Lithium battery and super capacitor fusion management method and device for acquisition terminal

Abstract

The invention relates to a lithium battery and super capacitor fusion management method and device for an acquisition terminal. The device comprises a main power supply, a monitoring module, a lithium battery, a super capacitor, a charging and discharging management module, a load and a controller. The main power supply is converted into direct current through the power supply conversion module, supplies power to the load and the controller in the system and manages charging and discharging of the lithium battery and the super capacitor through the charging and discharging management module in cooperation with the controller; the device is reasonable in design, compact in structure and convenient to use.

Description

Technical Field

[0001] The present invention relates to a method and device for integrated management of a lithium battery and a supercapacitor for a collection terminal. Background Art

[0002] With the continuous acceleration of the modernization process of the power system, the requirements for the real-time performance and reliability of data collection and monitoring are constantly increasing. Special transformer collection terminals play an important role in power monitoring and require stable and reliable backup power supplies to ensure the accuracy and real-time performance of data after a power outage. However, traditional power supply methods mainly rely on alternating current and lack effective countermeasures for power outage situations. In this context, supercapacitors have been gradually introduced due to their fast charge and discharge characteristics and high power density, which can provide sufficient power during instantaneous load demands, while lithium batteries are suitable for providing stable long-term power support.

[0003] Through a reasonable hybrid management strategy, the advantages of both lithium batteries and supercapacitors can be combined, thereby improving the reliability and efficiency of power supply, achieving efficient power distribution, extending the lifespan of supercapacitors and lithium batteries, improving energy utilization efficiency, and meeting the dynamic load demands. However, the existing technology still has deficiencies in charge and discharge management and cannot effectively coordinate the operation of supercapacitors and lithium batteries, resulting in low energy utilization efficiency and even affecting the normal operation of equipment. Therefore, it is particularly important to develop a new type of hybrid management system to address the increasingly severe power supply challenges in the field of power monitoring.

[0004] In modern power monitoring systems, special transformer collection terminals, as key devices, usually rely on stable alternating current power supplies. However, power outages and fluctuations will directly affect the normal operation of the equipment, resulting in interruptions in data collection and information loss.

[0005] In the existing technology, although supercapacitors and rechargeable lithium batteries are used as backup power supplies, their charge and discharge management is not intelligent enough, and there are problems such as long response times and insufficient load-carrying capacity. During the power supply switching process, if the output power of the lithium battery cannot meet the instantaneous load demand, the equipment will face the risk of abnormal operation. In addition, unreasonable charge and discharge management strategies will accelerate the aging of supercapacitors and lithium batteries and reduce their service life.

[0006] Therefore, how to achieve fast and reliable switching during a power outage, ensure continuous power supply to the equipment, and meet requirements such as backup power time, load-carrying capacity, and service life has become an important problem that needs to be solved urgently in the current technology. Summary of the Invention

[0007] Generally speaking, the technical problem to be solved by the present invention is to provide a method and device for integrated management of a lithium battery and a supercapacitor for a collection terminal.

[0008] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0009] A lithium battery and supercapacitor fusion management method and device for a collection terminal, including a main power supply, a monitoring module, a lithium battery, a supercapacitor, a charge and discharge management module, a load, and a controller.

[0010] The main power supply is converted into direct current through a power conversion module to supply power to the load and controller in the system and charge the lithium battery and supercapacitor through the charge and discharge management module.

[0011] The monitoring module includes a power-off monitoring module, a voltage sampling module, a current sampling module, a temperature measurement module, and an internal resistance measurement module;

[0012] The power-off monitoring module is electrically connected to the main power supply and the controller;

[0013] The voltage sampling module, current sampling module, and internal resistance measurement module are respectively electrically connected between the lithium battery and the controller and / or between the supercapacitor and the controller;

[0014] The temperature measurement module is electrically connected to the controller.

[0015] Furthermore, the power conversion module includes an AC-DC power supply and a rectifier.

[0016] The power-off monitoring module includes a voltage detection chip U1; in the voltage detection chip U1, pin 1 is connected to three paths. One path is connected to 3V3 through a resistor R1, another path is connected to the controller through POWER_DETECT, and the third path is grounded through a capacitor C1; pin 2 is grounded through a parallel resistor R3 and capacitor C2, and pin 2 is connected to ACDC_OUT through a resistor R2; pin 3 is grounded.

[0017] The voltage sampling module includes voltage-dividing resistors R4 and R5; one end of the voltage-dividing resistor R4 is connected to the positive electrode of the lithium battery BAT, and the other end is divided into two paths. One path is grounded through a parallel voltage-dividing resistor R4 and capacitor C3, and the other path is connected to the ADC sampling IO of the controller through ADC_VBAT.

[0018] The current measurement module includes a current sensor U3; the pins 1 to 4 of the current sensor U3 are connected in series to the lithium battery or supercapacitor; the output voltage value of VIOUT of pin 7 of U3 is connected to the controller through ADC_IBAT, and the current is obtained according to the linear relationship between the obtained voltage change amount and the current.

[0019] The lithium battery is connected in series to the current input IP+ and output IP- loops of the current sensor U3, and ADC_IBAT is the IO of the controller.

[0020] The temperature measurement module includes a voltage detection chip U2. The pin 1 of the voltage detection chip U2 is connected to the TEMP_DETECT pin of the controller; the pin 2 is divided into two paths. One path is connected to 3V3 through a resistor R7, and the other path is grounded through a parallel connection of a thermistor RT1 and a capacitor C4.

[0021] The resistor R7 and the thermistor RT1 form a voltage division circuit, and TEMP_DETECT is an IO of the controller.

[0022] The internal resistance measurement module includes a switching transistor Q1; the source of the switching transistor Q1 is grounded, the drain is connected to the BAT of the lithium battery through a dummy load R8; the gate is connected to the pulse output pin PP_DCHARGE of the controller; the internal resistance measurement module roughly measures the internal resistance of the lithium battery or the supercapacitor through a pulse discharge method. First, the controller IO pin PP_DCHARGE generates a pulse to control the on and off of the switching transistor Q1, and the discharge voltage and current of the lithium battery and the supercapacitor are obtained through the voltage sampling module and the current sampling module, and the internal resistance is obtained through Ohm's law.

[0023] The lithium battery is connected in series to the current input IP+ and output IP- loops of the current sensor U3. PP_DCHARGE is an IO of the controller.

[0024] A method for the integrated management of lithium batteries and supercapacitors in a collection terminal, the method includes the following steps; among them, the objective function includes utilization rate, response speed, and service life.

[0025] First, the definition of the objective function.

[0026] Then, based on the objective function; combine the objective function into a multi-objective optimization problem.

[0027] Objective function 1: Utilization rate objective function, which measures the utilization rate of the energy of the lithium battery in the case of the power failure of the main power supply 1, and is the ratio of the output power to the input power: Objective function 1: Utilization rate objective function L bat，1 Measures the utilization rate of the energy of the lithium battery in the case of the power failure of the main power supply 1, and is the ratio of the output power to the input power:

[0028]

[0029] Among them, σ bat is the power distribution ratio of the lithium battery and the supercapacitor, P bat is the output power of the lithium battery, P load is the power required by the load, P loss is the loss power;

[0030] Secondly, objective function 2: Response speed objective function L bat,2 Is the speed of the system switching from the main power supply to the backup power supply:

[0031]

[0032] Among them, T is the time required from the detection of the main power supply cut-off to the completion of the standby power supply switching;

[0033] Thirdly, the objective function 3: the service life objective function L bat，3 ;

[0034]

[0035] Among them: B bat，max is the maximum number of charge and discharge cycles allowed for the lithium battery, B bat，充 is the number of charging times, B bat,放 is the number of discharging times, ΔSOC bat is the change in the charge and discharge depth of the lithium battery, SOC bat,max is the safety upper limit value of the charging state of the lithium battery; α and β are weight coefficients used to adjust the influence weights of the cycle times and the discharge depth;

[0036] After that, the comprehensive objective function L bat :

[0037] L bat = a1·L bat，1 + a2·L bat，2 + a3·L bat，3 Equation (4);

[0038] Among them: a1, a2, and a3 are weight factors that satisfy Equation (5):

[0039] a1 + a2 + a3 = 1 Equation (5); bat represents the lithium battery parameters, and sc represents the supercapacitor parameters;

[0040] Then, the total objective function is defined as:

[0041] L = aL bat + bL sc Equation (6)‘’

[0042] a and b are the weight factors of the lithium battery objective function and the supercapacitor objective function respectively.

[0043] Next, the constraint conditions are defined:

[0044] Charge and discharge voltage constraint: V bat，min ≤ V bat ≤ V bat，max ,V sc，min ≤ V sc ≤ V sc，max Equation (12);

[0045] Charge and discharge current constraint: I bat<I bat，max ,I sc ≤I sc，max Equation (13);

[0046] SOC constraint: SOC bat，min ≤SOC bat ≤SOC bat，max

[0047] SOC sc，min ≤SOC sc ≤SOC sc，max Equation (14);

[0048] Energy utilization rate balance constraint during backup power supply:

[0049]

[0050] 10. The lithium battery and supercapacitor fusion management method for a collection terminal according to claim 9, characterized in that: by means of the device described in claim 1;

[0051] Wherein, for the supercapacitor according to the lithium battery, the function is as follows;

[0052]

[0053] L bat =b1·L sc，1 +b2·L sc，2 +b3·L sc，3 Equation (10);

[0054] b1 + b2 + b3 = 1 Equation (11);

[0055] Next, based on the objective function, the genetic algorithm in the optimization algorithm is selected to implement the multi-objective optimal strategy. The algorithm includes the following steps;

[0056] S1, after the system starts, initialize the system parameters, the charging and discharging currents I of the lithium battery and the supercapacitor bat , I sc the charging and discharging voltages V of the lithium battery and the supercapacitor bat , V sc , the SOCs of the lithium battery and the supercapacitor, SOC bat , SOC sc , the switching response time T, the load power demand P load ;

[0057] Use the monitoring module to monitor the status of the main power supply and the voltages, currents, operating temperatures, and internal resistances of the lithium battery and the supercapacitor;

[0058] S2. Calculate the values of each objective function \(L\) based on the charge-discharge cycles, actual energy used, and switching time of the current lithium battery and supercapacitor. bat and \(L\) sc ;

[0059] S3. Apply fuzzy logic. The fuzzy logic controller is used to dynamically adjust the objective weights. The objective weights include \(a1\), \(a2\), \(a3\), \(b1\), \(b2\), \(b3\).

[0060] In S3, execute the following charge-discharge strategy:

[0061] When the main power supply of the system is cut off, increase the weights \(a1\) and \(b1\) of the utilization rate of the backup power supply. Here, the lithium battery and the supercapacitor are collectively referred to as the backup power supply.

[0062] When the system is in the power-off switching state, increase the weights \(a2\) and \(b2\) of the response time of the backup power supply.

[0063] When the system is operating normally, increase the weights \(a3\) and \(b3\) of the service life of the backup power supply, and give priority to increasing the weight coefficient of the supercapacitor to minimize the charge-discharge cycles of the lithium battery.

[0064] When the load is relatively stable or the backup power time is long during the backup power period, increase the utilization weight \(a1\) of the lithium battery. When the transient load fluctuates greatly during the backup power period, increase the utilization weight \(b1\) of the supercapacitor.

[0065] When the temperature is low during the backup power period, increase the utilization weight \(b1\) of the supercapacitor. When the temperature is high during the backup power period, increase the utilization weight \(a1\) of the lithium battery.

[0066] S4: Execute the genetic algorithm:

[0067] S41: Randomly generate \(M\) groups of charge-discharge strategies as the initial population. Each group of strategies contains the charge-discharge parameters of the lithium battery and the supercapacitor. The number of the generated initial population can be increased or decreased according to the load condition of the controller:

[0068] \(M\) i =\(\{I\) bat , \(I\) sc , \(V\) bat , \(V\) sc , \(\sigma\) bat , \(\sigma\) sc ...... \} Equation (16);

[0069] S42: Calculate the fitness of each charge-discharge strategy based on the objective function.

[0070] The fitness \(F = L = a1\cdot L1 + a2\cdot L2 + a3\cdot L3\) Equation (17); Execute the genetic operation:

[0071] S43 Selection: Select a charge-discharge strategy with high fitness through roulette wheel selection or tournament selection;

[0072] S44 Crossover: Exchange some parameters between two solutions of parent M1 and parent M2;

[0073] Parent M1 = {I bat = b1, I sc = b2, V bat = b3, V sc = b4, σ bat = b5, σ sc = b6}

[0074] Parent M2 = {I bat = c1, I sc = c2, V bat = c3, V sc = c4, σ bat = c5, σ sc = c6}

[0075] Offspring M1 == {I bat = c1, I sc = b2, V bat = b3, V sc = c4, σ bat = b5, σ sc = c6} Equation (18);

[0076] S45 Inheritance: Add a small-range random perturbation to Equation (18) of the solution;

[0077] Execute the three genetic operations of Equation (18) to generate a new population M'; i ;

[0078] Repeat the fitness evaluation and genetic operations in step S4 until the set optimization goal is met or the maximum number of iterations is reached;

[0079] S5: Output the optimized strategy; According to the finally output optimization result, output the optimal charge-discharge strategy, and use the charge-discharge control module of the controller to manage the charge and discharge;

[0080] S6: Monitor the charge-discharge process in real time, adjust and correct the parameters according to the occurrence situation, and ensure the multi-objective optimization defined by the system.

[0081] The present invention improves the overall performance of the system by introducing a multi-objective optimization strategy, which is mainly reflected in the following aspects: (1) Energy efficiency optimization: By interfering with the power distribution of lithium batteries and supercapacitors according to the usage environment and their own characteristics, energy loss is reduced and energy utilization efficiency is improved. (2) Enhanced dynamic adaptability: Rapidly respond to dynamic load demands according to load changes to ensure power supply stability. (3) Extended service life: By adjusting the charge and discharge strategy, the aging of lithium batteries and supercapacitors is delayed, and problems such as overcharging, over-discharging, and over-temperature use of lithium batteries and supercapacitors are avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1 is a block diagram of the present invention.

[0083] Figure 2 is a block diagram of the monitoring module of the present invention.

[0084] Figure 3 is a schematic diagram of the principle of the power-off monitoring module of the present invention.

[0085] Figure 4 is a schematic diagram of the principle of the voltage sampling module of the present invention.

[0086] Figure 5 is a schematic diagram of the principle of the current sampling module of the present invention.

[0087] Figure 6 is a schematic diagram of the principle of the temperature measurement module of the present invention.

[0088] Figure 7 is a schematic diagram of the principle of the internal resistance measurement module of the present invention.

[0089] Figure 8 is a schematic diagram of the process of the present invention.

[0090] Wherein: 1, main power supply; 2, monitoring module; 3, lithium battery; 4, supercapacitor; 5, charge and discharge management module; 6, load; 7, controller. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0091] Please refer to Figure 1 , Figure 2 The method and device for integrated management of lithium batteries and supercapacitors for a collection terminal, the device includes a main power supply 1, a monitoring module 2, a lithium battery 3, a supercapacitor 4, a charge and discharge management module 5, a load 6 and a controller 7;

[0092] The main power supply 1 serves as the power supply during the normal operation of the system, is powered by alternating current, is converted into direct current through a power conversion module, and supplies power to the load 6 and the controller 7 in the system and charges the lithium battery 3 and the supercapacitor 4 through the charge and discharge management module 5. The power conversion module includes an AC-DC power supply, a rectifier, etc.;

[0093] The monitoring module 2 includes a power-down monitoring module, a voltage sampling module, a current sampling module, a temperature measurement module, and an internal resistance measurement module;

[0094] The power-down monitoring module is electrically connected to the main power supply 1 and the controller 7;

[0095] The voltage sampling module, the current sampling module, and the internal resistance measurement module are respectively electrically connected between the lithium battery 3 and the controller 7;

[0096] The temperature measurement module is electrically connected to the controller 7;

[0097] The monitoring module 2 is used to monitor the operating status of the system, the working status of the lithium battery 3 and the super capacitor 4 in real time, so that the controller 7 can perform corresponding operations to ensure that the system is in the best working state. The monitoring module 2 measures the voltage, current, temperature, and internal resistance of the lithium battery 3 and the super capacitor 4 respectively.

[0098] Among them, the power-down monitoring module is used to monitor the operation of the main power supply. When it detects a power failure of 220V, it immediately feeds back to the controller 7 and switches to the backup power supply composed of the lithium battery 3 and the super capacitor 4 to ensure that the system can continue to work;

[0099] Among them, the power-down monitoring module is used to monitor the operation of the main power supply, and its principle is as Figure 3 shown

[0100] The power-down monitoring module includes a voltage detection chip U1; in the voltage detection chip U1, pin 1 is connected to three paths. One path is connected to 3V3 through a resistor R1, the second path is connected to the controller 7 through POWER_DETECT, and the third path is grounded through a capacitor C1; pin 2 is grounded through a parallel resistor R3 and a capacitor C2, and pin 2 is connected to ACDC_OUT through a resistor R2; pin 3 is grounded;

[0101] When powered by strong electricity, the output of the voltage detection chip U1 is in an open-drain mode, and the IO pin POWER_DETECT of the controller 7 is pulled up to a high level by 3V3. When it detects a power failure of 220V, the output ACDC_OUT of the ACDC power supply starts to decrease. When it is lower than the detection threshold of U1, it controls POWER_DETECT to be pulled low. After the controller 7 detects the change of POWER_DETECT, it switches to the backup power supply composed of the lithium battery 3 and the super capacitor 4 to ensure that the system can continue to work;

[0102] The voltage sampling module 1 and the voltage sampling module 2 are respectively used to measure the charge and discharge voltage values of the lithium battery 3 and the super capacitor 4 and monitor abnormal voltage fluctuations of the two, and feedback the monitored data to the controller 7 in real time. Its principle is as Figure 4 shown, and only the lithium battery voltage sampling part of the circuit is shown here.

[0103] The voltage sampling module 1 includes voltage-dividing resistors R4 and R5. One end of the voltage-dividing resistor R4 is connected to the positive electrode of the lithium battery 3BAT, and the other end is divided into two paths. One path is grounded through the parallel-connected voltage-dividing resistor R4 and capacitor C3, and the other path is connected to the ADC sampling IO of the controller 7 through ADC_VBAT.

[0104] Its principle is as Figure 4 shown. Two voltage-dividing resistors R4 and R5 are used for voltage division. ADC_VBAT is the ADC sampling IO of the controller 7, and the internal analog-to-digital conversion of the controller 7 is used to obtain the battery voltage.

[0105] The current sampling module 1 and the current sampling module 2 are respectively used to measure the charge and discharge current values of the lithium battery 3 and the supercapacitor 4 and monitor whether abnormal currents occur in both. Only the lithium battery current sampling part is shown here.

[0106] Its principle is as Figure 5 shown. The current sampling module is used to measure the charge and discharge current values of the lithium battery 3 and the supercapacitor 4 and monitor whether excessive currents occur in both.

[0107] The current measurement module 1 includes a current sensor U3. The pins 1 to 4 of the current sensor U3 are connected to the lithium battery 3 or the supercapacitor 4. The pin 7 is connected to the controller 7 through ADC_I BAT to obtain the current...

[0108] The lithium battery 3 is connected in series into the current input IP+ and output IP- circuits of the current sensor U3. The VIOUT module of the current sensor U3 outputs a voltage value, converting the analog current to be measured into an analog voltage output. Therefore, the VIOUT of the current sensor U3 is connected to the AD sampling pin ADC_I BAT of the controller 7, and the VIOUT is measured through AD. Since VIOUT and the current to be measured show a linear relationship, the current to be measured is obtained by measuring the voltage change.

[0109] The temperature measurement module measures the temperatures of the lithium battery 3 and the supercapacitor 4 and the ambient temperature where the dedicated transformer terminal is located, and is used to monitor the heat generation conditions of both and the general working environment. When the surrounding temperature is too high, the charge and discharge of both are stopped.

[0110] The temperature measurement module includes a voltage detection chip U2. The pin 1 of the voltage detection chip U2 is connected to IOTEMP_DETECT of the controller 7. The pin 2 is divided into two paths. One path is connected to 3V3 through a resistor R7, and the other path is grounded through the parallel-connected thermistor RT1 and capacitor C4.

[0111] Its principle is as Figure 6As shown, the resistor R7 and the thermistor RT1 form a voltage division circuit. TEMP_DETECT is the IO of the controller 7, and the voltage detection chip U2 outputs Vout in an open-drain mode, which is pulled up to a high level when the temperature is normal. When the temperature rises, the resistance value of RT1 gradually decreases. When the voltage of the input pin Vdd of U2 is lower than the detection threshold of U2, Vout is controlled to become low level. When the controller 7 detects a change in TEMP_DETECT, the charging and discharging of the backup power supply are turned off.

[0112] The internal resistance measurement module 1 and the internal resistance measurement module 2 respectively measure the internal resistances of the lithium battery 3 and the supercapacitor 4 by using the pulsed current method. By checking the changes in the internal resistances, they are used to roughly evaluate the SOC of the lithium battery 3 and the supercapacitor 4, so as to replace the problematic lithium battery 3 and supercapacitor 4 in time, and avoid problems such as data loss and function abnormality caused by abnormal backup power of the acquisition terminal after power-off.

[0113] The internal resistance measurement module 1 includes a switching transistor Q1; the source of the switching transistor Q1 is grounded, the drain is connected to the BAT of the lithium battery 3 through a dummy load R8; the gate is connected to the pulsed output pin PP_DCHARGE of the controller 7.

[0114] Its principle is as Figure 7 shown. Here only the internal resistance measurement module of the lithium battery is shown. When the internal resistance needs to be measured, the IO pin PP_DCHARGE of the controller 7 outputs a pulse, and the lithium battery 3 is controlled to discharge a pulsed current to the dummy load R8 by controlling the on / off of the switching transistor Q1. At the same time, according to the voltages and currents before and after discharge collected by the voltage sampling module and the current sampling module, finally the controller 7 analyzes and processes them to obtain the internal resistances of the lithium battery and the supercapacitor.

[0115] The lithium battery 3 uses a lithium battery with higher energy and lower self-discharge rate, which is suitable for application scenarios that require long-term and large-energy supply. However, the lithium battery has problems such as relatively slow charge and discharge speed, relatively short cycle life compared to the supercapacitor, and being sensitive to overcharging.

[0116] The supercapacitor 4 has a faster charge and discharge speed and a higher power density, can release a large amount of energy in a short time to meet the demand for instantaneous high-power output, and has an extremely fast charge and discharge speed, which is very suitable for application scenarios that require rapid charging. However, the supercapacitor has a low energy density, is not suitable for long-term power supply scenarios, and high-frequency rapid charge and discharge may cause internal heating, capacity attenuation, and internal resistance increase.

[0117] Therefore, it is necessary to monitor the parameters and usage environment of the lithium battery and the supercapacitor through the monitoring module, and the controller uses the monitored data for decision-making and strategy adjustment to achieve the integrated management of the supercapacitor and the lithium battery, and realize the highest energy utilization rate, the fastest response speed, and the longest cycle service life.

[0118] The charge and discharge management module 5 can respectively implement multiple functions such as charge management, discharge management, protection, and monitoring of the lithium battery 3 and the supercapacitor 4. This module uses the charge and discharge power management chip IP5306_IC. Combining the information monitored by the monitoring module 2, the controller 7 can remotely control and configure the charge and discharge power management chip through the I2C interface, so as to respectively achieve precise management and protection of the charge and discharge of the lithium battery 3 and the supercapacitor 4.

[0119] Specifically: According to actual needs, the controller 7 can configure parameters such as the charging current, discharging current, and voltage range of the charge and discharge power management chip.

[0120] 1) Charge management: The controller 7 respectively monitors the charging voltage, charging current, and main power supply status of the lithium battery 3 and the supercapacitor 4 through the monitoring module 2, and decides whether to start or stop the charging process.

[0121] The charge and discharge power management chip automatically adjusts the charging current and voltage, switches the charging mode, etc. according to the configuration of the controller 7 and the actual status of the lithium battery 3 and the supercapacitor, ensuring safe and efficient charging. The controller 7 can read the charging status register of the charge and discharge power management chip in real time to understand the charging progress and the status of the lithium battery 3 and the supercapacitor 4.

[0122] 2) Discharge management: The controller 7 respectively monitors the discharging voltage, discharging current, and main power supply status of the lithium battery 3 and the supercapacitor 4 through the monitoring module 2, and decides whether to start or stop the discharging process.

[0123] The charge and discharge power management chip automatically adjusts the discharging current and voltage according to the configuration of the controller 7 and the actual status of the lithium battery 3 and the supercapacitor, ensuring safe and efficient discharging. The controller 7 can read the discharging status register of the charge and discharge power management chip in real time to understand the discharging progress and the status of the lithium battery 3 and the supercapacitor 4.

[0124] 3) Protection and monitoring: The charge and discharge power management chip is built-in with multiple protection mechanisms, and through the information collected by the controller 7 from the monitoring module 2, overvoltage protection, overcurrent protection, short-circuit protection, overcharge and over-discharge protection, over-temperature protection, etc. of the lithium battery 3 and the supercapacitor 4 are realized, ensuring the safety of the lithium battery 3 and the supercapacitor during the charge and discharge process.

[0125] The controller 7 uses SCM601L216UE as the core of the entire system. Through the information collected by the monitoring module 2, it controls the charge and discharge management module 5 to manage the charge and discharge of the lithium battery 3 and the supercapacitor 4, conducts the integrated management of the two, and realizes the optimization of multiple objectives such as the highest energy utilization rate of the backup power supply, the fastest response speed, and the longest cycle service life.

[0126] The specific process is as follows:

[0127] 1) Definition of objective function.

[0128] Based on utilization rate, response speed, and service life, three objective functions are defined and combined into a multi-objective optimization problem. Objective function 1: The utilization rate objective function measures the utilization rate of the energy of the lithium battery 3 when the main power supply 1 is powered off, which is the ratio of output power to input power:

[0129] Objective function 1: Utilization rate objective function L bat，1 Measures the utilization rate of the energy of the lithium battery when the main power supply 1 is powered off, which is the ratio of output power to input power:

[0130]

[0131] where σ bat is the power distribution ratio between the lithium battery and the super capacitor, P bat is the output power of the lithium battery, P load is the power required by the load, P loss is the loss power;

[0132] Secondly, objective function 2: Response speed objective function L bat，2 is the speed at which the system switches from the main power supply to the backup power supply:

[0133]

[0134] where T is the time required to detect the power failure of the main power supply and complete the switch to the backup power supply;

[0135] Again, objective function 3: Service life objective function L bat，3 ;

[0136]

[0137] where: B bat，max is the maximum number of charge and discharge cycles allowed for the lithium battery, B bat，充 is the number of charging times, B bat，放 is the number of discharging times, ΔSOC bat is the change in the charge and discharge depth of the lithium battery, SOC bat，max is the safety upper limit value of the charging state of the lithium battery; α and β are weight coefficients used to adjust the influence weights of the number of cycles and the discharge depth;

[0138] After that, the comprehensive objective function L bat :

[0139] L bat = a1·L bat，1 + a2·L bat，2 + a3·L bat，3Equation (4);

[0140] where: a1, a2, a3 are weighting factors, satisfying Equation (5):

[0141] a1 + a2 + a3 = 1 Equation (5);

[0142] bat represents the parameters of the lithium battery, and sc represents the parameters of the supercapacitor;

[0143] Next, the total objective function is defined as:

[0144] L = aL bat + bL sc Equation (6);

[0145] a and b are the weighting factors of the lithium battery objective function and the supercapacitor objective function, respectively.

[0146] Next, the constraint conditions are defined:

[0147] Charge and discharge voltage constraint: V bat，min ≤ V bat ≤ V bat，max ,V sc，min ≤ V sc ≤ V sc，max Equation (12);

[0148] Charge and discharge current constraint: I bat ≤ I bat,max , I sc ≤ I sc,max Equation (13);

[0149] SOC constraint: SOC bat,min ≤ SOC bat ≤ SOC bat,max

[0150] SOC sc,min ≤ SOC sc ≤ SOC sc,max Equation (14);

[0151] Energy utilization rate balance constraint during backup power supply:

[0152]

[0153] 10. The method for integrated management of a lithium battery and a supercapacitor for a collection terminal according to claim 9, characterized in that: by means of the device according to claim 1;

[0154] wherein, for the supercapacitor according to the lithium battery, the function is as follows;

[0155]

[0156] L bat = b1·L sc，1 + b2·L sc，2 + b3·L sc，3 Equation (10);

[0157] b1 + b2 + b3 = 1 Equation (11);

[0158] Next, based on the objective function, the genetic algorithm in the optimization algorithm is selected to implement the multi-objective optimal strategy. The algorithm includes the following steps;

[0159] S1, after the system starts, initialize the system parameters, the charge and discharge currents I of the lithium battery and the supercapacitor bat , I sc the charge and discharge voltages V of the lithium battery and the supercapacitor bat , V sc , the SOCs of the lithium battery and the supercapacitor, SOC bat , SOC sc , the switching response time T, the load power demand P load ;

[0160] Use the monitoring module to monitor the status of the main power supply and the voltages, currents, operating temperatures, and internal resistances of the lithium battery and the supercapacitor;

[0161] S2, according to the charge and discharge times, actual energy used, and switching time of the current lithium battery and supercapacitor, calculate the values of each objective function L bat and L sc ;

[0162] S3, apply fuzzy logic, and the fuzzy logic controller is used to dynamically adjust the objective weights; the objective weights include a1, a2, a3, b1, b2, b3;

[0163] In S3, execute the following charge and discharge strategy;

[0164] When the main power supply of the system is powered off, increase the weights a1 and b1 of the utilization rate of the backup power supply; here, the lithium battery and the supercapacitor are collectively referred to as the backup power supply;

[0165] When the system is in the power-off switching state, increase the weights a2 and b2 of the response time of the backup power supply;

[0166] When the system is operating normally, increase the weights a3 and b3 of the service life of the backup power supply, and give priority to increasing the weight coefficient of the supercapacitor to minimize the charge and discharge times of the lithium battery.

[0167] When the load is relatively stable during the backup power period or the backup power time is long, increase the utilization rate weight a1 of the lithium battery. When the transient load fluctuates greatly during the backup power period, increase the utilization rate weight b1 of the supercapacitor;

[0168] When the temperature is low during the backup power supply period, increase the utilization weight b1 of the supercapacitor; when the temperature is high during the backup power supply period, increase the utilization weight a1 of the lithium battery.

[0169] S4: Execute the genetic algorithm:

[0170] S41: Randomly generate M groups of charge and discharge strategies as the initial population. Each group of strategies contains the charge and discharge parameters of the lithium battery and the supercapacitor. The number of the generated initial population can be increased or decreased according to the load condition of the controller:

[0171] M i ={I bat , I sc , V bat , V sc , σ bat , σ sc ......} Equation (16);

[0172] S42: Calculate the fitness of each charge and discharge strategy based on the objective function,

[0173] The fitness F = L = a1·L1 + a2·L2 + a3·L3 Equation (17);

[0174] Execute genetic operations:

[0175] S43 Selection: Select the charge and discharge strategies with high fitness through the roulette wheel method or the tournament method;

[0176] S44 Crossover: Exchange some parameters between two solutions of the parent generation M1 and the parent generation M2;

[0177] The parent generation M1 = {I bat = b1, I sc = b2, V bat = b3, V sc = b4, σ bat = b5, σ sc = b6}

[0178] The parent generation M2 = {I bat = c1, I sc = c2, V bat = c3, V sc = c4, σ bat = c5, σ sc = c6}

[0179] The offspring generation M1 == {I bat = c1, I sc = b2, V bat = b3, V sc = c4, σ bat = b5, σ sc= c6} Equation (18);

[0180] S45 Genetic: Add a small - range random perturbation to the solution of Equation (18);

[0181] Perform three genetic operations on Equation (18) to generate a new population M'; i ;

[0182] Repeat the fitness evaluation and genetic operations in step S4 until the set optimization goal is met or the maximum number of iterations is reached;

[0183] S5: Output the optimization strategy; According to the finally output optimization result, output the optimal charge - discharge strategy, and use the charge - discharge control module of the controller to perform charge - discharge management;

[0184] S6: Monitor the charge - discharge process in real - time, and perform parameter adjustment and correction according to the occurrence situation to ensure the multi - objective optimization defined by the system.

[0185] The present invention proposes a hybrid management method for supercapacitors and lithium batteries based on a multi - objective optimization algorithm, which combines fuzzy logic control with a genetic algorithm to achieve dynamic adaptive scheduling and strategy optimization.

[0186] The present invention realizes the integration of hardware and algorithms through a monitoring module, a charge - discharge management module, and a controller, combines acquisition, decision - making, and execution to solve the drawbacks of previous single execution, optimizes the performance of the entire system, fully combines the working characteristics of lithium batteries and supercapacitors and system fluctuations, and flexibly adjusts the optimization strategy.

[0187] The present invention is fully described for the purpose of clearer disclosure, and prior arts are not listed one by one.

[0188] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: They can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; As those skilled in the art, it is obvious to combine multiple technical solutions of the present invention. And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. The technical content not described in detail in the present invention is well - known technology.

Claims

1. A lithium battery and supercapacitor fusion management device for a collection terminal, characterized in that: Including main power supply, monitoring module, lithium battery, super capacitor, charge and discharge management module, load and controller; The main power supply is converted into direct current through the power conversion module to supply power to the load and controller in the system, and the charge and discharge management module cooperates with the controller to manage the charge and discharge of lithium batteries and supercapacitors; The monitoring module includes a power-off monitoring module, a voltage sampling module, a current sampling module, a temperature measurement module and an internal resistance measurement module; The power failure monitoring module is electrically connected to the main power supply and the controller; The voltage sampling module, the current sampling module, and the internal resistance measurement module are electrically connected between the lithium battery and the controller and between the super capacitor and the controller respectively; The temperature measurement module is electrically connected to the controller.

2. The lithium battery and supercapacitor fusion management device for a collection terminal according to claim 1, characterized in that: The power conversion module includes an AC-DC power supply and a rectifier.

3. The lithium battery and supercapacitor fusion management device for a collection terminal according to claim 1, characterized in that: The power-off monitoring module includes a voltage detection chip U1; in the voltage detection chip U1, pin 1 is connected to three paths, one path is connected to 3V3 through a resistor R1, the second path is connected to the controller through POWER_DETECT, and the third path is grounded through a capacitor C1; pin 2 is grounded through a parallel resistor R3 and a capacitor C2, and pin 2 is connected to ACDC_OUT through a resistor R2; pin 3 is grounded; POWER_DETECT is the controller's IO, and ACDC_OUT is the power module output.

4. The lithium battery and supercapacitor fusion management device for a collection terminal according to claim 1, characterized in that: The voltage sampling module includes voltage-dividing resistors R4 and R5; one end of the voltage-dividing resistor R4 is connected to the positive electrode of the lithium battery BAT, and the other end is divided into two paths, one is connected to the ground through the parallel voltage-dividing resistor R4 and capacitor C3, and the other is connected to the ADC sampling IO of the controller through ADC_VBAT.

5. The lithium battery and supercapacitor fusion management device for a collection terminal according to claim 1, characterized in that: The current measurement module includes a current sensor U3; pins 1 to 4 of the current sensor U3 are connected in series to a lithium battery or a supercapacitor; the VIOUT output voltage value of pin 7 of U3 is connected to the controller through ADC_IBAT, and the current is obtained according to the linear relationship between the obtained voltage change and the current; The lithium battery is connected in series to the current input IP+ and output IP- loops of the current sensor U3, and ADC_IBAT is the IO of the controller.

6. The lithium battery and supercapacitor fusion management device for a collection terminal according to claim 1, characterized in that: The temperature measurement module includes a voltage detection chip U2. Pin 1 of the voltage detection chip U2 is connected to the TEMP_DETECT pin of the controller. Pin 2 is divided into two paths, one is connected to 3V3 through resistor R7, and the other is connected to ground through the parallel thermistor RT1 and capacitor C4. Resistor R7 and thermistor RT1 form a voltage divider circuit, and TEMP_DETECT is the IO of the controller.

7. The lithium battery and supercapacitor fusion management device for a data acquisition terminal according to claim 1, characterized in that: The internal resistance measurement module includes a switch tube Q1; the source of the switch tube Q1 is grounded, and the drain is connected to the BAT of the lithium battery through a dummy load R8; the gate is connected to the pulse output pin PP_DCHARGE of the controller; the internal resistance measurement module roughly measures the internal resistance of the lithium battery or supercapacitor through a pulse discharge method. First, the controller IO pin PP_DCHARGE generates a pulse to control the switch tube Q1 to turn on and off, and obtains the discharge voltage and current of the lithium battery and supercapacitor through the voltage sampling module and the current sampling module, and obtains the internal resistance through Ohm's law.

8. The lithium battery and supercapacitor fusion management device for a data acquisition terminal according to claim 7, characterized in that: The lithium battery is connected in series to the current input IP+ and output IP- loops of the current sensor U3; PP_DCHARGE is the IO of the controller.

9. A lithium battery and supercapacitor fusion management method for a data collection terminal, characterized in that: The method comprises the following steps; wherein the objective function comprises utilization rate, response speed, and service life, First, the objective function is defined; Objective function 1: Utilization objective function L bat，1 The ratio of output power to input power is used to measure the utilization rate of lithium battery energy when the main power source 1 is cut off: Among them, σ bat is the power distribution ratio of lithium battery and supercapacitor, P bat is the output power of lithium battery, P load is the power required by the load, P loss is the power loss; Secondly, objective function 2: response speed objective function L bat，2 The speed at which the system switches from primary power to backup power: Where T is the time required from detecting the power failure of the main power supply to completing the backup power supply switching; Again, objective function 3: service life objective function L bat，3 ; Among them: B bat，max B is the maximum number of charge and discharge cycles allowed for lithium batteries, bat，充 is the number of charging times, B bat，放 is the number of discharges, ΔSOC bat SOC is the charge and discharge depth change of lithium battery bat,max is the safe upper limit of the lithium battery charging state; α and β are weight coefficients used to adjust the influence weight of the number of cycles and the depth of discharge; Afterwards, the comprehensive objective function L bat : L bat = a1·L bat，1 + a2·L bat，2 + a3·L bat，3 Equation (4); Among them: a1, a2, a3 are weight factors, satisfying formula (5): a1+a2+a3=1 Formula (5); Among them, bat represents the parameters of lithium battery, and sc represents the parameters of supercapacitor; Then, the overall objective function is defined as: L = aL bat + bL sc Equation (6); a and b are the weight factors of lithium battery objective function and supercapacitor objective function respectively. Then, based on the objective function; the objective functions are combined into a multi-objective optimization problem; Next, the constraints are defined: Charge and discharge voltage limit: V bat，min ≤V bat ≤V bat，max , V sc，min ≤V sc ≤V sc，max Formula (12); Charge and discharge current limit: I bat ≤I bat，max , I sc ≤I sc，max Formula (13); SOC Constraint: SOC bat，min ≤SOC bat ≤SOC bat，max SOC sc，min ≤SOC sc ≤SOC sc，max Formula (14); Energy utilization balance constraint during power backup period: P load +P loss =σ bat ·P bat +σ sc ·P sc (15)。 10. The lithium battery and supercapacitor fusion management method for a collection terminal according to claim 9, characterized in that: By means of the device according to claim 1; Among them, according to lithium battery, the function for supercapacitor is as follows; L bat =b1·L sc，1 +b2·L sc，2 +b3·L sc，3 Formula (10); b1+b2+b3=1 Formula (11); Next, based on the objective function, the genetic algorithm in the optimization algorithm is selected to achieve the multi-objective optimal strategy. The algorithm includes the following steps: S1, after the system starts, initialize the system parameters, the charging and discharging current I of the lithium battery and supercapacitor bat , I sc Lithium battery and supercapacitor charging and discharging voltage V bat , V sc , SOC of lithium battery and supercapacitor, SOC bat , SOC sc , switching response time T, load power demand P load ; Use the monitoring module to monitor the status of the main power supply and the voltage, current, operating temperature, internal resistance and other parameters of the lithium battery and supercapacitor; S2, calculate the value L of each objective function based on the current charge and discharge times of the lithium battery and supercapacitor, the actual energy used, and the switching time bat and L sc ; S3, applying fuzzy logic, the fuzzy logic controller is used to dynamically adjust the target weights; the target weights include a1, a2, a3, b1, b2, b3; In S3, the following charging and discharging strategies are executed; When the main power supply of the system is cut off, the weights a1 and b1 of the backup power supply utilization are increased; here, lithium batteries and supercapacitors are collectively referred to as backup power supplies; When the system is in a power-off switching state, the weights a2 and b2 of the backup power supply response time are increased; When the system is operating normally, the weights a3 and b3 of the backup power service life are increased, and the weight coefficient of the supercapacitor is increased first to minimize the number of charge and discharge times of the lithium battery. When the load is relatively stable during the backup period or the backup time is long, the utilization weight of the lithium battery a1 is increased; when the instantaneous load fluctuation is large during the backup period, the utilization weight of the supercapacitor b1 is increased; When the temperature is low during the backup period, the utilization weight b1 of the supercapacitor is increased; when the temperature is high during the backup period, the utilization weight a1 of the lithium battery is increased; S4: Execute genetic algorithm: S41: Randomly generate M groups of charge and discharge strategies as the initial population, each group of strategies includes the charge and discharge parameters of the lithium battery and the supercapacitor, and the number of the generated initial population can be increased or decreased according to the load condition of the controller: M i = {I bat , I sc , V bat , V sc , σ bat , σ sc ……} Equation (16); S42: Calculate the fitness of each charging and discharging strategy based on the objective function. Fitness F = L = a1·L1+a2·L2+a3·L3 Formula (17); Perform genetic operations: S43 selection: selecting a charging and discharging strategy with high fitness through roulette method or tournament method; S44 crossover: exchange some parameters between the two solutions of parent generation M1 and parent generation M2; Parent M1 = {I bat =b1,I sc =b2,V bat =b3,V sc =b4,σ bat =b5,σ sc =b6} Parent M2 = {I bat = c1, I sc = c2, V bat = c3, V sc = c4, σ bat = c5, σ sc = c6} Offspring M1 == {I bat =c1,I sc =b2,V bat =b3,V sc =c4,σ bat =b5,σ sc =c6} formula (18); S45 genetics: add small-scale random perturbations to the solution of equation (18); Execute the three genetic operations in formula (18) to generate a new population M′ i ; Repeat the fitness evaluation and genetic operation in step S4 until the set optimization goal is met or the maximum number of generations is reached; S5: output optimization strategy; according to the optimization result outputted finally, output the optimal charge and discharge strategy, and use the charge and discharge control module of the controller to manage the charge and discharge; S6: Monitor the charging and discharging process in real time, adjust and correct parameters according to the situation, and ensure the multi-objective optimization defined by the system.

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