and power-off operations; voltage measurement There is an RS485 bus communication link between the management module and the group voltage detection module. The voltage measurement management module sends a query command through the bus and receives the single battery voltage fed back by each group voltage detection module. In addition, the voltage measurement management module also has the function of detecting the total voltage of the lithium battery with a multifunctional structure.

Under the control of the voltage measurement management module, the group voltage detection module obtains working power from the tested lithium battery pack; simultaneously collects the voltage of each single battery in each tested lithium battery pack, and uploads it to the voltage measurement management module through the RS485 bus. The internal voltage detection system of the multifunctional structure lithium battery is mainly used to collect the internal voltage of the new multifunctional solid polymer lithium battery. In this embodiment, there are N groups of lithium battery packs to be detected, and there are N corresponding group voltage detection modules, where N is a positive integer, and each lithium battery pack is composed of 4 lithium batteries connected in series. Each group voltage detection module inputs and collects the cell voltage of 4 lithium batteries in the lithium battery pack, and the internally collected cell voltage data can be output to the voltage measurement management module through the RS485 bus interface with optocoupler isolation. The RS485 bus interface adopts an optocoupler isolation design, which eliminates the influence of the common-mode voltage of each group voltage detection module on measurement and communication, and ensures the safety of data communication. By flexibly combining multiple grouped voltage detection modules, the measurement of a wider voltage range can be realized. When the group voltage detection module does not need to collect the voltage of the single battery, it can be controlled by the voltage measurement management module to disconnect the power supply connection with the lithium battery pack, so as to reduce the discharge of the power of the lithium battery pack under test.

The composition principle and connection relationship of the voltage measurement management module are as shown in Figure 2, the module comprises a data management circuit, a power supply interface circuit, a total voltage detection circuit, a control interface circuit, an external RS485 bus interface circuit and an internal RS485 bus interface circuit 6 parts.

The power interface is responsible for realizing the power supply and measurement and control interface between the voltage measurement management module and the external spacecraft platform, and its circuit composition is shown in FIG. 3 . The input of the power interface is the primary power supply of the spacecraft platform, and the overcurrent protection function of the primary power supply consists of two parallel fuses MGA-S-125V-1.4A (markers: F1, F2 in the figure) and resistor RX21-1W- The unbalanced protection circuit composed of 0.8Ω (marker: R in the figure) is completed. The power-on and power-off control relay uses the magnetic latching relay 2JB2-2-28B produced by the 165 factory. The magnetic latching relay receives the remote control command sent by the external remote control interface to realize the loading and disconnection of the external primary power supply. At the same time, the on-off state of the relay The switch can be connected to an external telemetry interface to feed back the telemetry signal of the on-off state of the relay. After the primary power supply passes through the relay switch, it is sent to DC/DC through the surge suppression circuit and IR anti-electromagnetic interference (EMI) filter AME280461X (power filter), and the primary power is converted into the total voltage detection circuit and data management circuit. The required secondary power supply, the output voltage includes +5V, +12V and -12V.

The data management circuit is mainly responsible for data management and control functions in the entire voltage measurement management module. Its input power supply interface circuit transforms the secondary power supply, outputs control and acquisition signals to the total voltage detection circuit, and receives the total voltage digital signal output from the total voltage detection circuit, which receives internal RS485 bus interface circuit and external RS485 bus interface The circuit forwards the voltage and control data, and at the same time outputs a control signal for power-on and power-off of the group voltage detection module to the control interface circuit. In the embodiment, the functional block diagram of the data management circuit is shown in Figure 4, which is an ARM basic system with NXP Company LPC2294HBD144/01 as the core; its main components include an ARM controller, a reset and watchdog circuit, a clock circuit, and a decoding control circuit, SRAM/PROM data storage circuit, etc., the specific circuit connection relationship is shown in Figure 4. The watchdog control chip is MAX706R, and the SRAM is the chip R1LV1616RSA-5SI produced by RENESAS. All selected chips have flight experience.

The total voltage detection circuit mainly realizes the detection operation of the total voltage of the external lithium battery pack, and internally realizes resistance voltage division and analog-to-digital conversion (ADC) operations, and its input is the secondary power supply and data management circuit transformed by the power interface circuit The acquisition control signal and the total voltage signal of the external lithium battery pack, output the total voltage digital signal collected by AD to the data management circuit. The analog-to-digital conversion chip uses a 12-bit ADC chip AD7892 with a conversion time of 2 μs, which can meet the requirements of 10-bit sampling accuracy.

Both the external RS485 bus interface circuit and the internal RS485 interface circuit adopt the LTC485MJ8 communication control chip of LINEAR Company to realize the data communication with the connected RS485 bus node. However, the internal RS485 bus interface circuit needs to output a +5V power supply, which is used to drive the optocoupler isolation communication circuit of the RS485 bus interface circuit in the packet voltage detection module.

The grouping voltage detection module mainly collects the single cell voltage of the lithium battery pack, and uploads it to the voltage measurement management module through the RS485 bus. Its composition is shown in Figure 5, mainly including a power switch control circuit, a DC/DC circuit, Voltage detection circuit, data management circuit and isolated RS485 bus interface circuit. Lithium battery group i represents the i-th lithium battery group, 1≤i≤N, the total voltage of lithium battery group i is only used to provide working power for the corresponding group voltage detection module, and the group voltage detection module does not need to collect lithium battery group i of the total voltage.

The data management circuit in the group voltage detection module is mainly responsible for data management and control functions. It inputs the power required for work from the DC/DC circuit, controls the single cell voltage detection circuit to collect the voltage of the single battery, and controls the isolated RS485 bus interface The circuit communicates with the voltage measurement management module on the upper layer, and its main components are shown in Figure 4, which will not be repeated here.

The power switch control circuit is mainly the control signal output by the input voltage measurement management module, through the control interface with optocoupler isolation function, the power-on and power-off control between the total voltage of the external lithium battery pack to be tested and DC/DC is realized. Its circuit structure is shown in Figure 6. When it is necessary to provide DC/DC with working power, the external input turns on the control signal, and the optocoupler controls the MOS transistor G1 and MOS transistor G2 to be turned on, and the MOS transistor G3 and MOS transistor G4 are turned off. Open, at this time the total voltage of the lithium battery pack is directly loaded on the input positive line of the DC/DC; when the power supply needs to be stopped, the external input disconnects the control signal, the optocoupler controls the MOS transistors G3 and G4 to be turned on, and G1 and G2 are disconnected At this time, the total voltage of the lithium battery pack is disconnected from the positive line of DC/DC, which can ensure that the detection circuit does not consume the power of the lithium battery pack. The fuse F3 is mainly used to protect the lithium battery pack from the short-circuit fault of the detection circuit. Optocoupler CD1, diodes D1~D4, transistors T1 and T2, resistors R1~R8 and capacitors C1~C5 are mainly used to realize the auxiliary switch control circuit.

The DC/DC circuit is mainly used to input the total voltage of the lithium battery pack and output the power required by the group voltage detection module. The single lithium battery pack in the embodiment includes 4 single cells, the total voltage output range is 10V-17V, and the output voltage includes +5V, +12V and -12V.

The single voltage detection circuit is mainly composed of 4-way differential amplifier circuit, multi-way selection one analog switch, follower and analog-to-digital conversion circuit. The differential amplifier circuit is built with low-temperature drift, low offset, low power consumption, high precision, and high common-mode rejection ratio instrument op amp AD620. The single cell voltage of the lithium battery pack is input to AD620, and differential mode and common mode filtering are performed. After the measures are taken, adjust the voltage to the range of 0V ~ 5V. One-to-many switch The analog switch HI-546 is used to form a two-level multiple-choice gating network to realize the logic of one-to-many selection. The amplifier/follower circuit selects the amplifier OP-27 with high impedance, broadband and low drift to ensure the high impedance isolation requirement for the input signal, and is mainly used to provide the input signal with low output impedance and large driving capability for the ADC. The analog-to-digital conversion (ADC) chip also uses AD7892 to meet the requirements of 10-bit sampling accuracy.

The RS485 general interface circuit with isolation mainly realizes the RS485 bus communication between the packet voltage detection module and the upper layer voltage measurement management module, and its composition is shown in the circuit on the left side of the dotted line in FIG. 7 . The right side of Figure 7 is the internal RS485 bus interface circuit diagram of the voltage measurement management module. The serial communication interfaces RX_A and TX_A of the data management circuit communicate through optocoupler CD2, optocoupler CD3 and RS485 bus communication control chip LTC485. Since the +5V power supply of LTC485 (marked as: +5V_B in the figure) is provided by the upper voltage measurement management module, it is physically isolated from the power supply +5V_A of the serial port, and the ground wires GND_A and GND_B of the two are also isolated, so It can realize non-common-ground isolation communication between two types of modules, ensuring the safety of each communication. The resistors R1-R14 in the circuit are mainly used to realize the photoelectric isolation interface function and the communication impedance matching function.

The above is only a preferred embodiment of the present invention, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications should also be regarded as protection scope of the present invention.

Claims (4)

1. a kind of multifunction structure lithium battery interior voltage detecting system, it is characterised in that：Including a voltage measurement management mould Block and multiple packet voltage detection modules, the voltage measurement management module is connected with spacecraft platform, for obtaining work institute The measuring and control data between power supply and realization and spacecraft platform is needed to transmit；The voltage measurement management module is detected by total voltage Line connects the two ends of multifunction structure lithium battery, the total voltage data for measuring multifunction structure lithium battery；The voltage is surveyed Amount management module connects each and is grouped voltage detection module by control line, and is examined from packet voltage by internal RS485 buses Survey module and obtain monomer battery voltage data；The voltage measurement management module passes through outside RS485 buses by total voltage data With monomer battery voltage data output to spacecraft platform；Described each packet voltage detection module connects multifunction structure respectively Each lithium battery group of lithium battery interior, the monomer battery voltage for detecting each lithium battery group.

2. a kind of multifunction structure lithium battery interior voltage detecting system as claimed in claim 1, it is characterised in that：The electricity Pressure measuring management module includes data management circuit, power interface circuit, total voltage detection circuit, control interface, outside RS485 bus interface circuits and inside RS485 bus interface circuits；The data management circuit connects power interface electricity respectively Road, total voltage detection circuit, control interface, outside RS485 bus interface circuits and inside RS485 bus interface circuits, For the data management being responsible in voltage measurement management module and control function；The input connection boat of the power interface circuit The primary power source interface of its device platform and remote measuring and controlling signaling interface, output end connect total voltage detection circuit and data pipe respectively Reason circuit；The total voltage detection circuit connects the total voltage interface of multifunction structure lithium battery；The control interface connects Packet voltage detection module is connect, power down control signal is added for transmitting；The internal RS485 bus interface circuits connection packet electricity Pressure detection module, for transmission of control signals and voltage data；The outside RS485 bus interface circuits connection spacecraft is put down Platform, for transmission of control signals and voltage data.

3. a kind of multifunction structure lithium battery interior voltage detecting system as claimed in claim 1, it is characterised in that：Described point Group voltage detection module include power on-off control circuit, DC/DC circuits, monomer voltage detection circuit, data management circuit and The RS485 bus interface circuits of isolation；The data management circuit connect respectively DC/DC circuits, monomer voltage detection circuit, every From RS485 bus interface circuits, be responsible for packet voltage detection module in data management and control function；The power switch Control two inputs of circuit connect voltage measurement management module and lithium battery group, output end connection DC/DC circuits respectively；It is described DC/DC circuits are respectively monomer voltage detection circuit and data management circuit provides power supply；The monomer voltage detection circuit connects The cell in lithium battery group is connect, for measuring monomer battery voltage；The RS485 bus interface circuits connection electricity of the isolation Pressure measuring management module, for obtaining required power supply and transmission of control signals and voltage data.

4. a kind of multifunction structure lithium battery interior voltage detecting system as claimed in claim 1, it is characterised in that：It is described every From RS485 bus interface circuits using light-coupled isolation design.